CORNELL UNIVERSITY LIBRARY BOUGHT WITH THE INCOME OF THE SAGE ENDOWMENT FUND GIVEN IN 1891 BY HENRY WILLIAMS SAGE Cornell University Library QM 505.S29 ^*^ Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924024791596 THE EMBRYOLOGY, DEVELOPMENT, AND ANATOMY OF THE NOSE, PARANASAL SINUSES, NASOLACRIMAL PASSAGEWAYS, AND OLFACTORY ORGAN IN MAN SCHAEFFER Photograi-bs ^__.^ _. ami faranasal ' access- >ry ) sinuses viewed from both the riyht labovej and cranial (bclowj aspects. From an adult male. Natural size. f. frontal sinuses; m. maxillary sinuses; s, sphenoidal sinuses; e. ethmoidal cells; /. nasolacrimal duct; Hf.'nasal (.a\'ity; c. right choana (posterior naris) ; np. nasoitharynx; im, interior nasal meatus. THE NOSE, PARANASAL SINUSES, NASOLACRIMAL PASSAGE- WAYS, AND OLFACTORY ORGAN IN MAN A GENETIC, DEVELOPMENTAL, AND ANATOMICO-PHYSIOLOGICAL CONSIDERATION BY J. PARSONS SCHAEFFER, A.M., M.D., Ph.D. PROFESSOR OF ANATOMY AND DIRECTOR Ol'" 1 HE DANIEL BAl.'.H INMiTl'TE OF ANATOMY 01-- THE JEFFERSON MEDICAL COLLEGE OF PHILADELPHIA; FORMERLY ASSISTANT ^pROl-ESSOR OF ANATOMY, CORNELL , L'NIYERSITY MEDICAL COLLEGE AND PROFESSOR OF ANATOMY, YALE UNIVERSITY MEDICAL SCHOOL WITH 204 ILLUSTRATIONS OF WHICH 18 ARE, PRINTED IN COLOR PHILADELPHIA P. BLAKISTON'S SON & CO. 1012 WALNUT STREET Copyright, 1920, by P. Blakiston's Son & Co. X H K I.I i !-• I^ K I* R K S S Y O E JC PA w J5o the ^tlsmory cf 5n? "J'atbcr-'n-lo""'- Kiitry »obb. 5n.T>. I3bis Volume is (BratsfullY ait6 "Affectloaatel? PREFACE The object of this monograiih is to present a study of the embryology, development and anatoni)', both microscojiic and macroscopic, of the human nose, the paranasal sinuses, the olfactory organ and certain other ancillary structures. The stud>- had its inception in work done on the maxillary sinus in iqo; at Cornell Universit}'. The held of investigation was gradually extended so as to include ultimately the entire nasal region and its immediate environs. The study was continued at intervals at Cornell University (1907-11), at Yale University (1911-14), and at the Jefferson Medical College since 1914. A number of papers on various phases of the study were published from time to time as the work ])rogressed, and the author now takes the liberty of drawing upon them in this connection; this being alike true for text, diagrams, tables and illustrations. Most of the matter, however, appears in new form and for the first time. All work must needs be based in ])art on the labors of the ])ast and the author is not unmindful of the help deri\'ed from the recorded observa- tions of other workers in the field. Xo attempt, however, is here made to review the literature on the subject: had this been done, the size of the book would ha\-e been increased far beyond the limits set for it. The aim has been to present a more or less comprehensive account of ])ersonal studies and obser\'ations on the genesis, de\'elopment, and anatom}' of the nose and its related parts rather than to compile a fairh' x'oluminous literature with its not infrequent di\'erse conclusions. In large measure, therefore, the descriptions and discussions as set forth in subsecjuent chapters and paragraphs are based upon researches by the author, extend- ing over a period of years. Likewise most of the illustrations are based upon preparations, reconstructions, and dissections by the author and reproduced either by him or under his directions. Of course, where vital points are at issue or where the author feels that his own observations are inadequate, due reference is made of the work and conclusions of other investigators. Moreover, a certain number of illustrations are after other writers for which proper credit is given in the respectix'e legends. vii Viu PREFACE Seldom, indeed, is it that all phases of a study reach a state of finality. Unfortunately, this is true in the present connection, for in some instances it has become necessary to assume certain conclusions tentatively from established and related facts and the clinical evidence at hand. This, however, seems warranted, for unless we exercise some scientific judgment and imagination no progress can be made. Further study and analyses may affirm or deny the assumptions. It is no easy task, for example, to establish with certainty all the fiber tracts in some neuron circuits. Moreover, when a few hours markedly alter a structure during its develop- mental stages, it is obviously difficult to have at hand and in serial sections human embryos closely enough graded to demonstrate every possible point that arises in a study such as this. Fortunately, experience has shown that mammalian embryos are of great value in filling in our gaps of knowledge of human embryology and until human embryos of the proper ages fall into the hands of competent observers, it is altogether proper to assume certain hypotheses based upon the study of other and related forms. In order to consider all portions of the nose and the cognate regions and structures and bring the results of the observations and studies within the limits of an a^'erage-sized ^'olume, it was necessary in many instances to omit the records of many detailed observations and to record the essen- tials only. This is more or less true throughout the work, but especially so in connection with the central olfactory organ and the individual bones that comprise the nasal framework. Important and essential points are, of course, treated in greater detail. Moreover, where brevity of description and discussion would have befogged clearness some otherwise unessential details are recorded. It is, of course, obvious that any one of the chapters and, indeed, in some cases parts of chapters could be profitably amplified into individual monographs. The purpose and plan of the book, however, did not require such amplification. Despite the large amount of materials studied over a period of years, the author recognizes that this work is incomplete, but hopes the descriptions, discussions and suggestions will be found helpful by physi- cians and surgeons and undergraduates in medicine. The author is not unmindful of the many opportunities afforded for the furtherance of this work at the Cornell University Medical College, the Yale University Medical School, and the Jefferson Medical College. Nor of his indebtedness to the flutter Museum of the College of Physi- cians of Philadelphia for the privilege of studying certain materials, and to its curator, Dr. Clarence Hofl'man, for many courtesies. Moreover TREFACE IX thanks are due Dr. H. E. Radasch for the preparation of tissues from the author's collection for Figs. i8i and 1S2, INIiss Bremerman for valued help in the preparation of the manuscript and proof-reading, and Miss Neely and ]\Irs. Schaeffer for certain translations. The index is the work of Dr. Benjamm Lipshutz. The author wishes to express his obligations to the publishers for their hearty cooperation and generosity. J. Parsons Schaeffer. 4634 Si'RUCE Street, Philadelphia, Pexxa. CONTENTS IXTKODUCTIOX xix CHAPTER I General EirBRVOLOGY axd De\elopmext 3 The Proton and Rudiment .3 The Nasal Pits 3 Frontonasal Process 4 Xasal Processes 4 Maxillary Process 4 The Primitive (Primary) Xasal Fossae 7 General Statement 7 The Bucconasal ^Icmbranes q The Primitive Choanie The Xares 10 The Primitive Palate 11 The Detinitive Palate 12 The Definitive Choanae 14 The Primary Xasal Septum 16 The Secondary Xasal Septum 16 The Definitive (Secondary) Xasal Fossa: 17 General Statement 17 The Lateral Xasal Wall iS General Statement 18 The Major Xasal Concha; and Meatuses 18 General Statement 18 The Inferior Xasal Concha 20 The Inferior and ^liddle Xasal Meatuses 20 The Ethmoidal Conchs and Meatuses 21 The Xasoturbinal (agger nasi) 26 The Xasal Atrium 26 The Olfactory Sulcus 26 The Sphenoethmoidal Recess 26 Xomenclaturc 27 The Minor Xasal Conch:t and ^leatuses 27 General Statement 27 The Descending Ramus of the ^Meatus Xasi Medius 28 General Statement 28 The Suprabullar Furrow or Recess 3° The Bullar Furrow 31 The Infrabullar Furrow 31 The Infundibulum Ethmoidale 31 The Superior Bullar Fold or Concha 32 The Inferior Bullar Fold or Concha 32 The Infundibular Fold or Concha ii The Processus Uncinatus 3,5 xi xii CONTENTS The Ascending Ramus of the Meatus Nasi Medius 33 Recessus Frontalis 33 The Frontal Folds or Conchae 33 The Frontal Furrows or Pits 33 The Descending Ramus of the Meatus Nasi Superior 35 The Rudiments of the Paranasal Sinuses 36 The Maxillarjr 36 The Ethmoidal 36 The Frontal 36 The Sphenoidal 36 The Definitive Nasal Septum 37 The Development of the Nasal Skeleton 38 The Cartilaginous Nasal Capsule 38 Ossification of Elements 40 The Ethmoid Bone 40 The Vomer 41 The MaxiUoturbinal 42 The Palate Bone 42 The Nasal Bone 42 The Lacrimal Bone 42 The Sphenoid Bone 43 The Sphenoturbinal 43 The Maxilla 44 The Frontal Bone 45 Skeleton Changes Incident to Growth 45 The Epithelium of the Primitive Nasal Fossfe 47 The Olfactory Nerves 47 The Nasal Glands 47 The Vomeronasal Organ 47 The Embryonic External Nose ■ 48 The Nasolacrimal Passageways 49 Congenital Defects of the Nose 51 CHAPTER II The DEriNiTiVE Nose 61 General Statement 51 The External Nose 61 General Statement 5j- The Bones of the External Nose 63 The Cartilages of the Ejiernal Nose 66 The Greater Alar Cartilage 68 The Lateral Nasal Cartilage 69 The Lesser Alar Cartilages yo The Sesamoid Nasal Cartilages 70 The Muscles of the External Nose 70 The Internal Nose »j General Statement -j The Nares. . . / 2 The Vestibule . . /3 CONTENTS xiii The Choana? (Posterior Nares) 73 The Floor of the Nasal Cavity 75 The Roof of the Nasal Fossa 77 The Median Wall of the Nasal Fossa 77 General Statement 77 The Osseous Portion of the Nasal Septum 78 The X'omer 79 The Mesethmoid 80 Other Osseous Elements 81 The Cartilaginous Portion of the Nasal Septum 81 The Cartilage of the Septum 81 The \'omeronasal Cartilages 82 The Greater Alar Cartilage 82 The Membranous Portion of the Nasal Septum 82 Asymmetry of the Nasal Septum 83 Perforation of the Nasal Septum 86 The Lateral Wall of the Nasal Fossa 86 General Statement 86 The Osseous Framework 87 The Inferior Nasal Concha 88 The Inferior Nasal Meatus 89 The Ostium of the Nasolacrimal Duct 89 The ^Middle Nasal Concha 90 The [Middle Nasal ^Meatus 91 The Ethmoidal Infundibulum 92 The Uncinate Process 93 The Ethmoidal Bulla 04 The SuprabuUar Furrow or Recess 95 The Frontal Recess 05 The Superior Nasal Concha 95 The Superior Nasal [Meatus 95 The First Supreme Nasal Concha 96 The First Supreme Nasal Meatus 96 The Sphenoethmoidal Recess 06 The Second and Third Supreme Nasal Conchae 97 The Agger Nasi 97 The Nasal Atrium 97 The Olfactory Sulcus 97 CHAPTER III The Maxillary Sixrs loi The Fetal Stage loi The Childhood Stage 104 The Adult Stage lOQ General Considerations 109 The Relations of the Sinus Floor to the Nasal Floor in The Relations of the Maxillary Sinus to the Teeth 112 Ridges, Crescentic Projections and Septa 116 Duplication of the Maxillary Sinus 113 The Size of the Maxillary Sinus 122 xiv CONTENTS The Maxillary Ostium I27 Duplication of the Maxillary Ostium 129 The Accessory Maxillary Ostium 130 Concluding Considerations i33 CHAPTER IV The Frontal Sinus 139 The Fetal Stage 130 The Childhood Stage 143 The Adult Stage 146 General Considerations 146 Size of the Adult Frontal Sinus 147 Extensive Pneumatizations 147 Supernumerary Frontal Sinuses 150 The Frontal Bulla 152 Frontal Sinus Diverticula 154 Agenesis of the Frontal Sinus 157 The Nasofrontal Connections 160 The Nasofrontal Duct 166 Concluding Considerations 168 CHAPTER \' The Sphenoidal Sini's 175 The Fetal Stage 175 The Childhood Stage 176 The Adult Stage .178 General Considerations 178 The Topography of the Adult Sphenoidal Sinus 180 Osseous Septa and Recesses of the Sphenoidal Sinus 183 Diverticula of the Sphenoidal Sinus 184 The Sphenoidal Septum 187 The Sphenoidal Ostium 187 The Size of the Sphenoidal Sinus 188 The Hypophysis Cerebri as Related to the Sphenoidal Sinus 188 The Optic Nerve and Commissure as Related to the Paranasal Sinuses 190 The Cavernous Sinus and Contained Structures as Related to the Sphenoidal Sinus ig-2^ Diminutive Sphenoidal Sinuses 107 Agenesis of Sphenoidal Sinuses igg Concluding Considerations inn CHAP'I^ER Yl The Ethmoidal Cells ,,q. The Fetal Stage 20- The Childhood Stage 206 The Adult Stage ^n General Considerations 211 Classification 212 CONTENTS XV Dehiscences ^ Size of the Ethmoicial Labyrinth .214 The Anterior Ethmoidal Cells 21- The Frontal Group 216 The Infundibular Group ,j5 The Bullar Group 21S The Frontal Bulla 21S The Posterior Ethmoidal Cells 219 The Conchal Cells '.....'.'....... I21 The Middle Conchal Sinus 226 Concluding Considerations 226 CHAPTER VII 'assageways General Statement The Nasolacrimal Passageways 237 237 Genetic and Developmental Anatomy 237 \'ariations and i\nomalies 242 The Lacrimal Fossa and the Nasolacrimal Canal 244 The Lacrimal Ducts 247 The Lacrimal Sac 248 The Nasolacrimal Duct 24S The Nasolacrimal-duct Diverticula and \'alves 250 The Nasal and Paranasal Relations of the Membranous Nasolacrimal Passageways . 252 The Nasolacrimal Ostium 2^5 Concluding Remarks 2,^ CHAPTER \TII The Nasal Mucous jNlEirBRANE 261 General Statement 26r The Nasal Vestibule 261 The Nasal Fossa 261 The Respiratory Portion 262 The Olfactory Portion 266 The Paranasal Sinuses 26S The Vomeronasal Organ 270 The Genital Spots (so-called) 27r CHAPTER IX The Blood- axd Lymph-\'ascular Systems of the Nose and the Paranasal Sinuses 275 The Arterial Supply 275 The Sphenopalatine Artery 275 The Anterior and Posterior Ethmoidal Arteries 277 The Descending Palatine Artery 278 The Pharyngeal Artery 278 The Infraorbital Artery 27S The External Maxillary (Facial) Artery 278 The Venous Supply 278 CONTENTS xvii The Parolfactory Area 331 The Subcallosal Gyrus ,i,^i The Supracallosal (atus ^.^^ The Fascia Dentata Hippocampi 333 The Hippocampus 334 The Uncus 334 The Fornix 335 The Septum Pellucidum 335 The Habenular Trigone .^,^6 The IMeduUary Stria of the Thalamus 336 The ^lammillary Bodies 337 Tlie Terminal Stria of the Thalamus 33S The Amygdaloid Nucleus m8 The Olfactory Rellcx and Cortical Connections 3.3''' The 01lactor\- Pathways 34i The Relations of the lirain to the Walls of the Nasal Fossa: and the Paranasal Sinuses 344 CHAPTER XII Physiulcigical Addenda 347 The Nose Proper 347 The Paranasal Sinuses 35° Olfactory Sensation 354 IxDF.x . 360 INTRODUCTION ]Much productive ground remains unworked in human anatomy and ancillan- subjects, despite the unfortunate belief of many graduates in medicine that the stud>' of anatom>' has reached a state of finality and that the anatomical field has been fully gleaned of its har\'est. When one recalls, howe^-er, that modern anatomical teaching and research no longer recognize the unfortunate historic distinction between macroscopic (gross) and microscopic (minute) anatomy; that the human body is now con- sidered from the phyletic, the ontogenetic, the physiologic, the histologic and the gross \'iewpoints: that modern anatomy is concerned with e\-olu- tion, heredit}- and \-ariation, it is clearh" obvious that anatomy is no longer restricted to a purely descriptive study, but that its domain has expanded into its proper spheres and that many problems await solution. Even descriptive or gross anatomy is not without its problems, mam' of vital and practical importance. Tt is ver}' dilficult and unsatisfactory to approach an anatomical problem without a basic conception of the underlying genetic and dcA'clo])- mental history. In order to properly interpret points in the adult anatomy of a region, it not infrecjuently is necessary to revert to',the embr^-ology of the part or region concerned. ]\Iany faulty statements extant in the literature are doubtless the result of drawing conclusions from a study of too few specimens, of stuch'ing adult material alone, and of errors in in- terpretation due to the fact that embryologic and adult studies were not carried on simultaneousi}'. A prominent surgeon reccnth' recommended a study and basic understanding of embryology "as one of the founda- tion stones of surgical training." Be that as it may, it certainly cannot be gainsaid that a knowledge of human anatomy is of paramount impor- tance in a comprehensive understanding and interpretation of both macro- scopic and microscopic anatomy, both for the medical student and the physician and surgeon in the practical field. Variations in the anatomy of the human bod}' are not uncommon, both ontogenetic and phylogenetic. In the former one has to contend with the very important group of human variants generally spoken of as errors in development — congenital defects. There are also progressive and reversional variants encountered. The phyletic variations have to do with the hereditary reappearance of ancestral characters. When one INTRODUCTION recalls that "each organism in the course of its individual ontogeny repeats the history of its ancestral development" the appearance of remote characters in man is more comprehensible. In order, therefore, to deal inteUigently with variations, one needs, indeed, not infrequently to hark back not only to the de\-elopmental history of the indiA'idual, but to the ancestral history of man as Avell. Entirely apart from the variations referred to above there are the e\-er-recurring \-ariations in what may be termed the gross anatomic type of a structure, organ, or region of the human body. These too, strictly speaking, are ontogenetic variations in that they result from the differen- tiation of the individual embryo and lead to the development of a certain anatomic type of the adult body. Some of these variations or types occur so infrecjuenth' and are so unlike all others that one must assume that they result from atypical differentiation of the embryo, leading to an anomalous or abnormal structure, organ, or region in the adult. On the other hand, certain \-ariations in the anatomy of many parts of the human body occur with sufficient frecjuence to justify the establishment of normal anatomic types. This, of course, opposes the conception of an un^'arying typical or ideal anatomic type and all departures therefrom as anomalies. In a general sense only do a large series of human bodies conform in their detailed gross anatomy to a so-called t}']3ical form. It would appear from some recent studies that not a few of our traditional ideas found in some clinical text-books in explanation of certain physical signs and other conditions encountered in the human body from time to time are at variance with anatomic facts. Conclusions draAvn hastily and not suf- ficiently verified by extensive anatomic studies are not of infrecjuent occurrence. The idea of an unvarying typical form in the gross anatomy of the human body appears more or less prevalent in the practical field. There is, of course, great need of extensive study of the various regions, organs, and other structures of the body; the conclusions to be based upon a large number of cadavers. This has been done for some regions and splendid monographs and records are extant on such researches. The work, howe\'er, must be extended and ulitmately be made to include all of the important regions of the body. Such studies, if based on a large amount of material and discriminating work, will establish anatomic types. What is desired is not the average nor the mean but the various gross anatomic tj'pes of a region, organ or structure, wherever and when- ever it is possible to establish such with a fair degree of certainty. After the normal anatomic types are established, the anomalies of the human body will naturally find their proper place, as wiU also the average and the INTRODUCTION XXl mean. This work should be made to inchide the sex-eral ages of the childhood period, the pubertal stage, and that of the adult. It is obvious that such exhausti\'e anatomical considerations of special regions and organs are not the pro\-ince of the general te.\t-l)ooks of human anatom>', but clearly the function of anatomic monographs. In stud>-ing a given region of the body in an exteiisixe series of cadavers one is profoundly impressed witli the e\er-recurring departure in the morphology of the j^art under investigation from the conNentional or typal description. This is particularly applicable to the gross anatom\- of the paranasal (accessory) sinuses. The primary function of a general text-book of anatomy is doubtless to describe and delineate a "tA'pical"' body and to refer to a few variants. It is oljviously impossible to do much more within the scope of a single volume. To \-isualize and under- stand the anatomy of a t}'pical body is probably also the primar}- function of a medical student in his initial work in human anatom)-. Unfortunateh", howe\"er, while there ma}' be a " t}-]:)ical " gross form for regions, organs and structures, it is, strict!}' speaking, not often encountered in nature. The t}'pical is ideal and the region, organ, etc., as regards shape, size, relations, conllguration, etc., \"er}' commonl}' in their actual or real anatomy are \ariants. It is, tlierefore, of the greatest importance that the student earh' recognizes the \-er}- common and con- stant anatomic variations that beset the human bod}-. All that the ob- serA'ant student need do is to witness the dissection ol' a series of cadaxers to have impressed upon him that there is no fixed and unalterable t}'])e in \'er}' many of the parts of the human bod}-. I'nforlunatel}-, howe\-er, some students never get be}-ond the belief and thought that exer}- struc- ture and organ and region conform to an arbitrar}- and fixed i-iornial, and if there is a slight digression from tlie conx'entional text-book desi riji- tion the term "anomal}'" is applied. W'itli this erroneous and unloi'lui-iate belief the\' go forth into the practice of medicine: To them the a])])endix is and must always be in the right iliac fossa; ex'er}- frontal sinus iiiA'ades the A'ertical portion of the frontal bone and if not, there is no fr(.>ntal sinus present: everv li\'er has the same sized and shaped left lobe and bears a constant topographic relationship to the \'entral abdominal wall; all stomachs conform to a single shape; every transxerse colon crosses from right to left at a specified plane; the ethmoidal air cells are limited to the ethmoid bone; etc., etc. The far-reaching and direful effects of such faulty conceptions of the anatoni}- of the human bod}' are so obvious that they need not be discussed here. It, of course, goes xvithout saying that one must primarily have a fundamental understanding of the ground xxii INTRODUCTION plan of the human body; however, it cannot be gainsaid that one should be equally cognizant of anatomical departures therefrom. Despite that the actual anatomy of a region or part is not infre- quently a variant of the ideal or typal form (if there really be such) it is possible in many instances to establish normal anatomic groups or tj^pes. This is of decided advantage over the method of taking, for example, a series of five hundred or a thousand dissections and establishing from them a composite form and accepting it as the typical or ideal anatomy for the region or organ. In a general way only should physicians and surgeons accept a so- called t}rpal or ideal form in gross anatomy. Initially, of course, in the study of a patient all regions and organs must needs be approached in large measure from the viewpoint of an "average anatomy" despite the fact that relatively few specimens wholly conform to it. Fortu- nately, roentgenology has come to the aid of the physician and surgeon in the determination and delineation of anatomic conformations. Ad- mittedly very many variations are insignificant and can be ignored in the practical field despite the fact that they may be of interest and of great value to the student of embryology and morphology. How- ever, it is a matter of grave concern to the physician and surgeon that many important normal variations and anomalies must be dealt with continuall)'. It is, therefore, clearly obvious that the adherence to a single fixed and arbitrary normal is fraught with danger; since with variations come altered size, altered shape, altered anatomical relations. Morpho- logical variation must necessarily have an important bearing on physical diagnosis, pathology, clinical medicine, and surgery. Indeed, the "ana- tomic t}T3e" always looms up before the man in the practical field as an important factor in treatment and prognosis. I-GENERAL EMBRYOLOGY AND DEVELOPMENT THE NOSE. PARANASAL SINUSES, NASO- LACRIMAL PASSAGEWAYS AND OLFACTORY ORGAN IN MAN CHAPTER I GENERAL EMBRYOLOGY AND DEVELOPMENT The Proton axd Ri'dimext The proton^ of the nose and the i)eripheral oh'actory organ is a paired con\-ex area of the cranial ectoderm near the location of the closed an- terior neuropore, and the rudiment or anlage of the organ is represented by a cellular thickening of the corresponding epithelium (sensory epithe- lium ) . The characteristic epithelium of the olfactory ])lacodes or nasal areas is recognizable as earh' as the third week of embr}'onal life (4 to 5 mm. embryos). At first the sensor}- ejMthelium of the ])lacodes merges imperceptibh' with the thin fo.oi mm.) surrounding head e]iithelium, later thickening with sharp delimitation. These thickened (0.04 to 0.05 mm.) ectodermal jilacodes are situated on both sides (bilaterally) on the ectal surface of the wall of the forebrain, immediateh- cephalic to the primitive oral fossa (Tig. i). The Nasal Pits During the fourth week (6 to 7 mm. embryos) the nasal areas be- come passively depressed by a positive increase in the thickness of the surrounding mesoderm which pushes the overlying ectoderm into relief. ijlie term proton (ttpwtos, first) is here used to apply to that portion of the indifi'erent surface ectoderm destined to establish the olfactory rudiment or anlage. I'roton is not infrequently used in a synonymous sense with rudiment and anlage. i 4 GENER.\L EMBRYOLOGY AND DEVELOPMENT In this manner each olfactory placode becomes surrounded by a fold which is well developed medially and laterally, but deficient ventro- caudally (Fig. i). Frontonasal, Nasal, and Maxillary Processes. — The depressed nasal areas become the nasal pits and are separated by a broad mass of tissue —the frontonasal (frontal) process. As the pits deepen they separate in a sense the caudal portion of the frontonasal process into medial and lateral parts— the rudiments of the medial and lateral nasal processes. Indeed, the latter processes have their precursors in the low folds of meso-ectodermal tissue which isolate the nasal areas. During the latter part of the fourth week, probably a bit later, the median portion of the J^fesoiloLst '^ Olfactorif placode '^""Nasofrontal process Fig. I. — Section through the head of a human embryo aged approximately 3 weeks. The sec- tion shows the olfactory placodes sharply delimited from the surrounding head ectoblast. Redrawn from Kollmann. frontonasal process undergoes further differentiation into a mesial or unpaired part and two lateral or paired parts. The latter are more specifically the medial nasal processes or the globular processes of His, and they form the immediate medial boundaries of the nasal pits. The lateral portions of the frontonasal projection grow caudally and form the lateral nasal processes — the immediate lateral boundaries of the nasal pits or the primitive (primary) lateral nasal walls. At this stage of development the maxillary processes of the first or mandibular arches grow ventrally and medially and abut, later fuse with the medial nasal processes. The fusion takes place from within outward, i.e., from the depth toward the surface, and closes in the superior bound- I'ROXTOXASAL, NASAL AND jNIAXILLARY PROCESSES S ary of the primitive oral cavity and at the same time early shuts off the cleft of communication between the nasal pits and the oral cavity. The coalescence of the maxillary processes with the medial nasal processes forms the primitive or primary inferior boundary of the nasal pits. Sub- sequently, however, the extensions of the lateral nasal processes medially and ventrally abo^'e the maxillary processes meet and fuse with the medial nasal processes to form the immediate delinitive inferior boundary of the A'cr. / -' I^fcfh'al 7 iusal process ■ PriiTiitive ckocincc G^obulur process ; IDZfi \ location For) \ '' wii'^e- YomeroitOysaZ or^an Zatij-aZ lut^al proci;i,s ?faJciUMr^ /process Fig. 2. — Drawing of a reconstruction by the author of the face region of a human embryo aged 35 days, illustrating the several embryologic processes and their coalescence in the formation of the early nasal fossae. X 39. nasal pits. Fusion takes place also laterally between the maxillary and the lateral nasal processes in the obliteration of the naso-optic furrow (Fig. 2). For a brief time the lines of fusion of the maxihary and the lateral nasal processes with the medial nasal processes are represented by strands of ectodermal tissue. These ectodermal fusion-lines or plates soon disap- pear ventrally and cranially and are replaced by indifferent mesenchyme ; that is, the mesenchymal tissue of the maxillary and lateral nasal proc- esses becomes continuous with that of the medial nasal processes. GENERAL EMBRYOLOGY AND DEVELOPMENT Jv-siort complete' (epit/zeliuTn lost) Epithdixjm, ---' between ahjJtin^ processes ^^^:,^ j Medial iiasal process _^Jyas^x,l fossa, fpriTnitive) Iusio?i Ji^axillarif process Fic 5 Succo 77-ccsal 77mj77ir£incs FuiS. Z~S- — PhotoniicroKraphs of frontal sections of the head of an embryo a^^ed 35 days. (Human em.bryo, No. 26, Cornell University series, slides iq and 20.) PRIMITUE XASAL FOSS,E 7 Fusion 111 this manner becomes permanent and absolute. Persistent eipthelial-cell masses may later in extrauterine life, or before, give rise to epithelial pearls and cysts. Farther dorsalh- the ectodermal tissue does not wholly disappear for some time, strands remaining between the abut- ting processes. In these i)ositi()ns the primitive choana; (primitive posterior nares) become established ultimately and the ectoderm of the nasal pits then becomes continuous with that of the oral cavity (Figs. 3, 4, 5 and 0). Primitire chixuia {position for) Fig. 6. — Drawing (if a reconstruction b\' the author of the left nasal fossa r)f a hiitnan embryo aged 35 da^-s lEmbr\'0 Xo. 6, see Fig. 2 . Es]ieciall\" n'A^j the simple lateral nasal \\-all at this period and the blind termination of the nasal fossa dorsalh'. X 72. The Primitr'e (Prim.ary) Nasal Foss.f, Thirty-five-da}' embryos show that the nasal i)its have deepened sufficiently to partake of the nature of cleft-like fossre. The olfactory organ is now representerl b\' t\v(j blindly-ending epithelial pouches h'ing in the mesench}'mal tissue just abo\'e the oral ca\'ity. The foss;e com- municate freely with the exterior by means of the nares (anterior nares), but in the absence of choaiice (posterior nares) end blindly at their dorsal and inferior termination. They are widely separated at this time by the thick frontonasal process. Reference to a 35-day embryo indicates the simplicitv of the lateral nasal waU at this time — an even and un- broken surface presents for study. The mechal or septal wall, on the Particularly note the manner of fusion of the embry^inic ]irucesses in the obliteration of the com- munication between the nasal foss;c and the oral cavit\-. In Fig. 5 on bnth sides the two layers of epithelium, oral and nasal, have Ijecome attenuated and thinned out to represent single layers of cells — the bucconasal membranes. The latter ultimateh- rupture to establish the primitive choanal. X 35- GENER,\L EMBRYOLOGY AND DEVELOPMENT Epithelial plugs occlud- ing nares Stptum nasi Pig. 7. Fig. Organon vomero- nasale {Jacobsoni) Mf>-^ Fig. 9. Eth.fold jji^^i Fig. 10. \ 4"' 'f* ^ Max. fold "S^ ,>F Fig. II. Lingua Fig. 12. Figs. 7-12.— Photomicrographs of frontal sections of the head of an embryo aged 43 days. (Human emliryo. No. 3, Cornell University series, sections 406, 380, 365, 360, 350, 325.) BUCCONASAL iMEMBRANES AND PRIMITIVE CIIOAN.E 9 contrary, is more complicated owing to the rudiment of tlie vomeronasal organ of Jacobson, which is indicated by a slight groove overhung by a mucosal fold (Fig. b). Nares Prhfi itive cJwanae PTanazhncd T/asprcc.) '\ Cerebral vesicle Upper lipimednasproc.) , 7/ppcr /ip/7/mxprocJ ' I Pala/hie process Soo/ of pharynx Prim i tive palate (Sept.portiun. med.7zas.proc } //azi/Iarj/ process f sacr/,o-f7 ] Fig. 13. — Reconstruction of the face and palate rcKions of a human embryo at the beginning of the 2d month. Especially note the primiti\'e palate and the early palatine processes which are beginninK to grow toward the mid-hne in anticipation of the definitive palate. (Redrawn from Keith after Kollmann.l The Bucconasal Membranes and the Primitive Choanae or Posterior Nares. — The dorsal growth or extension of the blind, pouch-like primi- tive nasal fossae meets the ectoderm of the oral fossa. One now iinds in Note the plugging of the nares in photograph 7; moreover, that the nasal concha; as illustrated in photographs 8-11 have no cartilage in them at this age. The inesenchymal tissue is, however, under- going condensation in anticipation of cartilage in the region of the nasal septum and the lateral nasal walls. Xote also the relation of the tongue to the palatal processes. X 12.3. P. pal. = processus palatinus; Eth. fold = ethmoidal fold; Ma.x. fold ^ maxillar\' fold. lO GENERAL EiMBRYOLOGV AND DEVELOPMENT these positions the bucconasal membranes composed of two layers of abutting epithelium (nasal and oral), separating the dorsal portion of the primitive nasal fossae from the oral cavity (lo mm. embryos). In 35- to 38-day embryos the membranes are so attenuated that rupture usually ensues and the primitive choana; (primitive posterior nares) are thus established, and with them communication between the nasal fosss and the oral cavity. Lack of rupture of the bucconasal membranes leads to atresia of the choante, a condition occasionally observed in fetuses and in the newborn. Secondary blocking of previously patent choanal aper- tures due to epithelial overgrowth has been observed by the writer. Epithelial plu(f Fig. 14. — Photomicrograph of a frontal section through the ventral portion of the nose of a human einbryo aged 4g days. (Embryo No. 28, Cornell Universit>" series, slide 40. J Especially note the epithelial pings occluding the nares. X 19. The primitive choante do not correspond in position to the definitive choanal. The latter are placed farther dorsad and are established in the third month when the definitive palate is completed. The primitive choana; are located well in advance of the buccal pituitary outgroAvth in the roof of the mouth and are separated by the primitive or primary nasal septum (Figs. 5, 6 and 13). The Nares (anterior nares). — When first formed the nares communi- cate freely with the exterior and their embryological anatomy is essentially that of the early nasal pits. The luminae of previously patent nares in very many instances become temporarily obstructed by a marked pro- liferation of the epithelial cells. In some cases the closure is absolute, in I'Kl.MITUK I'AL.VriO il Others deviating passageways exist. As pointed out by the writer in an earlier pubhcation^ the plugging is rather common from the fortieth to the sixtieth da>- of embryonic life. Later there is a solution of the closure by degeneration of the central masses and b)' an active shedding, and the nares are again o])en to the exterior. As evidence of shedding, one often tmds shreds of epithelial masses protruding from the nares. Lack of solution of the closure produced by these epithelial plugs leads to an atre- sia of the nares. The masses may become organized, as is attested by the membranous and bony atresias and stenoses of the nares that are encountered (Fig. 14). The Primitive Palate.— Fusion of the maxillar)- and lateral nasal proc- esses with the medial nasal processes and the rupture of the bucconasal Linffn,co Cavi2^?ii oris - - ' ■ IJ^^cepn^x lo fz BfhtnoTu ibmxxJ, Oculus ■^ '^'^ ^Processus pal-aiiftus Fig. 15. — Ph'.itograph uf a frontal section thrfiu^h the head of an eml^ryri aged 43 days. (Embryo Xo. 3.) X 15. membranes in the establishment of the primitive choana; or posterior nares delimit for the first time the primiti\'e palate. The latter presents a facial and an oral portion, the former giving rise to the upper lip and the latter to the premaxillary plate. It has been established that the mesoderm of both the facial and the oral portions is a derivative from the maxillary and medial nasal processes, the lateral nasal process par- ticipating only at the caudal border of the naris (anterior naris), e.g., the middle portion of the primitive palate is derived from the medial nasal 'Jour. Vlorph., Vol. 21, igio. 12 GF.NER-VL EJIBRYOLOGY AND DEVELOPJIENT process, the dorsolateral portion from the maxillary process, and the ventrolateral portion from the lateral nasal process (Figs. 6 and 13). The Definitive Palate.— The first step in the production of the defi- nite palate is the appearance of the palatal ridges. These are wedge- shaped processes which grow caudalh' and somewhat medially from the medial sides of the maxillary processes. The palatal processes appear from the forty-fifth to the forty-eighth day of embryonic life. They at first hang almost vertically toward the mouth cavity, on either side of -,.«src<. ()t Into ■^ . Con lias mcd. / #' / ~^ ''-' / J'lorrs'.ii'./xi/dlnni'i \ /"'i—^ Cleft iiitnnnniK ' sinks and comes to occupy a lower position n-L the mouth ca\-it>-. Concomitant with this change of the tongue the pahital processes become passi\-eh- rather than mechanicahy rotated, due to an unequal growth, from an almost vertical and sagittal i)lane to a horizontal plane and subsequently meet in the median sagittal plane over the tongue— fusion taking place from before backward along the opposed edges. Nests of epithelial cells may persist between the fused elements giving rise later to epithelial jiearls or e\en to cysts. The dorsal parts of the folds maintain their original direction. Subsequently bony plates extend into the membranous palatal processes to form the greater Xnr - Eih. n.iii M„.r. /;>/(/ /'. 1)1,1. Fig. 17. — Drawiii'^ of a reconstrLiction rif the lateral wall of the nasal fos.sa of an enibr\"o aged 43 days. I Human embryo No. 3. Cornell University .scries, section 300-420 inclusive. ) Particularly note that the palatal process (P. pal.) han),'s in the sagittal plane at this time. The maxillary fold (Max. fold), the rudiment of the inferic)r nasal concha, occupies the greater pnrti'.ni of the lateral nasal wall while the ethmoidal fold ( Eth. fijhl), the rudiment or anlagc of the ethmoidal nasal conchae, is relatively inconspicuous. X 24. i Aflrr J . P. S.) portion of the hard ])alate. Dorsalh^ these plates are wanting and mus- cular tissue extends into the ])rocesses, gi\'ing origin to the soft palate and to the uvula. In the formation of the defmitive hard palate a substantial portion of the primiti\-e buccal cavity is isolated and made part of the nasal cavity (Figs. 15, 16, 17, iS and ig). As was previously pointed out, the mesial nasal ])rocesses unite superficially to form the central part of the upper lij) and ])hiltrum and conjointi}' extend dorsad in the roof of the stomodeum to form the inter- 14 CKXERAL EMBRYOLOGY AND DEVELOPMENT maxillary process (the greater portion of the primitive palate, vide supra). The intermaxillary process projects farthest dorsad in the median plane and by its lateral borders abuts with the lateral nasal processes ventrally and with the maxillary processes farther dorsally. At the dorsal ends of the planes of contact fusion is imperfect, leading to the formation of the incisive foramina (anterior palatine canals). The latter transmit (a) nerves and vessels which course between the mucosae of the oral and nasal cavities and (6) the nasopalatine canals (canals of Stenson) which early connect the nasal and oral cavities, but in later life generally become oblit- ±f-'<- Concha itasalis \ i ^uprema J 'on eh a nasal in superior Concha nanalis media Concha nasalis inferior Processus palatinus Fig. i8. — Drawing of a rftonstruction of the lateral wall of the nasal fossa of an embryo aged 49 days. (Human embryo No. 28. Cornell University series, slides 40-51 inclusive.) EspeciaUy note that the palatal process has now assumed a horizontal position in anticipation of the completion of the palate. Moreover, note that the ethmoidal fold has enlarged and become dif- ferentiated into a number of ethmoidal conch^e. X 26. (After J. P. S.) erated,at least at their oral extremities (see page 76). Little of the primi- tive palate is so located as to participate in forming the adult palate proper. The Definitive Choana (posterior nares). — Coincident with the growth of the facial region and the formation of the palatal processes the primitive or primary choanae become elongated and form slit-like pas- sageways between the nasal and oral cavities (Fig. 13). The continued growth and the ultimate fusion from before backward in the mid-sagittal DKKixrrni-: choax.e IS plane of the palatal processes in the formation of the secondary palate, and the buccal and phar>-ngeal extensions of the primary nasal' septum, force the primiti^•e or ])rimar>- choame to undergo a stead}- dorsal migra- tion until communication with the cephalic and ventraftermination of the phar>-nx is established. This connection locates the delinitive choana; Concha fiasa/is supremo II Concha nasalh suprema I ('oiivha nasalis sujxrior Concha -nasa/is media Lobahis Concha nasalh. inj'cihir Dejinitive palate Fig. 19.— Drawing of a reconstruction of portion of the right waU of the nas:il cavity of an embryo aged 105 days. (Human embr3''o No. 43, Cornell University series, slides i-go inclusive.) Xote that the definitive palate is now completed and that the choana has assumed its final posi- tion. Th'i ethmoidal field has differentiated into four nasal conchae. Especially note the marked lobule in the region of the knee of the concha nasalis media. X 9-5- {Aflo' J. P. S .) or posterior nares. As the primary choame migrate dorsaUy^ due to the fusing of the palatal processes, the nasal septum fuses with the mid- palatal ridge to divide the nasal ca\'it}' into the right and left nasal fossa?. Here, too, the division and fusion take ])lace from before backward. i6 GENER.VL EMBRYOLOGY AND DEVELOPJIEXT The Primary Nasal Septum (the sej^tum nasi primum). — The mesial nasal processes — the symmetrical mesial and caudal extensions of the frontonasal process — fuse together and form the middle third of the upper lip, the intermaxihary process, and the primary nasal septum between the primitive (primary) nasal fossa?. ^Moreover, when the primitive nasal fossae establish communication with the roof of the buccal cavity by the formation of the primitive choana?, it is the primary nasal septum that in- tervenes between these apertures as a wide plate in the roof of the mouth. The Secondary Nasal Septum (the septum nasi secundum). — During the latter part of the second month of fetal life after the primitive choana? are formed, the primar}' nasal septum begins to grow buccalward and pharyngealward until the aperture of the buccal pituitary outgrowth is FiG. 20. -MuJd of the nasal cavity of a 40-day human embryo. Particularly nriie the connection (nasobuccal cleft) between the nasal fossa- and the mouth cavity. M. N. S, I. = Meatus nasi supremus I; M. N. S. = Meatus nasi sujicrior; M. N. M. = Meatus nasi medius; M , N. I. = Meatus nasi inferior. included in its dorsocranial border. Coincidently, the nasal fossa; are elongated in the ventrodorsal plane, the definitive palate is completed, and the definitive choanfe are estabHshed in the region of the naso-phar3mx (end of third month). ]\Ioreover, the secondary nasal septum has ex- tended sufficienth- buccalward to fuse with the mid-palatal ridge, which it does from before backward, in the division of the general nasal cavity into the definitive nasal fossa;. DKI'IX1'I[\K XASAL lUSS.E 17 The Definitr'e (Secondary) Nasal Foss.t; \Mth the completion of the boundaries, that is, the medial and lateral walls, the roof and floor, and the choanal apertures, the nasal foss;e are not hmited to their primiti\e site, but ha\-e incorj^orated a goodly portion of the buccal ca\-it>- on the nasal side of the hard ])alate and in a sense they pass into a secondarA- de\-elopmental stage. It is, therefore, suitable to FrG. 21. — Frontal section of the nose of a human embryo aged 120 days. On one side the section is through the region of the ostium maxillare and on the other dorsal to it. Xotc the fusion on the left side between the processus uncinatus and one or more frontal conehti?. This causes the infundi- buluni ethmnidale to end blindly ventrocephalically. Farther dorsad as illustrated on the right side the infuniJibulum clhnioidale is of course in wide ci.immunication with the meatus nasi medius \-ia the hiatus semilunaris. /. 10. F. cr. ant. ^ Fossa cranii anterior; Inf. eth. — Infundibulum el hmoidale; ( ). m. ^ Ostium maxillare; S. max. = Sinus inaxillaris; B. eth. = Bulla cthtmiidalis; FI. sem. = Hiatus semilunaris; Proc. unr. - Processus uncinatus; Os ^ maxilla undergoing ossifieatinn. speak of the primitive nasal fossce and the incorporated portion of the buccal cavitA' as conjointly forming the definiti\'e or secondarA' nasal fosste. It is during the secondary phase of development that the nasal bound- l8 GENER,\L EMBRYOLOGY AND DEVELOPMENT aries continue their cliondrification and ossification, tliat the elements entering into the boundaries attain definition. Moreover, the previously- simple lateral nasal wall undergoes profound metamorphosis in the forma- tion of the appendages which ultimately characterize its surface; the para- nasal sinuses begin to take form and position, while the septal wall, on the contrary, becomes relatively more simple as its definitive form is reached. It must, however, be understood that there is no sharp border line between the primitive and definitive growth periods of the nasal fossae; rather that growth processes begun in the primitive period are continued and carried to fruition in the secondary period. In a sense, during the primitive stage of development the foundation and superstructure of the nose are formed and in the subsequent period the interior and exterior are molded and modeled in the formation of many secondary, yet complex and important structures. The Lateral Nasal Wall The lateral wall of the nasal fossa of a 35-day embryo gives no evidence whatsoever of its later complexity. Indeed, the medial or septal wall is more complicated at this stage of development owing to the vomeronasal organ which is a prominent structure in the early embryo. There is an inherent tendency for the nasal cavity early and rapidly to increase its surface area. Even before the first appearance of the palatal processes as limiting shelves for the nasal fossae caudally, the lateral walls of the fossce have begun in a simple manner the complex configuration which ultimately characterizes them. The complexity in the anatomy of the lateral wall is due to the development of the major nasal conchae (turbinates), the minor (accessory) nasal conchs:, the major nasal meatuses, the secondary nasal meatuses, and the paranasal (accessory) chambers. The portion of the inferior nasal meatus that lies dorsal to the incisive canal, together with the space immediately behind the dorsal extremities of the ethmoidal conchse as far back as the ostium of the auditive tube (Eustachian tube), is derived from the primitive buccal cavity of the fetus, having become isolated by the formation of the definitive palate. The dorsal extension of some of the nasal conchae toward the choana beyond the confines of the primary nasal fossa is purely secondary. (A) The Major Nasal Conchae (endoturbinals) and Meatuses. — The conchal or turbinal apparatus of the human nose is much reduced, and its de\'elopment takes place entirely in the region of the sensory epithe- lium, e.g., in the primitive nasal cavities. The conchae arise on both the lateral and medial walls of the nasal fossa : The agger nasi (nasoturbinal) -MAJOR XASAL COXCH.Ii AND Al EATUSIvS 19 and the concha nasahs mferior (maxiUoturbinal) arise from the lateral wall, and the conchic of the ethmoid region (ethmoturbinals) arise in part (J. P. Schaeffer)! or wholly (Peter)'- from the median wall. By a process of unequal growth the ethmoidal conch;e are transferred whoUy to the lateral nasal wall. It is, of course, essential that approi)riately aged embryos are studied for the initial stage. The transference to the lateral waU occurs at an early time and this may mislead the investigator. r Fk,, 22. Figs. 22-25.— Reconstructions of portions of the ialcrai nasai \\'a various levels. (Human embryo, aged approximately 125 days.) Fij;. 22 farthest ventrad and Fig. 25 farthest dorsad. le. = Iniundibulurii ethmoidalo; Mnm. ^ Meatus nasi :ne(hus; Cum. Cni. = Concha nasalis inferior; Sn. = Septum nasi; Cns. ^ Coneha nasa ethmoidalis; Hs. — Hiatus seiTiilunaris; Om. ^ Ostium maxillarc; Pu. S. max. = Sinus maxillaris; Mni. ^ Meatus nasi infcrii.*r. Fi .. 2 V th c fr mt il pi ane and at rc iresent s tin ■ nasal wall = Conch I na alis media; lis sup erii r; B e. - -- Bulla = Pr "ICCSSUS uncinatus; The mechanism by which the nasal conch;e and meatuses are ini- tially formed is variously interpreted. At the outset it may be detinitcly stated that in the conch;e of the human nose the skeleton is not the primary structure as is so frecjuentl}' given. Cartilage does not grow into the primiti\-e (primary) concha', but develops or arises within prex'iously • Schaeffcr; The Lateral Wall ni" the C'avum Xasi in .Man with lospeeial Reference to the \'arious De\'elopmental .Stages, Jour, of Alorph., Vol. 21, roio. 2 Peter: Die Kntwieklunp; fler Xasenmuseheln bei Jlensch und SauKetierii, ,\rehi\- f. mikroskop. Anatom., Hd. 79, 1912. GEXER.\L EilBRYOLOGY AXD DEVELOPilENT established conchal rudiments or anlages composed of epitlielium and sub- jacent indifferent mesencliyme. In otlier words, tlie conchaj or turbinates are not primarily produced by inpushings of the nasal wall due to carti- laginous strands or bars. Indeed, the initial conchs are present before the precartilage stage of the mesenchyme (Figs. - embryos). These shallow groo\-es, the rudiments of the meatus nasi inferior and medius, throAv at once into slight relief the greater portion of the lateral nasal wall and es- tablish the initial stage of the concha nasalis inferior (maxiUoturbinalj. The indifferent mesench}'mal tissue contained ^vithin this primiti^-e fold simultaneousl}- undergoes proliferation and aids in making the fold more i)rominent. The mucous membrane over the fold is but slightly thickened at this time. The writer is not in accord with those who argue that the formation of a well-developed maxillary fold is wholly due to the formation and deepening of the bordering furrows. The formation of the shallow furrows is doubtless the primitive step in conchal formation. :major xas-U. coNCH.i; and .meaiuses 21 However, the proliferation of the indifferent mesenchyme contained in the fold aids materially in causing the primitive concha inferior to bulge into Ascending crural mass Descending crura of eifimoidal conchae Fl(.. 2-. — The lateral nasal ^\"all eif a term fetus the lumen of the nasal fossa and the bordering furrows to become passi\-ely deeper (Fig. 17). The Ethmoidal Concha, (conchae ethmoidales) and ///c Supcvior and First, Second and Third Supreuie Xasal Meatuses (meatus nasi superior et Ascending rami of „ meatus nasi ace g i Fig. 28. — The lateral nasal wall of a term fetus. suprema- I, II, III). — The ethmoidal fold (rudiment of the ethmoidal conchce; appears next in the extreme dorsal and superior portion of the 2 2 GEXERAL E.M BRYOLOGY AND DEVELOPMENT nasal fossa in the angle formed by the lateral wall and nasal septum. Since the primitive concha inferior (maxillary fold) takes up the greater portion of the lateral nasal wall at this time, there is little room for the primitive ethmoidal fold. In a former study the author^ concluded that the ethmoidal fold arose both from the septal and lateral walls. Peter,- on the contrary, believes that it arises in whole from the septal wall. With further and unequal growth of the nasal fossa in the dorso-superior direc- tion, the ethmoidal fold passively migrates from the septal to the lateral nasal wall. The mucous membrane over the ethmoidal fold is, as a rule, Ascending rami of meatus nasi Pig. 2y. — The lateral nasal wall of a term fetus. Particularly note the multiple furrows ein the medial surface of the concha nasalis media. thickened. Gradually, in place of the single ethmoidal fold, there are established rudiments of the individual ethmoidal concha; or turbinates. The development of these conchte proceeds from the most caudal to the most cephalic. One sees two ethmoidal conchfe in embryos aged appro.xi- mately 48 days, three concha; in embryos aged 95 to 100 days. In fetuses from the seventh month to term, one finds from three to fi^'e ethmoidal conchte with a corresponding number of intervening meatuses. After birth the ethmoidal conchfe are usually reduced in number by a coalescence of the uppermost and less de\'eloped members with a resultant obliteration of the inter\'ening meatuses. When the usual two or three ethmoidal conch;e are found in the adult, it is difficult to decide whether coalescence 'Loc. cil. ^Loc. cit. -AIAJOR \ASAL COXCH.E AXD :\IEATUSES 23 of parts (regression) or lessened differentiation (i)rogression) was tlie de- termining factor. In the adult one rarely finds more than three eth- moidal concha?. Therefore, numerical reduction must be a factor in some instances (Figs. 20 and 14b). Doubtless the personal equation is an im])ortant factor in the diverg- ent findings reported as to the number of fetal ethmoidal conch;c that are dift'erentiated. In man>- cases the more cephalic folds are extremely rudmrentary and are usually overlooked or considered too small to be counted as ethmoidal conch:e. The concha suprem;e II and III, when dift'erentiated, as a rule early lose their identity by fusion, and in infancy and adult life three ethmoidal concha? must be considered the typical number rather than two as usually given. An examination bv the author ^gger Fig. 30. — The lateral nasal wall of a 210-day fetus. Note especially the lobuli on the ethmoiihil conehas. of 264 infant and adult specimens showed ibo with three ethmoidal con- chae, gS with two ethmoidal conchte, 4 with four ethmoidal conch;e, and 2 with one ethmoidal concha. The ostium of the posterior ethmoidal cell which develops from the meatus nasi suprema I is a good and reliable point for orientation in determining the presence of a concha nasalis suprema I. The latter is present, according to the author's studies, in approximately 60 per cent, of the cases, and in 75 per cent, of them a posterior ethmoidal cell develojos from the corresponding meatus (Fig. 127). The latter anatomical fact needs explanation by those who argue that two ethmoidal conchse represent the typical field; especially so when one recalls that the cellula? ethmoidales develop from preformed nasal meatuses. The group of ethmoidal conchae and meatuses in a general wa>- early possess knees, thus giving rise to ascending and descending crura. The 24 GENER.\L EINIBRYOLOGY .\ND DEVELOPMENT angular condition lessens as one passes from the middle concha and its corresponding meatus to the highest concha and meatus present. In Concha nasalis suprema I Coruita nasalis superior Concha nasalis media Concha nasalis inferior YiQ. ^i. The lateral nasal wall of a 190-day fetus. Espeeially note the rudimentary character of the concha nasalis su]ierior. X 2.3. fact, the upper ethmoidal conchte are represented mainly by the descend- ing crura. Often the ascending crura are not at all differentiated, the ■ ;/ ' - '— Cor "1' l,„ «o Ill O.nrlui »asnlis mprcTna II I \ \ C'oiirli II II II \ a lix mipreiiKi I "^ V \ : \ yl/ffl/w / / \. % fupre^mi ^^' Cimrh'i nil siipcnor Meniiif- 1 «//. n k / ,;-. - --. siipeni'i fi ^-^ C';,clia nil ihi.'. I medio .Vi \ Fig. 32. — Drawing of a frontal section through the lateral wall of the nasal cavity in the region of the ethmoidal conchas (fetus aged from 7-8 months, series B. slide 48). The concha nasalis in- ferior is not included in the section. X 8. whole region being represented by a general undift'erentiated crural mass (Fig. 27). Ascending and descending crura are, however, constant for the LOBULES AXl) XODULLS 25 concha nasalis media and the meatus nasi medius. The concha nasalis superior and its corresponding meatus also freciuently persist in the adult as angular structures. Briefly stated, the integrity of the ethmoidal concha? and meatuses is more or less dependent upon the descending or inferior crura, the middle concha and meatus excepted. At the junction ol the ascending and descending crura of the eth- moidal concha' one commonly finds ovcrl/aiii^iiii^ lohitlc fonnatio)is (Figs. " "/J' Siipinhiillar furrow VcUnUic ethmoidnles Superior btillar fold Biillar furroir ^Inferior hnllar fold 4"?^^ ^^^^-r^T**— ^> ''Or.', ' Itifrahiillnr furrow '3.4|i\ v^'-^'^i,^ — ' ''"M: - J nfiindibiila'r fold — liifiiiidih. elhiiioidale Processus uiieiiialns Siino< ino.rillaris Fig. 33— Drawing of a frontal section of the lateral wall mI the left nasal fossa of a term fetus (series D, slide 5). Xote the individual folds comprising the bidla ethmoidalis. X 5-S. 19 and ;,o),the most marked and constant of which is found on the knee of the concha media. The latter lobule may be of such size as to lead to mechanical obstruction of the meatus nasi medius in the neighbor- hood. This lobule must not be mistaken for the later and very common distention of the middle concha due to an ingrowth of an infundibular or other anterior ethmoidal cell to become conchal in position. Mechanical obstruction of the meatus may likewise follow, depending upon the size 26 CF.NERAL EAIBRYOLOGY AND DEVELOPjNIENT of the cell. Secondary iiodulcs frequenth' form on each primary lobule (Fig. 30). The lobule and secondary nodules of the human ethmoidal conchae (ethmoturbinals) are the homologues of the rather sharp ventral projections of the ethmoturbinals of mammals. The concha nasalis media often presents a number of secondary furrows on its medial surface (Figs. 28 and 29). A single and deeply cut furrow often partially divides the concha into halves. Errors are fre- quently made in such instances in considering the portion inferior to the furrow as the concha media and the portion superior as the concha superior. Such an analysis would erroneously make of the furrow the meatus nasi superior. Zuckerkandl early made this error, but later cor- rected himself. A few recent publications continue to err in regards to the furrows found on the medial surface of the middle concha. The Nasotxirbinal fagger nasi) and the Nasal Atrium (atrium nasi, atrium meatus medii). — The nasoturbinal appears relatively late in man and is always extremely rudimentary as compared with the higher mam- mals, e.g., rabbit, sheep, pig, ox, etc. It appears as a slight elevation cephalic to the concha inferior (maxilloturbinal) and ventral to the concha media (ethmoturbinal). It develops more or less parallel to the bridge of the nose. Infundibular cells (anterior ethmoidal cells) frequently grow out from the infundibulum ethmoidale into the agger nasi (Fig. 75) and are often referred to as agger cells (see pages 221 and 223). The Nasal Atrium. — This is a shallow depression immediateh' infero- dorsal to the nasoturbinal or agger nasi and in a sense may be considered its related meatus, and since it is a sort of an antespace to the middle nasal meatus is frequently referred to as the atrium of the middle nasal meatus. The Olfactory Sulcus (sulcus olfactorius, carina nasi). — This is a cleft-like space developed between the agger nasi and the ental surface of the dorsum of the nose (dorsum nasi) and leads from the nasal vestibule to the olfactory part (pars olfactoria) of the nasal fossa (see page 97 and Fig. 146). The Sphenoethmoidal Recess (recessus sphenoethmoidalis).— The sphenoethmoidal recess is developmentally related with the posterior cupola of the cartilaginous nasal capsule and is located cephalic and dorsal to the highest ethmoidal concha that may be differentiated and is limited by the angle formed by the cribriform plate of the ethmoid and the ven- tral surface of the sphenoid. From its dorsal boundary or wall develops the sphenoidal sinus and in later life contains the ostium or aperture of this sinus (Fig. 127). MINOR XASAL CONCILE AND Ml'ATUSKS 27 Nomenclatxire.— From the foregoing it would appear that the general text-books of anatomy offer nomenclatures sufficiently extensive for adult conditions, but not for the late fetal and early infantile stages. The writer \A-ould, therefore, suggest the following terminology which covers not only adult conditions, but also the extreme ethmoidal differentiations found in infanc}- and late fetal life : Fig. 34. — A frontal section thrnuKh the lateral wall of the nasal fossa in the region of the superior nasal meatus (7-m<;)nth fetus, series C", slide 8). Especially note the accessory concha of the superior meatus and the crista suprema. X 10. Conch (r nasale-':^ Concha nasalis inferior Concha nasalis media Concha nasalis superior Concha nasalis suprema I Concha nasalis suprema II Concha nasalis suprema III Afffrer nasi Meolux tidsi iSIealus nasi inferior ^Meatus nasi medius jNIealus nasi su|)erior JMealus nasi supremus I Meatus nasi supremus II Meatus nasi supremus III .\trium nasi (B) The Minor or Accessory Nasal Conchse (ectoturbinals, conchae obtectjej and Meatuses or Furrows. — Nasal conchie and meatuses or furrows of a secondary or accessory nature are regularly diff'erentiated and developjed in the human nasal ca\'ity and are homologous with analo- gous structures found in the mammalia, r. ,(,'., raljbit, cat, etc. They are ■J. Parsons Schaeffer: The Lateral Wall of the Ca\um Xasi in Man, with I'^special Keferencc to the Various Developmental Stages, Jour. Mor[)h., Vol. 21, is'o. 4, loio. GEXERAL E.MIiRYOLOGY AND DEVELOP-MENT intimately associated with the genetic history of the paranasal (accessory) sinuses and unless one has a clear conception of the origin and development of these early secondary structures found in the middle and superior nasal meatuses, it will be impossible to properly interpret the early pre- natal and adult anatomy. Errors are repeatedly made in the analysis of the adult ethmoid labyrinth, the nasofrontal connections, etc., because adult and late fetal material alone are studied. The accessory nasal conchs and meatuses (folds and furrows) are located (i) in the descending ramus of the meatus nasi medius, (2) in the ascending ramus of the meatus nasi medius, and (3) in the descending ramus of the meatus nasi su]:)erior. These secondary or accessory struc- . Fronfal fwrrows Frontal folds (acccssori/ cutichae) — Concha luis.inj'^d.. Bulla, eth Pj-oc. 7i.n£iiiutvs Fig. 35- — A dissection of the lateral nasal wall of a term fetus. The concha nasalis media has in large measiire V)een removed thereby' exposinj; the accessory' folds or conchs and furrows of the as- cending (frontal recess) and descending raini of the meatus nasi medius. X 2. tures are more or less hidden and operculated by the conchae nasales media and superior: I . The Descending Ramus of the Meatus Nasi Medius. — Serial frontal sections of the nose of 40-day embryos show that the lateral wall of the meatus nasi medius is e^'en and unbroken. On the contrary, the same region in embryos aged from 40 to 60 days presents a crescentic- shaped fold breaking the evenness of the wall. This fold is the rudiment or anlage of the processus uncinatus and is the first of a series of accessory folds to appear on the lateral Avail of the meatus medius. The fold at once aids in forming a furrow immediately superior to it — the primitive infundibulum ethmoidale. It is quite probable that the furrow first estab- lishes a rudiment and this in turn throws into slight relief a portion of the mucous membrane inferior to it, thus establishing the anlage of the pro- cessus uncinatus. It may, however, be said that both structures are MINOR XASAL COXCH.E ANU MEATUSES 29 more or less dependent upon each other in estabhshing rudiments. The same principles are obviousl_\- here inx'ohed as they are in forming the primitive major nasal meatuses and conch;e. From the primiti\'e infundi- bulum ethmoidale, the sinus maxillaris develops its rudiment (65- to 70- da}' embryos) in the form of an e\'agination of the mucous membrane. This outpouching of the mucosa aids in early establishing the i)rocessus uncinatus and the infundibulum ethmoidale. Shortly after this \ve have the first evidence of the bulla ethmoidalis, appearing sujKn-ior and lateral to the processus uncinatus. The bulla ethmoidalis is first indicated by special thickenings (one or two) of the lateral plate of cartilage — the cartilaginous thickenings appearing on its medial surface. At first the bulla rudiments do not cause the mucous membrane to bulge toward the lumen of the nasal caA'ity and the early Frontal farrows Co7lc//4c 7UCS ■ r//c^ - ic?zt/ I Ty/f/iridii. eth. TZ TIC! 7m t lis - Fig. 36. — A dissection of the frontal recess of a term fetus showinR the early frontal furrows; e.g.. rudiments of anterior ethmoidal cells and potential ludiments of the frontal sinus. Particularly, note the relations of the infundibulum ethmoidale. X 1.5. Stages pass unobserved unless one examines serial frontal sections through the region. Later, however, say in a 120-day embryo, the cartilaginous prominences ha\-e de\-eloped sufficiently to push the mucous membrane on the lateral wall of the meatus medius into relief and to establish a fold, or folds fbullar folds), lateral and superior to the processus uncinatus. If two folds appear there is an intervening furrow and occasionally an eth- moidal cell develops from it. The folds represent the ]^rimiti\-e buha ethmoidalis which usually merge before or after birth in the formation of the definitive bulla ethmoidalis (Tigs. 33 and 38). Thus far no mention has been made of another fold that aj^pears in many instances inferior to the bullar folds and lateral to the infundibulum ethmoidale. Because of its relations to the infundibulum ethmoidale it is appropriate to speak of this as the infundibular fold. It is never very GEXER-VL EMBR^-QLOGY AND DE\'ELOP.MEXT prominent and forms in part the lateral wall of the infimdibulum ethmoid- ale. It may persist as a fold after birth, but it generally becomes leveled down to an even surface which imperceptibly passes on to the bullar surface. The minor or accessory conchas or folds of the descending ramus of the middle meatus ma>' appropriately be named the superior and inferior bullar folds, the infundibular fold and the processus uncinatus; the acces- sory furrows, the suprabullar furrow or recess, the bullar furrow, the infra- bullar furrow, and the infundibulum ethmoidale. The suprabullar recess and the infundibulum ethmoidale are constant and important furrows. The others are of little importance and are irregular and inconstant in their development: nRcessT^s frontalis - — Proc. i/,vci?mtus^.L _ Fronto,l farrows or pits S/'mj^ sphenoidalis ~ StiZla eth. Fig. 37. — A dissection of the frontal recess, etc., of a child aged s months. Note the pouching of the frontal furrows and the frontal recess in the formation of anterior ethmoidal cells and the frontal sinns. The sphenoidal sinus is also well established. X i-S. The siiprahitUar fiirrou' or recess is practicalh' constant. It ^■aries somewhat in its form and extent, but all specimens give some e\-idence of it. At times it continues ventrally and superiorly, almost to the crib- riform plate of the ethmoid bone; however, in the majority of cases it does not extend so far, due to partial fusion between the superior border of the superior bullar fold and the attached border of the concha media. It is freciuenth' also limited inferiorh' and dorsalh' b}' similar fusion. Again, there may be multiple points of fusion between the superior bullar fold and the concha media, thus breaking the suprabullar recess or furrow into several compartments (Fig. 40). The recesses in many cases early tend to deepen and pouch laterally and inferiorly behind the bullar folds. In this manner the bulla becomes more or less shell-like in structure and some of the so-called buhar cells established. The suprabullar recess is a constant point from which anterior ethmoidal cells develop. .MINOR XASAL COXCH.K .VXD MEATUSES 31 The hiiUar fiirnnv is placed between the two bullar folds or accessory conchcT. It is variable in its differentiation and not at all constant. It is generally obliterated by the superior and inferior bullar folds becoming continuous structures in the formation of the adult bulla ethmoidalis. This coalescence is, howe\-er, not always absolute in that an ethmoidal cell may develop from the furrow, leaving the ostium of the adult cell at the point of the i-)rimiti\-e furro^\'. E\-en in man}' adult specimens one finds e\-idence of this primiti\-e furrow in the form of a shallow groove on the medial surface of the bulla ethmoidalis. An ethmoidal-cell ostium on the medial surface of the bulla ethmoidalis is almost in\'ariabl}' the remains of the early bullar furrow. The injrahiiUdi- fiirroic is ])laced between the inferior bullar and the infundibular folds. It is very inconstant and not infrequently obliterated Folds or iuZia etTi -jTon/nJ, /hnvivs Proc.7jnci7iatiLs Fig. 38. — The lateral nasal wall of a term fetus. The cuneha nasalis media is eut away, thereby exposing the folds of the bulla ethninidalis. the i.)roeessus uneinatus and the fremtal fields and furrows for study. (See te.xt.) by the inferior surface of the bulla ethmoidalis becoming continuous with the infundibular fold. In some cases it is fairly well marked, but as a rule is of minor importance. Rarely an ethmoid cell dexelops from the furrow — the adult cell draining into the infundibulum ethmoidale (Figs. ,33 and 35 j. The infuniibiiliiin ethmoiJalc is invariabh' present in some form. It is formed earlv and ob\'iously aids in establishing the primiti\-e processus uneinatus. It is directed somewhat ^■entro-superiorly and at its ventral and superior termination may end blindl}' or develop into an anterior eth- moid cell. At other times it is \'ariously continued into one of the frontal furrows. Rarely it continues its development ventrally and superiorly, remaining lateral to the frontal furrows and in this wa>' may establish the 32 GEXER-\L EilBRYOLOGV AXD DEVELOPMENT frontal sinus (Figs. 36 and 127). Dorsally and inferiorly it either gradu- ally loses its depth and thus becomes continuous with the middle meatus, or it ends rather abruptly in a pocket, due to the superior and lateral curving of the dorsal end of the processus uncinatus at this point. From the infundibulum ethmoidale the sinus maxillaris develops, hence in the adult the latter sinus communicates with the infundibulum ethmoidale and only indirectly via the hiatus semilunaris with the meatus nasi medius. The superior hiillar fold or conclia is located immediately inferior to the suprabullar recess. It may continue independently ventrally and superiorly almost to the cribriform plate of the ethmoid bone. In other instances it is fused at certain points with the attached border of the concha FronM- fold or concha. - BvZla etk, jxt Tzus. SHprcTttall Concha nccs.svprcmaZ ji&c&ssv.s frontoj.is J'roc.-U'Tt£iltcUijus Concha, n^as . svup. - - Conch^a. Ticis. vTted. Concha. Tta.s.inf,' Fic. 3Q. — A frontal recess in which a single frontal fold or concha has been differentiated. Note the e(jnlinuit3^ of the infiindibukini ethmoidale with the furrows, frontal ftirrows, bordering the fron- tal fold. Compare this condition with Fig. 36. X 1.5. nasalis media. It is frequently continuous with one or more frontal folds. The superior bullar fold usualh' comes to form the chief bulk of the adult bulla ethmoidalis. In many cases there is no differentiation into superior and inferior bullar folds b}' an intervening furrow — the bullar furrow (Figs. 33 and 39). TJie inferior bullar fold or conelui is, as stated abo^•e, not always differ- entiated from the superior bullar fold. It is, however, occasionally well isolated and stands more or less as an independent fold. The latter con- dition is especially marked in the cases where an anterior ethmoidal cell de\'elops from the bullar furrow. The writer agrees with Killian that the superior and inferior bullar folds (obere und mittlere Nebenmuscheln, Killian) usually coalesce to form the adult bulla ethmoidalis. Sometimes, even in the adult, one sees evidences of the primitive bullar furrow which more or less grooves the medial surface of the adult bulla. In manv MIXOR XASAL COXCIl.E VXD MEATUSES 33 instances, however, coalescence is not necessary because tliere ^^'as at no time a differentiation into two portions. Tlic mjiindihular fold or coucha is ^'ery rudimentary and more or less inconstant. It is located lateral to the infundibulum ethmoidale and in part forms its lateral wall. It is more or less separated from the inferior bullar fold by the shallow infrabullar furrow. It usually loses its identity in the adult in that it imi)crceptibh- passes to the bullar surface by the obliteration of the infrabullar furrow. Occasionally it is avcH marked and more or less isolated from the inferior bullar fold by a rela- tively deep infrabullar furrow. Rareh' it retains its identitA' in the adult — this is esi)ecially so when an anterior ethmoidal cell develops from the infrabullar furrow. The processus iiiiciiiatiis is a constant structure, and is medial and inferior to the infundibulum ethmoidale. As stated before, it is the first of the accessor}- or hidden conchae to be differentiated. At its ventral and su])erior end it terminates in \-arious ways. In some cases it is con- tinuous with one or more frontal folds and at the same time its base con- tinued on to the agger nasi. In other instances it is fused with the lateral surface of the concha media at its ventral extremity or even fused with the A'entral extremity of the bulla ethmoidalis. Ventrally and inferiorly the base of the processus uncinatus becomes continuous with the surface of the agger nasi. Some obser\-ers erroneoush' class the processus uncinatus with the major ethmoidal conchie (Figs. 22 and 2^). 2. The Ascending Ramus of the Meatus Nasi Medius (the recessus frontalis). — The extension of the middle meatus toAvard the frontal region is the first step in the formation of the frontal sinus and certain of the ante- rior ethmoidal cells. To this extension or recess Killian' has gi\en the api)ro- priate name, "recessus frontalis." For some time the lateral wall of this recess (ascending ramus of the middle meatus) is even and unbroken. Frontal and horizontal sections of the recess of a 4-month fetus reveal the lateral i)late of cartilage thickened at certain points in the form of projections directed toward the lumen of the nasal fossa. For some time this condition prevails and the mucous membrane is not at first thrown into relief. These thickenings \-ary in number and are in anticipation of the accessory conchee which are present on the lateral wall of the frontal recess of later fetuses. The froiilal folds or conchev and the frontal furrows of the frontal recess of the late fetus are variable in number and as a rule are not very prominent. Their prominence depends largely upon the degree of devel- 1 .Vnatomie der X'ase menschlicher Embryoncn, Arclih- f. LaryriKoloK., i,Sg(,. 3 34 GE\ER-\L EilliRYOLOGY AXD DEVELOPMEXT opment of the intervening furrows or pits (frontal furrows). The con- chte or folds as a rule more or less lose their identity after birth, and the furrows or pits variously remain as ostia of anterior ethmoidal cells and the point of communication of the frontal sinus. As stated above the frontal concha; or folds and furrows vary in degree of development and differentiation. Specimens with four well- formed furrows and three resulting folds are not uncommon. In other cases, either by early coalescence or lessened differentiation, fewer folds and furrows are found. The first and second frontal folds or concha; are at times confluent with the processus uncinatus (Fig. 36) and in addition occasionally extend toward the agger nasi with which they are confluent. Jiecessus frontalis Bulla etji. , . _ _ In/vndib. etk Proc. TmciTicctv s - SbuLS froitUdis n/zs. me^i- STiprabvJJ'Or furrow es cc. eik.) Pig. 40. — A dissection from a child aged 14 months with the conclia nasahs'media turned aside. Apparently no frontal folds nor furrows were differentiated and the whole frontal recess is expanding toward the frontal region in the establishment of the frontal sinus. Note that the infundibulum ethmoidale and the recessus frontalis are discontinuous anatomically; moreover, that the supra- bullar furrow is represented by a series of depressions, rudimentary cellulse ethmoidales. X_o.8. moreover touch the lateral surface of the concha nasalis media with which they fuse. In Fig. 35 is represented a specimen in which the processus uncinatus js continued ventrally and cephalically to the agger nasi, in part fusing with the concha nasalis media at this point. The superior and inferior bullar folds in the latter instance are continued superiorly to become continuous with the first and second frontal folds. The third frontal furrow is more or less continuous with the suprabullar recess, and the latter continues almost to the cribriform plate of the ethmoid bone. The infundibulum ethmoidale continues ventrally and cephalically into a frontal furrow. Compare this condition of the infundibulum ethmoidale with that found in Figs. 36, 39 and 40. In Fig. 39 there is only one frontal fold or concha dift'erentiated. illNOR NAS.VL COXCII.l': AND MKATUSl';s 35 The concha is bordered b>- two frontal furrows, and the infundibulum ethmoidale is continued \'entrall>' and superiorly into these furrows. In Fig. 38 the processus uncinatus is continued ventrally on the lateral Avail of the frontal recess and apparently the frontal folds extend from it. At times the frontal folds or concha- fuse with the lateral surface of the concha nasalis media and obliterate the frontal recess as such. Tn these cases the sinus frontalis must de\-elop from an anterior ethmoidal cell, and not by direct extension of the frontal recess fFig. 150). In Fig. 147 the frontal folds have not fused with the lateral surface of the concha nasalis media, the frontal recess being maintained. In such a condition the sinus frontalis ma}- develop either from the frontal recess or from one or more anterior ethmoidal cells. It is difficult to say in the latter dissec- tion whether the frontal folds or conchae have coalesced Avith one another, thus constricting off small blind pouches (early anterior ethmoidal cells), or whether the frontal furrows in anticipation of anterior ethmoidal cells have pouched toward the frontal region, thus closely simulating coales- cence betAveen the scA^eral frontal folds, but making coalescence ap]:(arent rather than real. (3) The Descending Ramus of the Meatus Nasi Superior.— At this juncture mention must again be made of a frequent accessory concha differentiated rather early and Avell established by the fourth month of fetal life on the lateral Avail of the descending ramus of the meatus nasi superior. In specimens where the accessory concha of the superior meatus is Avell de\-elo])ed, fairly well formed superior and inferior recesses are established on the lateral meatal wall. The inferior recess is especially deep in the cases where the "crista suprema" of KiUian is Avell developed. This condition makes the superior meatus look much like the middle meatus, i.e., the accessory concha of the superior meatus takes the place of the buUa ethmoidalis (accessory concha of the middle meatus), and the "crista suprema" takes the place of the processus uncinatus (compare Figs. 21 and 34). The inferior recess of the superior meatus may continue ventro- cephalicalh- into the blind superior termination of the superior meatus. The accessory concha is, hoAvever, at times wholly or in part coalesced with the concha media, thus obliterating wholly or partly the inferior recess. Frequently a posterior ethmoidal cell dcA'clops from, the inferior recess. The superior recess is often obliterated by coalescence between the acces- sory concha and the concha superior. In other instances the superior recess too is continued \'entrocephalically to the blind end of the meatus superior. Occasionally an ethmoidal cell develops from this recess. 36 GF.XERAL EMBRYOLOGY AXl) DEYELOPMKXT (C) The Rudiments or Anlages of the Paranasal (Accessory) Sinuses. —The paranasal sinuses are preformed in the major and minor nasal meatuses (none develop from the meatus nasi inferior). This is true for all the paranasal sinuses save the sphenoidal which arises in connection with the posterior cupola of the cartilaginous nasal capsule, and in a sense is primarily a constriction of the nasal mucosa from the dorsocephalic part of the nasal fossa. After the preceding consideration of the nasal meatuses and concha? and the accessory concha; and furrows, the genesis of the paranasal sinuses becomes much simplified and fairh' eas>- of interpretation. Since the paranasal or accessory sinuses develop from preformed furrows and re- cesses, it is diificult to say just when they have established rudiments. The author belie\'es, however, that rudiments are established much earlier than is generally supposed. Indeed, the furrows and recesses from which the paranasal sinuses develop are, in a sense, the "primitive" rudiments of these chambers. The early tendency for the sinuses to establish their ''first" rudiments may be no mean factor in making the recesses and furrows what the}' early are. The pre-existing spaces from which paranasal air chambers de\'eIop, according to the writer's specimens and studies, are: (i) the suprabullar recess, (2) the bullar furrow, (3) the infrabuUar furrow, (4) the infundi- bulum ethmoidale, all of the descending ramus of the meatus nasi medius; (5) the frontal furrows, (6) the frontal recess, both of the ascending ramus of the meatus nasi medius; (7) the ventral and superior extremity of the meatus nasi superior, (8) the recessus superior, (9) the recessus inferior, all of the meatus nasi superior; (10) the meatus nasi supremus I. Of the foregoing named spaces, paranasal sinuses or cells rarely de^•elop from the infrabullar furrow and onl}- occasionalh' from the bullar furrow. Poste- rior ethmoidal cells develop rather frequently from the inferior and superior recesses of the meatus nasi superior, and in about 75 per cent, of speci- mens in which the meatus supremus I persists, a posterior ethmoidal cell develops from it (the meatus nasi supremus I is present in about 62 per cent, of adult specimens). The remainder of the aforementioned spaces are practically constant in the development of paranasal sinuses or cells. The paranasal sinuses as such are primarily evaginations of the nasal mucous membrane in fairly definite regions of the nasal meatuses men- tioned. These early evaginating sacs wander into neighboring portions of the nasal walls by a joint growth of the sacs and an absorption of bone, until goodly portions of the ethmoid, frontal, maxillar}' and sphenoid bones are pneumatized in the formation of the cellulae ethmoidales, the sinus fron- DEFINITIVE NAS.U. SEPTUM 37 talis, the sinus maxillaris, and tlie sinus si)henoidalis, respectively. 'J'he conchal cells are, of course, outh'in.u; ethmoidal cells and in their origin and de\-elopment are in all resjjects in agreement with the ethmoidal cells proper. In some cases, ])articularl_\- the ethmoidal cells, ossification of the cartilaginous walls of the mucous membrane sacs takes ])lace around the cells, the ]^oint of original outgrowth remaining as the jiermanent ostium of the respectix'c cell. Indeed, no matter how far a cell or sinus may grow into a neighboring bone, its initial point of outgrowth from the nasal fossa persists in the adult as the ostium of the cell or sinus. In subsecjuent ]xiragraphs each ])aranasal sinus and groups of cells will be discussed under three heads: (i) the fetal stage, (2) the childhood stage, and (3) the adult stage. In order that there may be no unnecessary repetition a further consideration of the early anatomy of the paranasal sinuses as exhibited in the fetus will be deferred for discussion in connection with the sinus concerned. The Definitive Nasal Septum The median frontonasal ])rocess, one of the "trabecuke cranii," is earlv divided into two lateral jjrocesses (lateral nasal processes) and two PK-X. Fig. 41. — The nasal septum of a ehild afied iS mmiths. Particularly note the septal iiliea; (iiliea; scpti) and the sinus sphenoidalis. X 0.7. Ps. = plicLE septi; Tp. = tonsilla pharyn^ea; Ss. = sinus sphenoidalis; Cs. = concha sphenoidaUs; He. = hypopjhysis cerebri. mesial processes (mesial nasal processes). These form the walls of the primitive nasal fossa-. The mesial nasal jirocesses fuse in the formation of the central portion of the upper lip, the premaxillary process (not to be confused with a premaxillary bone), and the primary nasal septum. Sub- sequentlv, as stated elsewhere, and coincidently with other changes, the primary nasal septum grows dorsally toward the ])har>'nx and caudally toward the mouth in the formation of the secondary nasal septum. 38 GF.XERAL EMBRYOLOGY AND DEVELOPMENT ultimatelv fusing with the nasal surface of the palate and forming a free border dorsaUy between the definitive choanas or posterior nares. It is, therefore, obvious that the definiti\'e or final nasal septum is made up of primary and secondary portions, both derivatives of the mesial part of the frontonasal process. The primary nasal septum is at first thick, separating widely the early olfactory fossa?, the secondary septum relatively thin. The definitive nasal septum gradually becomes thinner and thinner, the nares coming to occupy positions nearer the mid-plane, and a laminar plate of cartilage develops in its substance. A fairly heavy mucous membrane covers both surfaces of the septum, part of which forms a paired tubular organ in the ventrocaudal portion of the septum immediately dorsal and cephalic to the incisive foramen (the vomeronasal organ). The glands of the nasal mucosa develop as solid processes during the third and fourth months, but do not reach their complete de^'elopment until after birth. jNIoreover, the mucous membrane of the nasal septum of the fetus usually presents well-developed folds in the region of the later vomer (septal folds, plicae septi). The author has frequently noticed a preponderance of epithelial thickness in this region of the septum as early as the third month of uterine life. The septal folds and inter- ^'ening furrows increase in size until the seventh or eighth month, then undergo a retrograde metamorphosis. They usually disappear in earlv infanc}-. However, the septal plicse may persist, e\'en hypertrophy and form tumor-like obstructing masses in the adult (Fig. 41). Portions of the laminar plate of cartilage remain and form the septal cartilage and the vomerine cartilages, and other parts are replaced by bone. It is, therefore, obvious that the nasal septum passes through three distinct stages: (i) the membranous, (2) the cartilaginous, and (3) the adult mixed cartilaginous and osseous (see pages 78 and 81). The Development or the Nasal Skeleton (A) The Cartilaginous Nasal Capsule. — The nasal capsule and the ethmoidal region are the last portions of the chondrocranium to become cartilaginous (Fig. 42). Generally speaking, the nasal capsule and the ethmoidal region are membranous as late as the eighth month of em- bryonal life (20 mm. embryos); however, the lateral wall of the nasal capsule and the nasal septum are obviously in the precartilage stage as evidenced by mesenchymal condensation. By the middle of the third month of embryonal life the nasal capsule is well advanced as a cartilagi- C'ARriLACIXOUS XASAL CAPSULE 39 nous structure. C\irtilage extends into the nasal septum from the body of the sphenoid. The lateral walls of the nasal caxity chondrify inde- pendently, hrter joining the nasal septum \'entrally to form the cartilagi- nous roof and lateral walls of the nasal cavit>-. Subsequently, the lateral cartilaginous ^valls connect u]) dorsalh' where the sphenoidal and sejjtal cartilages are confluent. The inferior margin of the lateral cartilage infolds behind the naris and becomes the cartilage of the maxillo (inferior)- turbinate. This infolding, at first simple, becomes more complex by the formation of accessor}- processes and folds. During the seventh month Fig. 42. — The cartilaginous nasal capsule imm a human fetus aged 4 months. (Adapted from Kollinann -) fo —foramen opticuin; C. nasalls - capsula nasalis; lac, = lacrimal. it becomes separated from the lateral Avail. In the adult the maxillo ^inferior) turbinate (concha nasalis inferior) is an independent bone. The earlv membranous conchal (turbinal) folds, comprised of epithe- lium and underlving mesench}-me, develop cores of precartilage (condensed mesenchvme). The condensed mesenchymal cores chondrify during the fourth month of embryonal life. As stated before, the initial conchal or turbinal folds are not due to an inpushing of the mucosa b}- the cartilag- inous strands, e.g., cartilage develops within the folds, but does not grow into them ('see page 19 and Figs. 14 and 15). During the third month of fetal life a short, stumpy cartilaginous process (processus paranasalisj arises from the lateral wall of the carti- laginous nasal capsule to surround the developing nasolacrimal duct. 40 GENERAL EMBRYOLOGY AND DEVELOPMENT The fate of the several portions of the cartilaginous nasal capsule varies. Certain parts persist and are carried over as cartilage into the skeleton of the adult nose (the cartilaginous portion of the septum and the cartilages of the external nose) ; others become ossified as individual bones to participate in the formation of the adult nasal skeleton (the ethmoid bone, including the ethmoturbinals, the maxilloturbinal, and the sphenoturbinal) ; and, thirdly, some portions are soon overlaid by connect- ive tissue osseous rudiments or anlages and the cartilage for the most part absorbed. For example, parts of the septum and of the lateral wall above the maxilloturbinal disappear and are replaced by parts of the neighboring membrane bones. ]\Ioreo\'er, the original continuity of the cartilaginous nasal capsule is broken by division into smaller portions brought about by the ingrowth of connective tissue at various points. This leads during the sixth month to the formation of the individual alar cartilages and the detachment of the cartilaginous nasal septum from the anterior portion of the lateral cartilage. Posteriorly the connections with the lateral cartilage are retained. (B) Ossification of the Elements that Participate in the Boundaries of the Cavum Nasi. — In this connection it will be necessary to consider parts that arise in relation with the cartilaginous nasal capsule and others which from a developmental standpoint are not related. I. The Ethmoid Bone (os ethmoidale). — The greater portion of the pos- terior part of the cartilaginous nasal capsule becomes the ethmoid bone. The lateral and one medial primary and several secondary- ossification centers appear in the capsule. Each lateral center appears in the fifth or sixth fetal month and gives rise to an orbital plate (os planum, lamina papyracea), ossification extending into the lamina cribrosa and into the ethmoturbinals during the seventh and eighth months. In this manner permanent osseous foramina are formed for the olfactory nerves and the mucosa-walled ethmoidal air cells gain bony boundaries. During the first year of postfetal life ossification begins in the cephalic portion of the cartilaginous nasal septum to form the lamina perpendicularis of the ethmoid and extends into the crista galli and the cribriform plate. Secondary centers appear later. The date of the bilateral union of the three pieces (lamina cribrosa, lamina perpendicularis and lamina papy- racea) is uncertain. A study of a few specimens would indicate that the fusion takes place late in the sixth year. The ethmoidal cells are primarily evaginations of the nasal mucosa which grow into the lateral ethmoidal masses and their appendages (the ethmoturbinalia) and by further growth of the sacs and the absorption of bone become Avell established as the cellu- OSSII-IfATIOX ()!■■ XASAI. CAPSULE 41 lar ethmoidal labyrinth. The ossification of the ethmoid is not com- pleted until the end of the se\-enteenth }-ear. The lamina ])erpendicu- laris ultimateh- (45 to 50 >-ears) unites with the vomer. The ])osterior dome or cu]-)ola of the cartilaginous nasal capsule in man ossihes as the sphenoidal turbinate or concha (ossiculum Eertini). R| • ^'W > \ * * J , -. -. — -. . ,._h --i.nt.i-i; Fig. 43. — A photograph indicating stage of development of the osseous elements of tlie head in a fetus at term. X 0.45. (Courtesy of Miiller Museum, College of Physicians.) a = occipital; 6 = parietal; c = sphenoid; d — \'onier; e ~ ethmoid; / — palate; g — nasal; h = inferior turbinate; i = lacrimal; k = maxilla; / ^ frontal; ni = temjjoral; v = zygomatic; o = dentes; p = mandible; r = ear rjssicles. 2. The Vomer.- -The true \-omer develops bilaterally on each side of the caudal and dorsal portion of the cartilaginous nasal septum from a pair of ossiiication centers during the eighth week of fetal life. This is in agreement with Mall. These centers unite beneath the caudal border of the septal cartilage, but grow ce])halical]y on each side of the septum as two plates, thus enclosing the cartilage. The bilateral ])lates of the vomer unite from behind forward at the expense of the imprisoned cartilage, union being completed b}' the fifteenth year. The vomer of the young infant shows clearly its formation in two j)]ates (Fig. 43). In the adult, 42 GEXER.VL EMBRYOLOGY AND DEVELOPMENT on the other hand, the bilaterality of the ^'omer is indicated merely by the groove between the alte and by the groove on the lower part of the ventral border where it receives the triangular septal nasal cartilage. In spite of the fact that the ^'omer develops on each side of the cartilag- inous nasal septum and at its expense, it must be classed as a true membrane bone. Rarely a patch of cartilage persists between the bilaminar vomer and develops into a chondroma subsequently. 3. The MaxillotxirbiBal (concha nasalis inferior). — The inferior nasal concha or turbinal arises in cartilage from the lower inturned border of the lateral plate of the cartilaginous nasal capsule. It develops from a separate ossific center which appears about the middle of fetal life. 4. The Palate Bone fos palatinum). — The palate is a membrane bone arising according to recent studies from a single ossification center located at the junction of the horizontal and vertical portions of the bone (MaU^ and Fawcett"). The ossific center appears at the end of the second month of fetal life. The vertical portion of the palate bone extends upward on the medial surface of the lateral wall of the cartilaginous nasal capsule; the latter intervening, therefore, between the palate bone and the maxilla. At a subsequent period the inter\'ening cartilage undergoes resorption. The horizontal part ossifies in the dorsal portion of the definiti\'e palate which it helps to form. 5. The Nasal Bone (os nasale). — The nasal bone is bilaterally present and develops in membrane on the surface of the cartilaginous nasal capsule. The subjacent cartilage can be demonstrated as late as the first month of postfetal life, then becomes absorbed. It is generally believed that the bone develops from a single ossific center. Perna (1906)^ believes that the nasal bone develops from two rudiments, a lateral mem- branous and a small median cartilaginous. A small Wormian bone may develop in the median line between the nasals and the frontal. Ape-like the two nasals sometimes coossify. Bilateral and unilateral absence of the nasal bone occurs (see page 65 for a consideration of the variations of the nasal bones). 6. The Lacrimal Bone (os lacrimale). — The lacrimal bone arises in membrane on the lateral wall of the cartilaginous nasal capsule. It ossifies from one or more centers Avhich appear during the third month of fetal life. The adult bone is occasionally divided. According to Mall ' On ccntLTs of ossification in human embr>'os less llian loo days old, Amer. Jour. Anat., \o\. 5, 1896. - On the de\"elopnient, ossification, and t,'ro\vlh of the palate bone of man, Jour, of .\nat. and Physiol., \'ol. 40, 1Q06. ■' Die Nasenbeine, Arch. f. Anat. u. Physiol. ,\nat. Abt., 1006. OSSIFICATION OF XASAL CAPSULE 43 the bone ossifies from one center which appears on the eight}'-third day. 7. The Sphenoid Bone (os sphenoidale). — The sphenoid bone is in part preformed in cartilage and in part in membrane. Ten principal centers of ossification arise in the cartilage that corresponds to this bone, one for each great wing during the eighth week of fetal life (alisphenoid), one for each small wing (orbitosphenoid), two for the body between the great wings during the early part of the third month of fetal life (basi- sphenoid), two for the bod}' between the small wings during the second month (presphenoid), and one for each lingula during the fourth month. Alembrane bone forms the orbital and temporal portions of the great wings and the medial lamina; of the pterygoid processes (the hamular processes excepted). The presphenoid and the lesser wings unite before birth. About the eighth month of fetal life the pre- and basisphenoids unite, but at birth and for sometime longer these parts are still separated by cartilage on their inferior surfaces. During the first year of postfetal life the several parts of the sphenoid coalesce. The sphenoturbinals in the adult are fused to the ventral surface of the bodv of the sphenoid bone and form the \'entral boundaries of the paired sphenoidal sinuses. DevelopmentaUy, however, these turbinals are separate and individual bones and merit further discussion. The embryology and anatomy of the sphenoidal sinuses will be discussed in other paragraphs (see Chapter Y). S. The Sphenoturbinal (concha nasalis sphenoidalis, ossiculum Bertini). — The sphenoturbinal bone is a bilateral, thin, cap-like plate which appears before birth at the front of the presphenoid. It develops as an independent element from ossific centers associated with the posterior cupola of the cartilaginous nasal capsule during the latter half of fetal life. The centers appear in the medial and lateral wahs of the cupola, later to be connected by secondary ossific centers in the mem- branous portion of the cupola toward the termination of fetal life. At the time of the third year the cupola-shaped recess or terminal nasal sinus Cthe early sphenoid sinus) is surrounded by bone and lined with nasal mucosa, except toward the nasal fossa, where an opening or ostium persists (the primary ostium sphenoidale or opening into the sphenoidal sinus) . The sphenoturbinals cover the ventral and caudal surfaces of the presphenoid and at five years are still free from the sphenoid bone, membranous tissue intervening (Fig. 132). During the fourth year, 44 GEXER-\L EMBRYOLOGY AND DEVELOPMENT however, the cephaUc and medial parts of the nasal capsule begin to be absorbed and then the presphenoid participates in bounding the terminal nasal sinus, e.g., the sinus sphenoidalis. This gives the sphenoidal sinus an opportunity to grow into the body of the sphenoid bone, and the sphenoturbinals instead of presenting rounded openings in the disar- ticulated bone present notches. The persistent portions of the spheno- turbinals unite first (fifth year) with the ethmoid and ultimately (ninth to twelfth year) with the sphenoid and palate bones. Their identity and indi\-iduality is from then on lost. 9. The Maxilla. — Cartilage fails to appear in the maxillary process of the first branchial arch due probably to the rapid development of the parts concerned, wherefore the palate bone and the maxilla arise directly in membrane. Ossification of the maxilla commences in the sixth or se\-enth week of embryonal life as one center (Hertwig, INIall, Schaefl'er) from which an ossifying process soon extends toward the frontal bone in the formation of the frontal process of the maxilla. Later extensions from the primary ossific center develop into the orbital, alveolar, and palatine processes. jMoreover, a single ossific center appears in the related half of the intermaxillary mass which establishes union with the center in the maxilla proper early in the third month of fetal life. Albrecht erroneously believed that each premaxilla was made up of two bones. According to Mall both the centers of the premaxilla and the maxilla par- ticipate in the formation of the frontal process. Initially, the maxilla lies ectal to the cartilaginous nasal capsule. Subsecjuent absorption of a goodly portion of the nasal capsule allows the maxilla to participate in forming the lateral nasal walls, to complete the osseous boundaries of certain ethmoidal cells, to articulate with the maxil- loturbinal, and to become the bone for the reception and development of an evaginating nasal-mucous-membrane pouch destined to become the sinus maxillaris (antrum of Highmore). The formation of the alveolar process begins as early as the fourth fetal month, but is not completed until the twenty-fourth year. It will be recalled that in the third or fourth month a stumpy cartilag- inous process (processus paranasalis) arises from the lateral wah of the cartilaginous nasal capsule and surrounds the developing nasolacrimal duct. Apropos of this, one frefjuently finds cartilaginous masses in the al\-eolar part of the developing maxilla which have no connection with the nasal capsule. Mihalkovics suggests (1S99) that these masses of cartilage are portions of the processus paranasalis caught in the ossifying maxilla. The masses usuaUy disappear. 0SST1-ICA'|-U)X OF NASAL CAPSULE 45 The infraorbital \-essels and nerve occupy for some time a mere groo\'e on the orbital surface of the maxilla, later to become encased l)y an in- growth o^•er them of a lamina of bone. At times the osseous floor of the infraorbital canal remains deficient and the ner\-e and vessels are then separated from the ca\-ity of the maxillar>- sinus merel_\- by the mucous membrane. The sinus maxillaris in its relations to the maxiUa and to the deciduous and permanent teeth will be discussed subsequently (see Chapter III). 10. The Frontal Bone (os frontale). — The frontal bone ]xirticipates to a limited degree in Ijounding the nasal ca^■ity and is the bone of rece])- tion tor the e\-aginating mucous-membrane sac or sacs from the frontal recess of the middle nasal meatus to become topographically the frontal sinus OY sinuses. The bone is developed in membrane. According to the studies of Mall,' in Avhich the writer concurs, in the region of the future frontal eminences apjiear during the eighth week two major ossilic centers. Additional centers at times ap])ear. At birth the frontal bone is divided into right and left hal\es which become ap])roximated during the first }-ear and fuse along the meto])ic suture during the second year. This fusion ma}- be delaA^ed until the se\'enth or ninth year or may ne\er take place. The metopic suture may persist throughout or may be retained at its lower extremit}-; then forming a metopic fontanelle. Wormian bones (ossa metopica) may develop in the region of the metopic fontanelle during the process of ossification. ^Metopic ossicles ma}' develop in other parts of a persistent metopic suture. The frontal sinus begins to develo]) during the fourth or fifth month of fetal life in the region of the frontal recess of the middle nasal meatus, but is not topographically frontal until some time after birth. It develo])s slowlv until the seventh or eighth year, then more ra])idly u]) to the twentieth vear and increases somewhat in size uj) to old age. A persist- ent metopic suture precludes the development of a frontal sinus beyond the mid-sagittal plane; at least this is true in all such skulls observed by the writer fFig. 66). (C) Skeleton Changes Incident to Growth.— At birth the facial skeleton is relatively small due in part to the small size of the nasal foss;e and maxillary sinuses. The nasal foss;e are as wide as the}' are high. The bouA- nasal a])erture is relati\'el}' broad and its caudal border but little below the plane of the orbit. Moreo\'er, the nasal aperture and cavity are not clearh' separated from the face. The bony choante (posterior iLuc. cit. 46 GENER.\L EMBRYOLOGY AND DEVELOPMENT nares) are relatively small, 5 to 7 mm. in the vertical diameter and 7 to 8 mm. in the transverse (coronal). By the sixth month of extrauterine life the choanal diameters have doubled; however, the diameters remain such as to give more or less circular choanas. After puberty the vertical diameter is always greater than the transverse and the shape of the cho- ante is changed from circular to oblong. This change in the diameters of the choan« is due to unequal growth : At birth the dorsal border of the hard palate is on a plane with the occipito-sphenoidal articulation ; during the third year it drops to the mid-plane of the basi-occipital, and by the sixth year is essentially in the adult plane, e.g., the ventral border of the foramen magnum. It will be recalled that the maxillary turbinal field of the early nasal fossa occupies almost the entire lateral wall (Fig. 17). Later the ethmoidal turbinal field begins to be formed and soon outdistances the maxillary in the extent of its vertical plane. Indeed, at birth, as shown by Kallius, the ethmoidal part of the nasal fossa is twice the height of the maxillary in spite of the fact that in the adult the two portions are equal. This means that the maxillary portion grows faster after birth, catching up approxi- mately the seventh year when the adult relations are attained. Dentition and the development of the maxillary sinus may have some bearing on this relationship. The inferior meatus remains very narrow until after the deciduous teeth ha^'e erupted. Before this, owing to a relatively large inferior concha, there is little room in the inferior meatus for the passage of air — the concha almost touching the floor of the nose (see maxillary sinus, page 107). The skuU at birth shows a relati\-ely large cranial portion and a small facial when compared with the skull of the adult. Froriep estimated the ratios to be 8 : i in a "term" child, 4 : i at five years of age, and 2 : i in the adult. At birth the vertical diameters of the maxilla; and the nasal fossae are smafl. Added to these the alveolar processes, owing to the rudimentary condition of the teeth, are likewise small. It is frequently stated that the increase of the facial diameters after birth is in a measure due to the pneumatization of the maxillae, ethmoid, sphenoid and frontal bones by the related paranasal sinuses. While it is true that facial in- crease is associated with the development of the nasal sinuses, the writer is strongly of the opinion that it is erroneous to think of the paranasal sinuses as forcing the face parts to develop or that the development of the sinuses is dela)'ed until other parts have grown sufficiently to permit of their expansion. The writer believes that developmental processes go on hand in hand and that when a certain time is reached a structure KriTHEIJU.M OF PRIillTIVE NAS,\L F0SS.4-; 47 will normally ha^-e attained proportions for that period regardless of related parts. The Epithelivm or the Primitive Nasal Foss^ The Olfactory Nerves.^During the third or fourth week of em- bryonic life the lining of the primiti\-e nasal foss;t undergoes histogenic changes; indeed, not unlike those seen in the wall of the neural tube. The undifferentiated ejiithelium invaginated from the surface in the forma- tion of the olfactory foss;e undergoes proliferation and in addition to the ordinary epithelial cells of the early fosss forms neuroblasts. The latter become bipolar, forming short peripheral and longer central processes — the olfactory nerves. Most of the cell bodies of the neuroblasts remain permanently in the nasal epithelium, the central processes grow toward and ultimately into the olfactor}' bulb of the brain, while the peripheral processes project to the free surface of the epithelium. Some of the neuro- blasts wander somewhat and are later found along the course of the olfac- tory nerves. ^lihalkovics found that at first all])ortions of thee])ithelium of the nasal fosste contain olfactory elements and connections. Be that as it may, all connections with the olfactory nerves are lost save in the upper part of the f ossee (page 261). The non-olfactory portions of the fossa- assume the role merely of respiratory passages. At a subsecjuent stage (third month) the cartilaginous cribriform plate of the ethmoid is formed around the olfactory nerve fibers and the olfactory bulb is placed on the cranial side. Ultimately (seventh or eighth month) the cribriform plate ossifies and permanent foramina for these nerves are formed. The Nasal Glands. — The glands of the human nose develop in the third month of fetal life as solid cords and mature after birth. The Vomeronasal Organ ( Jacob sonii). — The \'omeronasal organ (Jacobsonii) is a rudimentar}' epithelial structure in man and reaches its maximum development in the fetus at approximately the twentieth week, and at this time, according to Kallius, receives twigs from the olfactory nerves. Embryologically it appears at the caudal or stomodo-al end of the olfactory pit as a bhndly-ending mucous-membrane sac (Fig. 9). After the caudal closure of the olfactory pit and separation of the latter from the mouth cavity, the pocket-like vomeronasal organ is located in the nasal septum slightly above the orifice of the nasopalatine canal. It now assumes the form of a narrow duct, more or less OA'al in transection and courses longitudinally in the septal tissue. At ten weeks of embryonal life one finds the organ bilaterally present with an approximate depth of 0.48 mm. After this it varies considerabh'. Complete degeneration in 48 GENERAL E^IBRYOLOGY AXD DEVELOPilEXT early fetal life may ensue. On the other hand, one frequently finds the vomeronasal organ in adult man. Special supporting cartilages are not developed for the organ in man. It is supplied by nerve fibers which arise from cells in its own epithelium (apparently not in adult man), also by the ncrvus terminalis, branches of the trigeminal nerve, and, according to Read, by a branch of the olfactory nerve, at least at the time of birth (see page 270). TtiE Embryonic External Nose The frontal process, one of the cranial trabeculcC, early divides into a medial frontal process and into two lateral frontal processes. As stated elsewhere (page 4) this di\'ision is initially due to the invagina- tion (sinking in) of the surface epithelium in the formation of the early nasal or oU'actory pits. The lateral frontal processes are in reality the lateral nasal processes. Moreover, the middle frontal process undergoes secondary dift'erentiation into the right and left medial nasal processes. The maxillary processes then grow ^'entromedially and fuse with the medial nasal processes, the medial and lateral nasal processes fuse at the caudal border of the nasal pits, and the lateral nasal and maxillary proc- esses fuse along the line of the naso-optic furrow. By these several fusions of embryologic processes the upper border of the primitive mouth cavity is formed by the medial nasal and the maxillary processes, and the ever deepening nasal fossae receive definite walls or boundaries. The bucconasal membranes now rupture and the primitive palate is established, and with it the medial frontal process narrows and the pre- viously widely separated nasal fosste are brought close together. Between the buccalward-projecting medial nasal processes is a depressed area which His^ named the infranasal area, and cephalic to the latter and caudal to the head prominence caused by the growing cerebral hemispheres is the triangular area of His. The indefinite area between the triangular and infranasal areas later takes form and gives rise to the border and tip of the nose. The triangular area becomes the dorsum of the nose and the infranasal area is modified to become the philtrum of the upper lip and the nasal septum between the nares. The combined medial nasal processes extend, of course, dorsad as the intermaxillary mass. The external nose does not acquire its definite individual form until after birth; indeed, the form and racial characteristics are delayed until after puberty. However, by the end of the second month of embryo- logic life, the external nose is fairly well defined as a broad, flat organ and ' Anatomie menschlicher Embryonen, Leipsig, iSSj. XASOLACRi:\l.VL J'ASSA( i i;\VA^'S 49 is limited from the foreliead b>- an arched groo\-e. The dorsum of the nose is especiall)- acti\-e in taking form early and later in fetal life the nostrils assume a more caudal and horizontal ])osition and the median portion of the dorsum grows caudally and \entralh' to become the ti]:i of the nose. In the newborn the bridge of the nose is low and the nose proper relatively broad and stump\-. Fig .14 >^«*r: Fk;^ 4.V ''^ *^ I'lG. 40. %2 Figs. 44-47. — Photomicrographs of frontal sectic>ns of the heads of liuman emljryos sliovvinj:; several stages in the development of the nasolacrimal passageways: Fig. 44 aged 33 days; Fig. 45 aged 33 days; Fig. 46 aged 36 days; Fig. 47 aged 43 days. X 7- {After J. P. S.) no/ = Remains of naso-optic furrow; / = nasal fossa; e = eye; d = different stages of the rudi- ment or anlage of the nasolacrimal passageways. The Nasolacrimal Passageways The lacrimal sac (saccus lacrimahs) and the nasolacrimal duct (ductus nasolacrimalis) are in no way connected with the sense of smell. How- ever, they are so closely related to the nasal fossa that a note concerning their embryology is warranted in this connection. The following sum- so GEXER.\L E.MBRYOLOGY AXD DEVELOPMENT mary from a previous publication (see Schaeffer, American Journal of Anatomy, Vol. 13, No. i, 191 2) on the genesis of the nasolacrimal passage- ways will suffice : 1 . The strand of thickened epithelium — the rudiment or anlage of the nasolacrimal passageways — along the floor of the rudimentary naso-optic fissure becomes entirely separated from the surface, and for some time is wholly surrounded by mesench}'mal tissue, Figs. 44 to 48. 2. The strand or cord of epithelial cells thus isolated from the surface is for some time without a lumen. r- f- V X" { Si'jj. iitn. Pig. 48. Selected sections from a series through the developing nasolacrimal passageways (human embryo aged from 43 to 45 days). Nowhere is the rudiment or anlage of the nasolacrimal passageways in connection with the surface epithelium. The "passageways" are solid cords of epithehal cells at this time and are indicated in deep black. X 14. (After J. P. S.) 3. From the mother cord of cells both lacrimal ducts and the nasal end of the nasolacrimal duct grow as sprouts. The cephalic portion of the lacrimal sac also grows as a sprout from the mother cord. 4. Considerable \-ariation occurs in the development of the lacrimal ducts, /.('., as to number, time, and degree of development. 5. The lumina of the several portions of the nasolacrimal passageivavs are estabhshed in an irregular manner. The ocular end of the mother CONGENITAL DEFECTS 51 cord is the first to establish a lumen. The point of coalescence between the nasal end of the cord and the mucous membrane of the inferior nasal meatus is the last to become patent— the lumen here is established ap- proximately at "term" or even later. The horizontal portions of the lacrimal ducts establish lumina before the vertical portions. The di\'ers types of ostia nasolacrimalia found in the adult are in accord with the potentialities of lumen formation at the point of fusion of the sohd epithelial nasolacrimal duct with the mucous membrane of the inferior nasal meatus. The ])lace and degree of fusion vary consider- ably (Figs. 51, 52 D: also Schaeffer, American Journal of Anatomy, \o\. 13, Xo. 2, 1Q12), thus leading to A'ariously located ostia, single and multiple ostia, unguarded and " x'ah'ed " ostia. The relations of the nasolacrimal ducts to the nasal foss?e and the paranasal sinuses and the communication of the ducts with the inferior nasal meatuses are discussed under the proper headings in connection with the adult anatomy (pages 2^2-2^;^, and Figs. 173 and 177). Congenital Defects of the Nose The manner in which embrA'ologic ej)ithelially-co\'ered mesenchA'mal processes unite in the formation of the early nose and roof of the mouth is illustrated in Fig. 3 in which the medial nasal and the maxillary processes are undergoing fusion. At ])laces the epithelial "union" is entirely lost and the mesoblastic tissue bridges or heals o\-er the previous embryologic fissure; e.g., the mesoblast of the maxillary process is con- fluent with that of the medial nasal process. These photographic repre- sentations of sections from a human embryo illustrate the manner in which all of the fissures about the nose and mouth are obliterated. If for some reason fusion of the se\-eral processes is too long delayed, con- tinued growth of the several elements bordering the fissures causes them to separate and once the breach in their continuity is established union cannot take place subsequently. Lack of fusion and separation of the seA'cral processes leads to the malformations known as cleft palate and harelip. Divers degrees of these malformations occur both unilaterally and bilaterally. In harelip the cleft or defect may appear laterally between the medial part of the lip formed by the medial nasal processes and the lateral part of the lip formed by the maxillary process (lateral harelip). Should the medial nasal and lateral nasal ])rocesses fail to unite at the floor of the naris (nostril) the lateral harelip would be continued into and be confluent 52 GENERAL EMBRYOLOGY AND DEVELOPMENT -lid Fig. 51J. nkf Fi(.. 51. Figs. 49-51.— Frontal sections thr<.aigh the nasolacrimal passageways of a human embryo aged 107 days. Note that both lacrimal ducts (Fig. 49) are in contact and fused with the epidermis in the region of the free borders of the eyelids, but that the ducts have not established lumina at all points. The remaining portions of the passageways are irregularly patent throughout, save that the connec- tion with the inferior nasal meatus is not established at this time (Fig. 51). {After J. P. S.) sld — superior lacrimal duct; ild = inferior lacrimal duct; eld = common lacrimal duct; Is = lacrimal sac; nld = nasolacrimal duct. Xii. CUXCIEXITAL J^Kl.'ECTS 53 with the nasal ^•estibule. Rareh- a cleft is found in man in the median Ime of the upper lip due to a lack of superficial union of the right and left medial nasal processes (median harelipj^a condition always present in the upper lip of the hare. Fig. ^2. — ^Photomicrograph.s of frontal sections throuj^li the nasolacrimal passagc\va>'s of a human embryo aged 128 days. Xote the solid portions of the lacrimal ducts in Fig. .4. In Fig. B, we have a patent section (Is) oi the ocular end of the nasolacrimal duct and in Pig. C. a section of the mid-portion of the nasolacrimal duct still solid (nld). X(jte the well established lumen [nld) at the nasal end of the nasolacrimal duct in Figs. D and E. Xote how extensive the contact point between the nasolacrimal duct and the inferior nasal meatus will be {Fig. D). sld = superior lacrimal duct; ild = inferior lacrimal duct; Is ^ lacrimal sac; nld = nasolacrimal duct; inc — inferior nasal concha; /»w = inferior nasal meatus. X 19. (After J. P. S.) Normally the sockets of all four incisor teeth are formed by the pre- maxillcT. However, in some cases of cleft palate the sockets of the right 54 CENERAL EMBRYOLOGY AND DEVELOPMENT and left lateral incisors are attached to the right and left maxilltis proper, respectively — the central incisors alone appearing on the premaxillae. Indeed, the lateral incisor may occasionally under normal conditions have its socket in the maxilla. Albrecht erroneously supposed that each pre- maxilla was made up of two osseous elements, a lateral and a medial, and that in cleft palate the fissure might lie between these supposed elements of the premaxillary or between the premaxillary and the maxillary proc- esses. While it is true that clefts do occur in both of these positions it is, however, obvious that cleft palate is not due to a failure of osseous centers to coalesce, but to a non-union of prc-osscous cmbryologic masses. Each premaxilla has a single ossification center as pointed out by Mall. Fig. S3. — Infant with complete harelip on left, partial on right, and cleft palate. Note the pro- trusion of premaxillary bones and the complete isolation of the vomer from both palatal plates. (After Brophy.) Keith finds that the partial suture "which may divide the palatal part of the premaxilla is due not to two centers of ossification, but to the formation of the palatal part by two processes (pre-osseous), one corresonpding to the middle incisor socket, the other to the lateral incisor." It is important to keep in mind that the rudiment of the lateral incisor tooth is formed at the point of coalescence of the medial nasal and the maxillary processes and in the event that these processes fail to merge that the lateral incisor tooth rudiment may be carried "away" by either the maxihary or pre- maxillary elements in their further and subsequent separation incident to growth. This accounts for the variability in the location of the lateral incisor tooth in cleft palate— now in the maxiha, again in the premaxilla. Keith's suggestion that the palatal portion of the premaxilla is at times in C()NG1':NIT AL 1 ) KFECTS 55 the pre-osseous stage made up of two processes, one corresponding to the medial incisor rudiment, the other to the lateral incisor, explains the occa- sional cleft in the newborn between the medial and lateral incisors. The fact that the lateral incisor rudiment ma\- be carried "away" by the maxillary process must not be forgotten in this connection. The cleft between the maxillar>' process and the medial nasal process may not involve onh- the lip and the alveolar process, but may extend dorsad toward or to the incisive canal. Moreo\'er, it may continue dorsad in the mid-sagittal plane in the formation of various degrees of partial cleft palate or if carried to the end of the soft palate to complete cleft palate. The same processes may be o])erative bilaterally, Assuring both sides of the upper lip and the ah'eolar processes and the forward portion of the palate as far as the incisi\-e foramina, and if occurring simultaneouslv Fig. 54. — Infant three months old with comi.lcte double harelip. (.1/Vcr liruphy.i with complete hssuration in the mid-saggital plane of theremainingportion of the hard and soft palates, a tripartite palate results. If, on the other hand, the hssuration is complete dorsally but unilateral ventrally, the bipartite palate results. As stated pre\'iously, many intermediate degrees of cleft palate occur, Figs. 5,^ and 54. The buccal border of the nasal septum may or may not be adherent to one of the lateral halves of a cleft palate. If attached to a lateral half one of the nasal fossae would be closed in caudally and the other in free com- munication with the mouth cavity. In the event that the septum projects freely in the roof of the buccal cavity, both nasal foss;c are in wide com- munication with the mouth cavity. Obx'iously, the degree of naso- buccal communication is dependent upon the degree of cleft palate. It is not the province in this connection to enter into the details of cleft palate and harelip. The reader is referred to an extensi\'e literature S6 GEXER-\L EMBRYOLOGY AXl) DEVELOPMENT on the subject, especially to the works of Keith, ^ Inouye,- His,^ Brophy,* Gaupp^ and Schorr." Congenital absence of the external nose is a very rare anomaly. Maisonneuve reports the case of an individual in which the projecting portion of the nose was represented by an even surface, perforated by two minute apertures three millimeters apart. Roberts reports the case of an infant in which there was no evidence of the external nose whatsoever, even the narial apertures were entirely wanting. Moreover, the condition was associated with harelip and a tripartite palate. Exaggerations in volume of the projecting nose are not infrequent. It is stated that one Thomas Wedders had a nose between seven and eight Fk; 55. — Congenital dermoid in a female child aged 3 years. The tumor was noticed directly after birth. inches long and was exhibited in Yorkshire earh' in the last centur}'. Under-sized external noses are less frecjuent. The writer, however, recently observed a nose which was markedly under-sized, the bridge being but little elevated above the plane of theface. Departures from what may be considered normalh' sized external noses are in many cases merely individual, family, and racial characteristics and must not be considered malformations. Pathological formations must not be confused with con- genital]}- large noses. ' British Medical Journal, August, 1909, - Anat. Helte, \"ols. 4.5 and 4'), 191J. " Anatomie menschlicher Embryonen, Leipsig, 1885. * Oral Surgery, Philadelphia, 1915. ■'Anat. liefte, \'ol. 42, 1911. '' .\nat. Hcfte, Vol. 36, 1908. C()xgi-:nital i )kf.I'X:ts 57 Keith cites the case of Kirchmayer in which one olfactory ])it and the lateral nasal process formed a free polypoid body, and another in which the condition of c>-clops with both nasal fossa? enclosed in a pro- boscis was encountered. Congenital occlusion of the nares due to epithelial i)ro!ifcration with subsequent organization was pre\-iously referred to (page lo). Similar occlusions ma}- block the choame. Howe\-er, at times the congenital occlusion of the choana^ is an osseous one. One readih* sees how ossifica- tion may block the choana' if the embryology of the region is clearly kept in mind. Fig. 56. — Congenital dermoiil fistula in a girl aged 21 years. On pressure o£ the tumor sebaceous matter -n-as discharged from the tunncl-likc opening on the dorsum nasi. {Adaplnl from Krieg.j flattened or dejiressed ala? usualh' accompany harelip, \\'hile crooked noses often accompaii}- traumatic or spontaneous de\-iations of the nasal septum. Congenital dermoids on the bridge of the nose are not unknown. A very common place for them is on a le\'el Avith the canthi (Fig. 55). Moreover, fistula- of congenital dermoids ha\-e been obser\ed at various levels on the dorsum nasi, Fig. 56. -THE DEFINITIVE NOSE CHAPTER II THE DEFINITIVE NOSE In this chapter wih be discussed the anatomy of the fully developed or definitive nose. Even after puberty certain important and fundamental developmental changes take place in the nose and these will be referred to at their proper places. It is not deemed profitable nor essential in this connection to describe the detailed osteology of each individual bone that participates in the make-up of the osseous cage of the nasal cavity. Suffice it in subsequent paragraphs to discuss certain of the more impor- tant anatomical points of indi\-idual bones and more especially to treat the osseous boundaries of the nasal fossae as a whole. The paranasal (accessory) sinuses will be dealt with in subsecjuent and separate chapters. The nose consists of two conspicuous portions — the external nose (nasus externus) and the internal nose (nasus internus). The latter, more stricth' the nasal cavity, is divided into two fosstc or chambers (fossae nasales) bv the nasal septum (septum nasi). Moreover, the nasal fossa; are extended by the nasal meatuses (meatus nasi) and the paranasal (accessory) sinuses (sinus paranasales). The nasal concha? (conchae na- sales) configure the lateral walls of the nasal cavity and further increase the surface area of the nasal mucosa. The EXTERN.A.L Nose Individual and family variations of the external nose (nasus externus) are extremely common and of little importance. However, entirely apart from individual variation, the human external nose is readily grouped into several more or less distinct anatomic types. The root of the nose forms with the tissues of the forehead a ^■ariable obtuse angle. Some sort of a frontonasal angle with a straight dorsum nasi may be taken as the ground type of nose (straight type of nose) from which there are, however, definite anatomic departures. If the frontonasal angle is wanting, e.g., the dorsum of the nose forms with the tissues of the forehead a straight angle, the Grecian type of nose is produced. The dorsum of the nose is not infrequently convex, giving rise to the nasus aduncus or aquihne type of nose. The nasus avicularis or Roman nose and the Jewish nose are variations of the aquiline type due to modification of the angle on the dorsum nasi. In the Jewish nose the tip is depressed, 6i 2 THE DEFINITIVE NOSE with a resultant general forward curvature of the entire dorsum nasi. The Roman nose, on the other hand, presents a rather acute angle at the point of confluence of the bony and cartilaginous portions of the dorsum nasi and a more prominent nasal tip. Another type of nose is encountered when the dorsum nasi is depressed (concavity). This leads to a relatively prominent nasal tip and gi\'es rise to the pug or saddle type of nose (the nasus simus or nasus nasicornis, the nez retrousse of the French). Such an individual is said to be flat-nosed, snub-nosed. Topinard's nasal types are: (i) the curved, (2) the straight, (3) the depressed or stumpy, (4) the Roman, (5) the Jewish or aquiline. Figs. 57-61. Topinard and others have shown that there is one kind of variation which is of considerable anthropologic importance, e.g., the degree or lateral expansion of the nares (anterior nares) as compared with the total length of the nose. This relationship is expressed by the cephalometric Fig. 57. Fig. 58. Fig. 59. F'ig. 60. Fig. 6i. Figs. 57-61. — Topinard's nasal types. Fig. 57, Roman; Fig. 58, straight; Fig. 59, curved; Fig. 60, depressed or stumpy; Pig. 61, Jewisli or aquiline. , . , greatest breath X 100 ., . , nasal index ^ v, ^i ■ It is found that m the white races greatest length of mankind the nasal index is below 70 (leptorrhines), giving the long, high nose; in the black races (African, Australasian) it is 85 and upward (plat- yrrhines) , giving the short, low nose ; and in the red and yellow races (Asiatic, Eskimos, American Indians) it is from 70 to 85 (mesorrhines), giving a ty-pe intermediate between the other two. The nasal index is sometimes determined by considering the length of the nose as extending from the frontonasal suture to the anterior nasal spine. Then the leptorrhine index is below 48, the mesorrhine from 48 to 55, and the platyrrhine above 55. The latter index obviously does not utilize the greatest length of the nose. The external nose forms a conspicuous triangular pATamid that projects from a point below the glabella, ventral- and caudalward to terminate in a free angle. The cephalic end is referred to as the root (radix nasi) and the free angle as the point or apex (apex nasi). Con- necting the two extremities in the form of a rounded median ridge is the liONKS OF I'X'PKRXAL NOSE 63 dorsum nasi. The cq^halic part of the dorsum is supported bv the nasal bones and is here cahed the bridge of the nose. The lateral surfaces of the nose (partes laterales nasi) extend from the dorsum to become con- fluent with the tissues of the face proper (nasofacial angles) and distally they end in rounded eminences, the ake nasi, which form with the upper Up the nasolabial sulci. The base of the nasal p>Tamid is pierced by two openings, the nostrils or nares (anterior nares). The entire external nose is supported by a bony and cartilaginous framework and covered by skin and muscles (Fig. bS). Oil. N. Cc Sna Fig. 62. — The osseous pyriform aperture of the nasal cavity. Xote the conchal ceU (ethmoidal cell) in the eoitcha nasalis media. On = OS nasale; ^1/ = maxilla; Cc = coni-hal cell; Sna = spina nasalis anterior. The Bones of the External Nose.— The bones that participate in giving shape and support to the external nose are the nasal bones (the nasal bridge), the maxilla\ and the nasal part (pars nasahs) of the frontal bone. The latter occupies the ventral portion of the ethmoidal notch and projects beneath the nasal bones and the frontal processes of the maxillae, thus lending support to the bridge of the nose. The arch-like construction in the coronal plane of the nasal bones and the frontal proc- esses of the maxillte is in itself reasonabl}' strong. Moreover, the elements that enter into the composition of the nasal septum act as a unit in suppor- ing the entire dorsum of the nose. The paired nasal hone (os nasalej is developed in membrane (accord- 64 THE DKFINITIVK XOSK ing to Perna and Livini, in membrane and cartilage, see page 42 on the ossi- fication of tfie nasal bone). The adult bone is narrow and robust above, but becomes thinner and wider at its lower extremity. The serrated cephalic border (margo frontalis) articulates with the medial portion of the nasal margin (margo nasalis) of the frontal bone and the notched caudal border in the dried skull is free and in the recent state gives at- tachment to the lateral nasal cartilage. The longer lateral border (margo maxillaris) articulates with the frontal process (processus frontalis) of the maxilla. The median border (margo nasalis) is robust above and less so below and articulates with its fellow of the opposite side in the forma- tion of the internasal suture. Entally the two nasal bones conjointly form a crest (crista nasalis) to meet with the frontal spine (spina frontalis) (ht..- Ona--' I- -Chz Fig. 63. — A drawing of a specimen showing asymmetrical nasal bones; also an accessory nasal bone. 0« = OS nasalc; (Jhq = os nasale accessoria. of the frontal bone, the perpendicular plate (lamina perpendicularis) of the ethmoid bone, and the septal cartilage (cartilago septi nasi). The ental or nasal surface at its cephalic end articulates with the frontal bone, elsewhere it is concave and smooth and is invested by the nasal mucosa. This surface is grooved— the sulcus ethmoidalis, for the nasal branch of the naso-ciliary nerve. The ectal or facial surface is concave from above down- ward for a considerable distance, caudally it is convex (Figs. 62 and 66). The foregoing description of the normal nasal bones is deemed ad- visable since departures from the normal are not infrequent. In X-ray photographs and in visual and manual examinations of the bridge of the nose due consideration must be given to variations in the osteology of the nasal bridge lest faulty interpretations be given. XASAL BONES 65 The shape and measurements of the nasal bones vary greatly in different indi\'iduals. Cleneralh' speaking, the}' are relatively large and prominent in the \yhite races and small and less prominent (flat) in the PfM Fig. 04. — A drawing of a s|iecimen showing ci.nn]jlctc agenesis or absenee of the nasal bones, also a detached osseous element of the frontal bone (('/)■ ' Particularly note that the nasal bones are replaced by the nasal or frontal'rroeesses (PfM) of the maxilla;. dark and vellow races. Ape-like the two nasal bones in man at times fuse bv obliteration of the internasal suture. The bones are frecjuently variously reduced in size and altered in shape h\ encroachment of the FfK. Fir 6=; ~A dra^ying of a specimen sho^ylng comi.lete agenesis or absenee of the nasal bones but in which the mesethmoid (Af.). e.g., the perpendicular lamina (yertical plate) of the ethmcnd bone comes to the surface between the frontal processes (Pfm of the maxdUc wh.ch replace the nasal bones. frontal processes of the maxilla- . Indeed, the latter may reduce the nasal bones to a mere mid-sagittal ridge or re])lace them altogether by articulat- 66 THE DEFIXITIVE XOSE ing with each other in the formation of the nasal bridge (like the catar- rhine monkeys). The author has in his collection a human skull in which both nasal bones are absent, the perpendicular plate of the ethmoid bone coming to the surface in the mid-sagittal plane between the frontal proc- esses of the maxillcT (often seen in the orang). Medial projections of the frontal bone rarely replace the nasals. Furthermore, each nasal bone ma>' appear as several pieces or may be divided by a vertical fissure. Additional ossicles are occasionally found in the line of the internasal suture or between the nasal and neighboring bones. The subjacent carti- lage of the nasal capsule may ossify at places and form minute plates of bone beneath the adult nasals proper. Again, the nasal bones are elon- gated and bound the pyriform nasal aperture along its lateral margins. Rarely the nasal bones are absent and the place filled in by membrane (Figs. 63, 64 and 65). In the skeleton the nasal fosste open externall}' on the face region by more or less asymmetrical pyriform apertures which conjointly form an in^'erted, cordiform-shaped opening at a level distinctly above the nares of the nose (in the recent state). The floor of the wider aperture is usuall}- at a somewhat higher plane than that of the narrower one. The cordiform aperture is bounded cephalically by the free border of the nasal bones and elsewhere by the maxillae. As stated elsewhere, the nasals at times project caudally along the lateral walls of the cordiform aperture. In the mid-sagittal plane, and projecting ventrad from the floor of the aperture, is the prominent anterior nasal spine, usually directed toward the widest aperture (Fig. 161). Usually the floor of the aperture is dull and rounded and directly continuous with its sharp lateral border. Occasionally, however, in the adult and nearly always in the infant and low races, extending from the lateral margin of the incisor crest and anterior nasal spine are two bony ridges, the ventral one confluent with the ventral surface of the maxilla and the dorsal one coursing inside the nose ventral to the inferior turbinated crest. These two ridges enclose a distinct depression — the fossa prenasalis, on the face, immediately below the bony nasal aper- ture. However, as a rule the identity of the two lines is lost by fusion in the adult, ^'ariations are encountered. The Cartilages of the External Nose.— As stated abo^■e, the pyriform aperture (apertura pj-riformis) of the dried and prepared skufl is bounded by the free borders of the nasal bones and the maxilke. In the recent state this aperture is enclosed and continued to the nares or nostrfls (anterior nares) by the nasal cartflages and contiguous tissues. Four major carti- CAK rii,A(,i:s ui' j;x'|-I':rxal nose I' IG. 6' I. — An adult skull wi i h 1 lie iiiili\'i(.lua] 1 )'incs sci"iaratu:.l, Ni )l"u the mi.'l.rijiic siiUirc and that the frontal sinuses do not extend Ijeycnd the midHne, the usual anali.any in such eases. Thu maxil- lary and frontal sinuses are shown in dotted outline. 68 THE DEFINITIVE NOSE lages (cartilagines majores) participate in the formation of the framework of the external nose. Moreover, a variable number of minor or accessory cartilages (cartilagines minores) are usually found. The major cartilages are the paired lateral and greater alar cartilages. The accessory elements are the accessory alar cartilages and the sesamoid cartilages. ^ Although the unpaired septal cartilage and the vomeronasal cartilages of Jacobson likewise assist directly or indirectly in the support of the external nose they will be discussed in connection with the nasal septum. Smn, Cnl (CI) f Fig. 67. — The cartilages of the external nn,e as disjila^ ed (trnntal view) after the removal of the skm and niU'^Lles Cam = cartilagines alares minores; C. ses. n = cartilagines sesamoideas nasi; Csn = cartilago septi nasi; Cnl = cartilago nasi lateralis; Camaj (CD = cartilago alaris major (crus laterale). Snm = sutura liasomaxillaris. The division of the major nasal cartilages is, in a sense, arbitrary and unwarranted. As mentioned previously, in connection with the embry- ology and morphology of the cartilaginous nasal capsule, the three major nasal cartilages (two paired, one unpaired) constitute one piece (cartilagino mediana nasi). The lateral nasal cartilages and the septal cartilage remain connected in the adult, while the greater alar cartilages become disconnected and appear as independent elements. The greater alar cartilage (cartilago alaris major) partially encircles the ventral part of the naris (nostril), assists in keeping the naris and CARTILACKS OF EXTERNAL XOSE 69 vestibule open, and with its fellow gives shape to the base of the nose. The cartilage consists of two crura — one medial (crus mediale) and one lateral (crus laterale), in relation to the naris. The crura are continuous with each other at the apex of the nose, giving the latter a rounded contour. The interval between the lateral crus of the cartilage and the maxilla is filled in by a strong sheet of fibrous tissue in which are embedded the lesser alar cartilages. At times the lateral crus is ])rolonged dorsolaterally so as to replace the lesser cartilages. JNIoreover, the lateral crus is bound to the lateral cartilage b}' a fibrous membrane and to the caudoventral -CnJ Ca.mxij '- (CI) , , CcJLjrvccj {Cm) "~ Stiti Fig. 68.— The cartilage ...f the e.xternal imse as disphiyc.l (i,n..file view) after the removal uf the skill and mtisclcs. On = OS nasale- Camin = cartilaK-nies alares minores; Cnl = eartihiK" nasi lateraHs; Csn = cartilasmes sesamo.de;c nasi ; Camuj (C7) = cartilago alaris niaiur (crus laterale); Ca maj = cartdago alaris major; Camaj iCm) = cartilago alaris major (eriis mediale); Smn = septum mobile nasi. part of the cartilaginous septum. Toward the median plane the lateral crus is curved backward to form the medial crus. Here the latter bounds a deep median groove, meets with its fellow^ of the opposite side and extends dorsalward in the columna nasi caudal to the cartilage of the septum. The medial crus ends dorsall)- in a free, out-turned border (Figs. 67, 68). The lateral nasal cartilage (cartilago nasi lateralis) is a flattened, triangular plate located in the middle part of the lateral surface of the 70 THE DEFINITIVE NOSE projecting portion of the nose, immediately distal to the free border of the nasal bone. One surface looks toward the nasal ca^'ity and the other ventrolateralh' toward the external face. The dorsal edge or border of the cartilage is thin and is attached to the maxilla and to the nasal bone; its ventral border is thick and above directly continuous with the cartilage of the septum. As stated before, its lower edge is attached by fibrous tissue to the upper edge of the lateral crus of the greater alar cartilage (Figs. 67 and 68). The lesser alar cartilages {cartilagines alares minores) are small and variable in number. They are found bilaterally embedded in the strong fibrous tissue of the wing of the nose in the interval between the lateral crus of the greater alar cartilage and the maxilla. Sometimes a dorso- lateral extension of the lateral crus of the greater alar cartilage replaces the lesser alar cartilages in part or in whole (Fig. 67). .^'S- Fig. 69. — The cartilages of the nose as related to the nares (anterior nares) or nostrils. Cam = cartilago alaris niajor (C/ = crus laterale, C)H = crus mcdiale) ; CiH. = cartilage septi nasi; 5)n?! = septum mobile nasi (columna nasi); F« = vestibulum nasi; Z,;; = limen nasi, limen vestibuli; A^ = naris. The sesamoid nasal cartilages (cartilagines sesamoides) of the nose Avhen present are located in the interval between the lateral nasal and septal cartilages medially and the lateral crus of the greater alar cartilage laterally. They are \-er}' small and var}- in number from one to three or more (Fig. 67). The Muscles of the External Nose.- The position of the als of the nose can be altered by the attached muscles and facial expression modified thereby. The pars transversa of the nasalis (compressor nares) ; the caput angulare of the quadratus labii superioris (levator labii superioris alseque nasi) ; and the dilatores naris, anterior and posterior, elevate and dilate the IXTERXAL NOSE 71 naris (nostril). The pars alaris of the nasaHs (depressor ahT nasi) and the depressor septi nasi depress and contract the naris. Poirier and Duchenne found that the pars transversa and the caput angulare act conjointh- in drawing kiterally and cephalically the Uiteral margin of the ala of the nose, the position of the nostril expressing sensuality. When the pars transversa acts with the pars alaris it may constrict the naris. Expressions of pain and anger are brought about b>- the pars alaris and the depressor septi nasi. The reader is referred to more extensi\'e trea- tises on facial expression and anthropolog}' for details. In conclusion the author wishes to urge the great cosmetic impor- tance of the external nose and that a knowledge of the types of face and nose, of the osseous and cartilaginous nasal framework, of the nasal mus- cles and the blood and ner\-e supph' is essential to those dealing with deformities and injuries of the organ; especialh' so since plastic surgery of the face is now ver}- much in the foreground. The Ixterxal Xose The anatomy of the internal nose (nasus internus) is that of the nasal cavity (ca^-um nasi) and ancillary structures. The general nasal ca^■it}■ is divided b}' a median septum (sej)tum nasi) into two more or less symmetrical halves — the nasal fosste (fossfe nasales). ^loreover, the fossa? are further divided into nasal meatuses (meatus nasi) by the nasal conchce or turbinates (conchie nasales) and are extended into neighbor- ing bones by the paranasal (accessory) sinuses (sinus paranasales). The fossa; communicate with the exterior through the nares (anterior nares) and with the nasopharynx dorsally through the choame (posterior nares). Conforming with the more s]:)ecific functions, the nasal fossa" are di\'ided into respiratory and olfactory portions, e.g., ])ars respiratoria and pars olfactoria respectively. There is great variation in the degree of de\-elopment and complexit)- of the nasal foss;e and contained structures and the olfactory lobes in mammals. This led Turner to divide them into three subdi\-isions: macrosmatics (rodents, carnivora, marsupials and most mammals); anosmatics (certain cetacea— porpoise) ; and microsmatics (man, most primates and some cetacea). Each nasal fossa is roughly triangular in frontal or coronal section. The narrow roof of the fossa may be considered the apex of the triangle and the wider floor the base. The median wall is usually unbroken and even and approximately vertical, meeting the floor at nearly a right angle. 7 2 THE DEFINITIVE XOSE The lateral wall, the hypotenuse of the triangle, is sloping and is config- ured by the major and minor nasal conchas and meatuses and by the impinging paranasal sinuses. In sagittal section the contour of the nasal fossa represents a quadrangle, the cephalic side or roof of which is approxi- mately parallel to the caudal side or floor. The ventral or anterior side of the quadrangle conforms to the profile of the external nose and forms with the caudal side or floor an acute angle at the naris. The dorsal side falls along the ventral surface of the body of the sphenoid bone, then passes through the choana (posterior naris) in front of the ostium pharyngeum of the tuba auditiva (Eustachian tube) to impinge upon the dorsum of the junction-point between the hard and soft palates. Laterally the dorsal limit of the nasal fossa is indicated by the nasal sulcus (sulcus nasalis posterior) which extends from the angle formed by the confluence of the \'entral and caudal surfaces of the body of the sphenoid bone to the junction of the hard and soft palates. There is considerable variation in the dimensions of the nasal fossae. The t}'pe of nose and the degree of arching of the palate obviously must aft'ect the dimensions of its chambers. The degree of development of the nasal conchae and the size, shape and disposition of the paranasal sinuses affect the symmetry of the nasal fossae in the same individual and in dif- ferent individuals. The following may be taken as representative dimen- sions based upon a large series of specimens studied by the writer; The greatest sagittal diameter, measured from the most prominent part of the naris along the floor of the nasal fossa to the dorsal border of the hard palate, is 74 mm., while the extreme sagittal diameter measured along the roof of the fossa is but 35 mm. or less. The greatest height (vertical diameter) is found by dropping a perpendicular line from the ventral third of the cribriform plate of the ethmoid bone to the floor of the nasal fossa — averaging from 40 to 45 mm. The nasal fossa is a mere cleft in the coronal or frontal plane (width) along the cribriform plate (roof) — 3 mm. or less. The widest part of its floor varies from 12 to 23 mm., measured at the greatest lateral expansion of the inferior nasal meatus. The width of the floor in advance of the knee of the inferior nasal concha is much reduced — 4 mm. or less. It is well to remember that after the normal point of constriction is passed the inferior nasal meatus is much more room}-. The Nares (nostrils, anterior nares). — The nares of man are remark- able on account of their position, looking as they do almost directly caudal- ward. The base of the nose varies considerably. Individual variations are extreme!}- commonplace and not important. There are, however, CHOANAli 73 several anatomic types which are of anthropologic interest and impor- tance. When the tip of the nose is depressed the transverse diameter through the alse is great and the greatest diameter of the nares is placed horizontal, e.g., in the black races. In those cases where the tip of the nose is fairly prominent, as in the white races, the transverse diameter through the ala? is lessened and the nares are nearly in the sagittal plane in the greatest diameter. The inter-alar distance is less in the red and yellow races than in the black races and the nares here occupy a half- way position between the horizontal and the sagittal planes. The Vestibule (vestibulum nasi). — The paired vestibule may be considered an antechamber to the nasal fossa. It corresponds more or less in its extent to the cartilaginous nasal wall. The vestibule is located immediateh' ental to the aperture of the naris (nostril) and is supported b}' the medial and lateral plates of the great alar cartilage and adjacent portions of the nasal septum and integument. The extension of the vestibule into the tip of the nose is often referred to as the ventricle of the vestibule {recessiis apicis). The deepest and lateral boundary of the vestibule is formed b}' the upper and arching border of the lateral plate of the great alar cartilage and the lower border of the lateral cartilage. The cartilages throw the overlying tissues into a prominent ridge, form- ing with the cartilages the limen vestibuli or the Umen nasi (Fig. 197). At the latter the skin lining the vestibule suffers a transition into the mu- cous membrane lining the nasal fossa proper (see nasal mucous membrane, page 261). The skin lining the vestibule is supplied with hairs (vibris- sae) — stout and coarse immediately within the naris and short, slender and scattered elsewhere, and with sudoriferous and sebaceous glands. Both the hairs and glands are wanting near the limen nasi. The Choanae (posterior nares). — The definiti\'e choance are the com- municating passageway's between the nasal fossa? and the nasopharynx (Fig. 141). The nasal meatuses and the dorsal extremities of the nasal chonchse con^'erge toward the dorsal apertures. However, the concha; are from 10 to 12 mm. in advance of the choame and do not configure the outlines of the openings as they do the lateral nasal walls. The dorsal extremities of the nasal conchse can be inspected through the choange, especially the inferior and middle. The defmitive choana; are located farther dorsad than the primitive choana; which connect the early nasal fossa; with the mouth cavity (see embryology, page 9). The choana; are bounded cephalically (above) by the ate of the vomer; laterally b}' the median plates of the pterygoid processes of the sphenoid; medially by the vomer; and caudally (below) by the horizontal plate of the palate 74 THE DEFIXITIVE XOSE bone. The muco-periosteum o^'er this osseous framework is continued from the nasal fossa; into the pharynx. The osseous boundaries of the choana; cause the nasopharyngeal communications to be permanently open and free unless blocked by other structures, e.g., adenoids, etc. The author observed a case of congenital atresia of the choana? in a term child. Such atresia may be the result of an organization of epithelial plugs which occasionally block the choanal earher in fetal life, rarely osseous tissue develops in the organization (Fig. 70). The vertical diameter of the adult choana; is always greater than the trans^'erse (coronal) ; the comparison being shown by the choanal index — transverse diameter X 100 vertical diameter The author found the index for the male to AtiesJM of cJiocincc CoizcljM nMsalii fnedia. Septum, nMS7- I t I Concha. nascUis inferior Fig. 70. — Congenital atresia of the right choana in a girl aged 19 years \Yith an accompanying anosmia of the right side. {Aflt'r Krifg.) be 61 and for the female 64.5. In this he is in close agreement with Escat' who gives 60 for the male and 64 for the female. While there may be slight differences in the diameters of the choanEe of the two sides, they are alike in this regard to a remarkable degree. The transverse diameter is greater at the floor (varying from 12 to 17 mm.) and least at the roof (varying from 7 to 10 mm.). The vertical diameter varies from 24 to 2^2, mm. The vertical diameter is relatively much reduced in the newborn child. There is considerable variation in the inclination of the dorsal free border of the vomer, and as Dwight has shown it is in direct ratio to the degree of prognathism. The gnathic index is the ratio of the line from the basion to the alveolar point to the line from the basion to ' Cavite Xaso-Pharyngienc, Paris, 1894. the nasion, ^'■S- FLOOR ()!■ XASAI, CA\ ITY basi-alveolar line X loo 75 An index below 98 indicates an basi-nasal line orthognathic skull; 98 to 103, a mesognathic skull; and abo\-c 103, a prognathic skull. The Floor of the Nasal Cavity.— The osseous framework of the nasal floor is formed b>- the palatal processes of the maxilhv and the horizontal processes of the palate bones, Fig. 7 1 . The floor of the nasal cavity ser\-cs also as the roof of the mouth. The broad palate is usually less ^-aulted than the narrow one. The ratio of the breadth to the length is expressed K ti 1^1-, breadth X 100 b> the palatal mdex, c.,t,'., ^^^- ^^ ; the breadth being measured through the sockets of the second molar teeth and the length from the alveolar process in the mid-sagittal plane to the posterior nasal spine. S^i^f- S?n FpM Fig. 71. — .V dissection illustraliinj; the floor .if the nasal fossa' as related to the maxillarx- simises. Snp = spina nasalis posterior; Sm = sinus niaxillaris; Ci = eanalis ineisirus; Sna = spina nasalis anterior; PpM = processus pialatinus niaxillse; PhOp = processus horizontalis ossis palatini. The generalization often made that narrow palatal arches invariablv lead to correspondingly narrow nasal floors is unwarranted. It is in verA' many instances assuming what is not a cause for narrow nasal floors to be a cause — iwii causa pro causa. The writer"^ first noticed the fallacA' of the general inference or premise when studying the relations of the max- illary sinus to the nasal floor (1907-10). Since then many observations have been made to show that the nasal floor and the ])alatal arch arc not necessarily synchronously wide or narrow. Wide ]5alatal arches may be accompanied b}' relatively narrow nasal floors and narrow arches b)' wide floors. ' J. Parsons Schacffcr: The Sinus Maxillaris and Its Relations in the I'imbryo, Child, and .Vdult Man, .Vmer. Jour. Anat., Vol. to, [gio. 76 THE UKKIXITIVK XOSE It is ob\-ious from a study of a sufficiently large series of specimens that the width of the iioor of the nasal fossa is more dependent upon the size of the maxillar}- sinus than upon the degree of arching of the palate, and when one recalls that the right and left maxillar}' sinuses are often \-cr}- asymmetrical in size, the diiterence in width of the floors of the two nasal fosste is more comprehensible. If the maxillary sinus is small, the nasal fossa near its floor, f.f/., the meatus inferior, may bulge laterally over the alveolar process and the related teeth. The reverse may also be true in which the maxillar_\' sinus hollows out beneath the inferior nasal meatus into the palatal process of the maxilla (hard palate, floor of nose) to form the palatal recess of the sinus (Fig. 85). These anatom- ical variations of the maxillar\' sinuses obviously must affect the width of the inferior nasal meatus, e.g., the floor of the nasal cavity, regardless of a high or low ])alatal arch. The floor of each nasal fossa is essentially horizontal in the sagittal plane, however, a distinct protuberance is present just inside of the limen nasi, o\'er which an instrument must be passed to enter the inferior nasal meatus proper. In the coronal plane the floor of the nasal fossa is concave. Ventrally the floor of the nasal fossa is thick and robust, this gradually diminishing to a very thin plate at the junction with the soft palate. The Nasopalatine Canals. — Approximateh- 2 cm. dorsal to the inner margin of the nostril and in juxtaposition to the nasal septum each nasal fossa presents a slight depression in its floor. This depression leads into a small canal lined with mucosa, prolonged from that which lines the inferior nasal meatus. This funnel-shaped tube of mucous membrane, the nasopalatine canal (canalis incisivus, canal of Stenson), courses obliquely caudalward and with its fellow of the opposite fossa con^'erges toward the nasal septum, descends almost vertically and passes through the Y-shaped incisive foramen (foramen incisivum, anterior palatine canal) in the hard palate. The right and left nasopalatine canals may join and pass through the stem, of the Y incisive foramen as a common channel, howcA-er, more commonh- each retains its individuality. The canals end on the roof of the mouth at the side of the palatine papilla (papifla palatina) or incisive pad (Fig. 196). The nasopalatine canals are remnants of the wide communication between the nasal and oral cavities found at an early period of fetal life. Occasionally the nasopalatine canals in adult man lead to a direct communication between the nasal fossEe and the buccal cavity. In the vast majority- of instances, however, the lumina of the canals are obliterated and represented by impervious cords of epithelial cells con- XASrVL SEPTUM 77 tinuous with the epithelium of the roof of the mouth at one extremity and with the funnel-shaped ciliated epithelial-lined depressions in the floor of the nasal foss^t at the other. Indeed, at times it is dil^cult to find any remnant of the canals \\'hatsoe\'er. The obliteration of the lumina often begins before birth. In many animals, on the contrary, the naso- palatine canals remain open and persist as such throughout hfe. Persistence of the lumina of portions of the nasopalatine canals may be the explanation for "ceUs" in the maxilkc dorsal to the upper incisor teeth. Indeed, such a "ceU" could communicate with either the inferior meatus or the buccal cavity; or in the event that both extremities of the canals became impervious, the central portion (or portions) would be with- out a drainage channel and could readih' become c}'stic (see sinus maxil- laris, page 121). The Roof of the Nasal Fossa. — The roof of the nasal fossa may be considered as horizontal and wholly formed by the cribriform plate of the ethmoid bone. It may also be considered as a craniallv arched structure, with the cribriform plate forming the horizontal middle portion; the body of the sphenoid bone together with the wing of the ^'omer and the sphenoi- dal process of the palate bone, the curved dorsal portion; and the frontal and nasal bones, the cur\-ed ventral portion. The entire framework is covered by nasal mucous membrane. A^entrall}- the roof of the fossa is A'ery narrow, but graduall}' widens as the choanal aperture is approached. The greatest breadth of the cribri- form plate (roof proper) is approximateh" 5 mm. Ventrally it nar- rows and allows the lateral ethmoidal masses to come in contact with the perpendicular plate. Craniallv the cribriform plate supports the olfactory lobe of the brain and is perforated by foramina for the pas- sage of the olfactory nerves. Ventrally close to the crista galli is a longitu- dinal fissure (the nasal fissure) for the transmission of the anterior eth- moidal branch of the nasociliary nerve and the anterior ethmoidal vessels. The Median WaU of the Nasal Fossa, e.g., The Xasal Septum (septum nasij. — The partition between the right and left nasal foss;e is formed: (i) b\' osseous elements, (2) by cartilaginous elements, and (3) by integu- ment (Fig. 74). The nasal mucous membrane covers all portions of both sides of the septum save the vestibular part which is invested by integument continued through the nares from the surface area. It is smooth and more or less constant in thickness. However, the more extensive glandular and vas- cular development here and there cause the mucosa to be thrown mto relief in the form of small ridge-like elevations and protuberances. A 78 THK DEFIXITIVK NOSE fairly constant elevation (the tuberculum septi) is found on the septum in juxtaposition to the ventral extremity of the middle nasal concha. More- over, oblique mucosal ridges or septal pliav (phca; septi) frequently con- figure the dorsocaudal portion of the septum. These folds or plicae, four to six in number, are placed in order from below upward and forward and have as their precursors the mucosal folds which appear early in Fig. 72. — Photcigraph of the separate iDones of the nasal fossa, etc. T = \-i.imer; / = frontal; t' — ethmoid; 5 — splienoid; /)(;/ - i.talate; Cni = concha nasalis inferiitr; ni = maxilla; / — lacrimal; n = nasal; t — temprjral; l>ay = parietal. fetal life (see page 37 and Fig. 41). They usually increase in size up to the eighth month of intrauterine life, then undergo regression and dis- appear earh- in infancy. Howe\-er, occasionalh' they persist, even hvper- trophy into tumor-like obstructing masses in the adult (see page 261 for detailed discussion of the adult nasal mucous membrane). (A) The osseous portion of the nasal septum (septum nasi osseum) is formed by the perpendicular plate of the ethmoid, the \'omer, the frontal XASAI. SEPTU^r 79 (nasal) spine of the frontal, the rostrum of the sphenoid and the crests of the nasal, maxillar>- and palate bones. I. The vomer is a thin, irregularly fiuadrilateral bone located in the dorsocaudal portion of the nasal septum. The dorsal border of the bone projects free toward the nasopharynx and sei)arates the choana;. The inferior border articulates with the nasal crests of the maxillary and palate bones. The superior border, the thickest ]xart of the bone, is di\-ided into two spreading ala- which articulate with the rostrum of the body of the Bulla frontaUs ^ Acfffor nasi /nMsoturbinaZ ) ^ ^ Proc. -UTzcin^v^ ^^ ossis etJmwicbjr^is ^ 7Z7idcrertj^l^ arocc of- 7-n^atzLS nasi rrreciiiis Fossa. 7izfpoplfyS(^s Sums spheiwi.dalei Proc. efktruiUIuUs Proc maxillccris (dexter et sinister) (concha nasalCsznAiiurX fcrncha futsal?:^ inferior \ Fk,. 73. — The rjsseous lateral nasal ^^■all ^\-ilh the ethmoidal C'mehx- cjt tnrhiiiateil b-jnes remo\'ed- Xote the undefended area of the meatus nasi nietlitis and its division into two parts (see text, page 92). Xote also the unusual position {frontal plane) of the osseous septum separating the right and left sphenoidal sinuses and the relations rif the h\-pophyseal fiissa. sphenoid bone. ^Moreover, the edge of each ala meets the vaginal process of the sphenoid and the sphenoidal process of the palate bone. The anterior border is grooved for the reception of the septal cartilage and in the dorsocephalic portion is ank}'losed on one or both sides to the per- pendicular plate of the ethmoid bone. Occasionally the septal cartilage is prolonged tongue-like between the vomer and the ])erpendicular plate of the ethmoid in the formation of the sphenoidal process of the septal cartilage (Fig. 74). The ventral extremity of the vomer forms a short 8o THE DEFIXITIVE XOSE vertical border which abuts the incisive crest of the maxillte dorsally and is extended \'ariously at its upper end in the groove of the crest. More- o\'er, the lower end of the ventral extremity at times projects between the incisive canals. Rarely the vomer shares in the formation of the hard palate by extending between the palatine processes of the maxillse (see development of vomer, page 41). 2. The jncsctlunoid or the perpendicular ])late (lamina perpendicu- laris) of the ethmoid bone represents the ossified upper portion of the primitive cartilaginous nasal capsule. It forms the cephalic third of the septum of the nose, articulating with the frontal (nasal) spine of the frontal Os n/xsa,le ^.C.p.tkvtoidalis posteiior '•Sinus splicnviduhs sinister Si'nas sphmioicUdi^ derter Fossa nypophuseoi \ Trace ssus s/o/iciwidaii i .M-*^"^""^^ septi cart.ilacfuiei ,>'' Carf,ila(fo vci//ero?iasu.Us Cartilago alaris ma/or Fig. 74. — A dissection showing the osseous and cartilafiinous septum of the nose. bone and the nasal bones ventrally, with the septal cartilage and the vomer ventrally and caudalh' (the vomer and mesethmoid may be joined by osseous tissue), and with the crest of the sphenoid dorsallv. The cephalic border of the mesethmoid appears in the cranial cavitv above the cribri- form plate as the crista galli and in doing so divides the roof of the nasal cavit}' into two hah'es. The ventral extension of the mesethmoid varies considerably and in this reciprocates with the related portion of the septal cartilage. Alore- over, this accounts for the apparent discrepancies in the literature con- cerning the osseous extent of the nasal septum. Not infrequently the NASAL SEPTUM 8l mesethmoid extends as far as the caudal or distal border of the nasal bones. Again specimens are encountered in which the mesethmoid is much smaller, terminating \entrally at the le^'el of the frontal (nasal) spine of the frontal bone. All degrees of develoi)ment between these two extremes are found in a series of specimens. Obviously the septal cartilage is reciprocally large or small in the structural formation of the nasal septum. The ^•ariations in the mesethmoid must have a consider- able bearing in connection with fractures of the nose and septal de\"iation. 3. The remaining osseous sejjtal elements — the frontal (nasal) spine of the frontal, the roslnii)! of the sphenoid and the crests of the nasal, Fig. 75. — The medial or nasal wall of the maxillary sinus exposed from the sinus side. Xote the undefended area (4) and that the uncinate proces.s docs not aruculatc with the inferior nasal concha. (Compare with Fig. 73. J J = ethmoid; 2 = lacrimal; 3 = uncinate process of ethmoid; 4 = mucous membrane; 5 = palate bone; 6 = inferior concha or turbinate; 7 = maxilla. maxillary and palate bones— serve as articulating points for the ^-omer, mesethmoid and septal cartilage and thereby participate in com])leting the septal margins (Fig. 74). (B) The cartilaginous portion of the nasal septum (septum nasi cartilagineum) is formed b>- the septal cartilage, the vomeronasal carti- lages and the medial crura of the great alar cartilages. I. The cartilage of the septum (cartilago septi nasi) is hregularly quadrilateral in shape and completes the median partition ventrally be- 82 THE DEFINITIVE NOSE tween the right and left nasal fossae. It represents the ventral extremity of the primordial cartilaginous cranium. Its dorsocephalic border is attached to the perpendicular plate of the ethmoid (mesethmoid) ; its dorsocaudal border to the ^•omer and maxilla (incisive crest, as far as the anterior nasal spine). Its thick ventrocephalic border is fixed along the internasal suture abo\-e and below it becomes confluent with the lateral nasal cartilages, the latter extending wing-like from it. After leaving the position of the lateral cartilages, the ventrocephalic border of the septal cartilage extends between the greater alar cartilages to within a half inch of the tip of the nose, the medial crura of the great alar cartilages inter\'ening between the septal cartilage and the nasal tip. The rotundity of the tip of the nose is due to the rounded confluence of the medial and lateral crura of the greater alar cartilages. Dorsally the septal cartilage extends ^'ariously between the vomer and the perpendicular lamina of the ethmoid (mesethmoid), thus form- ing the so-called sphenoidal process of the septal cartilage (processus sphe- noidalis septi cartilaginei). Indeed, the latter may be suflrciently elon- gated to reach the sphenoid bone — especialh' in children — and very frequently is the seat of a Crista or ridge-like horizontal projection into one or the other nasal fossa, causing septal asymmetry (Fig. 74). 2. The vomeronasal cartilages (cartilagines ^'omeronasales) are two narrow longitudinal strips, 7 to 15 mm. in length, which lie along the ventral portion of the caudal border of the septal cartilage. In this position the vomeronasal cartilages are attached to the vomer dorsally and to the maxilla and the septal cartilages \-entrally. The vomeronasal cartilages are not alwaj's differentiated from the septal cartilage and appear as lateral processes from its caudal border (Fig. 74). In man these carti- lages reach their maximum development in the embryo. They are, however, alwa}"s most conspicuous in animals in which the ^'omeronasal organ is well developed, forming a protecting and supporting framework for the organ. It is doubtful in man whether the diminutive vomeronasal cartilages have anything in common with the rudimentary vomeronasal organ, since the latter is always located in the septal tissue cephalic to the position of the vomeronasal cartilages (Fig. 189). Strictly speaking, therefore, one should not say that the latter cartilages are supporting structures for the vomeronasal organ (organ of Jacobson) in homo. 3. The greater alar cartilage or cartilage of the aperture (cartilaginea alaris major) is discussed with the cartilages of the external nose to which the reader is referred (Figs. 68 and 6g). (C) The membranous portion of the nasal septum (septum nasi ASYMMETRY OF NASAL SEPTU^r 83 membranaceum) is formed by the medial crura of the great alar cartilages and by integument and subcutaneous tela, the septal cartilage stopping short of it. Owing to the absence of the latter the membranous septum is much more flexible and is often referred to as the septum mobile nasi (see greater alar cartilage, page 08, Fig. 08). Asymmetry of the Nasal Septvmi.— During fetal life and in infancy and in earh- childhood, the nasal septum is usually s)'mmetrical and in the mid-sagittal plane throughout. Ho\ve\-er, the author has seen asymmetrical nasal septa in indi\'iduals of the earl)- childhood period and several markedly de\-iated septa in fetuses. Notwithstanding these exceptions, asymmetries of the nasal sejjtum usually appear after the childhood period, the majority of adults presenting asymmetries varying from slight irregularities to deviations which completely occlude one or the other nasal fossa. Indeed, deflection of the human nasal septum is so common that one almost thinks of it as normal anatomy in spite of the fact that the results of the asymmetry are often so direful that surgical intervention is necessary. One must, however, bear in mind that a goodly number of adults ha^•e essentially symmetrical septa and not be misled by the extravagant statements occasionally made that straight septa are extremely unusual. Xo accurate anatomical classification of se])tal asymmetries can be made owing to the di^•ers types that may be assumed. The asymmetry may involve all the constituents of the septum or be limited to the septal cartflage or the osseous ])arts, respectively. Strangely, the dorsal or free border of the nasal septum is nearly always in the mid-sagittal plane so that the choanal apertures arc regular!}' of ecjual size. In a general way, one may say that septal asymmetry is due to se])tal deflection as a whole or to one of its major constituents, or to spurs, ridges, etc. Not infre- quently the latter in some form accompany septal deflection. Often spurs and ridges are referred to as septal deflections as well. Very common seats of deflection occur along the articulation between the vomer and the septal cartilage, and the articulation between the mesethmoid and the A'omer. The latter articulation is particularly vul- nerable when the sphenoidal process of the septal cartflage is interposed for a goodly distance (Fig. 74). At these articulations angular deflec- tions toward one or both sides take place and in addition may give rise to ridge-like folds and crests or to more localized spurs. It must be re- membered, however, that the septum may be essentially straight, yet a marked ridge or spur on one or the other side produce an asymmetry. Not infrequently one or the other of the septal elements is, in a sense, 84 THE DKFIXITIVE XOSE dislocated. A ver_v characteristic crest (crista lateralis) frequently devel- ops along the sphenoidal process of the septal cartilage, and this not neces- sarih- accompan>-ing septal de^■iation in the strict sense. Corresponding to the ^'ariable degree of deAxlopment of the sphenoidal process of the septal cartilage the lateral crista extends variously along the lateral aspect of the nasal septum, at times as far as the body of the sphenoid bone. At times the entire nasal septum forms a general convexity or bulging into one nasal fossa with a reciprocal concavity and enlargement of the other fossa. Again, the septum may deviate in a double or S-shaped manner, thereb}' encroaching simultaneously upon both nasal fossa;. No hvpothesis yet formulated seems to adequately explain the occur- rence of non-traumatic asj'mmetr}' and deflection of the nasal septum in all cases. Many etiologic theories have been advanced and are extant in the literature. The same cause cannot be ecjually operative in all cases. It is frequently stated' that non-traumatic septal deformity is largely a product of ultra-civilization and that it is unknown among animals and savages and rare in all semi-civilized races. The studies of Zuckerkandl seem to confirm this. Moreover, the author recently ob- served in a mixed series of skulls that the greatest percentage of septal deviation was found in the skulls of Europeans, which is in accord with Zuckerkandl's tables. Apropos of the latter it may be of interest to mention that the skull in man, as in all mammals, consists of two parts — the facial part, carrying the teeth and developed according to their size, and the brain capsule, which develops in accord with the size of the brain. The larger the brain, the smaller the face and the less does the face project in front of the skull; and, on the contrary, a small brain means a larger face and a greater facial projection in front of the skull. The degree of facial projection from the axis of the skull is spoken of as the facial angle, which is, to a certain degree, an index of brain development. The facial angle is smallest in the ultra- civilized races of man, considerably larger in the lower races, and larger still in the anthropoids. This means that the degree of flexion (angle of flexion) of the cranial axis (basion to nasion line) is greatest in the highly civilized races and lessens as one passes from the lower races to the an- thropoids. jNIoreover, the nasal septum is seemingly encroached upon more and more by the forward cranial extension incident to brain growth as one passes from the anthropoids to the ultra-ci\'ilized races of man. The problem, of course, is whether or not there is a balanced adjustment of all parts of the cranium and face in this evolution. If there is, the grad- ual alteration of the facial angle cannot be a factor in septal asymmetry. ASYMMl'-.TR^' OF XASAL SliPTUM 85 On the other hand, if all parts do not develop in accord with the changes incident to the lessening of the facial angle, one readily sees that the"irxed" position of the nasal septum might be encroached upon and the septum correspondingh' deformed. In studying the nasal se])tum one is impressed with its anatomical situation. Located as it is between the unyielding frontal and ethmoid bones above and the spheiioid bone behind and the hard palate below, the septum is essentialh' fixed in ixisition. Any increase in its cejjhalo- caudal (vertical) diameter must necessarih" lead to a buckling of the sej)- tum as a whole or to a de\-iation of one of its component elements. It is not clear what would cause the sei)tum to outgrow the region set for it. Possibly a remote and slight trauma may have altered the balanced nutrition and in conseriuence cause one or more of the septal elements to outgrow its region. The xomer especially seems to be at fault owing to increased de\elopment in the \-ertical j^lane. Ossification along the line of union between the mesethmoid and the ^■omer is often excessive and doubtless is an important factor in the deviation of the septum in its ventral two-thirds. Should the cranial and facial bones grow at the expense of the nasal septum the re\erse ccmdition would pre^•ail, namely — a deA'iated septum owing to encroachment upon its area. Xot infrecjuently one finds enlarged nasal conchcC and enlargement of the entire ethmoidal labyrinth as the obvious causes of septal deviation (Fig. 161). Great imi)ortance is gi\-en by Trendelenburg and Freeman to a i)er- sistent high or Gothic arch of the hard palate as a causative factor of a deflected nasal septum. This condition would seemingly lead to encroach- ment upon the \-omer and the mesethmoid and cause them to buckle. However, when one finds markedh' de\-iated septa in extremely fiat palatal arches he questions the (iothic arch as a factor. Jarvis and others strongly support the theory of hereditA-; while Talbot believes that deflected septa are "stigmata of degeneracy" in all cases where traumatism is not a factor. Incoordination or unbalanced development in the growth of the skeleton of the nose and face doubt- less account for many deflected septa. Presumabh" this is the thought Dr. Talbot wishes to convey. Traumatism, often remote and tri\-ial, is according to many in\-esti- gators the most frequent cause of septal as)'mmetry (Bosworth). The author was impressed recently in an examination of a large series of skulls of the relative frequency of some evidence of a previous trauma to the bridge of the nose. The architecture of the framework of the nose is 86 TH?: DEFINITIVE NOSE such that trauma mtiicted to the nasal bridge readily influences the cartilaginous portion of the nasal septum. Despite the elasticity and pliability of the nose of the child at term trauma inflicted during birth may be the underlying factor in dislocation of the ventral portion of the nasal septum from the depression formed by the crest of the intermaxillary bone. Indeed, Kyle believes " that many cases of the so-called congenital deformity in the bones of the nose are due to the fact that at birth during labor, owing to the position of the head in the birth canal, considerable pressure has been exerted on the soft, almost cartilaginous, bones of the nose. It is Avell known that much can be done toward the shaping of the nose at this time." Ballenger, while believing that trauma is a factor in a certain number of cases does not believe that it explains a majority or even a large percentage of deflected septa. He feels that Talbot strikes at the "root of the matter."^ Hurd'- likewise believes that "deviation of the septum, which is sometimes traumatic, is usually due to unequal develop- ment of the bony frame of the face." It would, therefore, appear estab- lished that as}'mmetries in development and trauma, the latter not infre- quently unrecognized at the time, are the most frequent and important etiological factors in septal deformity. Apparently rickets and septal asymmetry co-exist, as do also septal asymmetry, high-arched palate and nasopharyngeal obstruction. The inter-relations of these conditions, however, need further investigation before any conclusions of value can be given. Perforation of the Nasal Septvim. — Congenital perforation of the nasal septum is apparently a rare condition. In a large series of specimens (well over 300) the author found two instances of congenital perforation, both of which occurred in infantile heads. The vast majority of perforations of the nasal septum are due to disease: syphilis, tuberculosis, acute infectious diseases (diphtheria, scarlet fever, typhoid fever). Bahenger' thinks that atrophic or perforating ulcer of the septum is probably the most common type of perforation. It is well known that septal perforation has followed surgical procedures, moreover, that the persistent use of the patient's finger in attempting to remove crusts from the cartilaginous part of the septum has ultimately led to septal perforation. The Lateral Wall of the Nasal Fossa.— The lateral nasal wall is divided into two unequal portions by the limen nasi — a small ventral and caudal ' BallengL-r: Diseases of the Nose, Throat and Ear, Philadelphia, 1914. - Kinney's Treatise of Regional Surgery. 'Loc. cit. LAri:RAL WALL Ol' XASAL I'OSSA 87 portion corresponding to the lateral wall of the nasal vestibule and a larger dorsal portion representing the lateral wall of the nasal fossa ]:)roper. It is the latter, the most complex of the boundaries of the nasal fossa, that concerns us in this connection. The wall is characteristically con- figured by the projecting and operculating major and minor (accessory) nasal conchie or turbinates and b>' the resultant nasal meatuses and secondary furrows. ^Moreover, the ]iaranasal (accessory) sinuses, de\elop- mentally outgrowths of the nasal mucous membrane, b>' their ostia and nasal expansion, xariously mold the lateral wall. Indeed, the ethmoidal cells may so throw the lateral wall into relief at j^laces that the nasal fossa is reduced to a mere potential cleft. The osseous framework' of the lateral wall is formed vnilrally, from abo\-e downward, by the deep surface of the nasal bone and the medial surfaces of the frontal process and body of the maxilla; centrally, from abo\-e downward, by the medial wall of the ethmoidal labyrinth and its conchal apju-ndages, the lacrimal bone, the inferior nasal concha and the medial surface of the body of the maxilla; dorsal! \\ b>- the medial surface of the perpendicular plate of the palate bone and pharyngealward by the medial surface of the medial lamina of the pterygoid process of the sphenoid bone (Fig. 72). The oblong Iab}Tinth or lateral mass of the ethmoidboneissusi)ended from the nasal surface of the lateral jiortion of the horizontally i)laced cribriform plate and, in addition to enclosing numerous irregularly shaped spaces (ccIIuLt ethmoidales), gives rise to scroll-like masses of oxerhanging turbinated bones (conchte ethmoidales). Divergent opinions are held regarding the number of such bones that constitute the typical ethmoidal field in post-fetal life. In a stud}' of 264 lateral nasal Avails, the writer found 160 with three ethmoidal concha-, q8 with two, 4 with four, and 2 with one. From this examination it would appear that three ethmotur- binals f conchie nasales media, superior, et suprema I) should be considered as the t}-pical ethmoidal field rather than two as is usually stated (Fig. 146J. However, it would be better to consider both fields (two and three ethmoidal conchte) as normal anatomic ti-pes since they occur so fre- quently. Departures from these are relatively few and unimjjortant (see embryology. Chapter I). ^Moreover, the independent maxilloturbi- nal, the concha nasalis inferior, projects from the caudal portion of the bony lateral wall and is similarly overhanging in character. The naso- turbinal ('agger nasi) is extremely rudimentary in man and courses parallel to the dorsum of the nose. 1 Osteological details of indi\-idual bones are omitted. 88 THE DEFINITIVE NOSE The se^■eral nasal conchs together with the floor of the nasal fossa form ventrodorsally-directed oblong fosscc — the meatus nasi inferior, media, superior, et suprema I. The conchs are always located cephalic to the corresponding meatuses which with the contained structures they partially operculate. Lateralward from the nasal septum and medial- ward from the projecting and o^'erhanging nasal conchs remains a cleft- shaped space which extends from the nasal floor to the nasal roof— the common Jiasal meatus (meatus nasi communis), into which the nasal meatuses proper open. Dorsahy the nasal meatuses open into the naso- pharyngeal meatus (meatus nasopharyngeus) which in turn communi- cates with the choana (posterior naris) and the nasopharynx. Immediateh' beyond the \-estibule the bony nasal fossa rapidly expands into the nasal atrium (atrium nasi, atrium meatus medii). This expansion is wholly due to a saucer-like depression in the lateral nasal wall in ad\-ance of the entrance into the middle nasal meatus. Ventrally and cephalically the nasal atrium is limited by the agger nasi, a rudi- mentary nasoturbinal which in many mammals, e.g., the sheep, dog, pig, etc., attains a very large size. Ventral to the agger nasi and limited by the ental surface of the dorsum of the nose and extending from the nasal aperture to the roof of the nose is a cleft-like passage — the nasal carina of Meckel (carina nasi IMeckelii), the olfactory sulcus (sulcus olfactorius). Over the entire irregular osseous skeleton of the lateral nasal wall is stretched the nasal mucous membrane; moreover, is continued through the various ostia into the paranasal sinuses and becomes continuous with the mucosa of the nasolacrimal duct. In addition to covering the osseous framework, the mucous membrane bridges over dehiscences in the lateral bony wall of the middle meatus and the median wall of the maxillary sinus (see mucous membrane, page 261, and base or median wall of maxil- lary sinus, page in). The inferior nasal concha (concha nasalis inferior, maxilloturbinal) is an independent, slender, scroll-like lamina of bone developed by ossifi- cation in the infolded caudal border of the lateral plate of the cartilaginous nasal capsule. It articulates by its attached border with the turbinate crest (crista conchalis) of the maxilla, then ascends sharply, forms the lacrimal process (processus lacrimalis) which completes the osseous nasolacrimal canal and articulates with the lacrimal bone. Farther dorsad the attached border is folded caudalward in the maxfllary process (processus maxiflaris) which aids in closing the bony hiatus of the maxillary sinus, and by its convex imbricated border overlaps the margin of the maxillar}- hiatus and articulates with the palate bone dorsallv. A variable LA'n:RAL WALL OK NASAL FOSSA 89 projection (the processus ethmoidalis) extends from the dorsosuj)erior portion of the attached border of the inferior concha to articulate with the uncinate process of the ethmoid across the maxillary hiatus and with the conchal crista (crista conchalis) of the palate bone behind. The thick- ened caudal or free border is laterally curled upon itself and at times con- tains one or more incisurie, gixing rise to bi- or tri-lobed forms of the in- ferior nasal concha. The lateral surface is conca\-e, the medial con\'ex. The longitmlinal ridge on the medial surface may rej)resent (in a rucfi- mentary form) the upper curled plate seen in the gibbon. The elongated dorsal extremit}" of the inferior concha is sharp and pointed, the mucosa giving it a blunt and rounded ai)pearance in the recent and living state. The ^•entral extremit)' is liat, broad and edged and with the overlying mucosa merges gently with the lateral wall. The concha is cox^ered by a thick mucous membrane which contains in its. tela submucosa numerous venous plexuses which assume the character and role of an erectile tissue — phwiis cavcniosi coiicharuiu (Fig. 1S3). The mucosa-covered lamella of bone extends from a held some distance behind the limen nasi to a point from 10 to 12 mm. in advance of the choana, and in its course overhangs the inferior nasal meatus and the contained ostium of the nasolacrimal duct. In the recent state the attached border of the inferior concha is distinctly arched in the ^•entrod()rsal i)lane. The inferior nasal meatus (meatus nasi inferior) is of considerable size, being limited by the arched attached border of the inferior nasal concha cephalically, by the nasal floor caudally, and by the nasal sei)tum and the lateral nasal wall medially and laterally, respectively. It measures from 4.5 to 5.8 cm. in length, beginning \arioush' from 2.5 to 3.7 cm. dorsal to the tip of the nose. As mentioned previoush' in connection with the floor of the nose, the inferior nasal meatus is narrow at its ventral extremity, however rapidly eximnding in width and height and again gradually narrowing as the choanal extremity- is reached. The ostium of the nasolacrimal duct (ostium nasolacrimale) is variously located on the ventral portion of the lateral wall of the inferior nasal meatus. Its position varies from 15 to 20 mm. dorsal to the limen nasi and from 30 to 40 mm. dorsal to the naris (anterior naris). Moreover, its location in the cephalocaudal plane varies likewise. It is frecjuently found in the extreme cephalic portion (apex of dome) of the inferior meatus immediately caudal to the attachment of the inferior nasal concha to the lateral nasal wall. Again, the lacrimal ostium may be 10 mm. caudal to the above point. Between these two extremes ostia are found at various levels. The ostium nasolacrimale is usuall\- a single opening, however. go THE DEFINITIVE NOSE duplication and triplication occur (see embryology, pages 50 and 51, and Fig. 177). The unciualified statement found in many text-books that the ductus nasolacrimalis at the point of communication with the inferior nasal meatus is provided with a mucous-membrane valve (plica lacrimalis or the so-called valve of Hasner) is at variance in very many instances with the real anatomic condition. A study of the ostium nasolacrimal in a large series of cadavers demonstrated to the author that there is no unvarying typical form, rather several normal anatomic types. The ostium may pass through the nasal mucosa obliquely, be slit-like and indefinite, and essen- tially a potential cleft guarded by a mucosal flap. Again the ostium may pass through the nasal mucosa directly and be surrounded by osseous walls, thus causing it to stand permanently open as a wide mouth, immediately caudal to the junction-point of the attached border of the inferior concha and the lateral nasal wall. Ostia in the latter position are never guarded by vah'es or mucosal flaps and are easily located and probed. Another common type of ostium is one in which, extending from the aperture proper, is a fairly deep, gutter-like groove. The latter may become shallower and shallower as the floor of the nose is approached, or become deeper, ultimately ending as a blind pouch. Xipple-like mucosal pro- jections on the lateral wall of the inferior meatus, surmounted bv the ostium nasolacrimale, are likewise encountered. Minor departures from these types are common, but unimportant fsee Fig. 177 for types). The middle nasal concha (concha nasalis media) is relatively large. Hanging \-alve-like o^■er the middle nasal meatus it hides or operculates a number of minor or secondary concha and furrows and a ^-ariable number of anterior ethmoidal ceUs. The skeleton of the middle concha is not an independent osseous element, but an appendage of the lateral ethmoidal mass. Over it is stretched a thick mucous membrane rich in A-enous networks that assume the character of an erectile tissue similar to that of the inferior concha. The heavy mucosa giA'es the middle concha a robust appearance (Fig. 159). The free border of the middle concha in the recent state is from 40 to 50 mm. long. It usually presents a marked genu, giving rise to a short ventral vertical limb and a longer dorsal horizontal limb. Occasionally little, if any, angulation occurs. Not infrequently the middle concha undergoes enlargement at the genu in the formation of a distinct lobule. Moreover, a secondary nodule often develops on the free surface of the lobule. Both the lobule and nodule are better developed relatively in the fetus and newborn than in the adult (see page 25 and Figs. 19 and LATERAL WALL OF NASAL FOSSA 91 30). It seems established that the lobule and secondary nodule of the human ethmoidal conchce (particularly well developed in the middle) are the homologues of the sharp ventral projection of the ethmotur- binals of mammals. Occasionally the lobule of the middle concha assumes large dimensions and mechanicahy obstructs the middle meatus at this point. Indeed, the mass may crowd the nasal septum toward the opposite side. These lobules must not be confused with enlargements due to ethmoidal (conchal) cells (see page 221 and Figs. 159, 160 and 161). The attached border of the middle concha ascends ventrally on the surface of the lateral ethmoidal mass to near the roof of the nasal fossa and from here it curves caudally and dorsalh' to terminate below the junction-point of the ventral and caudal surfaces of the body of the sphe- noid bone at the posterior nasal sulcus. The ascending limb of the attached border in the recent state is inconstant in its extent owing to the variabilit}- in development of the ascending limb of the superior meatus. The lateral surface of the middle concha is not infrequently distinctly concave in frontal section owing to a lateral and cephalic curling of its free border. Indeed, the curling ma}' be so marked that a pseiido para- nasal sinus is formed with a sht-like aperture on the lateral surface of the concha. Such sinus-like inclusions must not be confused with true paranasal sinuses often found in the middle concha (see page 226). The medial surface of the middle concha frecjuently presents second- ary fnrroivs, best marked in the newborn child. Single and deeph" cut furrows partially divide the middle concha into superior and inferior portions, the former often erroneously considered the superior nasal concha (see page 26). Occasionally the superior surface of the middle conchanear the attached border gives rise to a ridge-like elevation (crista suprema, Kilhanj which passiveh' deepens the inferior recess of the superior nasal meatus fsee page 35 and Fig. 34). The middle nasal meatus (meatus nasi medius) is the most im- portant and complex of the nasal meatuses, and is developmentally and topographically divided into ascending and descending rami. The latter is spacious and arched, conforming to the contour of the middle and inferior nasal conchas; the former much less roomy and in a sense a mere extension toward the frontal region of the descending ramus or middle meatus proper. Moreover, the middle meatus is largely overhung, and its contained structures— the minor or accessory nasal concha? and meatuses and portions of the ethmoidal ceUs, together Avith the ostia of 92 THE DEFIXIXni-: NX)SE the latter and those of the frontal and maxillary sinuses — are hidden from \'iew by the valve-like operculating character of the middle nasal concha. Indeed, it is necessary to entirely ablate the middle concha in order to expose the middle nasal meatus for a detailed study (Figs. 153 and 197)- At this juncture it is essential to recall that in the fetus, minor or accessor}' nasal concha; or folds with resulting secondary meatuses or furrows are formed on the lateral wall of both the ascending and descending rami of the middle nasal meatus (see page 27). Some of these persist, others lose their identity as such by merging into one, and some disappear altogether (Figs. 25 and i,_-]). In the descending ramus of the middle meatus are de\'eloped from the early secondary folds and furrows the definitive ethmoidal bulla (bulla ethmoidalis), the uncinate process (pro- cessus uncinatus), the suprabullar furrow, and the ethmoidal infuiidibuhim (infundibulum ethmoidale). Occasionally a furrow — a persistent em- bryonic bullar furrow, is formed on the lateral aspect of the ethmoidal bulla. Aloreover, the accessory furrows contain ostia of paranasal sinuses. In the ascending ramus (the frontal recess) of the post-pubertal nose are found remnants of fetal frontal or accessory conchse and furrows in the form of low ridges separating variously anterior ethmoidal cells and the ostia of such cells. Moreover, the frontal sinus bears a varied relation to these regressed folds and furrows. The lateral wall of the descending ramus of the middle meatus between the caudoventral border of the uncinate process and the inferior concha, between the dorsal extremity of the uncinate process and the perpendicular plate of the palate bone, and between the dorsal extremity of the uncinate process and the ethmoidal bulla mav be termed the un- dejcnded C-shaped region of the lateral nasal wall. Here the mucous membranes of the nasal fossa and the maxillary sinus come into actual contact with each other, there being no intervening osseous skeleton as elsewhere. Moreover, it is in this region that the accessory ostium of the maxillary sinus (ostium maxillare accessorium) is \-arioush' established (see page 130 and Figs. 75 and 145). Very frequently the C-shaped membranous space is broken into two portions b}' the articulation of the caudally directed root of the uncinate process with the ethmoidal process of the inferior nasal concha (Fig. 73). The ethmoidal infundibulum (infundibulum ethmoidale) is the deep crescentic groove or secondary meatus coursing along the lateral wall of the descending ramus of the middle nasal meatus. It is bounded cephal- ically and laterally by the ethmoidal bulla, certain anterior ethmoidal LATERAL W.VLL OF NASAL FOSSA 93 cells and the undefended mucous membrane, and caudally and medially by the uncinate process. At its ventral and cephalic extremity the ethmoidal infundibulum usually ends blindly with or without dilatation by forming an anterior ethmoidal ceh (Figs. 124 and 125). Moreover, it occasionalh- terminates in direct continuity with the nasofrontal duct (infundibulum of frontal sinus) or the frontal sinus when the duct is wanting (Fig. 127). The ethmoidal infundibulum either ends bUndly dorsocaudally (posteriorly) in a pocket, due to a prominent cephal- ically arched lamina of the uncinate process, or it ends by graduall)- becoming shallower and shallower, ultimately losing its identity in the middle nasal meatus — the latter when the upturned lamina of the uncinate process fails to develop sufficiently to form a ledge over which the mucous membrane must course in the formation of a pocket (Figs. 73 and 127). The ethmoidal infundibulum is in communication with the middle nasal meatus b}' wa}- of a cleft-like aperture — the semilunar hiatus (hiatus semilunaris), located between the free border of the uncinate process and the ethmoidal bulla. The semilunar hiatus is from 15 to 20 mm. long and ^•aries considerably in width, owing largely to the vari- abihty in size of the ethmoidal bulla. Indeed, the bulla may be of such size as to come in contact with the free border of the uncinate process, in which case the semilunar hiatus is merely a potential cleft (Fig. 161). The semilunar hiatus extends to the frontal recess and there establishes various relationships with anterior ethmoidal cells and the nasal part of the frontal sinus (see page lOo). The ethmoidal infundibulum is wider near its floor than it is at its semilunar hiatus. ^Moreover, it gradually becomes wider as its dorssl extremity is neared. The depth, e.g., the distance from the free border of the uncinate process to the floor, ^'aries from i to 12 mm., with an ap- proximate average of 5 mm. Xear its dorsal extremity and either in its lateral Avail near the floor or in its floor, the ethmoidal infundibulum con- tains the ostium of the maxillary sinus (ostium maxillare, page 127). At this point the infundibulum is usually at its maximum width. More- over, the ostia of certain anterior ethmoidal cells (infundibular cells) are variously located in the ventral half of the ethmoidal infundibulum (Figs. 159 and 197). The uncinate process (processus uncinatus) is a long, thin accessory concha Avhich projects from the ventral portion of the lateral ethmoidal mass or labyrinth under cover of the lacrimal bone. It courses or curves dorsalward, caudalward, and lateralward under cover of the middle q4 THE DEFINITIVE NOSE nasal concha in the lateral wall of the middle meatus, and in the articu- lated skull lies across the hiatus of the maxillary sinus, forming part of the medial or nasal wall of that cavity. The uncinate process at its dorsal and free extremity usually terminates by forming two roots : One, fairly constant, is made up of one or more irregular, caudally-directed projections for articulation with the ethmoidal process of the inferior nasal concha; the other, less constant, curves cephalically behind the dorsal extremit}' of the ethmoidal infundibulum and when prominent causes the latter in the recent state to terminate in a deep pocket just dorsal to the ostium of the maxillary sinus. This pocket is significant since it is so located that it will direct anv fluid coming to the dorsal extremity of the infundibulum ethmoidale through the ostium maxillare into the sinus maxillaris. The uncinate process with its covering of thin mucous membrane forms the caudomedial boundary of the ethmoidal infundibulum and by its free edge the caudal boundary of the semilunar hiatus. It varies in breadth in the recent state from i to 12 mm., thereby affecting the depth and the eiflciency as a carrier of fluid from the frontal region of the ethmoidal infundibulum (Figs. 127 and 197). The ethmoidal bulla (bulla ethmoidale) is a bleb-like protuberance of bone, extremely variable in size and shape, projecting from the medial surface of the lateral mass of the ethmoid under cover of the middle nasal concha (Fig. 157). It is excavated by a variable number of ethmoidal cells to which it owes its prominence. The bulla is bounded caudally and dorsallv by the semilunar hiatus and the ethmoidal infundibulum and cephalically is limited by the suprabullar furrow into which open most of the cells that honeycomb its mass. Occasionally grooving the medial surface of the bulla is a persistent fetal bullar furrow, which at times contains the ostium of an ethmoidal cell (bullar cell). Rarely in the adult a faint infrabullar furroAv (a fetal condition) partially separates the eth- moidal bulla from an infundibular fold (page 31). The furrow may con- tain the ostium of a small ethmoidal cell. The usual condition, however, is a fusion of the superior and inferior fetal bullar folds in the formation of the adult ethmoidal bulla and for the infundibular fold to lose its iden- tity by obliteration of the infrabullar furrow (see embryology, page 30). As stated elsewhere, the ethmoidal bulla varies considerably in size, at times feebly developed, again assuming relatively large proportions (Fig. 124). The size of the bulla greatly influences the width of the semilunar hiatus. The bulla when large may come into actual contact with the free margin of the uncinate process. Indeed, it may impinge upon the confines of the uncinate process and crowd it away (Fig. 161). When LATKRAL W ALL OF XASAL FOSSA 95 the bulla is feebly developed the semilunar hiatus is of considerable width and the drainage of the ethmoidal infundibulum enhanced thereby (Fig. 125). The suprabullar furrow or recess is a variable, secondary channel grooving the lateral wall of the middle nasal meatus superior to the eth- moidal bulla, e.g., between the latter and the attached border of the middle nasal concha. Notwithstanding that it varies in its form, all specimens give some evidence of it. It may course ventrally and cephalically almost to the cribriform plate of the ethmoid. In the majority of cases it is limited, however, ventrally by fusion between the ethmoidal bulla and the attached border of the middle concha. Similar fusion mav limit it dorsally. Xot infrecjuently multiple points of fusion break the suprabullar recess into several compartments, each receiving the ostium of an eth- moidal cell located in the bulla or elsewhere (Figs. 40 and 197). Again, the whole recess may deepen and sink into the body of the ethmoidal bulla, thus forming a large single buUar cell, Avhich causes the ethmoidal bulla to be large and to encroach upon neighboring structures. Ethmoidal cells constantly develop from the suprabullar recess and in the adult such cells are, of course, in communication with it. Rarely the frontal sinus seems to have its genesis from this recess. The frontal recess (ascending ramus of the middle nasal meatus) is a direct extension developmentally of the middle meatus proper and is intimatelv related to the genetic and adult anatomy of the frontal sinus and certain of the anterior ethmoidal cells. Its detailed adult anatomy is discussed under the nasofrontal connections (page i6oj and the ethmoidal cells (page 205). The superior nasal concha (concha nasalis superior) is a short thin lamina of bone which ])rojects from the lateral ethmoid mass and over- hangs the superior nasal meatus and the structures contained therein. However, it is much less operculating in character than the middle nasal concha (Figs. 129 and 146). The superior concha of the adult is usually represented b}- a horizontal or descending ramus only. Occasionally, however, a vertical or ascending ramus is differentiated as well. The osseous lamella is covered by a thin mucous membrane directly continued from the general nasal lining. The mucosa is thinner and much less erectile in character than that of the middle and inferior concha-. In the series of 264 lateral nasal walls examined, the superior nasal concha was absent twice. The superior nasal meatus (meatus nasi medius) is a channel-like depression on the medial surface of the lateral ethmoidal mass immedi- 96 THE DEFINITIVE NOSE ately caudal to the attached border of the superior nasal concha and is often referred to as the ethmoidal fissure (Figs. 146 and 195). It is, as a rule, not angulated into ascending and descending limbs as is the middle meatus, but forms a fairly straight channel directed caudalward and dor- salward. Moreover, it is approximately half the length of the middle meatus and overhung to a less degree. Occasionally the superior meatus has a prominent ascending limb grooving the lateral ethmoidal mass almost to the cribriform plate (Fig. 29). Not infrequently an accessory concha molds the lateral wall of the superior nasal meatus and divides the latter into superior and inferior recesses. The inferior recess is usually the better developed and often "erodes" into the superior surface of the attached border of the concha media in the formation of a sinus-like depression which lends prominence to the crista suprema of the middle concha. A thin mucous membrane lines the superior meatus and extends into the posterior ethmoidal cells which communicate with the ventral extremity of the superior meatus and with its superior and inferior recesses. The first supreme nasal concha (concha nasalis suprema I) persists in the adult in approximately 60 per cent, of individuals. It is a very short, thin lamina projecting from the dorsolateral portion of the lateral ethmoidal mass, slightly overhanging the corresponding nasal meatus. A very thin mucosa covers it. The first supreme nasal meatus (meatus nasi supremus I) is a shallow, short furrow located on the dorsolateral aspect of the medial surface of the lateral ethmoidal mass immediately caudal to its corresponding concha. As the latter, the meatus is present in about 60 per cent, of individuals, and in approximately 75 per cent, of them a posterior eth- moidal cell communicates with it, indicating a genesis of an ethmoidal cell from it in the fetus (see page 23). A thin mucous membrane lines the meatus and the related ethmoidal cell (Figs. 26 and 127). The sphenoethmoidal recess (recessus sphenoethmoidalis) is a re- stricted portion of the nasal fossa located cephalic and dorsal to the high- est or most cephalic ethmoidal concha that may be present in the particular case (in approximately 40 per cent, of cases the concha superior is the caudal boundary and in 60 per cent., the concha suprema I). The recess is bounded above (cephalically) by the cribriform plate of the ethmoid bone and dorsally by the ventral surface of the body of the sphenoid bone. The recess is lined by a very thin mucous membrane and contains the ostium of communication of the sphenoidal sinus (ostium sphenoidale) on its dorsal wall. The sphenoethmoidal recess must not be confused LATER.VL \\'ALL OF NAS.U. FOSSA 97 With the superior and the supreme nasal meatuses. Nasal meatuses are alwa}'S located caudal (inferior) to the corresponding nasal concha;. The second and third supreme nasal conchae (concha; nasalessupre- ma? II et III) and the related meatuses (meatus nasi supremus IT et III) are rareh- present in the adult human bod>-. Notwithstanding that these structures are at times well differentiated in the fetus (especially the concha suprema II) the>- usually undergo regression in late fetal and early infantile life and are seldom seen after the second year (Figs. 26 and 2'ond the nasal \'estibule. The expansion is primarily due to a variable saucer-like de])ression or lateral arching in the lateral nasal wall in ad\-ance of the entrance to the middle nasal meatus. Coursing obliquely caudalward and \-entralward the agger nasi delimits the nasal atrium from the deep surface of the dorsum of the nose. In a sense the atrium is the related meatus of the agger nasi (nasoturbinal) and is much more prominent in those forms with a well-de\-eloped naso- turbinal. In man it frecjuently encroaches upon the lumen of the maxil- lary sinus by causing the nasal or medial wall of the sinus to be convex (Fig. 146;. The olfactory sulcus (sulcus olfactorius, carina nasi) is a channel- like space lying ventral to the agger nasi and limited by the rounded or arched confluence of the medial and lateral nasal walls. It extends from the vestibulum nasi along the ental surface of the dorsum of the nose to the pars olfactoria of the nasal fossa. At the roof of the nose it becomes confluent with the space immediately caudal to the cribriform ])late which 7 98 THE DEFINITIVE NOSE in turn becomes the recessus sphenoethmoidalis farther dorsally. The latter contains the ostium sphenoidale on its dorsal wall. It is obvious, therefore, that by following the several segments of this continuous chan- nel along the dorsum and roof of the nose the ostium of the sphenoidal sinus may be located. Moreover, it is believed that odoriferous gaseous substances readily reach the olfactory mucosa through the olfactory sulcus (Fig. 146). Ill-THE MAXILLARY SINUS CHAPTER III THH MAXILLARY SINUS The Fetal Stage The maxillary sinus (sinus maxillaris, antrum of Highmore), primi- tively a pouching or evagination of the mucous membrane of the floor or lateral wall of the ethmoidal infundibulum (infundibulum ethmoidale), is evident about the se\-entieth day of fetal life. It is diflicult of appre- ciation in its initial state from an examination of serial sections onh', but is well demonstrated by reconstructing at a considerable magnitication the ethmoidal infundibulum. The rudiment or anlage of the sinus is usuallv represented by a single pouch; however, two ])ouches growing side bv side from the ethmoidal infundibulum ha\'e been obser\-ed by the writer. Again, the pouch may be relatively large at the outset, making it difficult to deter- mine where the ethmoidal infundibulum ends and where the initial rudi- ment or maxillary sinus begins. In such cases the ethmoidal infundibulum is in a sense a part of the maxillary sinus. One should, however, consider the maxillary sinus as de\-eloping from the pre-existing furrow (infundi- bulum ethmoidalej and not consider the latter a part of the sinus. How- ever, as stated before, it is difficult at times to draw this distinction, es- pecially so when the primiti\-e maxillary sinus is extensive and occupies the greater portion of the infundibulum ethmoidale in its early pouching (Figs. 76-77). The duplication and extensive pouching of the primiti\e maxillary sinus, occasionally encountered, is in accord with adult conditions. The adult ostium maxillare varies from a small round or oval aperture to a long slit-like cleft, and is either single or dui)licate. The initial doubling of the maxillary sinus doubtless explains some of the duplications of the adult ostium maxillare. It is not unreasonable to beheve that in some instances fusion of the double maxillary pouch takes place distally, leaving the points of initial outgrowth as the duplicate ostium. Further- more, the doubling of the primitive maxiUary-sinus pouch may explain some of the rare double adult maxillary sinuses, each with an independent ostium in communication with the ethmoidal infundibulum, i.e., each evaginating sac developing independent of its mate. 102 THE jr.VXILLARY SIXUS Instances in which one of two unilateral maxillary sinuses communi- cated with the superior nasal meatus have been recorded by Zuckerkandl and others. The writer recenth' made a number of similar observations (Figs. 73 and loi). There is no doubt whatever that the additional maxillary sinus in these cases is truly an ethmoid cell which developed be}-ond the confines of the ethmoid field into the maxilla. Genetically, such a sinus is ethmoid; topographically, maxillary. Indeed, the maxilla Fig, 76. Fig. 77. Figs. 76 and 77. — Drawings of reconstructions of portions of the right nasal fossa including the meatus nasi, infundibulum ethmoidale, hiatus semilunaris and sinus maxillaris. The figure to the reader's left is from a human embryo aged 105 days and that to the right from a human embryo aged 120 days. It must be understood that both models represent cavity and are, therefore, negatives. Particularly note the maxillary sinus at these ages, and the unlike size and shape of the ostium maxil- lare in the two specimens. X 12. Mns = meatus nasi superior; Hs = hiatus semilunaris; Mnm = meatus nasi medius; le = in- fundibuluiTi ethmoidale; Om = ostium maxillare; Sm = sinus maxillaris; Myii = meatvts nasi in- ferior. regularly aids in completing the osseous boundaries of certain ethmoid cells. Brlihl's case in which an additional maxillary sinus, that is, a sinus present in duplicate, communicated with the inferior nasal meatus is difficult of genetic interpretation, since ordinarily no paranasal sinus FK'I'AL SlWCl-; 103 communicates with tliis meatus and none de\-elops from it. In all prob- ability the ostium of communication in Briihl's case was secondary and doubtless formed in a manner similar to the \'er>' common ostium maxillare accessorium found in the middle nasal meatus in connection with the usual single maxillary sinus (Fig. loS). The frequent great dimensions of the adult ostium maxillare may be due to a merging of two or more primiti\-e maxillar>- pouches, or the ])rimi- tive pouching ma>- ha\-e Ijcen single, but \-ery e.xtensve, occupying a goodly portion of the floor of the ethmoidal infundibulum. Fic. 78. Fi< Fig. Fig. si. Figs. 7S-81. — The linin;.^ mucous membranes ijf ma.xillary sinuses remia-ed from formalized cada\'ers. The illusf raf ions represent tile exact shajies of tlie maxillar\" sinus as fi nmd in these bodies. X4- (After J. P. S.) Fig. 78, from a fetus aged 4 months; Fig. 79. from a fetus at term; Fig. 80. from ,'i child aged 18 to 20 months; Fig. 81. from a child aged 20 to 2;} months. The early maxillar}' sinus is for a time a slit-like caxity in the mem- branous lateral wall of the nose. It extends interiorly into the recess formed by the union of the lateral cartilaginous plate with that of the inferior nasal concha. By resorption of the cartilaginous nasal capsule intervening between the maxilla and the developing maxillary-sinus sac the latter ultimately comes into actual and direct relationshi]) with the maxilla. By the simultaneous processes of resorption of surrounding bone and the growth of the maxillary pouch, the primitive cavity gains more and more capacity and sinks into the body of the maxilla. It has 104 THE MAXILLARY SINUS its greatest measure in the ventrodorsal direction, while mediolaterally the cavity occupies comparatively little space. In embryos aged from loo to 105 days the ventrodorsal measurement is about 2 mm. In a 120- day embryo the distance is about 2.5 mm. In a 100-day embryo the most ventral spur of the sinus is about 6.5 mm., and the most dorsal spur 8.5 mm. from the tip of the nose (Figs. 78, 79, 80 and 81). It will be remembered in the embryo the processus alveolaris of the maxilla is in proximity to the orbit, and when one recalls the fact that the unerupted teeth are contained in this situation, it at once becomes evident that the maxillary sinus must be correspondingly small at this time. Because of these facts the sinus of a 7-month fetus measures only 5 mm. in the ^'entrodorsal plane and in a fetus at term approximateh' 7 mm. During the latter months of intrauterine life the sinus gains in the medio- lateral plane and at term measures from 3 to 4 mm. The extension of the maxillary sinus into the body of the maxilla takes place para passu with the growth of the face (Fig. 84). The appended table. A, gives the approximate size of the maxillary sinus at various stages of fetal life: T.^LE A . Ventrodorsal "^'=''' , (length) 100 days 2.0 mm. 120 days 2.5 nim. 210 days 5.0 mm. Term fetus 7.0 to 8.0 mm. Mediolateral (width) Potential Potential 2.0 mm. 3.0 to 4.0 mm. Cephalocaudal (height) 0.5 mm. 0.8 mm. 4.0 mm. 4.0 to 6.0 mm. The Childhood Stage ^ The size and shape of the maxillary sinus at birth varies considerably as is evidenced by a study of a large number of still-born babies; indeed, the variation continues into adult life. However, one must not be misled by an apparent variance in size, due to sectioning the sinus in unlike planes — horizontal, coronal and sagittal. Writers often give measure- ments without stating the plane and this obviously leads to error and an apparent rather than a real discrepancy in results. The \-entrodorsal (length) measurement is always the greatest and up to the end of the third year the cephalocaudal (height) measurement of the sinus is intermediate between the ventrodorsal and mediolateral ' The term ''childhood" is sometimes restricted to the time between infancy and vouth; however, here the term is meant to apply to the period from birth to puberty. CHILDHOOD STAGl", lOS (width). Howex-er, during the sixth year the mediolateral measurement gams, but seldom exceeds the cephalocaudal measurement. The cavity IS ne^'er spherical as is often stated. For some time the maxillary sinus Fig. S.'.— Photograph ot a senn-lrontal section of a chtlchs face aged from i6 to iS months. Particuharh- note the infraorbital canal and nerve and the maxillary sinus. x O.S Xinforb = Nervus infraorbitalis; Smax = Sinus maxillaris. is not sufficiently developed in width to reach beneath the orbit. By the end of the first year it has grown sufficiently in this plane to extend beneath the orbit, but not beyond the position of the infraorbital canal. ./^,- Proc. UT^ciTi , - BvJ.lar cells fee. eth.) - I?/fi/^//l. etk Ost.7f/Mjri.Ua7r: ' "" ■ - r ffwif''<'orlltal7s $ Fir.. 83. — A frijntal section through the nasal fossjt- ami the jiaranasal sinuses at the le\-cl of the ostium of the maxillar\' sinus in a child aged ajiproximatcly seven years. X i. and at the twentieth month it has elongated in the ventrodorsal plane to 20 mm., and has, as a rule, extended above the rudimentary first per- manent molar tooth. During the third and fourth years the maxillary loO THK MAXILLARY SINUS sinus makes a conspicuous growth in the mediolateral plane (width). B}' the se\-enth year the sinus measures on the average 27 mm. in the ventrodorsal plane, 17 mm. in the superoinferior plane, and 18 mm. in the mediolateral plane (Fig. 83). It is generally stated that the deciduous teeth hold the maxillary sinus in check, and that the cavit}' rapidly assumes larger dimensions as Fig. 84. — Skulls indicating the increase of distance between the infraorbital foramen and the mid- point of the upper jaw from birth to adult age. the first dentition progresses. The author finds, however, that the growth of the sinus is rather uniform and that the first dentition has little to do with an}- rapid increase in the size of the cavity. The age of the child, dentition, and the size of the maxillary sinus progress para passu. It is, however, obvious that until the teeth erupt and the alveolar process de\-elops there can be little room for the maxillary sinus (Fig. 84). CHILDHOOD STACK 107 It is well to remember that in the infant the inferior nasal meatus does not come into the same intimate relationship with the maxillary sinus as in the periods following the eighth to the twelfth years. The relations with the middle nasal meatus are much more intimate and should be borne in n-iind when the maxillar}' sinus is to be explored endonasalh' in the A'oung child. ]\Ioreo\-er, the inferior nasal meatus is exceedingly narrow at this time due to the relatively large inferior nasal concha and the heav>- mucosa (see page 20). Seemingly, the middle nasal meatus and the general nasal ca\'ity alone serve as resi)iratory passages at this time. By the eleventh or twelfth year the inferior meatus is enlarged and the maxillary sinus has grown suflicienth' toward the ah'colar process to be accessible for puncture in the usual adult site, e.g., in the inferior nasal meatus. However, the writer has obser\-ed maxillary sinuses in intimate relationship with the inferior nasal meatus at term (Fig. 156). The operator needs to be cautious in endonasal procedures on the maxillar}- sinus of the infant from the inferior meatus. The instrument is readih" jnished through the soft structures of the cheek and the sinus caA'ity missed entirely, or both the medial and lateral walls may be pene- trated. Again, it would seem Avise to use the middle nasal meatus until after the eruption of most of the permanent teeth. The operator must always remember that the rudiments of both the deciduous and i)ermanent teeth are present in the maxilla at the time of birth, there undergoing further development up to the time of dentition. Injur}' to a "tooth germ" would lead either to death of the part or to the eruj^tion of a de- formed tooth ultimately. Surgically, in both the endonasal and the canine fossa approaches of the maxillary sinus in the }'oung child, the narrow mediolateral (transverse) diameter of the maxillar}- sinus must not be forgotten. The appended table, B,' gi\-es the size of the maxillary sinus in a series of specimens from birth to 15 years of age. Owing to the scarcity of material at the childhood period some observations are limited to few specimens. After the fifteenth year the sinus in a sense passes into the adult stage. It will be noted that after this period the sinus enlarges principally in its vertical diameter (superoinferior) and in its diagonals. The ventrodorsal and mediolateral measurements are nearly the adult average : 1 See also Warren B. Davis, Nasal Accessory Sinuses, Philadelphia, 1914, for \-aluable and in- structive tables of measurements of (he j)aranasal sinuses of Ihe c]iil- of the nasal fossa. While the age of the child is a ADULT STACK IC9 ^ -aluable guide (see table B, ])age io8), the skiagram after all must gi\'e the surgeon the definite and precise information concerning the pneumati- zation of the alveolar process in the case before him. In the interi)retation of skiagrams one must recall that in ventrodorsal pictures of the maxillary sinus the second and third (sometimes the first also) molar teeth throw a heavy shadow ujion the tloor of the sinus, which is confusing. Haike has shown that the recessus ah-eolaris, c.t;., the degree of pneumatization of the alveolar process, is best demonstrated in the child by taking a profile view of the face. The profile skiagrams show this recess in children as early as the sixth and se\-enth )-ear, especially so at the \-entral ])art of the floor of the maxillary sinus. It is well to remember, however, that the alveolar process of the maxilla is not fully pneumatized by the alveolar recess of the maxillary sinus until the time when the permanent teeth have erupted. TiiE Adult St.\(;e General Considerations. — The adult maxi]lar\- sinus was known to Galenus (i30--2ori, but Dr. Xathaniel Highmore was the first to gi\'e an}' detailed description of it. In his work (1G5U), " Corporis Iliiimiiii Dis- qiiisitio Andto»iica," he describes the ca\'it}- in the maxilla, to which his attention was drawn b}" a lad_\' patient, in whom an abscess of this ca^•ity, since freciuently referred to as the antrum oi Highmore, was drained by the extraction of the left canine tooth. The sinus described b}' Highmore must have been exce])tionall}- large since the canine tooth does not as a rule come into relationship with the sinus. S<:)me writers e\-en tnda}' reter to the canine tooth as the ])roper drainage site in sinus treatment when the endonasal approach is not utilized. The belief that the canine tooth socket commonly bears an inlimalr relationshij) to the floor of tlie maxil- larv sinus is archaic and must be abandoned. The adult maxillary sinus, located in the body of the maxilla, is the largest of the paranasal sinuses, sa\-e in exceptional cases when it is com- paratively small and exceeded in size by the frontal and sphenoidal sinuses. It hes lateral to the cavum nasi and resembles in shape a three-sided pyramid. It follows in the main the sha])e of the body of the maxilla; and may be described as ha\-ing a roof, a floor, and three walls. The walls of the sinus var}- in thickness, usuall\- from 5 to 8 mm., but may be reduced to a papery delicac}-. The writer has, indeed, observed dehis- cences in the facial or \-entral osseous wall of the sinus. The median wall or base is directed toward the ca\um nasi and the apex extends into the median root of the processus zA'gomaticus of the maxilla, or beyond it into the maxillary border of the zygomatic bone. I 10 THI-: ilAXlLLAR^' SINUS The ventral wall of the cavit}' corresponds to the anterior or facial surface of the maxilla, looking ventrolaterally. Part of this wall is at times greatly approximated to the dorsal wall and base of the sinus due to a very prominent canine fossa (fossa canina). Occasionally the whole ventral wall bulges markedly into the cavit\' of the maxillary sinus. 5/7? «,5 froni/ilis dextsr Sinus FroniaJis sim'ster JfecessitSpcUatiJzus sitzus rnjxpc ' Jfeccssus aj.veolurls S!'??:us maj._ Reccssu^ paZtdinua sirais 77zax. Fig. 85. — Photograph of a skuh ^^-ith the frontal and maxinar\- sinuses exposed for study. Par- ticularh" note the as\"mmetry of the frontal sinuses and the buUa-like appearance of the left frontal sinus (see text, page 152). Xote also the extreme development of the palatine recess of the maxillary sinus. On both sides the maxillary sinus extends luarkedly into the palatine process of the maxilla, thereby gaining a conspicuous relationship to the floor of the nasal fossa. The dorsal ivall of the sinus corresponds to the infratemporal surface of the maxilla. It is a thin plate of bone, also forming the ventral bound- ary of the infratemporal and pterygopalatine fossa?. The dorsal is usually ADULT STACK III the thickest of the sinus walls. It is, ho\ve\-er, occasionaHy extremely thin (the processus al\-eolaris being recognized as the floor of the cavity and not as a walD. The median icall or base is directed toward the ca\'um nasi. It normally juesents a \-ery irregular orifice {liialiis maxilUiris) in the dis- articulated bone. In the articulated skull the hiatus is ])arth' filled in by the pars perpendicularis of the palate bone, the processus uncinatus of the ethmoid bone, the processus maxillaris of the inferior nasal concha and a portion oi the lacrimal bone. In the recent and li^'ing state the nasal mucous membrane bridges o^•er the dehiscences or defects in the osseous median Avail, covers the bones and is continued into the maxillary sinus in the formation of a rounded opening (the osliitm maxillaye). The latter may be duplicated, but such duplication must not be confused with the ostium ))iaxillayc acccssoyiii)}!, which is a direct passageway between the sinus and the nasal fossa. The ostium maxillare (or ostia maxillaria) establishes communication between the sinus and the infundibulum eth- moidale. The medial wall immediately inferior to the attachment of the inferior nasal concha is thin and easily punctured. This wall also forms the lateral boundar>- of the nasal fossa which often encrixiches upon and reduces the size of the cavity of the maxillar)' sinus. The nasal fossa is, of course, correspondingly increased in size (Fig. 85). The roof of the maxillary sinus is a very thin plate of bone, at times of a paperv delicacv, forming the floor of the orbit and the orbital surface of the maxilla. Xot infreciuenth' it is modeled by a ridge thrown into relief by the infraorbital canal. In some instances, the ridge is replaced by a groove which is co\'ered over by the mucous membrane of the maxillary sinus. At times the roof of the sinus is partially divided into two plates, separated by ethmoidal air cells (Fig. 102). ()ccasionall\- the i)alate bone aids in forming the roof of the maxillary sinus. The floor of the maxihary sinus is formed b>' the processus alveolaris of the maxilla. It is by far the thickest of the osseous boundaries of the cavitA-— the thickness of the floor depending ui)on the degree of pneumati- zation of the process. In cases where the pneumatizing process has been carried far, the floor of the sinus bears an important relation to some of the teeth and their sockets. The floor may be thrown into irregular eleva- tions bA- the fangs of the teeth, depending upon the thickness of the layer of spongy bone. The latter varies in thickness in different skulls. More- over, there is considerable asymmetry on the two sides of the same skull. The Relation of the Sinus Floor to the Nasal Floor. Idie relation of the floor of the maxillary sinus to the floor of the nasal fossa depends 112 THE ^[AXILLARY SINUS largeh' upon the degree of hollowing out of the processus alveolaris of the maxilla. The degree of arching of the hard palate, thereby affecting the floor of the nose, also has some bearing on this relation. When the layer of spongy bone is thin, 'e.g., the processus alveolaris markedly pneumatized b}' the maxillary sinus, the floor of the nasal fossa is caudal to the floor of the sinus. On the other hand, when the processus alveolaris is relatively thick the floor of the nasal fossa is caudal to that of the sinus. Occasion- ally both floors are in the same plane. When the A'entral (facial) surface of the maxilla and the lateral wall of the nasal fossa are simultaneousl}' bulging toward the maxillary sinus and at the expense of its lumen, the floor of the nasal fossa is, as a rule, caudal to the floor of the sinus. Not- withstanding these departures, the majorit}' of maxillar}'' sinuses have their floors at \-arying distances caudal (below) the level of the floor of the nasal fossa. In an examination of 120 adult specimens 78 were found in which the sinus floor was the more dependent, 24 in which the fossa floor was the more dependent, and 18 in which the sinus and fossa floors were in the same plane. The difference in levels of the floors of the maxillary sinus and the nasal fossa varies from h to 10 mm. C. Reschreiter^ claims that it is a male characteristic to find the sinus floor at a level caudal to that of the nasal fossa. The writer's obser^-ations do not confirm this. In an examination of 30 specimens taken from female cadavers, 20 showed the sinus fioor to be the more caudal, 6 the nose floor, and in 4 instances the floors to be on the same lc\-el. ^Moreover, the dift'erences in level between the two floors varied in accord with that given above for the male. Relations of the Maxillary Sinus to the Teeth. — Since the maxillarv sinus \'aries greatly in size in dift'erent skulls and on the two sides of the same skull, it is obvious that the relations of the teeth to the sinus cannot be constant. As stated before, the layer of spongy bone between the roots of the teeth and the floor of the maxillary sinus varies in thickness in different skulls and the asj'mmetry on the two sides of the same skull is at times marked. When the la}'er of spongy bone is relatively thin the projecting tooth fangs form elevations, of a greater or less degree, on the floor of the sinus. These elevations at times aid in recess formation (Figs. 86 and 87). Direct communication between the fangs of the teeth and the mucous membrane of the sinus, due to extreme hollowing out of the processus alveolaris of the maxilla, occurs most frequently in the aged; howe^•er, it does occur in the young adult. That very intimate relations frequently exist between the teeth and the maxiUary sinus is a fact that one ' Zuc Morphologic des Sinus :\Iaxillaris, Stuttgart, 1878. -MAXILLARY SLXUS-TELTJI KKLATIOXS Fig. So. — A dissection showing the relations of the permanent teeth to the sinus maxillaris. (Com- pare with I'ig. 87.) S. TnaxLllai-is ^'"^Cr.. <^r(^s Dens caj^Inibs Fig. 87. — A dissection showing the relations of the permanent teeth to the sinus maxillaris. Note that the first molar and the two premolars are not in intimate relationship to the floor of the maxillary sinus. Note the deep canine fossa and the emergence of a perforator pushed from the inferior meatus, escaping the maxillary' sinus altogether (see page 114). 114 THI' MAXILLARY SINUS should be cognizant of. However, the writer beheves that these intimate relations have been exaggerated b}' some authors. Some clinicians hold to the beUef that more cases of dental trouble are due to maxillary sinus disease than the reverse. The number of teeth that bear a direct relation to the sinus is neces- sarily inconstant. In exceptional cases when the cavity of the maxillary sinus is very large— especially in the line of the ventrosuperior diagonal- all of the teeth of the fnic maxilla may be in relation to the floor of the sinus. It is, however, only an occasional occurrence to have the canine tooth in direct relation to the sinus. In a certain number of cases the first premolar tooth bears a direct relation to the cavity and in a slightly Fig. 88. Fig. S8A. Pig. 88. — Prom an old person. Note the atrophy of the alveolar process and the projection of the remaining tooth into the lumen of the ma.xillary sinus. Fig. 88.4. — Prom a young adult. Note that despite a thick alveolar process the roots of the molar teeth project into the maxillary sinus. larger percentage the second premolar bears a similar relationship. The three most constant teeth, however, in intimate and vital relationship with the floor of the maxillary sinus are the molars, and when the sinus is small the first molar must be omitted in this relationship. It is a fair]}' safe rule to follow when the canine fossa (fossa canina) and the lateral nasal wall are simultaneously approximated at the expense of the lumen of the maxillary sinus, that the canine and premolar teeth do not bear a direct relation to the maxillary sinus. In such cases a per- forator pushed through a premolar-tooth socket might readily enter the lateral nasal wall — even pass through it, passing entirely free of the sinus cavity. Again, if the perforator were pushed through the lateral nasal wall, caudal to the inferior nasal concha, the instrument could readily be MAXILLARY SIXUS TI'.L TH RKLATIOXS "5 Os tiu m It a so I at rh nil Je Meatus /laai int'enor Dens moha-is TH Ostium ruaiillurre bijin& muKillar/s Duis uwIa/y'sHI Fig. 89. — A dissection looking into the roof rif the inferior nasal meatus and into the rr.of of the maxillary- sinus. The ostia of the nasolacrimal ditcts anil of the maxillar>' .sinuses are, therefore, displayed. Particularly note the impacted third molar Iccth aliout to erupt into the maxillary sinuses. J] ^ Dens Tiiolaris JIL--^. (dens serotinus wisdom, tooth) Fig. 90.— An arlult maxilla with an impacted r,r unerupte.l third molar tooth expose.l by the re- moval of a superficial shell of bone. The inset {uflcr Kfllli) .shows "the manner in which the development of the maxillary antrum affects the .size of the palate and position of the molar teeth." .,, . , I = posterior border of maxilla at birth; 2 = maxillary sinus at birth; .? = maxillary sinus of adult; 4 = posterior border of maxilla of adult; 5 = ostium maxillarc; = deciduous teeth at birth. ii6 THE :\1AXILLARY SIXUS pushed through the soft structures of the cheek, unless the point were directed well superodorsally (Fig. 87). In the years of adolescence, as shown by the studies of Keith, Schaeffer and others, the maxillary sinus continues its pneumatizing process until it extends into the A-arious processes of the maxilla. Moreover, as the sinus expands dorsalward the dorsal border of the maxilla which con- tains the rudiments of the permanent molar teeth, undergoes rotation caudalward, so what was located on the dorsal border ultimately comes Fig. 94. \ ' ' • Fig. 95. Fig. 96. Figs. 91-96. — Photographs of dissections sho"\ving the relations of the teeth to the developing maxillary sinus. In each case the sinus is indicated by a dotted line. Fig. 91, front a term child; Fig. 92, from a child aged 18 months; Fig. 93, from a child aged 3 years; Fig. 94. from a child aged 7 years; Fig. 95, from a child aged 9 years; Fig. 96, from a young adult, with all permanent teeth, save the third molar, erupted. to occupy a position on the alveolar border of the maxilla. If for some reason or other growth and rotation are arrested, the third molar tooth is left on the dorsal border of the maxilla where it may become impacted and call for surgical attention (Figs. 89 and 90). Ridges, Crescentic Projections and Septa on the Walls of the Max- illary Sinus. — It is very important to note how frequently the walls of the SEPTA ANT) RECKSSES 117 sinus are found uneven. These irregularities may consist of mere ridges or of different sized crescentic projections. The crescentic projections liave been reported occasional!}' replaced b}' septa which completely divide the sinus into two ca\-ities, each haxing its independent opening into the nasal fossa, but not communicating with each other. The smaller ridges are of little consequence and may be omitted from further consideration. The Sept — OOX^>^ Fig. 100. Fig. gg. Figs. 97-ioo.-Drawings of specimens showing incomplete septa with resuhant recesses on the walls of the ma.xillary sinus. Om = ostium maxiUarc; Oma = ostium maxillare accessorium; S,-pi = septum. larger ridges and crescentic projections, on the other hand, tend to form pockets and recesses of var}-ing depth within the ca^•ity. The septa, when they exist, are placed either cephalocaudally or ventrodorsally, thus forming either ventral and dorsal, or caudal and cephalic compart- ments, respectively. In an examination of 1 20 adult maxillary sinuses by the author, 58 were found in which the walls showed minor ridges and large crescentic projec- Il8 ■ THF. MAXILLARY SINUS tions; the remaining 62 presented walls with regular and even mucoperi- osteal surfaces. It must be borne in mind that in the 58 positive sinuses quite a number showed mere ridges and can be omitted from further study. The remaining number of the positi\-e group fall, however, into a very important class of specimens. That these crescentic projections offer almost insuperable obstruction at times in attempting to drain the maxil- lary sinus through an opening in the processus ah'eolaris or in the meatus nasi inferior, is an anatomic fact of which the operator must be cognizant in emp}-emas that do not yield readily to treatment. This was repeatedly demonstrated in this study by first filling the sinus with a licjuid, then making an opening at some point on the processus alveolaris and draining what would come away. If some of the fluid was retained, allowing for adherence to the mucous membrane, the facial or anterior surface of the maxilla was remo\-ed to find where the remaining fluid was lodged. As a rule, the portion of fluid Avas retained by a recess or recesses on one or more of the sinus walls. At other times a second and e\'en a third opening was made, either through the alveolar border, or through the meatus nasi inferior, before the remaining fluid would come away. If after re- peated attempts the fluid could not be located, the ventral wall of the cavity Avas removed to ascertain the reason for its retention and the fact was thus disclosed that repeated punctures, in some cases, would not reach all of the recesses. Just what these recesses mean in all cases is difficult to say. Some of them are, of course, formed by elevations caused by tooth fangs, but these as a rule are of minor importance and only occasionally form deep recesses. Others are formed by projections of mucous membrane, which may or may not be caused by crescentic bone projections. Where excep- tionally large septa exist the maxillary sinus probably developed from two primary pouches, the inter\-ening wall disappearing in part lea\'ing the larger crescentic projections in the adult sinus. A double pouching of the primitiA-e maxillary sinus was mentioned in a previous paragraph on the development of the cavity (page loi). Unequal resorption of the bone during the growth of the sinus is doubtless the chief cause for the osseous projections on the wafls of the cavity, c.,;,'., the sinus growing in the cUrection of least resistance (Figs. 97, 98, 99 and 100). Duplication of the Maxillary Sinus.— Duplicate unilateral maxillary sinuses haA'e been recorded by Zuckerkandl, Brtihl, Gruber and others. The writer recently made a number of simflar observations. Zucker- handl found that the superior and dorsal of the two sinuses communi- cated with the superior nasal meatuses and the inferior and ventral cavity SUl'KRXLAIKRARN' SLXUSKS 1 K) with the usual infundil)ulum ethmoidale of the middle nasal meatus. The writer finds that the so-called additional or accessory maxillary sinuses in communication ^\■ith the su])erior nasal meatus are of fref|uent occurrence anci that they are readily explained from a genetic standpoint. They are clearly posterior cUiuioid cells which de\'eloi~)ed be>'ond the ethmoid held into the body of the maxilla, dorsal to the maxillary sinus jjroper. Topo- graphically, in the adult, they must, of course, be considered maxillary- sinuses. Clinically, too, their classitication is more maxillary than eth- moidal, because here one is more concerned with the tojjograjjhy of the sinus than with its genetic history (Figs. 98 and loij. Ccittalis 77ifrao7-htta/i-5 \ Sums, 7n.ari./lnns \ \ Si'jius etiimuma/c/llans r ) » \ K Fig ioi— a specimen with two entirelv separate sinuses in the rnaxilla. The dorsal sinus (smus ethmomaxillaris) communieates with the superior nasal meatus an.l the A-entral one with tlie infundibuhim ethmoidale o£ the middle nasal meatus (see text, page iiS). The aberrant posterior ethmoidal cell in question ma)- occup}- but a small portion of the dorsal and superior angle of the body of the maxilla or it may pneumatize more than half of the space more usually occupied by the maxillary sinus. The degree of encroachment on the maxillar>- sinus is, therefore, dei)endent upon the size of the ethmoidal cell. Con- forming with the size of the encroaching cell, the septum intervening be- tween the cell and the maxillary sinus is variously ])laced ; now in the vertical and sagittal plane, again in the oblique and semi-coronal plane. The se])- tum may, therefore, extend from the alveolar border of the maxilla (floor of the maxillary sinus) to the infraorbital wall (roof of the maxillar>- sinus), or from the dorsal wall of the sinus to the roof of the sinus. 120 THE AI AXILLARY SIXUS Clinically, an intelligent appreciation of this not infrequent anatomic type of the maxillary field is important. The dorsal compartment of tlie maxillary sinus (aberrant posterior ethmoidal cell), often of considerable size, when diseased would in all likelihood giye the typical symptoms of an inyoh'ement of the maxillar}' sinus. The usual routes of draining the maxillary sinus by way of the inferior nasal meatus, through the alveolus, or through the canine fossa, would, more than likely, lead into the unaffected maxillar}' sinus proper and with negative findings. Of course, endonasal inspection would assist the operator in the diagnosis, as would also the skiagram. These aberrant posterior ethmoidal cells, topographically maxillary, practically always communicate with the suj:ierior nasal meatus. The author observed one specimen in which a cell in communication with the first supreme nasal meatus extended into the maxilla and encroached upon the maxillar}- sinus. The supernumerary maxillary sinus described by Brlihl in communi- cation with the inferior nasal meatus is difiicult of genetic explanation since no paranasal sinus develops from this meatus and in the adult none communicates with it. In all likelihood the ostium of communication in Briihl's case Avas establislicd in a manner similar to the formation of the ostium maxillare accessorium and the duplicate sinus grew from one of the usual points (see page loi). (iruber claims to have found a complete di\''ision of the maxillary sinus in 2^ per cent, of cases. This is in approxi- mate agreement with tl"ie author's studies if the posterior ethmoidal cells which so commonly grow into the maxilla from the dorsal and caudal por- tion of the superior nasal meatus are classed as maxillary sinuses. Indeed, it must be recalled that the maxilla regularly aids in completing the osseous boundaries of certain ethmoid cells. These are topographically ethmo- maxillar}-, genetically ethmoidal. At times the maxiUary sinus grows into the hard palate by an exten- sion of the alveolar recess between the plates of the palate in the formation of the so-called rccessns pahitinus (Fig. 85 ) . While the latter recess is usu- al!}- in wide communication Avith the maxillary sinus, it is plausible to think that a narrow channel of communication ma}' through disease become obliterated and the recess thus isolated an indi\'idual chamber. One readily sees how these palatine recesses may become cysts in the hard palate. Meyer' describes "a unicjue supernumerary paranasal sinus direct]}- above the superior incisors." He was not certain of its communi- cation, and its genesis is difficult of explanation in the absence of exact ' ]"\\T. -\nal. and Phy., \'ol. 4S, 3rd series, \\A. q, 1914. srl'ER^■uMERAR^■ sixusi:s 121 knowledge concerning its communication. Its total sizewas 16 b>- 13.5 by 22 mm. In this connection one naturall>- thinks of the recessus palatinus previously referred to and to dentigerous cysts. Indeed, the Y-shaped mcisive foramen with the contained remnants of the nasopalatine canals at tmies give rise to qMthelially-lined cells or cA'sts. If one recalls that the nasopalatine canals at one time in the embr>() connect the inferior nasal meatuses with tlic moutli ca\-it\- it is readily understood \vh>' cells arising 1 _.- Sj?ius iiffraorhltCLlls '■f'^\ _..----' 'C07iti(.'ctin.g passaaewa-y 't*JKJL:SZr^''-'^f^ff^i_,.'-r--" '"' (Si?7us Tna /culcuh) \ I ^_ Caa^lis iufraorbitalis ^ *y>-- -) ^- infraoilitalis j — Si/ius fnaxillarls Oi-iita, *" '" , ), ^-■ Fossa, sacci iMcrimalis '"''''^^' , ..«..™. -^^ t^J Toram/:??. infraorbitalM .^^. _ . . 4^3^.^^^^^^ \/, ^ Sinus in/raoriita.lis. ^^^~~A- -^-^-z *^^ ^, Lacrimal pivtijhcruTtce a | t l ^ '' ■^I'nics iiutxiUaris -< ' J^Kv A Fig. 102. — In .1, the facial wall of the maxillary sinus has beun removed thereby exposing the median or nasal wall of the sinus. An extremely prominent lacrimal proturberance presents. More- over, it should be noted that there is a blindly-ending recess in the roof of the maxillary sinus (sinus infraorbitalisj and that the infraorbital canal courses from the infraorbital wall to the facial wall of the maxillary'" sinus, leaving a connecting passageway over the canal and contained ncr^'c (indicated by the arrow in the larger figure). The inset h, represents a saggital section just lateral Im ihc infraorliital foramen. from them ma}' communicate in later life with cither the inferior nasal meatus or the mouth cax'ity. However, should both extremities of the nasopalatine canal become obliterated and the inter\'ening part remain patent, it could readily gi\'e rise to a cyst. Of course, unusual and anoma- lous structures at times dex'elo]) and j\re}-er's case ma_\- have represented 122 THE -MAXILLARY SINUS a freakish accessor}' nasal sinus wliich de\-eloped from the inferior nasal meatus. If so, the case is unique so far as the writer knows. ^ The Size of the Maxillary Sinus.— The maxillary sinus varies greatly in size in different indi\'iduals. Moreo^'er, there may be considerable asymmetry on the two sides of the same individual. The belief that all old people have large sinuses is very fallacious, as is also the statement that aU females have smaller sinuses than males (tables C, D, and E). The in\-estigations of Zuckerkandl,- in which the writer concurs, have shown that enlargement of the maxillary sinus is produced by: (a) Hollowing out of the processus alveolaris of the maxilla (recessus alveolaris) (Fig. 85). (/)) Excavation of the floor of the nasal fossa by a pushing of the recessus alveolaris between the plates of the palatum durum (recessus palatinus) (Fig. 85). (c) Extension of the maxillary sinus into the frontal process of the maxilla (recessus infraorbitalis)'* (Fig. 175). (d) Hollowing out of the processus zygomaticus of the maxilla (recessus zygomaticus). (c) Extension to, and appropriation of an air cell within the processus orbitalis of the palate bone. To these should be added, according to the author's findings:^ (/') Extreme hollowing out of the body of the maxilla in all directions, thus causing the sinus walls to be thin and the recesses all markedly de- veloped (Fig. 174). (g) The rarer condition in which the lateral nasal wall is bulging toward the cavum nasi. (//) The extension of the recessus z3'gomaticus of the sinus maxillaris into the maxillary border of the zygomatic bone. The sinus is made smaller, on the other hand, by: (a) Deficient absorption of the cancellated bone on the floor of the sinus. ' Since concluding tlic aljo\"e discussion llie author oljserved a specimen in wliicli a goodly sized epithelially-lined cavity existed in the line of the original nasopalatine canal. It was a bl nd cavity and communicated neither with the buccal ca\'ity nor the nasal fossa. Careful study of it strongly indicated that it was a remnant or persistent portion of the embryonic nasopalatine canal. - Anatomic der Nasenhohle, Leipzig, 1893. ■ The term ''recessus prelacrimalis" is, however, more applicable for this recess. The term "reces- sus infraorbitalis" should be retained for the occasional extension of the maxillary sinus into the infraorbital wall of the maxilla (see Fig. 102). Indeed, the term ''recessus frontalis" is more suggestive; however, is liable to be confused with the recessus frontalis of the middle nasal meatus. ' Schaeffer: The Sinus ilaxiUaris and Its Relations in the Embryo, Child and -Adult Man, Amer. Jour. .\nat., Vol. 10, Xo. j, loio. SIZM Ol' SIM'S 123 (/') Encroachment of the ^■entl■al wall of the ca\-ity {Fig. 87). ((■) A ileep fossa canina (]Mg. 87). (- dehcacw The statement that all large ca\ities have thin ■walls and small ca^•ities in\-ariably thick walls does not hold in all cases. The smallest sinus measured in this series had the thinnest walls, the small size of the ca\ity being in part due to the marked simultaneous approximation of the \-entral and medial walls. The size of the maxillary sinus is best determined by a series of measurements, \"iz.: Dorsocephalic diagonal. ^'entrocephalic diagonal . Cephalocaudal (height). 4. \'entrodorsal (length). 5. Mediolateral (width). These se\'eral measurements are determined thus: 1. The dorsocephalic diagonal, from the most dorsal and lateral part of the sinus floor diagonally across the base or median wall of the sinus, to the most medial and cephalic part of the recessus infraorbitalis. 2. The \-entrocephalic diagonal, from the most ventral and medial part of the recessus alveolaris diagonally across the base of the sinus to the most lateral and cephalic point of the ca\'ity. 3. The cephalocaudal, from the roof or infraorbital wall of the sinus to the sinus floor (always using uniform points). 4. The A'entrodorsal, from the most \'entral point of the ca\ity mid- way between the roof and the floor, to the dorsal wall. 5. The mediolateral, from the base midway between its most \'entral and dorsal points to the ])rocessus zygomaticus of the maxilla (in some cases this extends into the maxillary border of the zygomatic bone, due to the extension of the recessus zygomaticus of the maxillary sinus into this bone). The ventrodorsal distance is especialh' affected by the degree of approximation of the ventral wall of the sinus; the cephalocaudal by the degree of pneumatization of the processus alveolaris of the maxilla; the mediolateral by the degree of encroachment of the lateral nasal wall; the ventrocephalic diagonal by the extent of the recessus alveolaris; and 124 THE MAXILLARY SIXUS the dorsocephalic diagonal b}' the extent of the recessus infraorbitalis. Of course, there are other contributing factors to shorten or lengthen these distances, but these are the primar}' factors especially affecting the several measurements. In order that the measurements of the maxillary sinus may be of most \-alue, it is necessar)- to compare the two sinuses of the same indi- \'idual ; to compare them with the respective sinuses of another individual ; also to consider the age and the sex. The following tables, C and D, are appended for comparison as indi- cated above: A careful examination of tables C and D shows conclusively that the maxiUary sinus has a rather wide range of variation. ^Moreover, the tables indicate that, in the adult, age does not have any bearing on the size of the cavity. Although the maxillary sinus averages slightly larger in the male than in the female, sex affects the size of the cavity but slightly. Table E indicates the variation range found in the study of a series of specimens. It will be noted that the smallest cavity is that of an old man aged 70 A'ears, while the largest cavity is that of an old man aged 77 years. The same table shows that the ca^'ity of a young adult, aged 21 years, is a close second to the largest sinus found in the entire series. Table C. — ]\L\xillarv Sixus Male — Measurements in Jlillimeters Age / Side Ventrodorsal Mediolateral Cephalocaudal Dorsocephalic diagonal Ventrocephalic diagonal 54 right left 26 30 IS 16 20 22 30 32 26 26 68 right 40 22 5° 5° 50 left 35 24 35 45 50 36 J 1 / right left 30 32 18 40 40 40 41 38 41 65 right 30 IS 30 33 30 I. left 25 IS 25 35 36 55 I right 40 25 40 45 45 1 left 40 22 38 36 45 57 right left 40 3^ 21 25 32 30 50 32 38 43 71 / I / right left 35 40 22 18 45 35 45 40 40 45 59 right 40 22 33 45 45 1 left 40 35 40 5° 45 79 / right 30 30 35 41 40 1 left 43 20 30 41 37 55 I right 31 24 30 30 38 1, left 3-" 25 35 40 40 SIZK OF SINUS 125 Tablk I). — MvxiLi.ARV Sixrs Female — Measurements in Millimeters Age Side ^'ent^odo^sal Mc.liolaterol 1 35 Ccphalucauda! 35 Dorsocephalic diagonal 40 VentTOcephalir diagonal 6S r ] right 30 left 40 16 30 43 36 1 right .T,"! 21 30 40 40 I left vV'^ 24 28 38 45 53 ' nght left 40 25 30 30 45 60 45 42 46 47 i right left 3'"* 26 28 25 35 37 35 37 37 73 1 1 right left 33 24 24 31 37 38 30 40 42 5° right 33 17 30 35 40 1 left 3 -i 22 33 38 34 3i 1 1 right left 30 30 iS 21 32 30 30 30 35 40 39 1 right left 34 33 25 22 3i 3i 32 32 35 2^ 7^ ) right 3S 25 3S 32 3t 1 left 35 23 38 33 35 5^ right 35 21 30 40 36 left 35 21 32 38 35 T.\BLE E. — Maxillary Sinus Aleasurements in Millimeters Age Side Sex V-d .M-1 C-c D-c D V-c D 70 R M 15 12 21 21 18 70 L M 16 12 21 21 20 35 L M 22 20 30 31 25 54 L M 25 15 22 32 27 54 R F 2() 15 20 30 2() 60 L M 30 20 22 3« 23 52 R F 35 -5 30 37 3« 59 L M 40 22 32 35 45 21 R M 4'' 33 26 50 50 y 7 L M 47 40 50 57 60 The following may be gi\-en as average measurements of the adult maxillary sinus, based on the measurements of 150 specimens: 1. Dorsoce])halic diagonal 3S0 mm. 2. Ventrocephalic diagonal 3<^- 5 ™ni. 3. Cephalocaudal 33 ■ <> mm- 4. Ventrodorsal 34-0 mm. 5. Mediolateral 23.0 mm. 126 THE ^L\XILL.\RV SINUS Due to the great differences in the several measurements, the capac- ity of the sinus in different indi-\'idua]s must also diff'er. The range in capacity, of the sinuses studied to ascertain this fact, was from 9.5 cc. to 20 cc, with an average of 14.75 cc The conditions which produce the varied differences in the dimen- sions of the maxillar}' sinus ma}' be readih' ascertained. Take, for ex- ample, the following two cases which show a marked difference in the mediolateral plane with an iuA-ersion of the other measurements: Specimen V-(l, mm. .^O M-1, mm. 18 35 C-c, mm. D-r D. mm. V-c D, mm. 40 35 41 40 41 3° In specimen "a" the lateral nasal wall was markedly bulging toward the maxillary sinus. In consequence of this encroachment the mediolateral distance was greatly lessened. In specimen "b" the recessus alveolaris was poorly developed, hence the short ventrocephalic diagonal in com- parison with the respective measurement in specimen "a." These speci- mens show that even though a sinus may greatly exceed another in one of its measurements, it may be exceeded in size in its other planes. Again, there ma}' be a great difl'erence in the ventrodorsal distance. This means a marked inpushing or depression of the ventral or facial wall of the sinus on the one hand and a shallow fossa canina with a lessened encroachment on the other. Thus: Specimen V-d. M4, c-c, D-c D, v-c D, mm. mim. mm. mm. mm. 2S 1 IS 1 2S 35 36 43 20 30 41 1 37 If the bod}' of the maxilla is pneumatized to a marked degree in all directions the measurements will be correspondingly lengthened. When the hollowing out process has not been carried far, and when associated with some of the above-mentioned conditions, the measurements will be markedlv lessened. Thus: Specimen V-r], mm. M-l. mm. C-C, mm. D-c D, mm. V-c D. mm. e. . . . 47 16 40 12 SO 21 11 60 20 f MAXILLARY OSTIUM 127 These few examples slu)\v how anatomie eoinUlions affect the measure- ments of the maxillary sinus. It ai)i)ears reasonable, therefore, that, by examination oi the \'entra,l surface of the maxilla and the lateral nasal wall, the size of the sinus ma>- be a])i)r()ximatel_\- determined and the teeth relations judged with fair accurac}'. It does not necessarily follow, how- ever, because the \entral and median walls of the sinus are closely ap- proximated, that the cajxicity of the maxillar}- sinus is markedly lessened. Such sinuses may ha\e marked infraorbital recesses and the ])r<)cessus alveolaris ma}' be hollowed out toward its dorsal termination. In this manner compensation ma)' be made for the marked encroachment of the A'entral and median walls of the sinus. It remains, howexer, that in the ^'ast majoritA' of cases AX'liere these walls are simulatneoush' bulging in the ca\itv the sinus is correspondingly reduced in size and the canine and ]')remolar teeth not in direct relation to the sinus. The Maxillary Ostium (ostium maxillare). — The ])rimitive maxillary pouch is in relationship with the processus iDiriiiatiis, the i>ifii)idihiiJum ethmoidal^ the hiatus scini/iiiiaris, and the bulla clhiiioidalis. The location of the maxillar}' ostium of the adult corresi)onds to the place of the primiti\'e maxillary pouch. The pouch gradual))' de\eloi)s into the pyramidal-shaped cavit}' of the adult, leaving the place of communication with the infundibulum ethmoidale at the point of primary evagination. It is, therefore, obvious that the abo\'e structures, which in the embryo bore so close a relation to the anlage of the maxillar_\' sinus, must bear even more im])ortant relations to the maxillary ostium of the adult sinus. It is, therefore, essential to recall the regional anatomy of the communication of the maxillary sinus with the nasal tossa. On raising or removing the middle nasal concha, in the adult, a rounded elevation— the bulla ethmoidalis— is seen. As stated elsewhere, the latter is directed caudally and ventrally. Immediately beneath the bulla is the well-defined curved margin of the ])roeessus uncinatus ot the ethmoid bone. Between these structures is a narrow slit or semilunar cleft—the hiatus semilunaris— horn J5 to 20 mm. long. The semilunar hiatus is an important opening, since it is the communication between the meatus nasi medius and the gutterdike infundibulum ethmoidale. The bulla ethmoidalis varies considerably in size. At times it is feebly developed, again may assume relatixely large proportions. The size of the bulla greatly influences the width of the hiatus semilunaris (Fig. ibi ). It is easy to conclude what efiect these conditions hax'conthe maxil- lary ostium directly and on the maxillary sinus indirectly. In some cases the cleft of communication between the maxillary ostium and the meatus 128 THE MAXILLARY SINUS nasi medius is practically shut off, while in the others a freer communi- cation exists. It must be remembered, however, even though the bull touches the free margin of the processus uncinatus and thereby greath' narrows the hiatus semilunaris, that the infundibulum ethmoidale may be of a^•erage dimensions. This is an important fact and must be borne in mind when considering the fronto-maxillary relations and the possibility of drainage from the frontal region into the maxillary sinus (see page i6o). The processus uncinatus with its covering of mucous membrane pro- jects inferiorly and dorsally. By its free superior border it forms the caudal boundary of the hiatus semilunaris. This process not infrequently Shiii.i fronfa/is Ottium mtiri//n>e Fig. 103. — A dissection with the medial or nasal wall of the maxillary sinus exposed from the sinus side. Note especially the large and elongated ostium maxillare and its intimate relation to the frontal smus. Obviously in such cases the frontal sinus drains almost wholly into the maxillary sinus (see text, page 160). terminates dorsally in what may be termed two roots: The inferior roof passes toward the cephalic edge of the concha nasalis inferior, while the superior root curves superiorly behind the dorsal termination of the bulla ethmoidalis and causes the infundibulum ethmoidale to end in a pocket (Fig. 127). This fact is of extreme importance because the pocket is so situated that it will direct fluid or infectious materials coming to the dorsal end of the infundibulum ethmoidale into the maxillary sinus, ^'ia the maxil- lary ostium which is in the immediate location. The infundibulum etlimoidale is a groove or gutter situated upon the lateral nasal wall. It is bounded cephalically by the caudal surface of nUPLlCATIOX OF MAXILLARY OSTIUil I2g the hitUa ethmoidal is throughout the greater part of its extent, ssLve ven- tralh' and superiorly where the buha is replaced by some anterior eth- moidal cells. The caudal and mesial boundary of the groove is formed by the lateral surface of the proeessus inieinatits. The infundibulum ethmoid- ale communicates with the meatus nasi medius through the hiatus semi- lunaris and, as stated elsewhere, either ends in a pocket or loses its depth gradualh" b}- merging with the meatus nasi medius proper (Fig. 125). The cephalic and ventral end of the infundibulum may terminate blindly, dilate into an air cell, or be continuous with the nasofrontal duct. The lateral Avail of the infundibulum is formed parth' b)' mucous membrane. The depth of the gutter-like infundibulum ethmoidale, i.e., the distance from the free border of the processus uncinatus to the floor of the groove, varies from i to 12 mm., with an approximate a\'erage of 5 mm. The maxillary sinus communicates indirectly with the meatus nasi medius b}- means of a series of openings — { i ) the maxillary ostium which pierces the superior and ventral part of the base of the sinus to open into (2) the infundibulum ethmoidale, thence \\a, (3) the hiatus semilunaris into the meatus nasi medius. It must be clearly kept in mind that the ostium is located in the superior part of the sinus and that it opens into the infundibulum ethmoidale and not into the hiatus semilunaris, as manv writers say. The maxillary ostium is located either in the most dependent part of the infundibulum or in the lateral wall of this channel, and varies from i to 12 mm. in distance from the hiatus semilunaris. The distance is dependent upon the width of the processus uncinatus and the resultant depth of the infundibulum ethmoidale at this point. The maxillarv ostium may be round, but as a rule is either oval or eUiptical. In a series of no cases examined by the writer it had a great range of dimensions, varying from i to 22 mm. in length and from i to 6 mm. in width. In cases where the ostium reaches considerable size it may entirely replace the lateral wall or floor of the infundibulum eth- moidale, thus forming a long slit-like communication between the maxil- lary sinus and the infundibulum ethmoidale (Figs. 77 and 103). Duplication of the Maxillary Ostium.— In a previous paragraph mention was made of the double pouching of the primary maxillary sinus. Distal fusion of two pouches would leave the points of evagination as the adult ostia maxillaria, and the cavity proper would appear as a single chamber. Most duplications of the ostium maxillare proprius are, how- ever, doubtless caused in a manner similar to the establishment of the ostium maxillare accessorium; that is, by the attenuation and ultimate rupture of the mucous membrane in the neighborhood (undefended region l,:;o THE -MAXILLARY SIXUS of the middle nasal meatus, page 92). Disease may be the underlying factor in some instances. The duplicated maxillary ostium is always located dorsal to the regular aperture and in the dorsal end of the infundi- bulum ethmoidale. It varies much in size. The Accessory Maxillary Ostium (ostium maxillare accessorium). — The accessory maxillary ostium is, as a rule, situated in the membranous portion of the lateral wall of the middle meatus, a short distance above the cephalic and attached border of the inferior nasal concha at about the junction of its middle and posterior thirds. In some instances it is located immechately dorsal to the infundibulum ethmoidale — occasionally extend- ing into the latter. The accessory ostium is usually single, but may be duplicated. Rarely three accessory apertures are present in this portion of the middle meatus. The aperture must not be confused with the duplication of the maxillary ostium previously referred to. Nathaniel Highmore, who apparently was the first anatomist to describe the maxillary sinus, does not mention the accessory ostium. Giraldes in 100 cadavers found it "acht bis zehn Mai." Zuckerkandl reports it present "in jedem neunten bis zehnten Falle." Chiari and Hajek found an accessory ostium in every fifth case. Turner found it four times in nine dissections. The fourth annual report of the committee of collective investigation of the Anatomical Society of Great Britain and Ireland states that in an examination of 152 specimens 17.6 per cent, showed accessory maxillary ostia. Warren B. Davis' in an examination of 114 lateral nasal walls from cases between 4 and 24 years of age reports accessory ostia in 15 per cent.; moreo^'er, reports one instance in a child just past four years of age. The frecjuence of occurrence as reported by Davis can hardly be compared with other reports since accessory ostia are not common before the fifteenth year. In a former paper'' the writer reported the accessory maxillary ostium present 35 times out of 80 adult specimens examined, a percentage of 43.75. Three of the specimens had two accessory ostia. In another study" of 125 adult specimens the writer reported accessory ostia in 42.4 per cent, of cases, three of the specimens presenting two such apertures. In a third series, not previously reported, of go adult specimens, the writer found 37 per cent, with accessory ostia. J. A. Giraldes"' was apparently the first to consider this opening from a de\-elopmental point of A'iew. He came to the conclusion ''dass in aUen ' Xasal Accessory Sinuses, Philadelphia, 1Q14. - Schaeffer: Amer. Jour. Anatomy, Vol 10, iqio. ■' Schaeffer: The Ostium ilaxiUare .\ccessorium, Twenty-sixth Session .\merican Association of Anatomists, December, iqio. * .\rchiv 1. path. Anat. unci Physiologie unci f. klinische Aledicin, Bd. g, 1S56. ALX"KSS(JRV MAXILLARY OSTIUM i;,i Fallen, wo dicse abnorme OclTnung bcslcht sic immer das Product cincs pathologischen ^'orga^gcs und durch cine wirkliche Perforation zai Stande gekommen ist." He considered llic ai)erturc much less common than it is, thinking it present in only 8 or lo ])er cent, of instances. Ciiraldes bases his pathologic theory on the fact that he had the i)ri\'ilege of folloAving the "Entwicklungsphasen A'on der \'erdunnung der Schleimhaut des Ganges bis ziu- volstiindigen P)urchbolirung." Zuckerkandl corroborates the Fi(-.. io8. Fi<- i''9- Figs 104-109 — Diasranis of the latcratnasal wall with the eoneha Tiasalis media partly cut away. Note the position.s and relative sizes of the ostium maxillare aecessoru.m. mdicatcd by the deep black circles. See text, page 130. thinning of the muc(;us membrane, but does not hold to the pathologic theory. The latter author has seen some cases where an accessory aper- ture was caused by the gradual wearing of a "zugespitzer Hakenfortsatz der Nasenscheidewand," which finally resulted in an opening on the lateral wall of the middle meatus. While some accessory a])ertures are obviously due to a pathologic process as suggested b\' Giraldes, and others caused in a mechanical manner bv spurs on the nasal septum as suggested by Zuckerkandl, we 132 THE lilAXILLARY SINUS must certainly look elsewhere in most cases for the genesis of this very common aperture. The author agrees that there is a thinning of the mucous membrane in the position of the accessory maxillary ostium, but believes the explana- tion for this is found in the development of the maxillary sinus. In the fetus and infancy the walls of the sinus are relati^'el)' thick. The sinus cavity increases by the simultaneous growth of the sac and the resorption of surrounding tissue, these processes taking place para passu with the growth of the face. In this manner the sinus walls become thinner and thinner up to a limit as age advances. The thinning apparentl}' progresses unevenly, as is evidenced b}' the very uneven walls of many adult cavities. On the base or median wall of the cavity there is an area that is in time composed merely of two layers of abutting mucous membrane: one the mucous membrane of the middle meatus, the other the mucous membrane of the maxillary sinus. These two layers with no intervening bone (tlie midefended area, Fig. 73) offer \txy little resistance to the growing maxillary cavity. In time they become so thinned out and attenuated that ultimately an opening is formed, thereby establishing the ostium maxillare accessorium. This process reminds one of the early thinning and attenuation and ultimate rupture of the two layers of abutting epi- thelium — the bucconasal membranes — in the establishment of the primi- tive choance (page 9). If the above h>i3othesis as to the genesis of the ostium maxillare accessorium is well grounded one would not expect to irnd the aperture in fetuses or in young infants. Indeed, one would not expect the incidence of occurrence to be frequent before the fifteenth year; that is, when the maxillary sinus passes into the adult stage. Aloreover, one would look for its appearance, especially in the adult, after the waUs of the maxiUary sinus have been sutliciently thinned out by the enlargement of the cavitv. In support of the above the writer has been unable to find an accessory maxil- lary ostium in the fetus and in the young child, but found it very frequently between the ages of 13 and 90 years. Symington ^ says: "In children I have never found more than one aperture, viz., that in the infundi- bulum." Da^•is,- on the contrary, found an accessory opening between the fourth and fifth year.'' 1 The Anatomy of the Child, Edinburgh, 1887. " Eoc. cit. 3 Since the completion of the manuscript on the maxillary sinus the author observed in a post- mortem on a child aged 11 years a large bilateral accessory maxillary ostium. Careful examination showed the mucous membrane of the nasal fosscc and paranasal sinuses to be in a good state of health (EiK. IS.?)- CONCLUDING CONSIDERATIONS 133 The writer has, therefore, come to the conclusion that the ostium maxillare accessorium is, in most instances, estabhshed by the developing maxillary sinus; the growth of the sinus causing the two layers of abutting mucous membrane to become thinned and attenuated, resulting ulti- mately in an additional aperture in A'er}- man>' adult noses. Some of the accessory ostia are, doubtless, due to a pathologic process, and others produced in a mechanical manner by septal spurs. It is, of course, dilh- cult to give the exact percentages in the classification of causes. Indeed, it matters little. The fact remains that the accessory maxihary ostium, a direct communication between the maxillar)' sinus and the middle nasal meatus, is of ver}- frequent occurrence, often of goodly size and more advantageously placed as a drainage and exploring point of the maxillar}' sinus than is the regular maxillar}' ostium which is located farther cephal- icall}- and in the depth of the narrow infundibulum ethmoidale. The writer Avould urge that operators utilize this accessory ostium more fre- quentl}- in irrigations of the maxillary sinus, moreover would point out that the incidence of occurrence, as given by Giraldes and so commonly referred to in text-books, is archaic and far too low. Concluding Considerations. — A'aluable information ma}- be learned of the size, contour and relationships of the adult maxillary sinuses by the use of the X-rays. The ventrodorsal (anteroposterior) skiagram usually clearly delineates the position of the lateral nasal walls and the degree of development of the palatal recess of the maxillary sinus. Moreover, the relationship of the sinus floor to the nasal floor is indicated, as is also the degree of pneumatization of the alveolar process (alveolar recess of the maxillary sinus). Such information is, doubtless, of some value in antici- pation of operative procedures, either by the endonasal, alveolar, or canine fossa approaches. Inspection itself not infrequently gi^•es the experienced observer a fairly definite clue as to the type of maxillary sinus before him. HowcA-er, the skiagram is an invaluable supplement to inspection. As mentioned elsewhere (page 114), the simultaneous approximation of the medial (lateral nasal wall) and ventral (facial) wafls of the maxillary sinus almost always precludes the possibility of a palatal recess and of an alveolar recess in the ventral third of the alveolus. A deep canine fossa and a lateral bulging of the lateral nasal wall are, of course, readily deter- mined by inspection ; the skiagram confirming this by showing a restricted maxfllary sinus in its \-entrodorsal diagonal and fewer teeth in true rela- tionship to the sinus floor (usually the second and third molars only). One must always recall the possibility of dealing with a maxillary sinus incompletely divided by septa into sub-compartments and that some J 34 THE .MAXILLARY SINUS of these may be of considerable depth. :Moreover, that the compartment opened into may not establish drainage for the entire sinus. Indeed, the infection maA' be in a posterior ethmoidal cell which has pneumatized a goodly ]M:)rtion of the bod>' of the maxilla. In most cases the normal max- illary sinus would be explored, with negative results (see page ii8, Figs. 98 and loi). The location of the ostium of the maxillary sinus, in the depth of the ethmoidal infundibulum, would seem to preclude the possibihty of exploring the maxillary sinus through its normal aperture. In this con- nection it is well to recall the structures in relation to the maxillary osti- um; that is, the ethmoidal bulla, the uncinate process, the semilunar hiatus, and the ethmoidal infundibulum. The bulla when large practi- cally shuts off the semilunar hiatus or entrance into the infundibulum. An examination of a large series of specimens leads the author to beheve that it is impossible clinically in the vast majority of cases to sound the maxihary sinus through its normal ostium (Figs. 128 and 197). This conclusion based upon anatomic facts is in conformity with the clinical findings of Cryer,^ Skillern'- and many others. In those cases where successful sounding of the maxillary sinus through the normal aperture is reported it is more than likely that an artificial opening was made into the maxillar}- sinus through the undefended floor and lateral wall of the ethmoidal infundibulum. It is only fair to state, however, that at times the ethmoidal bulla is small and the uncinate process narrow and probably turned nasalward with a resultant shallow and more or less wide-mouthed ethmoidal infundibulum (Fig. 125). It is in such cases that the operator succeeds in exploring or sounding the maxillar}' sinus through its normal aperture — the ostium maxillare. Perforation of the lateral wall of the inferior nasal meatus for purposes of exploring or medicating the maxillary sinus seems to be the preferred route by clinicians. One must, however, always bear in mind that the floor of the maxillary sinus is in the majority of cases at a level inferior to that of the inferior nasal meatus and that an artificial aperture by way of the inferior nasal meatus does not give the most dependent drainage for the maxillar}' sinus. The freciuency of the accessor}' maxillary ostium connecting the middle nasal meatus and the maxillar}' sinus directly should not be for- gotten when attempting to sound the sinus by way of normal apertures ' Internal Anatomy of the Face, Philadelphia and New York, 1916. - The Catarrhal and Suppurative Diseases of the Accessory Sinuses of the Nose, Philadelphia and London, 1916. CONt'LUDIXC, CONSIDMRATIONS 135 (see page 130). The aecessory aperUire is frequently of goodly size and is probed with mueh greater ease than is the constant aperture in the depth of the ethmoidal infundibuluni. Prolde skiagrams of the maxillary sinus are frequently confusing in that it is cHfficult in the health)- state to distinguish between the right and left sinuses in the picture. Tlie \-entrodorsal ^•ie\v is to be ])referred. When subjecting the maxillar}- sinus, hlled with iiuid, to ])ressure the undefended part of its medial wall (]xirs memljranacea) yields and bulges into the middle nasal meatus. Cliniealh", it is stated that such bulging is almost always jiathognomonic of an emin'ema of the sinus in which the normal aperture is either blocked or, because of its size and faulty ana- tomic location, leads to deficient drainage. IV-THE FRONTAL SINUS CHAPTER IV THE FRONTAL SINUS TnK P'etal Stage The nasofrontal region is genetically an outgrowth from the ventral and cephalic end of the middle nasal meatus operculated bA' the middle nasal concha (middle turbinated bone). The mucosa of this part of the middle meatus is, therefore, the proton of what subsequently becomes the recessiis Jrontalis (a term \'er}' suggestive, and to be preferred to the recessus conchalis used by others) of the middle nasal meatus (early in evidence) and derivatives therefrom. The recessus frontalis in turn is the rudiment of the sinus froiilal is and certain of the anterior group of the cc/lu- Ice ct!n}widjlcs (also called cellulce frontales by Killian, Onodi and others). Fro/(tal furrows P^oc- M~ '^^^^^^-^^^^^^^^^^^SS^si^ * "' ^ Bulla etJi. Fig. no. — A dissection of the frontal recess of a term fetus showing the early frr.ntal furrows nr pits; e.g., rudiments of anterior ethmoidal cells and p.itential rudiments of the frontal sinus. y 1.5. As early as the end of the third or beginning of the fourth month of embryonic life, one sees evidence of a beginning extension of the middle nasal meatus in a ventrocephalic direction. This early extension is the beginning of the recessus frontalis, and is, strictly speaking, the first step in the formation of the frontal sinus and certain of the anterior grouj) of ethmoidal cells. For some time the lateral waU of the recessus frontalis is even and unbroken and gi\-es no eA'idence of the later configuration and complexity which characterizes the region in the adult nose. Coronal sections and transections of the recessus frontalis of a 4-month fetus show the lateral nasal plate of cartilage thickened at certain points. These thickened cartilaginous areas— the precursors of the folds or 139 j^o THE FRONTAL SINUS access()r\- conch;c which later configure the lateral wall of the recessus frontalis— var^' in number and are for a period low and inconspicuous and do not throw the nasal mucosa into relief. U])on examining the recessus frontalis in the late fetus, one finds a variable number of low accessory concha; on its lateral wall (Figs. 35 and 36). The folds, with the cartilaginous skeleton now partly ossified, are at this time sufiicienth' de^-eloped to throw the nasal mucosa into relief. Between the folds are found pits or furrows, the positive growth or outpouching of which aids materially in making more prominent the folds. It is appropriate to speak of the latter as accessory or hidden frontal folds or concha? and the pits as frontal furrows of the middle nasal meatus. As mentioned above, there is no constancy in the degree of dift'erentiation and de^-elopment of the frontal folds and furrows. The number ^'aries from a complete absence to four or five. In some instances, therefore, the recessus frontalis remains a simple blind outgrowth from the middle nasal meatus without configuration of its lateral waU (Fig. in.) The processus uncinatus and the folds composing the buUa ethmoid- ahs should likewise, as pre\'iously stated, be considered accessory conchae of the middle nasal meatus (analogues and homologues of the frontal conchte), and the infundibulum ethmoidale and the suprabuUar furrow as accessorv meatuses or furrows of the middle nasal meatus (analogues and homologues of the frontal furrows). The frontal furrows or pits early evaginate and form certain of the anterior grouj) of ethmoidal ceUs or the so-called frontal cells. Semi- coronal sections through the recessus frontalis show these early cells. X^'hen the latter cells are followed in serial sections toward the recessus frontalis, they are shown to be extensions or outpouchings of the frontal furrows and in communication with the recess (Figs. 147 and 148). Some of the ethmoidal cells having their genesis in frontal pits remain diminutive and ethmoidal in topograph}', Avhile others grow to considerable size and often develop beyond the confines of the ethmoid bone. It is a well-established fact that the frontal sinus develops variously; (i) by a direct extension of the whole recessus frontalis, (2) from one or more of the anterior grou]) of cellula; ethmoidales which have their point of origin in frontal furrows, and (3) occasionally from the ventral extremity of the infundibulum ethmoidale, either by direct extension or from one of its cellular outgrowths. Indeed, the frontal sinus is frequently unilaterally or bilaterally present in duplicate or triplicate, indicating a genesis from more than one of the aforementioned areas. The frontal sinus is, embryo- logicall}- speaking, in many instances, an anterior ethmoidal cell which FKTAL STA(;K 141 has grown sufficiently far into the frontal region to be topographically a frontal sinus. The first e\-idence of the frontal sinus must not be sought in the frontal bone, but in the recessus frontalis of the middle nasal meatus. Lack of obser\-ance of this embryologic truth has led to such statements as: "in the newborn infant no trace of a frontal sinus is \'isible;" "the earliest sign of a frontal sinus is seen about the end of the lirst _\ear in the form of a shallow depression;" "the frontal sinus is comi)leteh' absent in the newborn infant." Poirier states that the frontal sinus is hrst seen about the end of the second >-ear. Tillaux i)uts it as late as the twelfth year. Onodi, Davis, Schaeffer and others recognize the frontal sinus as such in some instances early in extrauterine life. Killian operated upon a diseased frontal sinus in a child 15 months old. As stated before, the recessus frontalis of the middle nasal meatus is demonstrable as early as the fourth fetal month and late in fetal life it becomes complex by the formation of the frontal furrows or jMts, etc. One is not justitied as a rule in the term child to hazard an o])inion as to the specific point from which the sinus frontalis will ultimateh' develoj). There are ex- ceptions to this rule: occasionally at birth the genetic i)oint for the sinus frontalis is ob\'ious; again, one cannot be certain until the second or third year. The A'arious potential rudiments (frontal recess and certain anterior ethmoidal cells, etc.) of the sinus are, however, far advanced by the end of fetal life. One must alwa>-s bear in mind that the sinus frontalis is genet- ically and topographicall}' ethmoidal before it is frontal and in this sense is conspicuously present at birth in all cases. From the suprabullar furrow develop most of those anterior ethmoidal cellswhich in time honeycomb thebullaethmoidalis (Figs. 1 5(3, 1 57 and 158). Rarelv the suprabullar furrow seems to be the genetic point for the sinus frontalis. This may be a])])arent only and not the actual condition, since the most dorsal and cephalic of the frontal i)its and the suprabullar furrow- are at times continuous channels. This may lead to the interpretation that the frontal sinus de\-eloped from the suprabullar furrow, when in reality it developed from a frontal pit (early anterior ethmoidal cell). The infundibulum ethmoidale at its \-entral extremity usually ends bhndh- b^' forming one or more anterior ethmoidal cells (infundibular ceUs; of variable size and location. In the majority of cases such cells are lateral to the frontal recess. The}- may, however, grow far from the point of genesis and form conchal and agger cells (see page 221). Indeed, they may grow sufficiently far into the frontal region to become frontal sinuses. In anv e\-ent the\- communicate always with the infundibulum 142 THE FRONT.VL SINUS ethmoidale. The infundibulum ethmoidale and one or other of the frontal furrows or pits are frequently in the same axis in the fetus and at times are contiguous. Early resorption of the intervening barrier would cause a frontal furrow and the infundibulum ethmoidale to become continu- ous channels, and in the late fetus and infant, as well as in the adult, it would be difficult to prove that the channels were primitively discontinu- ous. It would be equally difficult to state the genetic point of the frontal sinus, e.g., whether in the infundibulum ethmoidale or in a frontal cell. It must, however, here be pointed out that it is unusual initially for the infundibulum ethmoidale to be directly continuous with a frontal furrow or pit (Fig. 127). Of course, one must observe the embryonic and fetal nose at the proper ages to see the justice of this statement. Continuity of channels is, however, an occasional occurrence. Furthermore, the adult nasofrontal duct and the infundibulum ethmoidale are, strictly speaking, in the majority of cases, discontinuous channels. The latter is significant when one recalls the careless statement, frequently made without qualification, that, in the adult, the "infundibulum ethmoidale is continued upward as the nasofrontal duct into the sinus frontalis." It will doubtless aid in making the adult conditions one meets more comprehensible if here reference is made to specific fetal conditions. In Fig. no the infundibulum ethmoidale is in line with the third frontal furrow, but not directl\' continuous with it. If in this case the frontal sinus should de\'elop from the anterior ethmoidal cell of the first or second frontal furrows or from the frontal recess directh', the nasofrontal duct of the adult sinus would doubtless communicate directly with the middle nasal meatus and not with the infundibulum ethmoidale. If, on the other hand, the frontal sinus should develop from the cell of the third frontal furroAv, the nasofrontal duct would be continued down to the infundibulum ethmoidale, but not be directly continuous with it, unless the bridge of intervening tissue were absorbed, as occasionally happens. A frontal sinus developing from the cell of the third frontal furrow would in all probability have a tortuous nasofrontal duct. This would, of course, depend largely upon the disposition and size of the other anterior ethmoidal cells. In the dissection shown in Fig. 35 the infundibulum ethmoidale and the first frontal furrow are practically continuous with each other. Should the frontal sinus develop from the first frontal furrow in such a condition, the nasofrontal duct would be directly continuous with the infundibulum ethmoidale in the adult. One must not err, however, in such a condition by believing that the sinus frontalis necessarily developed CHILDHOOD STAi;ii 143 from the infundibulum ethmoidale. From adult relations it would appear as if the latter interpretation were correct; embrj^ology, howe\-er, shows the error of this contention. If in the specimen shown in Fig. 35 the frontal sinus formation should take place from the cell of the second frontal furrow, the nasofrontal duct would be continued down to the infundi- bulum ethmoidale at an angle, but not be directly continuous with it. In the specimen shown in Fig. iii (from a child aged 14 months) the whole frontal recess is extending and de^'eloping into the frontal sinus. In the latter case the adult sinus would in all probability have no true nasofrontal duct, but the sinus would open directly into the \'entral and superior portion of the middle nasal meatus. In a general wa}- one ma>' say that, when the frontal sinus de\'eIops from an anterior ethmoidal cell, the adult cavity will more frecjuently have a nasofrontal duct — the tortuosity of the duct depending upon the cell from which the sinus de\'eloped and ui:>on the degree of de\'elopment and disposition of the neighboring anterior ethmoidal cells. On the other hand, when the frontal sinus develops by a direct extension of the frontal recess there will in all likelihood be no true nasofrontal duct. The Childhood Stage The sinus frontalis as such may or may not be demonstrable at birth. The various potential rudiments of the sinus are far advanced; none, how- Jiixessiis frontalis -.,_ , / ^%^ , . ' ^ ^^^i^^ c«>>^ ~'~'/' '.^^^^^\ ^"^ ^* -~Ji^A : -" r ------ -^nprahiJJ-ar farrow l7,fu:ndib. etk "X^^teiV-lfc"^"' ^ Q--y -''-^^^' (anlxx^es cc.etk.) Fig III ~A dissection of the frontal recess illustrating the decree of devclo,.nncnt of the iVontal sinus in a child aged 14 months. Note that the whole frontal recess is expanding mto the trontal sinu5. X 0.8. ever, topographically frontal. As a rule, tme cannot be certain of the actual frontal sinus until the sixth to the twelfth month of ])ost fetal hfe. Notwithstanding, in some newborn babies the frontal sinus is more pre- 144 THE I'RONTAL SINUS cocious than in the average and can be determined with reasonable cer- tainty at tliis time. The various outpouchings from the recessus frontalis continue to extend their boundaries and the one destined to form the frontal sinus (if the frontal recess is the source) ultimately comes in contact with the horizontal portion (pars orbitalis) of the frontal bone, and up to this time the mucous-membrane sac has a thin, compact bone matrix. Extension into the horizontal portion of the frontal bone now follows, thence between Sinus sphenoidaJis 'I ,' ' . I Sinus froiifalis ^,-'/\ CeUiilae etitmoidales Ostium maxiUare--^^ i Sinus maxillaris - - S a reus lacrimalis Fig. 112. — Photograph of a dissection of the paranasal sinuses of a child aged 6 ^-ears, 6 months and 15 da\'s. (Dissection b>' Dr. Warren B. Davis.) the tables of the vertical portion (squamous frontalis), by the simul- taneous growth of the sinus and resorption of the cancellous bone. There is a great variation in growth. However, by the eighteenth or twentieth month the frontal sinus has "eroded" into and begun to ascend the vertical portion of the frontal bone, and by the middle of the third year the cupola of the sinus is above the level of the nasion. It should be here noted that in many instances the frontal sinus never invades far into the vertical portion, but grows extensively into the horizontal portion of the frontal CHILDHOOD STAGE US bone, forming a large air si)ace (or spaces) oxer the orbit. This leads to the erroneous belief that there is freriuently an agenesis of the frontal sinus. When the sinus first in\-ades the \-ertical ])ortion of the frontal b(jne, it is nearer the inner than the outer i)late. This leads to a thin dorsal wall — almost wholh- comjxict bone — as oj^i^osed to a fairh- thick ^•entral wall composed of both compact and cancellous (diploe) bone. From the outset, in the inxasion of the frontal bone, the frontal sinuses \-ar\- in size and shape and are usually asymmetrical. The sejitum frontale is seldom in the mid-sagittal plane, sa\e at its base, \-entralh-. It is, howe\-er, well known that a persistent metopic suture usualh' precludes the likelihood of development of the sinus beyond the median plane (Y\g. bb). Table F gi\"es the measurements in millimeters of the frontal sinus in a series of specimens from b months to 20 A-ears of age. There is a gradual increase in the size of the sinus in one diameter or another as age adA'ances. In a general way, this is true of all measurements. How- ever, in some instances a certain diameter may lag far behind. Witness, for example, the short ce])]Tal()caudal diameter and the deep ventrodorsal diameter in the 17- to i8-}'ear specimen — a sinus of the supraorbital type. This must, of course, not be taken as indicatiAX- of the t}'i)e of sinus at 'I' \HI,I Dist ance of Distance of .McasLirementr, At e Side ostium frnn- talc liclnw cupola of sinus frontalis Ccphalo- .Mcdio- Ventro- Size of os- tium fr(,((!t(de n. sion alj(,i\'c nas ion cauda! latcral dorsal R 4.5 2 be 1.) \\" (height! 2 . 1 width! I . 5 (length 1 3.5 6-12 mos. 2,5X0.7 L 4.5 1 , 5 be nw 2 .0 2 3 5 2.5X0,4 1-2 yrs. R 3.0 2 .0 5.0 24 4.0 2,5X0,7 L 3 . 5 1.6 4-9 2.6 5 2,(1X0,8 3-4 yrs- R i'5 2 .0 50 .^ 5 4 5 2,8X0,8 I, 4.0 2 5 7 .0 4 5 5 2 , S X , 8 5-6 \TS. R ,^ . 5 3-5 8.0 3-5 f) 2,0X0,7 L 4 3° 7.0 35 6,0 2,8X0,8 7-8 yrs. R 4 9-5 13.0 10.0 8, 5 2,5X0,2 L 40 10. 15,0 10. 7 2,7X2,1 10- 1 1 yrs. R i-O 12 .0 Id ,0 8.0 8,0 .3,0X2,0 L '> S 12 ,0 17.0 go 5 5 3.0X2,5 1,3-14 yrs. R 3.0 7-5 10 5 8.5 100 4,oX 2 ,0 L 4.0 II ,0 150 0.0 12,5 .15X2,0 14-15 yrs. R 2 .0 16.0 18.0 iS.o 110 3.0X2,0 L 3.0 15-5 18.5 20,0 1 1 ,^,0X2,0 17-18 yrs. R 3.0 4.0 7,0 10,0 20,0 ,^ 5 X 1 , 5 L 6.0 II .0 16.0 18,0 16,0 4,oX 2 ,0 19 20 yrs. R 2 .0 26.0 28,0 27,0 17,0 Q , X 8 L 2 .0 ibo\'e 2,S,0 26,0 20,0 1(1 5 0X2 146 THE FROXT.VL SINUS this age, another specimen of the same age might show a totally different series of measurements. The further de^'elopment and variations in the anatomy of the sinus frontalis are best considered in connection with the adult stage. The Adult Stage General Considerations.— It is a well-established fact that the an- atomy of the adult frontal sinus varies greatly— there being no constancy in size, shape or type. The sinuses in the same individual are usually asymmetrical and either or both may be present in duplicate or triplicate. The Avriter has, indeed, observed as many as four frontal sinuses on one side, each independent of another and with its own communication with the nasal cavity. Moreover, there is considerable variation in the manner of communication of the frontal sinus with the nasal cavity — a fact in accord with the varied embryology. Agenesis of the sinus has also been observed by a number of investigators. All of these variations are of utmost importance to the clinician, and an appreciation of them will doubtless aid in clearing up obscure cases. The frontal sinus of the adult is seldom a simple chamber. It is frequently more or less divided into subcompartments or recesses by incomplete bony partitions. It lies between the two plates of the frontal bone in both the vertical (squamous frontalis) and horizontal (pars orbit- alis) portions of the bone. Its ventral and thicker wall usually forms the prominence of the forehead abox'e the e}'ebroAvs (the thickness varies from I to 10 mm.). .1 prominent supraorbital swelling {superciliary ridge) must, hoivever, not be taken to mean an undoubted large frontal sinus. The prominence is \-er}' misleading at times if thought to be indicative of the size of the frontal sinus. The dorsal and cephalic wall separates the frontal sinus from the frontal lobe of the brain. When the frontal sinus is extensively developed over the orbit it is in relationship with the gyri frontales: inferior, medius, and superior. The caudal Avail of the sinus is in relationship with the tissues of the orbit and in part overlies the anterior ethmoidal cells. Indeed, if the frontal sinus has developed far dorsad between the plates of the horizontal part of the frontal bone, it will overlie the posterior ethmoidal cells likewise. The frontal sinus occasionally extends into the crista galli. The septum frontale is always present: seldom, however, in the mid-sagittal plane throughout, and according to the author's specimens is very rarely perforated, saA'e in disease. It is, howe\'er, often of a paper}- thickness in certain parts. ADUI/r STACE 147 Size of the Adult Frontal Sinus.— Briihl in a study of the frontal sinus found the capacit>' of the combined sinuses to ^'a^y from 6 to 16 cc. The writer's in\'estigations show the combined ^'olume of the right and left frontal sinuses to \-ary from i cc. to 45 cc. Idie extremes in capacity repre- sent, of course, relatively few specimens and should not be taken into account in speaking of the a\-erage measurements. The following table (G) taken from the studies of three writers gives the average size in milli- meters of the sinus frontahs in the ditl'erent planes: TAni.i', C'y Author Cephalocaudal (height) Mediolateral (width) Ventrodorsal (length) Boege 20.8 34 .o 27-0 23.6 23.0 16 I Loeb Schaeffer. . . 21 .0 10.25 A series of specimens taken at random from a larger series investigated by the writer show variations in the several diameters as follows (table H) : T.VBLE II Xo. Cephalocaudal (height) Mediolatera' (width) \ entrodorsal (length) R L R . L R L I 1 26 30 31 24 45 44 2 18 18 24 29 19 33 3 8 12 13 22 6 10 4- i 29 22 27 1 32 40 42 s , 10 9 S 19 5 7 6 , 26 30 16 21 35 40 7 ! 16 1 20 20 35 27 36 8 17 17 24 30 20 37 Extensive Pneumatizationsby the Frontal Sinus.— The writer recenth- encountered frontal sinuses of enormous size, far exceeding Brulil's maxi- mum. Witness, for example, the dissection of an adult male shown in Fig. 1 13 . The skull has three frontal sinuses, one on the right side and two on the left, in communication with the frontal recess of the related side. The Avhole of the orbital (horizontal ) ix:)rtion of the frontal bone is pneuma- tized. Indeed, the frontal sinuses are not confined to the frontal bone: Laterally and dorsally they extend into the great or temporal wings (ake magncej and dorsally and medially into the small or orbital wings (ake; parvsj of the sphenoid bone. The medial one of the two left sinuses 148 THE FRUXTAL SINUS extends into the crista galli of the ethmoid bone. Moreover, the sinuses extend into the frontal or nasal processes of the maxilla; alid into the nasal bones. Numerous finger-like projections of the sinuses have hollowed out the frontal (vertical) portion of the frontal bone to an unusual degree. The total capacity of the three frontal sinuses represented in Fig. 113 is ?S cc. E\-ervwhere the walls of the sinuses are extremely thin. The Fig. 113. — Skull from an adult uTale. The frontal sinuses in the vertical portion of the frontal bone, in the great wings of the sphenc.iid, and in the temporal bones arc represented by cross-hatching. Note that there are two sinuses on the left side and one on the right. The orbital extension of the sinuses is, of course, not shown. The combined capacity of these unusually large frontal sinuses was thirty-eight cubic centimeters. {After J. P. S., Annuls of Suri^fry, December, 1916.) enormous capacity of the sinuses in this specimen can better be appreciated when one recahs Briihl's findings (page 147). Clinically it is of importance to appreciate the additional anatomic relationships of the frontal sinuses in such extensive pneumatizations. Even more extensive are the frontal sinuses illustrated in Figs. 1 14 and 115. The dissections are from an adult male. Every part of the orbital (horizontal) portion of the frontal bone is hollowed out. The SIZI' OF SINUS 149 intracranial walls of the frontal sinuses are crowded bullous-like toward the anterior cranial fossa. Extensive and numerous linger-like recesses of the sinuses project variously into the vertical portion of the frontal bone (F]g. 115). On both sides the sinuses extend into the great or temporal wings (ahe magnie) and into the lesser wings (ahe i)ar\-ie) of the sphenoid Sr /^^^ fro i^a7i Slnuj frc^r/ajz 3 Fig. 114. — A dissection of enormously de\'el'.)ped frontal sinuses. The intracranial walls of the sinuses have been removed (see text, pa^^' 147). bone. There is even an extension bilaterally into the tem])oral bones and well down to the root of the nose into the nasal bones and into the frontal or nasal processes of the maxillae. In P'ig. 114 the intracranial wall of the sinus is remo\'ed, thus exposing the sinuses in their entirety. It is especially important to note the extensi\'e anatomic relationships of the frontal sinuses in this specimen. The two sinuses are markedly asym- ISO THIC FRONTAL SL\US metrical. Many recesses and incomplete bony septa are present. The capacity of the two sinuses (Figs. 114 and 115) is 45 cc. In a stud}^ of the heads of hundreds of cadavers the author frequently encountered ver}^ large frontal sinuses, but such extensive pneumatization of the frontal and related bones by the frontal sinuses as found in these two cadavers (Figs. 113 and 115) is unicjue in his experience and in all probability in the literature on the subject. Supernumerary Frontal Sinuses. — Unilateral and bilateral supernu- merary frontal sinuses are extremely common. They occur in both the CXA-k'^ .'« Fig. 115. — An adult skull showinf; extensive pneumatization by the frontal sinuses of the vertical portion of the frontal bone. In Fig. 114 is illustrated the supraorbital extent of the frontal sinuses in the same skull (see text, page 147). (AfU-r J. P. S.. Annats of S iirgfry. December. 1916.) vertical and horizontal portions of the frontal bone. Multiple frontal sinuses are placed either side by side in the coronal plane or one dorsal to the other in the sagittal plane. Intermediate relations are encountered. The writer has observed as many as six frontal sinuses in one skull, four on one side and two on the other. Cr}'er obser^■ed as manv as five in one skull. Regardless of the numl^er, each sinus is normalh' independent of another and has its own ostium of communication with the frontal reo-ion of the middle nasal meatus. SUPERXUJrKRARV FRONTAL SINUSES 151 Cr>-eri m commenting on a specimen with four frontal sinuses placed side b)- side in the coronal plane aptly sa>-s : "Some writers would class the two middle sinuses as anterior ethmoidal cells which had invaded the frontal bone. If these cells should exist without the two large sinuses, they would then be called frontal sinuses by these same writers." In a certain sense the frontal sinuses are alwa>-s anterior ethmoidal cells which have im-aded the frontal bone. Howex-er, one cannot get awa>- irom the topography of these supernumerary sinuses and their classification as frontal rather than ethmoidal paranasal chambers is eminently proper. Genetically, there is abundant reason for multiple frontal sinuses (see page 140). Fig. ir6. — The frrmtal sinusrs of an adult, Xnlr the inarkrd asyimnetr\'. In Figs. 125 and 126 are rei)resented dissections of adult naso- frontal regions in which two frontal pits (early anterior ethmoidal cells) developed sufi&cientl}- far to be topographically frontal sinuses. In Fig. 126 the first and second frontal pits developed into frontal sinuses; in Fig. 125, the second and third. In both instances the sinuses communi- cate independently with the recessus frontalis of the middle nasal meatus. At times when the frontal sinus exists in duplicate (or triplicate) one sinus ma}' encroach bullous-like on the other. The name hitUa frontalis is, howe\'er, applied to infundibular and other cells which encroach upon the dorsocaudal boundary of the frontal sinus (P^igs. 117 and 118). A common type of duplicate frontal sinus is illustrated on the left 'Loc. cJl. 152 THE FROXTAL SINUS side of the skull shown in Fig. 120. In this skull the single right sinus has pneumatized both the horizontal and vertical portions of the frontal bone. On the left side the frontal sinus is present in duplicate. The left ventral sinus has invaded both the horizontal and vertical portions of the frontal bone and immediately dorsal to it is another, absolutely independent frontal sinus which has pneumatized the remainder of the horizontal part of the frontal bone as well as portions of the greater and lesser Avings of the sphenoid bone. This type of sinus is often overlooked in operative procedures, owing to its depth from the frontal region, its position and relations. In order to expose it from the frontal region, the removal of two plates of bone would be necessar}'. The Frontal Bulla (bulla frontalis). — Not infrequently one or other of the anterior ethmoidal cells encroaches upon the floor of the frontal S. frontalis SffOit/aJis Cc etkjfwidaJcs IStJJM fi-o/ttcUis Fig. 117. — The frontal sinuses and encroaching ethmoidal cells of an adult skull. sinus, pushing the latter balloon-like into the lumen of the sinus. To these frontal extensions of ethmoidal cells is applied the term frontal bulLx. There is no constancy, howe\^er, as to which of the ethmoidal cells impinges or encroaches upon the confines of the frontal sinus in the for- mation of a so-called frontal bulla. It may be an extensively developed cell of the bulla ethmoidalis (bullar cell), of the infundibulum ethmoidale (infundibular cell), or of the recessus frontalis (frontal cell). The frontal buUa is, therefore, merely an extension of an ethmoidal cell at the expense ol the kmien of the frontal sinus with, however, no connection whatever IROX'PAL liULLA 153 With the sinus. At times anterior ethmoidal cells arrange themselves tier-hke m the floor of the frontal sinus (Fig. i iS). Not infrequently they encroach markedly upon the nasofrontal duct and cause it to assume a sinuous course. The frontal bulla ma>- be so ])rominent (essentially a frontal sinus) and so located that in the usual Killian operation upon "the frontal smus it would be the frontal bulla and not the frontal sinus that would be opened (Fig. j 18). Fig. 118. — A dissection sho\\-ing anterior ethmi.iidal cells arranj::ed tier-like in the floor "[ the right frontal sinus. Sf = sinus frontalis; Bf - bulla frontalis; Cc - cellula cthmoielalis. The belief that the balloon-like structure in the floor of the frontal sinus is always an ethmoidal cell accompanied by a frontal sinus of the same side is not based upon facts. Witness, for example, Fig. 85, in which is represented a dissection of the frontal sinuses showing marked asymmetr}-. It will be noted that the right frontal sinus in both in- stances projects to a marked degree to the left of the mid-sagittal plane. The only evidence of a right frontal sinus is the elongated balloon-like swelling in the floor of the left extension of the right frontal sinus. Obvi- 154 THE FRONTAL SIXUS ously had the left side alone been dissected the natural inference would have been that the sweUing over the orbit was a bulla frontalis and that the frontal sinus oA^er it was an asymmetrical left frontal sinus. Strangely, however, the "bulla frontalis" happens to be the left frontal sinus and the right frontal sinus occupies the greater portion of the fields usually occupied by the conjoint right and left sinuses. Such specimens are of not infrecjuent occurrence and argue against the statement that frontal bulke are akvays cranial extensions of anterior ethmoidal cells into the lumen of the frontal sinus of the same side. Frontal Sinus Diverticula. — Rarely frontal sinuses depart markedly from the average and early give off buds which develop into diverticula^ Fig. lig. — A dissection of tlie frontal sinuses of an aelult. On tlie n-ht side is a goodly sized frontal sinus, in a sense a diverticulum, immediately dorsal to the usual frontal sinus. Yale Uni- versity Anatomical Series. (See text, page 154.) that communicate with the parent sinus in the adult. The dissection of a male head shown in Fig. iig is apropos. The ventral view of the right sinus is more or less typical. The sinus projects beyond the mid-sagittal plane to the left, a very common variation. Its greatest transverse measurement is 50 mm. and the greatest ventrodorsal measurement is but 10 mm. It does not extend to any appreciable degree over the orbit, but projects far into the squama frontalis. In these respects it contrasts strongly with the left frontal sinus. On the dorsal wall of the right frontal sinus, as shown in the ventral ' J. Parsons Schaeflt-r, .\nnals of .Suri^ery, Sept., 1912. DIVERTICULA 155 view in the larger figure, immediately lateral to the line X-Y, at point B, is noted a round ostium, about 2 mm. in diameter. This ostium led to the finding of the large di^■erticulum immediateh^ dorsal to the usual and normal sinus. Careful dissection demonstrated the diverticulum as communicating with the right frontal sinus i)roper onl}', through the small aperture 7>, shown in both figures. In the small figure to the left, a sagittal section through the right frontal sinus is revealed, the large diver- ticulum from the sinus proper, dorsal in position. A reference to the figure will show the outline of the diverticulum, passing well o\er the orbit, beneath and dorsal to the right frontal sinus proper. It Avill be noticed that three plates of bone intervene between the soft tissues of the forehead and the dura mater: first, the plate (i) ventral to the right frontal sinus proper; second, the plate (2) dorsal to the sinus jn-oper and ventral to the diverticulum; third, the plate (3) dorsal to the diverticulum and forming the ^•entral boundary of the anterior cranial fossa (F in the figure designates the anterior cranial fossa). The diverticulum measures 37 mm. in its greatest transverse dimen- sion and 30 mm. in its greatest ^■entrodorsal extent. It projects somewhat into the scjuama frontalis, and extends well dorsad into the i)ars orbitalis of the frontal bone. The frontal sinus proper of the right side communicates with the frontal recess of the middle nasal meatus indicated by the black arrow (the middle nasal concha, C, is partly cut away so as to expose the fron- tal recess). The ethmoidal infundibulum (£) ends blindh^ in an anterior ethmoidal cell. The large diverticulum communicates Avith the right frontal sinus proper through the ostium marked B as indicated b}' the white arrows in both figures. Had the right frontal sinus proper, as shown in the large figure, been opened surgically in the living subject, the large diverticulum, dorsal in position, would in all likelihood have been entirely overlooked. The natural inference, of course, would have been that the bony ])late marked "2" was the plate separating the frontal sinus from the dura mater and brain. A reference to the sketch in the sagittal ])lane demonstrates the fallacy of such a conclusion. In concluding this note a word as to the ]^robable genesis of this large diverticulum may not be amiss. There is all evidence in the specimen that the right frontal sinus pro])er had its genesis in an anterior ethmoidal ceU, which in turn had its genesis in one of the frontal furrows on the lateral wall of the frontal recess of the fetus. The ethmoidal cell continued its development sufficiently far to become topograi)hicall>' the right frontal iS6 Till': I'ROXTAL SIXUS sinus. The natural inference is, since all of the paranasal chambers are primarily outgrowths from preformed nasal spaces, that sometime during the de\-elopment of the right frontal sinus a dorsal evagination from the frontal sinus grew into the plate of bone which separated the right frontal sinus from the dura mater. The evaginated sac continued to grow and the bone immediately surrounding the sac was resorbed; the two processes, SiiiJiS froniaji.s Sinus frorr-&r.Us Fig. 120. — A specimen in which there is a duplication of the frontal sinus on the left side. The anterior of the two sinuses is largely confined to the vertical portion of the frontal bone and the poste- rior to the horizontal portion. In the usual Killian operation on the frontal sinus the posterior of the two left sinuses would in all likelihood be overlooked. The posterior sinus might be diseased and the anterior one opened with negati\'e findings. (After J. P. S.) growth of the sac and resorption of bone, taking place para passu with the further growth of the sinus proper. In this manner the large diverticulum or accessory frontal sinus was formed dorsal to the frontal sinus proper. The plate of bone marked B, although very thin, not being entirety resorbed, remained as a partition, completely separating the two cavities, save at the point of the original budding of the diverticulum; the point of ACEXKSTS OF FRONTAL SINUS 157 origin of the sac remaining, of course, as the ostium of communication between the two ca\'ities in the adult. Agenesis of the Frontal Sinus.- Unilateral and bilateral absence of the frontal sinus has been re])ortcd. Boege claims to have found bilateral absence in 4 jier cent, of 203 skuhs examined. The writer questions the frequenc>- of agenesis in Boege's results, because in a large series of specimens (well over 300) the nearest api)roach to an absent Fig. 121. — An adult skull in which it was believed that the frontal sinuses were wholly wanting. A large frontal wedge of bone exposed the cerebral hemispheres, yet failed to expose frontal sinuses. Ftirther dissection showed the frontal sinuses present in duplicate on both the right and left sides in the horizontal portion of the frontal bone, hugging the ethmoidal lab\'rinth and extending ^^"ell o\"er the orbit. The frontal sinuses are indicated by cross-hatching and b\' dotted lines. frontal sinus is shown in Figs. 129 and 123. In Fig. 129 a ca\'it}' in communication with the frontal recess extends above the nasion which in reality is a frontal sinus. However, it is totally absent in the vertical portion of the frontal bone and doubtless would be considered a case of absent frontal sinus by many investigators. In the specimen represented in Fig. 123 both frontal sinuses are seemingly wholly wanting. How- ever, this is true only of the vertical portion of the frontal bone. The 158 THE FRONTAL SINUS small openings expose goodh' sized frontal sinuses in the horizontal or orbital portion of the bone, hugging closely the ethmoid labyrinth through- out and extending medial!}- along the orbit. Frontal sinuses in this posi- tion would be wholh' missed by the usual frontal approach surgically and in all likelihood Avould be classed as wanting. Frequently sinuses in this position are, of course, ethmofrontal rather than purely frontal. How- ever, in this particular instance the sinuses are wholly within the confines of the frontal bone. i\Ieyer reports bilateral absence of the frontal sinus in a white male, aged 52 years. His case likewise showed a frontal recess which enlarged in a shghtly dilated extremit}' about 3 mm. superior to the nasofrontal suture. Siitvs f/v//f'iz1-(_s, '^ •Si, It. '^iiiii^froiifaUs Fig. 122. — An adult skull \\\\\\ extremely small frontal sinuses. Errors haA'e doubtless been made in assuming the frontal sinus absent in those cases in which there was no pneumatization of the frontal or vertical portion of the frontal bone (squama frontalis). It is well to recall that the frontal sinus is geneticalh' an outgrowth from the middle nasal meatus and that the first e\-idence of the sinus must not be sought in the vertical portion of the frontal bone. Indeed, in some instances the frontal sinus never does in^'ade the A'ertical portion of the frontal bone, develop- ment taking place \vh0ll3' in the horizontal or orbital portion. Witness, for example, the skull represented in Fig. 121. This specimen was exhibited as a skull Avith absent frontal sinuses. The verti- cal saw-cut exposed both frontal lobes of the brain and met at right angles ACIIXKSIS Ol' FROXTAl. SIXUS 1 59 a deep horizontal cut made at the le^■el of the nasion (])oint of contact of the frontal bone with both nasals). Even with this large wedge of bone removed, no frontal sinus was exposed, and in a sense the exhibitor of the skull was justified in declaring the frontal sinuses absent. Through the kindness of Doctor Hoffman the writer \\-as gi\-en an opiiortunity to examine the skull. The orbital type of frontal sinus was at once suspected. Small trephine openings made at the highest i)oint of the nasal processes of the maxilhr re\-ealed two fairly large frontal sinuses hugging closely the Si'f2fs f'oiUcilis (Me topic sutrjre) Siitus f/vnAil/'s Os izasuZe Fig. 123. — An adult skull \\"ilh a persistent frontal ijr nu'topiL' sutuix'. N(jtu that, the frontal sinuses are completeh' wanting in tlic vertical <>\- frontal portinn of the fremtal bi.'ue, but present in the horizontal or orbital portion. The vertical saw cut in the frontal plane failed to re\'eal frontal sinuses, and it was believed that there was total agenesis of these paranasal chambers. Further search, however, resulted in finding frontal sinuses as depicted in the illustration. ethmoidal labyrinth and extending for some distance into the horizontal portion of the frontal bone over the medial and ce])halic wall of the orbit. On the left side a supernumerary sinus was found immediately dorsal to the one ventrally placed. ]\Ioreo\"er, a supernumerary frontal sinus was found on the right side medial to the frontal sinus first exposed and lateral in position. In the drawing the outlines of the four frontal sinuses are given. They are wholly dorsal to the \-ertical saw-cut. The ordinary procedure for exposing the frontal sinuses would, of course, ha\'c failed i6o THE FRONTAL SIXUS to reveal the chambers in this case. Four frontal sinuses, therefore, existed where a total absence was thought to be the condition. Very careful examination is necessary before one is justified in de- claring a total agenesis of the frontal sinus. ^ It is very rare. Of course, some would call such sinuses ethmofrontal. At times the frontal sinus remains extremely diminutive in size. It is very common to err in these cases and declare the frontal sinuses absent. Only careful search and a realization of the great variations in the anatomy keep one from "going wrong." The Nasofrontal Connections in the Adult. — As stated in the intro- duction, in order to properly interpret points in the adult anatomy of a Sinus frontalis DvctiLS nasoFrantalis-,. Concha, rur^. jned. Infundib. eth.. IVoc. UTicmatus Cellulae eth.air.t. Bvlla eth: ^Si?7.jz5 splte/ividixlis Jfypophvsis cc7vbri C( iicha 7V/3, supremzil Ostiv.m, ?nax.cKo,h: WL iias.supa-wr Pig. 124. — Dissection of an adult lateral nasal wall with especial reference to the frontal recess and the nasofrontal connections. Note that the nasofrontal duct and the infundibulum ethmoidale are discontinuous channels. (See text, pages 161-164.) region, it is frecjuently necessary to re^^ert to the embryology of the part or parts concerned. This, indeed, is true of the nasofrontal region.- Doubtless many of the erroneous statements extant in the Hterature on the connections of the frontal sinus with the nasal fossa are the result 1 J. Parsons Schaeffer: Further Observations on the Anatomy of the Sinus Frontalis in Man, Annals of Surgery, December, 1916. "- J, Parsons Schajffer: The Genesis, De\'clopment, and Adult .Anatomy of the Nasofrontal Region in Man. .Vmer. Jour. Anatomy, Vol. 20, July, iqiO. NASOFRONT.VL CONNECTIONS i6i of drawing conclusions from a stud)' of too few specimens, of studying adult material alone, and of errors in interpretation due to the fact that embryologic and adult studies were not carried on simultaneously. The adult nasofrontal region presents a A'aried anatomy— a fact in accord with the varied genesis of the parts in\'olved. In the adult, one usually finds e\-idence of the pre\-ious embryologic condition that must have obtained in the particular case. Careful analysis of the nasofrontal region reveals, as a rule, the deri\'atives of the frontal furrows or pits and ^ Smzts rrontalis -Cdlala etk.cau _ _ - J?ec(issics frontalis CeJlvIa. ifh.avt.^Pi ovta7 topoif jp/iii^ CuUnlae t'fh aut.(m,i.i,l - - Cdhdac t't/i.posL- - •-s-^-^^^^mhA' Ostium maxil/^Te J '-y ~ Fig. 125. — A dis.section of the lateral nasal ^^'all .showing the ethmoidal eells open and one of the posterior ethmoidal cells projecting into the body of the sphenoid bone at the expense of the sphenoi- dal sinus. It will be noted that the latter is e.xtremely small. The frontal recess receives the frontal sinus and certain anterior ethmoidal cells. The uncinate process is curved caudally and laterally, thereby exposing the ma.xillary ostium in the depth of the ethmoidal infundibulum. It is in such cases that probing of the maxillary ostium is possible. of the frontal folds or conchae; provided, of course, these structures were differentiated. As stated elsewhere, there are instances in which the lateral wall of the recessus frontalis does not become configured by pits and folds. Moreover, in some specimens the adult anatomy is so altered that interpretation is very difficult, even impossible. It may be Avell here to refer to specific dissections of the region for study and analysis. In Fig. 124, for example, is represented an adult l62 THE FROXT.\X SINUS nasofrontal region exposed for study by the removal of the operculating middle nasal concha. There is positive e\-idence of four embryological frontal furrows or pits. The first or most ventral of the latter differ- entiated into an anterior ethmoidal cell of small dimension, communicating directlv with the middle nasal meatus medial to the processus uncinatus. The third and fourth frontal furrows or pits likewise developed into anterior ethmoidal cells, both of which communicate with the middle nasal meatus cephalic to the semilunar hiatus of the infundibulum eth- Siiuisfroutalis Prohtiii (iutius luviofiviiialis Sinn£ frontalis - - ~ l7/ftjndii. et/i ^ Proc.zinci7ia,tzzs - /^ Bulla ethr ' CeZhifMe ei7z.ant. ,.^ " Hypophi/si^ cerchri Smns sp^noidalw Concha. itMs.med. Ost.iv,mpljxiri/Vffeii,T7t '' tuJjae aiiditivae Fig. 126. — A dissection in which tlic infundibulum ethnioidale and tlie nasijfront.al ducts are not only discontinuotis channels, but channels in non-alignment. (Compare with Figs. 124 and 127.) moidale. The second frontal furrow or pit after first developing into an anterior ethmoidal cell continued to extend its boundaries until it became topographically the frontal sinus. It should be noted that the duct of the frontal sinus (ductus nasofrontalis) is in the position of the embryonic second frontal furrow or pit and that it is in the same axis as the infundi- bulum ethmoidale and the hiatus semilunaris, but not in direct continuity with them. The sinus frontalis in this instance (Fig. 124) communicates, therefore, Avith the rccessus frontalis directlv via the ductus nasofrontalis. N ASOFRONTAI. CONNECTIONS 163 INIoreover, the infundibulum cthmoidale ends blindly as an anterior eth- moidal cell (infundibular cell) lateral to the recessus frontalis and the ductus nasofrontalis. The anatoni}- represented in Fip;. 124 is that found in a large number of adult specimens and is illustrati\-e of one of the anatomic t^■pes of this region. It should be noted that the infundibulum ethmoidale is not directly continuous witli the nasofrontal duct, but that it bears an intimate and important relation to it. The relation is, in a sense, ea con- Sinus frciiti-d?s — ._ Pi-ole i?t dvch s ^ " "f-L ^ £\ TiasofTOTitalis Cdlula etk a/it _ Concha iias i/icd - - * i- w- A. - - ' T, s ^^''^ . Cel.Jvlae etl/,M7it. >- _Cellula dh. ant (mod) Cdlulae eth post — Ostium sphmvidaJe .^1 1 I yCoiichaj/as.supieiJial TrocTmcmuivs , -- '!^;;i^ ^-'T U r-WP^^ Conclta ?ias.siip. ^Concha, nasinf. Fig 127— a dissection of an adult lateral nasal wall. Especially note that the mtundibulum ethmoidale is in direct continuity with the frontal sinus— a bridge of mucous membrane (O) extend- ing across the frontal end of the infundibulum ethmoidale; moreoyer, that the uncmate process at its dorsal termination causes the infundibulum cthmoidale to end m a deep pocket (A), just over the ostium of the maxillary sinus. The anatomy of this specimen is such that the maxdiary smus would perforce become a cess-pool for an infected frontal sinus. (Compare with Fig. 124.) iigxwus hut not a continuous one. Drainage from the frontal sinus would find its way partly into the middle nasal meatus directly and parth' into the infundibulum ethmoidale. An exploratory probe passed toward the frontal region via the infundibulum ethmoidale would, of course, Imd its way into the ventral, blind end of the latter and not into the frontal sinus. To probe the frontal sinus in this case it would be necessary to pass through the proximal ostium of the ductus nasofrontalis located m the recessus frontalis. 1 64 THE FRONTAL SINUS It is very interesting and instructive to compare the embryologic anatomy of the recessus frontaUs illustrated in Fig. no with the adult anatomy illustrated in Fig. 124. In the former the third frontal furrow and the infundibulum ethmoidale are in the same axis; in the latter, the second frontal furrow (now the nasofrontal duct) is in the same axis as the infundibulum ethmoidale. If in Fig. 36 the sinus frontalis had developed from the same frontal furrow as in Fig 124, the relation be- tween the ductus nasofrontalis and the infundibulum ethmoidale would have been less intimate. The dissection of the adult nasofrontal region illustrated in Fig. 125 gi\'es evidence of the early embryologic frontal furrows or pits. The adult derivatives of the latter are readily identified. The first frontal pit developed into a small anterior ethmoidal cell which is in direct com- munication with the recessus frontaHs by means of its ostium. The second and the third frontal pits developed into the frontal sinuses (sinus frontalis in duplicate). Both of the latter communicate directly by means of independent ostia with the recessus frontalis, no ductus nasofrontales being present. A study of the dissection shown in Fig. 125 clearly points out that the infundibulum ethmoidale terminates blindly (indicated by a probe) as an anterior ethmoidal cell (infundibular cell) lateral to the recessus frontalis. Loose interpretation of the anatomy of the frontal region in this instance might lead to the erroneous statement that the frontal sinus developed as an extension of the infundibulum ethmoidale. One sees even a channel-like depression on the lateral wall of the recessus frontalis connecting in a sense the frontal sinus with the infundibulum ethmoidale. It is obvious that the drainage from the frontal sinus would in part find its way into the infundibulum ethmoidale, thence via the latter to the ostium maxillare and into the maxillary sinus (antrum of Highmore). In Fig. 128 we have evidence of four embryologic frontal pits. The deri\'ati\'es of these pits are two anterior ethmoidal cells and two frontal sinuses, all in communication with the recessus frontalis of the middle nasal meatus. The first (most ventral) and fourth (most dorsal) frontal pits developed into two small ethmoidal cells. The second frontal pit developed sufficiently to be topographically a frontal sinus (indicated in the drawing as an anterior ethmoidal cell). The frontal sinus proper took its origin from the anterior ethmoidal cell which had its genetic point in the third frontal pit. The result of the encroachment of the cell from the second frontal pit, is a narrow, tortuous nasofrontal duct communicating between the frontal sinus and the frontal recess. As in Figs. 124 and 125, XASOFROXTAL COXXIX'TIOXS i6s in Fig. 1 28 the infundibulum ethmoidale ends blindh' lateral to the recessus frontalis. Elsewhere mention is made of oecasional adult specimens in which the ductus nasofrontalis and the infundibulum ethmoidale are continuous channels. In Fig. 127 is represented a dissection of an adult nasofrontal region in which the ventral extremit>- of the infundibulum ethmoidale is directh- continuous with the ductus nasofrontalis and secondarih' with the sinus frontalis. :\Ioreo^•er, the dissection shows a plate of tissue intervening between the free border of the processus uncinatus and the bulla ethmoidalis, thus bridging over the ventral extremity of the infundi- Cdlulc/C Cf/i .ff7/f. CeJh}7ac ttl-./jcst. _ Si// us sp7/c7io?da7ii ffj/popki/sis cerebri Concfia nas. supnmal 7^'*''' k ConcJia 7MS. sup. ^ - 1- , - ^ejJ-'«,-; . - Surus fronfcdis -I"/ obe 771 /f.vcf/jj /7asofro/if7t7i.-i ^. .Cdl/dr/T: cf/7. a7/f. ,. Co//cka//as./r/(d. _ . , _ I/if7}7/(7ib. ef//. -- Osfiii/// 7/iaxillare \\- - froc. i/nchtai?! w Fig. 128. — Dissection of an adult lateral nasal \\-all. Especially note the tortuous and narrow nasofrontal duct and its discontinuity with the ethmoidal infundibulum. Moreover, note the im- pingement of one of the anterior ethmoidal cells on the confines of the nasofrontal duet. Such nasofrontal connections are inefiicient as drainaj^e channels, and readily occluded b>' inflammatory conditions. bulum ethmoidale and, in a sense, replacing the hiatus semilunaris in this position. One encounters difficulty in interpreting the anatomy of the nasofrontal connections in this specimen. Did the frontal sinus develop from the ethmoidal infundibulum (by a direct extension or from an in- fundibular cell) or from a second frontal ]^it (early anterior ethmoidal cell) ? The infundibulum by its ventral and cephalic extension usually comes into topographic relationship with some of the anterior ethmoidal cells which arise from the frontal pits. In this instance (Fig. 127) a l66 THE FRONTAL SIXUS relationship ma}' early have been estabhshed with the second frontal pit. Resorption of the intervening barrier would, of course, bring the ethmoidal infundibulum and its semilunar hiatus into direct continuity with the anterior ethmoidal cell arising from the second frontal pit, likemse with the frontal sinus. INIoreover, the specimen gives positive evidence of three frontal pits (now celluhT ethmoidales anterior). AMiether an addi- tional frontal pit, A\-hich ga\-e rise to the frontal sinus, was present in the position of the adult nasofrontal duct is, of course, impossible to say. Two of the anterior ethmoidal ceUs are separated by a considerable interval. This space may have been the second frontal pit. Again, the two frontal pits in question (cellulae ethmoidales anterior) may have been crowded apart hv a buUousdike A-entral and cephalic growth of the ethmoidal in- fundibulum in the establishment of the frontal sinus. Drainage from the frontal sinus in such instances (Fig. 127) would pass almost wholly into the ethmoidal infundibulum and via the latter to the ostium maxillare, thence into the maxillar}- sinus. Should the floor of the ethmoidal infundibulum in such cases be largely replaced by an elongated ostium maxillare (a rather common occurrence. Fig. 103), the frontal sinus and the maxillary sinus would from a practical vinv- poiiil be in direct communication. It should be recalled that the maxil- lare' sinus is genetically an outgrowth from the floor or lateral Avail of the infundibulum ethmoidale and that the initial area of the outgrowth varies considerably in extent, thus accounting for the varied size of the adult ostium maxillare. The Nasofrontal Duct (ductus nasofrontalis, infundibulum of the frontal sinus). — The duct leading from the frontal sinus to the nasal fossa is extremely A'ariable in its anatomy. Indeed, a large number of frontal sinuses do not haA-e true ducts connecting them Avith the frontal recess of the middle nasal meatus. In such cases the frontal sinus extends Avell doAvn toAvard the nasal fossa and communicates directly by means of an ostium Avith the frontal recess. In a general Avay it may be stated Avhen the frontal sinus develops by a direct extension of the frontal recess that its relations Avith the frontal recess in the adult Avill be more intimate. On the otlier hand, Avhen the sinus develops from one of the anterior ethmoidal cells it will more frecjuently communicate Avith the frontal recess by means of a variable duct. It should, however, be stated that a goodly number of adult frontal sinuses Avith a genesis from anterior ethmoidal cells do not haA'e nasofrontal ducts. Indeed, there are more frontal sinuses encountered in Avhich true ducts of communication Avith the frontal recess are Avanting than otherAvise (Figs. 125 and 129). XASOFROXT.U. DUCT 167 The nasofrontal duct when present ma}- be straight and short, or straight and rekitively long. Again, it may be long and more or less tortuous or serpentine. Witness, for example, the specimen shown in Fig. 1 28, in which the nasofrontal duct is long, narrow and curved. It has ver}- delinitely two ostia frontalia, one i)roximal or nasal in position and the other distal or frontal. The duct is encroached upon by an an- terior ethmoidal cell (rcalh' a second frontal sinus) which de\'eloped from the second frontal furro^^•. The slightest swelling of the mucosa of such narrow and tortuous nasofrontal ducts will, of course, occlude the passage of communication between the sinus and the nasal fossa. OstiiLni frontaZi Reccssij^ Frviitalis -^ Concha fr/iLS.Tned (cut) Bnl.la, eth . . SiTtus frontalis Proc . imciTzaJMs Fig. 129. — The lateral nasal wall of an adult, with a small frontal sinus and an absent naso- frontal duct. Indeed, the sinus is ethniofrontal and the anatomx" such that one niiKht consider the frontal sinus absent. It would not be reached by the usual Killian operation. In some instances the nasofrontal duct is roomy and possesses large nasal and frontal ostia, thus affording a Ix'tter drainage channel for the sinus. The efficiency of the duct is usualh' in direct ratio to its length, diameter and directness (Figs. 126 and 1,^0). The nasofrontal duct witli its proximal or nasal ostium, or in the absence of a true duct the ]n-oximal ostium frontale (in the latter case there is no distal ostium frontale), bears a varied relation to the ventral extremity of the infundibulum ethmoidale. The latter usually ends blindly lateral to the terminal (nasal) portion of the nasofrontal duct. The ethmoidal infundibulum and the nasofrontal duct are at times in the i6S THE FROXTAJ. SINUS same axis (Figs. 124 and 197). Again, the nasofrontal duct with its proximal or nasal ostium is not in alignment with the ethmoidal infundibu- lum. Witness, for example, Fig. 126, where the proximal ostium frontale is located medial to the cephalic extremity of the processus uncinatus. Drainage in the latter instance would in a large measure be diverted into the middle nasal meatus directly. Moreover, one encounters speci- mens in which shallow gutter-like depressions on the lateral wall of the iS fi-ontcilis 6.7nar.ilf,aris \ v5. -mMx.i7la.rib Jhjx:. 77Msofron,tali.!^ Fig. 130. — The mucous membranes of the right frontal and maxillar>' sinuses e.xposed. Xote the reg- ular nasofrontal duct. The old term "infundibulum of the frontal sinus " applies well in this case. frontal recess connect up the nasofrontal duct with the ethmoidal infundi- bulum. Such depressions must not be confused with the nasofrontal duct (Fig. 125). Finally, it is well to remember that occasionally the nasofrontal duct and the ethmoidal infundibulum are continuous channels. In the vast majority of instances, however, the nasofrontal duct and the ethmoidal infundibulum are discontinuous channels, save for a slight depression that occasionally extends between them. Concluding Considerations. — In most cases in the first years of childhood, and in many instances in the adult, the frontal sinus owing COXCLUDIXC, COXSrOKKATlOXS 169 to its relations cannot rcadih- be reached from the forehead. As pointed out elsewhere, in many young children and not infref|uenth' in adults there is no frontal sinus in the S([uama frontalis (frontal or vertical portion of the frontal bone) or at best but sparsel.\- de\-eloped in its base. In such cases the sinus is best exjiosed in the region where the frontal bone meets both the nasal bone and the frontal (nasal) process of the maxilla. The clinician must bear in mind that there is no un\'arying tvjjical type of trontal sinus. Clreat ^ ariations are encountered. The prominence of the superciliar_\- ridges or eminences {amis siiprrciHarcs) is verx un- reliable as an index of the location and extent of the frontal sinuses. Indeed, the author's studies and obser\"ations would seem to indicate that the ridges should be entireh' ignored in clinical work. While it is true that the right and left sinuses are separated b}' a bon\- jiartition {scptiiD! siiiiiii))! froiitaliinii), it is ecjualh- true that the di\-iding jiartition is rareh- located in the mid-sagittal ])lane, save immediateh' dorsal to the nasal bones. Indeed, one or the other frontal sinus ma_\' occupy the "whole frontal regi(in, the se])tum being j^laced oblifjuely in both the semi-sagittal and semi-coronal planes, S(3 that the larger sinus occupies a ventral position: that is, in front of the smaller sinus. 'Hiis is important clinicalh', for a health}' sinus may be opened surgicalh' on the op])osite side, the diseased and sought sinus being dorsal to it. Moreo\'er, it is easy to err in such cases by belie\-ing that a supernumerary frontal sinus is present when in realit}- it is merely an extension of the sinus belonging to the other side (Fig. 85). Deficiencies or dehiscences in the osseous walls of the frontal sinus are of occasional occurrence. The del'ects are either congenital or patho- logic in origin; others are the result of extreme pneumatization. The author finds that dehiscences in the orbital wall are the most frequent. The cerebral wall and the frontal or ventral wall abo\e the supraorbital border (margo siipraorbitalis) have been found defective in a few instances. But one specimen was found in which the inter-sinus septum was per- forated, leading to a connection of the two sinuses. The dehiscences are either covered over with a mucoperiosteum or Avith a mucous membrane only. When the defect is a congenital one the periosteum apparently ends at the margin of the ostium dehiscence. The possibility of infection extending to the tissues of the orbit and to the meninges through such osseous defects must be kept in mind. Partial septa of varying degree frequently project from the walls of the frontal sinus. They divide the cavity of the sinus incompletely into subcompartments, some of which not infref|uently partake of the nature 170 THK I'RUXTAL SINUS of deep recesses and in consequence are drained with difliculty. The behef that these recesses at times form enclosed cells Avithin the frontal sinus is, according to the Avriter's observations, unwarranted. It would appear that supernumerar}' frontal sinuses and impinging ethmoidal cells have at times been erroneously designated as "enclosed recess cells." Moreover, the olfactory fissure at times projects into the dorsomedial wall of the sinus as a bleb-like ridge. Care must be exercised in operative procedures lest the impinging olfactory fissure be broken into and the dura mater exposed to the infection. The impingement of the olfactory fissure is especially prominent when the dorsal portion of the inter-sinus septum is deviated to one side. Agenesis of the frontal sinus is rare; duplication and triplication common. The diseased sinus may be the one dorsal in position and orbital in type (Fig. 120). The skiagram may not reveal it. In some cases the frontal sinus is entirely absent in the Irontal or vertical portion of the frontal bone, but present and roomy in the orbital or horizontal portion, hugging closely the ethmoid labyrinth and extending far dorsad and laterad into the roof of the orbit. Indeed, in adults where the frontal sinus exists in duplicate of the t}'pe shown in Fig. 119 it may be necessary to open the ventral sinus to get to the one dorsal in position. The skiagram is of great value in determining the presence and extent of the frontal sinus in the region of the forehead, e.g., in the vertical portion of the frontal bone. Where supernumerary frontal sinuses exist and where the sinuses are of the orbital t}'pe, e\'en skiagraphy may furnish erroneous results. Of course, rhinoscopic examination is an iuA-aluable supplement in the diagnosis. Electrical transillumination is unreliable. In this connection it may not be amiss to cjuote briefly from Turner and Porter.^ "Although the older method of investigating the frontal sinus b}' electrical transillumination undoubtedly possesses some value as a means of delineating the vertical portion of the caA'ity in the frontal bone, it frequently fails us when it is most desirable that we should obtain definite information as to whether the sinus is present or not. Further, it is rjuite useless as a means of ascertaining the existence of a horizontal or orbital extension of the caA-it}' or for the purpose of defining its relations with the ethmoidal cells. If a frontal sinus exists it is possible to demon- strate its presence by skiagraphy, proA'ided the picture is a good one and that the rays haA-e passed through the head at the correct angle. Should the skiagram not be satisfactory, a second or e\'en a third one should be taken in order to settle this point. ' The Skiagraphy of the Accessory Xasal Sinuses, Edinburgh, 191 2. COXCLUDINC; CONSIDERATIONS 171 If the rays have been incorrectly directed through the sagittal di- ameter of the head from a ]>oint too far abo\'e the external occipital protuberance a small frontal sinus may, in consequence, be invisible in the lower part of the frontal bone. If, on the other hand, the rays have been transmitted through the skull from a point some distance ])elo\v that land- mark, the ethmoidal cell ma>' be projected onto the frontal sinus area and thus deceive us as to the true condition. Coakley' has ])ointed out that a small frontal sinus h'ing parallel with the supraorbital margin may escape detection upon the skiagram. Apart from these faulty or exceptional con- ditions, if a frontal sinus exists the anteroposterior skiagram will reveal it, and if there should be any doubt in the obser\-er's mind a profile view of the head will pro^■e of further assistance. From time to time the surgeon has operated upon the frontal sinus area and found that the ca\'it\- was absent; with apreliminar}use of the X-rays, this mistake should no longer be made." In a general wa}', as stated in a jircNious paragraph, when the frontal sinus de\-elops from an anterior ethmoidal cell — frontal or infundibular — the adult cavit}' will more frequently ha^-e a nasofrontal duct. The tortuositv of the duct will, of course, depend upon the location of the cell from Avhich the sinus frontalis develo])s and upon the degree of develop- ment and disposition of neighboring ethmoidal cells. On the other hand, when the frontal sinus develo])s by a direct extension of the frontal recess there will, in all likelihood, be no nasofrontal duct and the sinus proper be in direct relationship and communication with the adult recessus frontalis of the meatus medius. The connection of the nasofrontal duct is, of course, dependent upon the genesis of the frontal sinus; usually, however, the frontal sinus communicates with the frontal recess of the middle nasal meatus. The outlet of the frontal sinus is readily influenced by variations in the anatomy of the related i)arts and b>' inflammatory conditions. An asymmetrical nasal septum ma>' encroach upon the frontal ostium or the terminal portion of the nasofrontal duct. The size and disposition of the anterior group of ethmoid cells likewise have an important bearing. Enlargement of the uncinate process and the ethmoidal bulla frequently encroach upon the ethmoidal infundibulum and the semilunar hiatus and secondarily aflect the outlet of the frontal sinus. A large middle nasal concha, because of its relationship, readily impinges upon the site ol the frontal outlet. Then, again, the whole middle meatus ma)' be so narrowed toward the frontal region that the si)ace is insufiicient for good frontal drainage. The latter may be the condition in apparently normal noses. 1 Annals of Otology, Khinolog\- and Laryngology, 1905. 172 THE FRONT.VL SINUS The well-known clinical fact that the sinus maxillaris (antrum of Highmore) is frequenth' a cess-pool for drainage from the frontal region of the meatus medius, doubtless leads to the erroneous belief that the in- fundibulum ethmoidale is, in the majority of instances, directly continuous anatomically Avith the nasofrontal duct or, in the absence of the latter, directly with the sinus frontalis. Il should, however, be pointed out, despite the fact that direct anatomical continuity is uncommon, from a clinical view- point in as many as 50 per cent, of adult cases the relationship is so intimate between the infundibidmn ethmoidale and the sinus frontalis or its duct {ductus nasofrontal is) and certain of the anterior ethmoidal cells {some infundibular, others frontal) that drainage from these paranasal chambers finds its ti'av in ivhole or in part into the infundibidum ethmoidale, thence via the latter to the ostium maxillare arid through it into the sinus maxillaris. If in those cases in which the sinus frontalis (or its duct) is directly continuous anatomically with the ventral extremity of the infundibulum ethmoidale the ostium maxillare should occupy the greater portion of the floor of the infundibulum ethmoidale fa condition encountered) the frontal sinus and certain of the anterior ethmoidal cells (frontal and infundibular) would, anatomically and clinically, be in direct communication with the sinus maxillaris. Intranasal opening of the frontal sinus for the purpose of drainage in chronic suppuration is now deemed feasible and is attended with no greater risk than is the extranasal operation. As stated before, the surgeon must continually bear in mind that the ventral portion of the ethmoidal laby- rinth is intimately related with the sinus frontalis and that both of these paranasal chambers present great variations. X-ray examinations are of great help in determining the anatomy of the particular field. Moreover, certain landmarks, e.g., the concha nasalis media, the processus uncinatus, the bulla ethmoidalis and the entrance to the recessus frontalis are fairh- constant in their location and are of aid to the operator in the intranasal approach of the sinus frontalis. The proximal or nasal ostium of the frontal sinus is usually located in the recessus frontalis, and is related ventralh- to a crest on the sinus surface of the ectal table of the frontal bone; dorsally to the ethmoidal labyrinth; laterally to the anterior cellule ethmoidales located between the ostium and the lacrimal bone; and medi- ally to the nasal process of the frontal bone. It is, of course, obvious that ethmoidal cells must be ablated in establishing good drainage for the sinus frontalis and that the surgical approach is more direct than is the natural and often tortuous nasofrontal connection. Aloreover the latter is not infrequently closed by inflammatory states of the mucous membrane. V-THE SINUS SPHENOIDALIS CHAPTER V THE SINUS SPHENOIDALIS The Fetal Stage The sphenoidal sinus (sinus s])henoidalis) primarily arises in relation with the posterior cupola or dome of the cartilaginous nasal cai)sule and is geneticalh- demonstrable as earh- as the fourth month of fetal life, l^he cupola-shaped recess or terminal nasal sinus (sinus terminalis), above referred to, is poorly developed in man; yet is, strictly speaking, the primi- ti\-e sphenoidal sinus. The wall of the terminal sinus gi\-es the foundation for the sphenoidal turbinal or concha (ossiculum Bertini). The actual bone arises through ossification which begins in the fifth month of fetal life as two primary and several secondary centers (see page 43). Lui,^„l,,h:U 0/ \ ■ / \ \ X -*;,»., ,j,l,,m„l„l,. Fig. 131. — Outline drawing of a frontal section tlirongli tlie dor.s.-il portion of ilio nasal ca\-it\-. X 10. Hnman oml)r\"o, aged rjrj daA's. It must be clearly understood that no portion of the fetal s])henoidal sinus is contained within the sphenoid bone. It is necessary that resorp- tion of the intervening nasal capsule takes place before the terminal nasal sinus (early sphenoidal sinus) can come into actual contact with the body of the sphenoid bone. Indeed, such resorption does occur subsecjuently. In a certain sense, therefore, the fetal sphenoidal sinus is a constricted portion of the nasal fossa. The proximal end of the constriction remains as the ostium of the sinus and is ahvays located cephalic to the highest nasal concha that may be present in the particular case. 1 70 THE SINUS SPHENOID.\LIS The average sphenoidal sinus of the term fetus has a capacity of from 6 to 8 cubic mm., measuring approximately 2 by 2 by i. 5 mm. The ostium sphenoidale varies in diameter from 0.5 to 1.5 mm. The Childhood Stage Even in infancy the sphenoidal sinus continues to be nasal in position rather than sphenoidal. However, by the end of the third year the rudi- ment of the sphenoidal sinus is surrounded by bone save ^'entrally toward the nasal fossa where an opening, the primitive ostium sphenoidale, exists. During the fourth 5'ear the superior and medial parts of the Sinus splu'nniAn7J,s ^ f/ifpop/a/sib cerebri^ \ — ConcJ/a sph('n/j7/ij:t,7i5^\ \ -»iu*»i.Jfe^~ Fig. 132. — A sagittal section througli the sphenoidal sinus of a child aged iS months. Particu- larly note that the sphenoidal sinus does not occupy any portion of the sphenoid bone proper at this age, but is distinctly related to the sphenoidal concha or ossicle of Bertin. X 0.9. bordering nasal capsule are resorbed and the body of the sphenoid bone allowed for the first time to bound the terminal nasal sinus (the primitive sphenoidal sinus). The superior and lateral parts of the sphenoidal concha (bony capsule) are also resorbed. This resorption causes the ostium sphenoidale in the sphenoidal turbinal to be notched instead of rounded. Later the inferior part and those portions partially surrounding the ostium sphenoidale of the turbinal in c|uestion fuse with the ethmoid bone and the body of the sphenoid bone. This gives the primitive sphenoidal sinus (sinus terminalis) opportunity to grow into and pneu- CHILDHOOD STACK 177 matize the body of the sphenoid bone in the production of the definitive sphenoidal sinus. The sphenoidal sinus in earh' childhood is more precocious than one would infer from di^'ers statements in the literature. It is well known that in its initial growth into the bod>' of the sphenoid bone the sinus has a marked tendency to de\'elop in the dorsolateral plane at the expense of its direct ventrodorsal growth. This leads to an early thinning of the lateral wall of the sinus and to relatively thick septal and dorsal walls. Indeed, the dorsolateral aspect of the sphenoidal sinus may thus early come into intimate relationship with the ophthalmic and maxillary nerves and be a potent factor in childhood neuralgias of the trigeminal nerve, O-stiivm sp/miwulale A. carotis irttfrn-ct -C>" Sinus spheno'idalia , _ _ ott. C.7?as,7n.ed. ..^ _^ j^ •Cx C-ltCtS. 77? f.- -*_- ■-};i:i "" N. optic7j,s __^ - - ' N oculoirrotvrljj^s • ' .--N.trochhuxris ■^N.7narillar7.s " N.can pteri/ffoicletts Fig. 133. — A frontal section through the nasal fossx- and sphenoidal sinuses of a child aged 7 years. X 0.8. even as early as the third year. Moreover, the pterygoid (Vidian) canal with its contained nerve and vessels likewise early— sixth or seventh years— establish close relationship with the developing sphenoidal sinus (see page 3 20). It is obvious that the sphenoidal sinus is early of im- portance clinicaUy and that by the second or third year has assumed proportions sufficiently large to become the seat of pathologic processes and to retain infectious material in its cavity. Table I indicates the growth of the sphenoidal sinus during the childhood period, e.g., from birth to puberty. The distance of the ostium sphenoidale from the cribriform plate of the ethmoid bone varies from 2 to 5.5 mm. There is no constancy in size of the ostium, the writer finding it to vary from i X i mm. to 12 178 THE SIXUS SPHEXOIDALIS 3.0 X 3.5 mm. in a limited, but graded series of specimens of the childhood stage. Table I Age Side Cephalocaudal (height) In luilljincters Mediolateral (width) ist yr. R 2-5 2-5 i-S L 2-S 2-5 1.8 211(1 yr. R 4.0 3-4 2 .0 L 4.0 3-S 2 .0 3rd yr. R 5-5 4.0 - ■ 5 L S-2 4.0 2.8 5lh yr. R 7.0 6.5 4-5 L 6.5 6.8 4.8 7th yr. R II .0 7-S 8.0 L II .0 7.0 7.0 9th yr. R iS'O 12.0 10. L 14 S II-5 11 -0 nth yr. R 14.0 130 16.0 L s.s 10. 8-5 14th yr. R 15-0 10. 12.0 L 14.0 14.0 S.o Ventrodorsal (length) The Adx^lt Stage General Considerations. — The adult sphenoidal sinus occupies a more or less central position in the skull and ^•aries to an unusual degree in size and shape. ^ It is commonly located in the ventral and cephalic part of the body of the sphenoid bone. However, very frequently the paired sinuses pneumatize the entire sphenoidal body, even extend into the basilar process of the occipital bone and into the pterygoid processes and lesser wings of the sphenoid. Moreover, the sinuses not infrequently extend in the form of recesses into the superomedian aspect of the orbit, especiallv into the orbital process of the palatal bone (palatal sinus) , into the anterior and posterior cHnoid processes and bases of the greater wings of the sphenoid bone and into the ethmoid bone. Of course, not all of the recesses are necessarih' present in the same specimen. Frecjuenth' there is marked asymmetry, giving rise to a prominent recess into one or other neighboring point. Rarely the rostrum of the sphenoid is invaded. The recesses of the sphenoidal sinus are of great clinical importance since the}- encroach \'ariously upon the foramen rotunditm with the con- tained maxillar}' ner\'e; the foramen ovale with the mandibular nerve; ' The plaster casts of the sphenoidal sinuses liy Dr. Hanau \V. Loeb are vahiable and instructive in this connection. The reader is referred to Dr. Loeb's (Jperative Surgery of the Nose, Throat and liar, St Louis, 1917. ADULT STAGE 179 and the siifycn'or orbital (s]ihenoida]) fissure with the o]:)hthalmic, oculo- motor, trochlear and abducent nerves, etc. (Fig. 195). When the lesser wing and the anterior clinoid ]:)rocess are partially hollowed out, the sphenoidal sinus encroaches upon the optic ner\'e, and if the pneumatiza- tion is extensive the ner^•e lies, in a sense, within the cavit}' of the sphe- noidal sinus. The clinical importance of this relationshi]) cannot be over- estimated (Figs. 140 and 107). \'ery freciuently, indeed, the body of the sphenoidal sinus is so hollowed out toward and into the bases (jf the pterygoid processes that the pterygoid or \'idian canal with the contained nerve (Mdian) and \-essels throw the floor of the sinus into a ridged relief. In many cases the ner^'e and vessels are separated from the mucous mem- brane of the sinus by the merest shell of bone. Indeed, osseous dehiscences may be present (Figs. 139 and 195). The author has encountered not a few cada^'ers in which the sphe- noidal sinus not only pneumatized the entire ^'entral portion of the body of the sphenoid bone, but extended be^'ond into the palate and ethmoid bones in the formation of ])alatine and ethmoidal recesses. Indeed, in a number of instances one or more posterior ethmoidal cells were entirely replaced by such sphenoidal-sinus extensions. The latter may be suf- flcienth' extensi^•e to be bounded by the ethmoid, palate and maxillary bones and to establish immediate relationship with the maxillarv sinus — a shell-like lamella of bone alone intervening between the mucous membranes of the respective sinuses (Figs. 135 and 136). Rarely the sphenoidal sinus extends sufliciently far into the pterygoid process of the sphenoid bone to come in contact with the wall of the maxillary sinus. Rarely the ethmoidal extension of the sphenoidal sinus is found to be in actual contact with the supraorbital extension of the frontal sinus. The pterygopalatine (sphenomaxillar}-) fossa inter\'enes between the osseous boundaries of the sphenoidal and maxillary sinuses and precludes intimate relationships between the two sinuses at this point, and any extension of the sphenoidal sinus to come into contact with the maxillary sinus must either be over the sphenopalatine fossa, then in front of it, or dorsal and inferior to the fossa, as is the case when the pterygoid process is hollowed out. The pterygopalatine fossa is normally the angular interval between the pter}'gomaxillary and the inferior orbital fissures, and, as stated above, occupies the space between the maxilla in front and the root of the pterygoid process behind. ^Medially the perpendicular plate of the palate bone and nasal mucous membrane separate the fossa from the nasal cavity. However, the osseous medial wall is deficient, containing as it does the sphenopalatine foramen. The latter lies between l8o THE SIXUS SPHENOID.\LIS the orbital and sphenoidal processes of the palate bone and the inferior surface of the bod}' of the sphenoid. The roof of the sphenopalatine fossa is formed by the inferior surface of the body of the sphenoid and the orbital process of the palate bone. The fossa contains on its dorsal wall the orifices of the pharyngeal canal, the pterygoid canal (Vidian) and the foramen rotundum, from within outward. Caudally the fossa contains the superior opening of the pterygopalatine canal together with the orifices of lesser palatine canals (Figs. 135 and 145). The sphenopalatine fossa with its contained sphenopalatine (nasal, Meckel's) ganglion is obviously very intimately related with certain of the paranasal chambers which pneumatize the aforementioned osseous boundaries. Practically alwaj'S the sphenoidal sinus is located immediately over the fossa and the ganglion, and when the sphenoidal sinus extends recess-like into the pterygoid process it gains an intimate dorsal relation- ship as well. Again, when the sphenoidal sinus extends forward into the ethmoid bone and orbital process of the palate bone there may be even a sphenoidal-sinus relationship to the sphenopalatine fossa ventrally. UsuaUy, however, the maxillary sinus and one or more posterior ethmoidal ceUs are the paranasal chambers related ventrally to the sphenopalatine fossa with its contained ganglion. It is, therefore, very clear that the sphenopalatine ganglion is continually subjected to the influences of the very intimately related paranasal sinuses, particularly the sphenoidal. The nasal fossa is, of course, in constant relationship (Fig. 195). Not infrequently a posterior ethmoidal ceh (or cells) grows into the body of the sphenoid bone at the expense of one or both sphenoidal sinuses; indeed, may largely or entirely replace one or both of them. Such eth- moidal extensions into the body of the sphenoid bone are, however, readily distinguished from true sphenoidal sinuses since they never communicate with the sphenoethmoidal recess — the constant position for the aperture of the sphenoidal sinus [ostium sphenoidale). These ethmoidal-cell ex- tensions into the sphenoid bone may be referred to as ethmosphenoidal cells. The cells at times overlie the sphenoidal sinuses so that the latter appear in sections as duphcated or triphcated (Fig. 141). The location of the ostia is, of course, the deciding factor in the classification. More- over, it is especially the uppermost of such posterior ethmoidal cells that come into such very intimate relationship with the optic nerve, optic commissure, and even with the hypophysis cerebri (Fig. 155). The Topography of the Adult Sphenoidal Sinus.— The paired sphe- noidal sinus is located in what maybe termed the danger position in the skull. Occupying a more or less central position dorsal to the cephalic portion TOPOCRAPHV OF SPHKXOIDAL SIXUS l8l of the nasal ca^•ity, it comes into intimate relationship dorsally with the h}'pophysis cerebri and not infrequently with a portion of the brain stem; lateral!}-, with the dural cavernous sinus and its contained and related structures; cephalicalh", with the optic commissure and frequently with the h>-poph>-sis cerebri; caudalh-, with the Vidian nerve, the choanal (posterior nares), and the nasopharynx; ventrolateral!}-, with the optic nerve and the ophthalmic artery. The relationships of the optic commis- sure and the h}-ixiiiliysis cerebri to the s])henoida! sinus are variable and dependent upon the degree of pneumatization of the bod}- of the sphenoid (vide infra). The voitral uvll of the sphenoidal sinus projects dorsalward and caudalward, forming an obtuse angle at its junction with the cribriform plate of the ethmoid. The wall is usually relativel}' thick below and Septum .siiiuuiii sphenoidaliv.m Trohe in ostium splienoioLccZc Sinizs sphenniciahs da. zier Sinus sphcnoidalis sinistur Fig. 134. — A sagittal section through the sphenoidal sinuses. Note the horizontal position of the septum of the sphenoidal sinuses and that the sinuses are realh- superior and inferior to each other rather than right and left. (Compare with Figs. 141, 142 and isy.) frequently of extreme delicacy as it nears the cribriform plate. Clinically, the ventral wall is the most important of the sinus boundaries because it contains the aperture of the cavity (ostium sphenoidale, see page 1S7). The size of the nasal surface of the ventral wall of the sphenoidal sinus is largelv dependent upon the depth of the sphenoethmoidal recess. When the latter is deep the aperture of the sinus is, as a rule, farther remo\'ed from the mid-sagittal plane. Posterior ethmoidal cells and the dorsal extremities of certain ethmoidal concha; bear various relationships to the ventral wall. By following the olfactory sulcus, the roof of the nasal fossa, and the upper portion of the \-entral sphenoidal wall, the aperture or ostium of the sphenoidal sinus is readily located fsee ])age 97). The lateral wall of the sphenoidal sinus participates in bounding the middle cerebral fossa and comes into immediate and direct relationship with the dural cavernous sinus and the contained structures (seepage 193). i82 THE SINUS SPHENOIDALIS J^Ioreo^•er, the lateral is usually one of the thinnest walls of the cavity, often reduced by extensive pneumatization to a papery delicacy. Indeed, osseous dehiscences are not infrequently found. In surgical procedures it is, therefore, necessary to work with care on the lateral wall of the sphe- noidal sinus. Curetting seems to be contraindicated because of the inti- mate relationships with the cavernous sinus and the frec|uent osseous defects, whereby the sinus mucosa is in direct contact with the dural wall of the vascular sinus (Figs. 195 and 197J. The dorsal wall of the sphenoidal sinus is usually relatively thick and less subject to variation as compared with the other walls. However, not infrequently one encounters specimens in which the sphenoidal sinus has pneumatized beneath and dorsal to the sella turcica, leading to an extreme!}' thinned-out dorsal wall. This variation must be borne in mind in operative procedures, because the wall is readily broken through, and the basilar artery and pons immediately dorsal subjected to injury (Figs. 175 and 195). Further mention will be made of this relationship in connection with the hypophyseal-sphenoidal relations (page 188). The cephalic icall of the sphenoidal sinus is extremely variable in its contour, thickness and extent. It is usually composed of thin, compact bone; howe\'er, mav contain a considerable amount of cancellated bone between two compact lamelke. The contour and extent of the cephalic wall are largely dependent upon the degree of pneumatization of the sphe- noid bone and the shape, position and size of the sella turcica (Figs. 146 and 154). Moreover, osseous defects are occasionally encountered whereby the sinus mucosa and the ectal la}'er of the dura mater are in actual con- tact. Conforming with the size of the sphenoidal sinus, the relations of the intracranial structures ^'ary. However, the hypophysis cerebri and the optic commissure are fairl}' constant in some form of relationship to the cephalic wall (see page 188). The caudal wall of the sphenoidal sinus has its mid-point approximately over the choana (posterior naris), being half nasal and half pharyngeal in location. Not infrequently, owing to marked asymmetry, one or the other s})henoidal sinus is superimposed over both the right and left choanfe or posterior nares (Fig. 135). It varies from 2 to 13 mm. in thickness, according to a series of specimens in\'estigated. This Avail was at one time used as an approach to the sphenoidal sinus, via the buccal cavity. The ascending palatine artery (a. palatina ascendens, pharyngo-palatine artery), a branch of the external maxillary (facial) artery, crosses the lateral angle of the ectal surface of the caudal wall of the sphenoidal sinus and is here endangered in surgical procedures in the neighborhood. The OSSEOUS SKPTA AND RKCKSSES 183 floor of the sphenoidal sinus mu>' be so hollowed out that the ner\'e of the pterygoid canal (Mdian ner^•e) is at best separated from the sinus mucosa by a tissue-hke plate of bone. Indeed, as stated elsewhere, the osseous canal may be defecti^•e here and there, thereb)' exposing the Vidian nerve and vessels to the direct influences of the outside air (Fig. 195). See also page 320 for a consideration of the \'idian nerve. Xot infrer[uently in the extension of the sjAienoidal sinus into the pterygoid process of the sphenoid bone and into the perpendicular plate of the palate bone and the lateral mass of the ethmoid bone there is marked encroachment upon the confines of the pterygopalatine fossa (see page 31S) with its contained structures, c.;^., the sphenopalatine ganglion, etc. The medial icall of the sj^henoidal sinus is the inter-sinus septum re- ferred to on page 1S7. Dehiscences of this wall have been reported; however, the author encountered no such defect in a large series of healthy specimens. The medial wall is usually asymmetrical in location and not infrequently inclines in a semi-horizontal plane instead of its more usual vertical and semi-sagittal position (Figs. 134, 135, and 159). Partial Osseous Septa and Recesses of the Sphenoidal Sinus.^ While it is true that many sphenoidal sinuses have e^•en and regular in- terior osseous wafls, it is equally true that of all the paranasal sinuses the sphenoidal presents with the greatest frecjuency the most irregular walls (Fig. 195). Crescentic partial osseous septa are extremely commonplace. These vary from slight elevations to bridge-like osseous barriers which incompletelv diA'ide the sinus into subcom})artments. Indeed, these septa are at times very misleading in sections of the sphenoidal sinus, since multiple sinuses are simulated in certain planes of section. Serial sections, of course, demonstrate the true anatomy; that is, that the septa are incomplete and but partially di\-ide the sinus. The irregularities form recesses which in many cases ob\-iously must retain infectious material despite the establishment of good drainage surgically. In some cases it would seem necessary to break down some of the recesses. However, the operator must bear in mind that these recesses and di\-erticula often ha\'c extremely thin outer walls and that there is danger of spreading the infec- tion intracranially and intraorbitally by breaking into these cavities. Moreover, related structures are endangered (see elsewhere). As stated elsewhere, entirely apart from the recesses formed by the very common i)artial osseous septa the sphenoidal sinus not infrequently pneumatizes extensively into the greater and lesser Avings of the sphenoid, into the orbital plate of the palate bone, into the ethmoid bone and into the pterygoid process. Recess extensions into the pterygoid processes are 1 84 THE SINUS SPHENOID.'VLIS always fraught with danger since they form deep pockets in the floor of the sphenoidal sinus and cause the dependent portion of the sinus floor to be still farther from the aperture of the sphenoidal sinus (Fig. 139). As stated elsewhere, the aperture — ostium sphenoidale — is at best very dis- advantageously located for efficient drainage and in this regard parallels the ostium of the maxillary sinus, e.g., the ostium maxillare. Sphenoidal Sinus Diverticula. — Diverticula of the sphenoidal sinus may be divided into two groups: (i) the recess-like extensions of the sphenoidal sinus into outlying portions of the sphenoid bone and into bordering bones, the osseous boundaries of such diverticula or recesses being complete; (2) mucosal diverticula or evaginations through dehis- cences in the osseous wall of the sphenoidal sinus, the osseous boundaries of such di\-erticula being wanting. 1. The recess-like extensions of the sphenoidal sinus in which muco- periosteum and bone participate as boundaries were referred to in the previous paragraph and will be dealt with at greater length in subsequent paragraphs. They can, therefore, be ignored in this connection. 2. Zuckerkandl, Onodi, Spee, Meyer and others have reported defects in the osseous lateral wall of the sphenoidal sinus. The writer likewise made similar observations and reported at length concerning them at an Anatomical Seminar at Cornell University in 1910. Many of these defects or dehiscences merely lead to such a condition whereby the mucous membrane of the sphenoidal sinus comes in direct contact with the ectal layer of the dura mater. At times, however, the mucous membrane evaginates hernia-like through an osseous defect or dehiscence. The author observed two such specimens in the Cornell University collection and a third in the Yale University collection. All three were unilateral. These mucosal diverticula or herniae protruded for variable distances — 3.5 and 5.5 mm. — into the epidural space by crowding the dura mater ahead of them. One of the mucosal diverticula projected into the cav- ernous sinus by pushing the ectal or outer layer of the dura mater bag-like into the lumen of the sinus. Meyer observed a specimen in which there was a defect in the ventral portion of the lateral wall of the right sphenoidal sinus immediately be- neath its roof. Through this osseous opening, oval in shape, protruded a diverticulum of the sinus mucosa, 6 mm. long, into the subdural space. The wall of the diverticulum was exceedingly thin and extended forward and upward into a triangular space bounded by the optic nerve antero- medially, the carotid artery posteromedially and the reilection of the dura mater laterally. The dura surrounded the base of the diverticulum on DIVKRTrCULA i8S all sides but, contrary U ry to the author's specimens, did not envelop or cover the mucosal fundus. The dura merel\- came in contact with the mucosa at the margin of the osseous defect. In other words, the dura mater as well as the bone was dehcient, permitting the sphenoidal-sinus mucous membrane to protrude through them. The mucous membrane or the sphenoidal diverticulum extended, thereb}', directly into the subdural space and must have been in direct contact with the arachnoid. Rramai ma^ii»f/i . A. <.■ Sinus spliawidales .,,'•,.. ■*-'''0i, . '■,^i.,. '^.-;^ / Fossa ptcrtf^opcclatii _,- C etkpost. 1-- S mo-KlU^i^is ,Foi: iiif'ra.urh. Sep. smuum sphcmidalt _ _ S. niaKilUiris _ CaiM,lis due 7iasijl-(ie_ \ \ I^\ ii Id Fig. 135. — A basal dissection of the sphennidal and ma.xillary sinnses. Particularl>- n^lc that the right sphenoidal sinus has pneumatized frirward into the utttmfjidal region and established an immediate relationship with the ma.xillary sinns, a thin lamella of bone alone intervening. Note also the asymmetry' o( the sphenr)idal sinvises. The ventral half of the lateral wall of the left sphenoidal sinus con- tained a similar defect to that in the right sinus. A diverticulum of mucous membrane protruded through the oval defect for a distance of 3.5 mm. and extended across the dural reflexions over the optic and oculo- motor nerves and enlarged slightly distally. The relations of the diver- ticulum to the surrounding structures were exactly the same as in the diverticulum from the right side. The diverticulum measured 6 mm. in length and 7 mm. in width. 1 86 THE SINUS SPHEXOIDALIS Surel}- dura mater must have co\'ered these diverticula at the time of their initial outgrowth from the sphenoidal sinus. Ho^^'e^'er, at the time of obser\ation the dura mater Avas perforated and the diverticula in actual relationship with the arachnoid. Why the dura mater should be perforated is, indeed, diificult to explain. The more likel}' thing would seem for the dura to be pushed in advance of the e\'aginating diverti- fossa succi Jacrnnab's Cc. ethjuoidaies Si/ius /naxjJlaris Lamella of ione ictia/een sjiTienoidaJ and rr/uK/JIarif ,' tillllJStS Tiiaxill.aris ■■■- ' Fossa jiteri/ffopuZcttiniz Foramen Totimduvi Si.Tius spln'iioidalis Pig. 136. — A dissection showing a marlced extension of tlic splienoidal sinus forward into the etltmoidal held, replacing certain posterior ethmoidal cells, to come into immediate relationship with the maxillary sinus. This unusual relationship is of importance clinically. cula. Of course, the basal dura mater is extremely adherent and in all likelihood is perforated with greater ease by the growing mucosal sac than crowded awa}- from its bony attachments. Clinicall}-, dehiscences in the osseous wall of the sphenoidal sinus are significant and Avhen such defects lead to mucosal diA'erticula (in a sense, mucosal hernicT), which come in relationship anatomicahy with the SPHENOID.U. SKPTURE AND OSTIUM 187 subdural space and the dura and arachnoid maters, they become even more important. The Sphenoidal Septum (the septum sinuum sphenoidaHum).— The paired sphenoidal sinuses are separated by a septum of variable thickness and location. The thickness is largely dependent upon the degree of pneumatization or size of the sinuses. The intersphenoidal septum ma}' be placed more or less ^'ertical and in the median plane throughout. Alore frequently, however, it is i)laced either to the right or to the left of the mid-sagittal plane, save ventrally where it is usually in line with the septum nasi. This leads to as3'mmetrical sphenoidal sinuses. Indeed, the septum may be placed obliquely in a semi-horizontal plane so that the right and left sinuses are in a sense cephalic and caudal in relation to each other. According to the writer's studies, the sphe- noidal sinuses never normalh' communicate with each other due to a de- fectiA'e septum. HowcA'er, such communications have been obser\'ed in pathologic states. A few cases ha^'e been reported in which the inter-sinus septum was belie^'ed to be wholh' absent, the two sinuses being represented bv one large caAit}- with a single ostium. The writer, howe\'er, cjuestions this interpretation and contends that the real condition is an agenesis of one sinus, thus allowing the single sinus to develop beyond the mid-line in pneumatizing the body of the sphenoid. The single ostium supports this \iew. Indeed, it is not uncommon for one sinus to be enormously developed and for its mate to be a mere ruchment. The latter might lead to the belief that the sinus is wholly wanting. Careful analysis, howcA'er, usually reveals the diminutive sinus (Tigs. 134, 136, 141, 143, 144 and 159). The Sphenoidal Ostium. — The sphenoidal ostium (ostium sphenoidale) or orifice of the sphenoidal sinus is alwaA's located on the dorsal wall of the sphenoethmoidal recess, therefore, cephalic to the uppermost eth- moidal concha that may be present. The right and left ostia are not necessarily on the same level. They are in most cases located slightly cephalic to the mid-plane of the ventral wall of the sinuses. There is, however, often marked deviation from this location as may be inferred from the measurements (in millimeters) given in Table J of a number of specimens selected from a larger series: It is obvious from the folloAving table that the ostium of the sphenoidal sinus is very disadvantageously placed for efficient drainage in case of empyema of the cavity. iSS THE SIXUS SPHENOIDALIS T,\BLE J Side Distance from center of ostium noidale to roof of sinus splie- Distance from center of ostium sphe- noidale to floor of sinus R 12 17 L lO 13 R 12 12 L 12 9 R 2 3 L i6 U R 2 20 L 12 T7 R 3 6 L 12 4 R IS 17 L ly i6 Size of Sphenoidal Sinus. — The appended Table K of measurements (in millimeters) of a few specimens selected from a larger series shows the great ^'ariation in size of the sphenoidal sinus. Extremely rudimentary sinuses are encountered; again, enormous pneumatizations of the sphenoid bone are not uncommon, even extending beyond the body of the bone (Figs. 136 and 143). Table K Cadaver Side Ccphalocaudal (height) Mediolateral (width) Ventrodorsal (length) . !'; R L 27 21 32 28 30 28 • ll R L S 25 3 18 3 20 3 {. R L 20 18 16 10 17 14 = ( R 34 14 18 L R 35 10 27 9 35 9 L 21 27 22 ' {' R 19 12 18 L 8 6 7 ' {' R L 26 16 27 12 30 20 ' 1 R L 23 32 34 28 43 37 Averaj;es 21.2 18.9 21.3 Conforming with the variations in size, the capacity of the sphenoidal sinus was found to vary from less than 0.5 cm. to 30 cm., with an ap- proximate average of about 7.5 cm. The Hypophysis Cerebri as Related to the Sphenoidal Sinus. — The hypophysis cerebri (pituitary body) is a small ovoid gland, flattened HYPOPHYSIS CEREBRI cranio-caiidally, and with its long axis directed transversely. It occupies the hypophyseal fossa (fossa hypophyseos, sella turcica), a deep depres- sion over the middle of the superior (cephalic) surface of the body of the sphenoid bone. Dorsally the hypophyseal fossa is o^'erhung by a sloping ridge, the dorsum selke, and ^'entral to the fossa is the olivary eminence (tuberculum sella?). The hypophysis is roofed over by a spheroid pocket of dura mater — the diaphragma sellse. The latter separates the hypo- physis from the optic commissure and the optic tracts, which lie im- mediately cephalic (abo^■e) to it. The stalk (infundibulum) of the hypo- physis penetrates the dura mater dorsal to the optic commissure and midway between the optic tracts. Laterally the cavernous sinus with the contained internal carotid artery comes into relationship with the hj'pophysis and the sphenoidal sinus. The exact relations of the hypophysis to the sphenoidal sinuses must necessarily vary, since the shape and size of the sinuses are inconstant (Figs. 143, 146 and 175). In many cases the hypophysis is dorsal (posterior) to the sphenoidal sinuses and located much nearer the sinus roof than the floor. Xot infrequently, however, the sphenoidal sinuses pneumatize the body of the sphenoid bone caudal (beneath) and dorsal to the hypo- physeal fossa. When the latter anatomy prevails the hypophysis bears a dorsocephalic relationship to the sphenoidal sinuses. The thickness of the bone inter\-emng between the sinuses and the hypophysis varies with the size and location of the sinuses. The hA-poph^'sis ma}' be exposed b}- an endonasal operation through the sphenoidal sinuses after first removing the ventral wall and the septum of the sinuses. Of course, when the sinuses are markedly asymmetrical, the removal of the septum may not be necessary, provided the operator selects the proper sinus in the approach. In order to expose some hypo- physes the dorsal wall of the sinuses should be ablated immediately caudal (inferior) to the plane where the roof and dorsal walls are confluent (Fig. 146). However, when the sphenoidal sinuses have developed beneath the hypophyseal fossa with the contained hypophysis cerebri and dorsad toward (maybe into) the basilar process of the occipital bone, it is the roof and not the dorsal wall of the sphenoidal sinuses that must be ablated in order to expose the hypophysis cerebri (Fig. 195). In the latter, the anatomy is such that the operator could readily cut through the dorsal waU of the sinuses, miss the hypophysis altogether, and injure the basilar artery and brain (ponsj. Moreover, the operator must have due regard for the important structures located lateral to the hypophysis. It is not the province here to discuss the detailed embryology, histol- igo THE SINUS sphp:noidalis ogy and gross anatoni}' of the hypoph3'sis cerebri, suffice it to say that it consists of three portions; the ventral, dorsal and intermediate portions. The ventral, glandular or buccal lobe usually embraces, cap-like, the smaller dorsal or cerebral lobe. The dorsal lobe is connected by means of the infundibulum with the tuber cinereum in the floor of the third ventricle. The latter often extends canal-like into the infundibular stalk for a con- siderable distance. The \'entral lobe may be regarded as the functional portion of the hypophysis and the portion in most intimate relationship with the sphenoidal sinus. Tumors of the hypophysis cerebri may encroach upon the lumina of the sphenoidal sinuses, even penetrate into the cavities. Encroachment on any of the surrounding structures maj' lead to serious results. The Optic Nerve and Commissure (chiasm) as Related to the Para- nasal (accessoryj Sinuses. — It is essential that the intimate anatomic forumcN roiunJunc ----- \ Fo7-c47ne?i ovale --^i--'-- fissura oibituJii sup Foranien. opticu-rn Ostium sphenoidale foremen rotundu m - foraTf/en ro/undam. [ ■'? sphenoidah $ ^^y'' ^ fo Cannhi ptf.rLjgoidcusiyidll) 5 sphen^oidalis Can 7liz pteryc^oiUeusiVidii) Processus ptxryyoidzu, RcCts,il,ptEry<^oideu3(5 spJlcmidalU) Fig. 137. Fig. 138. Fig. 139. Figs. 137, 13S, 139. — In Fig. 137 note the extension of the sphenoidal sinus {dorsal exposure) into the great wing of the sphenoid bone with resultant intimate relations to the foramina rotundum (maxillary nerve) and ovale (mandibular nerve). Note also that the pterygoid or Vidian canal forms a conspicuous mound in the floor of the sphenoidal sinus. In Fig. 138 note the relations of the foramen rotundum and the pterygoid canal w'hen the sphe- noidal sinus has not pneumatized into the pterygoid process of the sphenoid bone. In Fig. 139 note the extensive prolongation of the sphenoidal sinus into the pterygoid process of the sphenoid bone (recessus pterygoideus), with a resultant wide separation of the foramen rotundum and the pterygoid canal (ventral exposure). The inset illustrates the superior orbital (sphenoidal) fissure with contained strictures. 6 = abducent nerve; 4 = trochlear nerve; 5' = frontal nerve; 5 = lacrimal nerve; 5" = nasal nerve; 3 ^ inf. div. oculomotor nerve; 3' = sup. div. oculomotor nerve. relationships which exist between the paranasal sinuses and the optic nerve and commissure be understood by ophthalmologists and rhinolo- gists. It is established that disease of the paranasal sinuses may lead to an optic neuritis, even to blindness. Of the paranasal sinuses, the sphe- OPTIC NKR\-I-; AND COAIRIISSURE 191 noidal and the posterior ethmoidal especially concern us in this connec- tion (P^igs. 140 and 155). The optic nerve in its course from the eyeball to its juncture with the optic commissure pursues a more or less direct course dorsalward, medial- ward, and cranialward toward the apex of the bom- orbit. At the apex of the orbit it is surrounded by the origins of the recti muscles, while in the orbit it is embedded b>' orbital fat. It traverses the optic foramen in the sphenoid bone in compan)' with the ophthalmic arter>' — the latter, latcro- caudal in relation to the nerve. Intracranial]}- the optic nerve converges toward its fellow of the opposite side with \\-hich it forms a junction to form the optic commissure in the vicinity of the tuberculum sella; (oli- vary eminence). The o]itic ner\'c varies from ^2,2 to 55 mm. in length. Of this 25 to 40 mm. is intraorbital in position while the remaining portion is located in the optic foramen and the anterior cerebral fossa. It is ob^-ious when one recalls the direction of the o])tic nerves, far remo\'ed from each other distally and in confluence at the commissure, that the relations to the paranasal sinuses become m(jre and more intimate as one passes from the e>-eball toward the optic commissure. Indeed, for a considerable distance from the eyeball, the oi)tic ner\-e is so far remo\ed from the paranasal sinuses that \'ery intimate relationship is precluded bv the inter^'ention of a considerable mass of orbital fat. However, as the optic nerve approaches the orbital apex and passes through the optic foramen to the optic commissure, \-ery intimate relationshii)s exist be- tween some of the ])aranasal sinuses and the nerve and its commissure (Figs. 140 and 145). The optic commissure bears a very intimate relationshii) to the sphe- noidal sinus in the A-ast majority of cases. The exact relationships, how- ever, varv Avith the size, shape, symmetry, and location of the sinuses. The commissure is frequently placed immediateh' cephalic (above) to the roof of one or both sinuses. In this connection it is well to recall that asymmetry is commonplace between the two sphenoidal sinuses. The thickness of the bone inter\-ening between the sinuses and the optic com- missure varies considerabl}', c.i^., from a papery delicacy to that of a sub- stantial thickness. In approximatel}- 50 per cent, of instances the optic commissure lies dorsal (posterior) in relation to the sphenoidal sinuses. As a rule, the posterior ethmoidal cells do not come into relationship with the optic chiasm. However, when the posterior ethmoidal cells grow into the body of the sphenoid bone intimate relationships are likewise established (Figs. 155 and 162). The optic nerve pursues a course ventral ward from the optic com- 102 THE SINUS SPHENOID.^IS missure along either the roof or lateral wall of the sphenoidal sinus. Fre- quentl}- a posterior ethmoidal cell is more or less intimately related as well. After the optic nerve passes beyond the \'icinity of the posterior ethmoidal cells, it diverges more and more from the ethmoidal field and is no longer in intimate relationship with the other ethmoidal cells. The thickness of the bone between the optic foramen and contained structures and the cavity of the sphenoidal sinus varies according to the author's studies from 0.2 mm. to 2 mm., with an average of not over 0.5 mm. In very large sphenoidal sinuses the optic nerve joins the optic Nji.olf^'dcrii etlai/iina. cnbrosa- C.efhi'toidahs jx'^t Hulhu.s omli N.opticuii Sinus rroritah'.s ^. \ Cc ct^7mo/'daIcs unt ..-' Orbital Fort Nypopliysis ccmbn S/7//IS sf'fvrioidr^hs V^. opticas Fig. 140. — An exposure of the paranasal ehambers from the anterior cerebral fossa. Moreover, the supraorbital walls have been removed, thereby exposing the optic nerve and eyeball. Particu- larly note the relationships of the right optic nerve and that the sphenoidal sinus extends beneath and over it, a thin lamella of bone alone separating the nerve from the sinus mucosa. On the left side the optic nerve bears a very common relationship to the sphenoidal sinits and a posterior ethmoidal cell. The inset is a photograph of a transection of the ethmoidal lab^-rinth and sphenoidal sinuses. Note the larger number of individual ethmoidal cells as compared ^^■ith the main figure. commissure (chiasm) in the roof of the sphenoidal sinus some distance in advance of the dorsal wall of the sinus. This may apply to one or both sides. Opposed to this, in small sphenoidal sinuses the optic nerve usu- ally joins the optic commissure dorsal to the sphenoidal sinuses (Fig. 144). There is considerable variation in the distance between the caudal surface of the optic nerve and the ostium sphenoidale. The two sides C.WKRNOUS SINUS 193 in this regard are frequently asymmetrical. Usual!)' the o]:)tic ncr^'e is cephalic to the level of the ostium sphenoidale. They may, however, be on the same plane or the reverse relationshi]) may obtain, t'.,g., the ostium be cephalic to the ner\'e. It is not uncommon for the nerve to be within 2 to 5 mm. of the ostium of the sphenoidal sinus. Again, a distance of 15 or more millimeters my interx'ene. The ner\'e is ne\-er more than a few millimeters caudal to the ostium of the sinus when such relationship exists. Occasionally the sphenoidal sinus almost surrounds the optic ner\-e. Witness, for example, the specimen shown in Fig. 140 in which the sphe- noidal sinus has de\-eloi)ed beneath and over the optic nerve. Lateral to the optic ner\"e the two sinus extensions are separated merelv h\ a thin lamella of bone. ^loreover, the nerve is separated from the sinus mucosa by a thin, tubular mass of compact bone. As mentioned previously, the most dorsal of the posterior ethmoidal cells freciuently comes into intimate relationship with the optic nerve. This also applies with less frerjuenc}' to the other posterior ethmoidal cells not in actual contact with the sphenoidal sinus. Xot infreciuenth' two or more posterior ethmoidal cells are in immediate relationship with the sphenoidal sinus instead of the more usual single cell. These cells mav be arranged tier-like one o\'er the other, the uppermost one estab- lishing most intimate relations with the optic ner\'e and commissure (Fig. 145). The frontal sinus, when of the supraorbital t>-i)e and when well developed dorsomedially, may establish close relationships with the optic nerve, otherwise the latter does not bear important relations to the frontal sinus. The maxillary sinus is separated from the optic nerve by the inter- vening osseous boundary and by a considerable amount of orbital fat and other structures. The relationship is, therefore, not intimate as a rule. The Cavernous Sinus and Contained Structures as Related to the Sphenoidal Sinus.- The ca^•ernous sinus is an endotheliall>- lined channel contained within the dura mater and is traversed by irregular trabecuhe of fibrous tissue. This paired vascular sinus, of considerable size, extends along the lateral side of the body of the sphenoid bone from the superior orbital (sphenoidal) fissure to the apex of the petrous portion of the tem- poral bone. In this position the cavernous sinus with its contained struc- tures is in intimate relationship with the sphenoidal sinus. The internal carotid artery and the ahduccns nerve traverse the sinus, while the ociilo- motor, the troc/ilear, the ophtliahnic and the maxillary nerves are imbedded 13 104 THK SINUS SPHENOIDyVLIS in its lateral wall. Indeed, when the ca^'emous sinus is elongated dorsally the mandibular nerve may be in like relations. These nerves, save the abducens, lie in order from above downward and backward. The abducens nerve in the region of the sphenoidal sinus is com- monly located lateral to the internal carotid artery. The exact relationship depends upon the size and conformation of the sphenoidal sinus and the course of the internal carotid through the cavernous sinus. Not infre- quently, indeed, the abducens nerve is located lateral to the internal carotid artery where the latter immerges into the cavernous sinus, then courses 7^. opticus . , Cc .c/hinoijla],C5 post. F/'ssura orhi talis superior zuith coiitaiju'-il structures Oitiain sphA^rujidah: ' Cvi/fha 7/asa/.!^ i/tfri-wr I I Tf /iia/tiHaTia S. splieitvi/icc/£s Fig. 141. — A coronal or frontal section through the head of an adnlt. Xote the posterior ethmoidal cells extending into the sphemjid bone and encroaching upon the sphenoidal sinuses. caudal to and parallels the artery for a greater or less distance, and finally again passes lateral to the artery as the latter assumes a final vertical course and the nerve emerges from the cavernous sinus into the orbit. The abducens nerve is, therefore, in very many instances in direct contact with the lateral wall of the sphenoidal sinus for a goodly portion of its course — dura mater and \'ery thin bone intervening between the nerve and the mucous membrane of the sinus (Fig. 199). If osseous dehiscences exist in these cases the mucous membrane alone serves as a barrier between the abducens ner\-e and the outside air or any secretions that may be contained in the sinus. Moreover, when the sphenoidal sinus expands CAVERXOUS SIXUS 195 into the ventral portion of tlie root of the great wing of the sphenoid bone, there is a corresponchng encroachment upon the superior orbital (sphenoidal) hssure with again a sinus contact for the abducens nerve as the latter emerges from the cranial cavit>- through the superior orbital hssure into the orbit (Fig. 139). Again, the abducens nerve may come # opticM.s ^ ^ N'.ocido 7^otorhj,s " " - ^ \ ; ' -JV. 0J3ht/uUni7£7J,S Ifij/wpJ/ifsis cerdrl \ \ \\ \ - ]V.a'bdzi,ce7e,s A.carohs 27rk7ym ; ; \ \\\\\N.7^^.asticcctorl7J.s Tyjicc ct7id7£7rc \ \ > '\ - ' ' ' 'l\^-yn(^-^^dib7j.'kcris fcT^, / ; \ \^n \\\\\\ \ ■■»«»»-• ' (^^ » ) t ' I < I M , ■■I ' \ CocJfJ^xi. Ga7€^.scr7/ilvy77are(Qai>seri,j ', \ Si77M^ caver7?os7JS Kif-soph/xiynx /' Si'n/?^ sp^/^77oidalzs Fig. 142. — A dissection of the cavernous sinuses and related parts. On tlie right side tlie plane of section is oblique, while on the left side the plane of section is i>urely frontal. Particularly note the extension of the sphenoidal sinus of the ri;^ht side beneath the caA'crufjus sinus. It is in these cases that the Gasscrian ganglion and the mandibular nerve come into relationship with the sphe- noidal sinus; moreover, that direct relations with the temporal lobe of the brain are established. in contact with the sphenoidal sinus dorsal to the internal carotid arter}' when the sinus pneumatizes or extends into the sloping surface of the body of the sphenoid bone dorsal to the h}'pophyseal fossa (clivus blumen- iq6 thk sinus si>hexoid.\lis bachii, Blumenbaclvs slope). Indeed, the oculomotor nerve likewise may be encroached upon in the latter extension of the sphenoidal sinus. The internal carotid artery in its third or intracranial course ascends from the position of the foramen lacerum medium, where it escapes from the carotid canal, in the direction of the posterior clinoid process, soon, however, to bend forward and immerge into the dural ca^'ernous sinus. It courses forward in the dural sinus accompanied by the abducens nerve on its lateral and caudal sides (see above), to again bend sharply upward at the level of the anterior clinoid process and emerge from the cavernous sinus by piercing its wall, i.e., the dura mater. In the vast majority of cases the internal carotid artery as it traverses the dural cavernous sinus pushes the lateral wall of the sphenoidal sinus into a conspicuous serpentine-hke mound (Figs. 195 and 197). The promi- nence of the arterial relief is, of course, largely dependent upon the degree of lateral expansion of the sphenoidal sinus. However, not infreciuently in relatively small sinuses is the relationship very intimate. The osseous wall intervening between the sinus mucous membrane and the dura mater and the internal carotid artery is \-ery commonly of extreme delicac>'. Indeed, congenital dehiscences or bony defects over the artery are of fairly frequent occurrence. In such cases the thin outer dural layer alone intervenes between the artery and the sinus mucosa (Fig. 195). As the artery- emerges from the ca\'ernous sinus, it courses very closeh- to the lateral side of the hypophyseal fossa, a relationship to be recalled in hypophyseal operations. The almost constant and extremely intimate relationships of the internal carotid artery to the lateral wall of the s])henoidal sinus make operative procedures on this wall of the sinus exceptionally hazardous. Moreover, since the osseous barrier between the sinus and the artery is not infrec|uently deficient or at best but of a papery delicacy, it would appear that any procedure involving cutting or curretting to be unwar- ranted. In addition, the ^•ery common irregularities on the lateral sphe- noidal wall must not be forgotten as well as other structures often as much exposed as the internal carotid artery; for example, the abducens nerve. In conclusion it may be said that the intimacy of the relationships between the structures contained in the cavernous sinus and the sphenoidal sinus is dependent upon (i) the extent of the cavernous sinus and (2) the degree of pneumatization of the body of the sphenoid bone and the extensions of sphenoidal-sinus recesses and diverticula into neighboring parts. If the sphenoidal sinus extends far dorsolaterad, the semilunar ganglion (Gasserian) and the mandibular nerve may be intimately related. DrMuxrrnK simikxoidal sinuses 197 If the root of the lesser wing of the sphenoid bone is partially hollowed out, the optic foramen and ncr\-c are encroached upon. The maxillary nerve comes into intimate relationshij:) with the sphenoidal sinus when the latter grows in the direction of the foramen rotundum — a very common condi- tion (Fig. 195). Indeed, the ma.xillary ner\'e may be in close proximity Si7^^^■s sph£?/OLda.lis Fossa Ji^pophyseos Corpus ossis sjjkenoldalii Cc. ethfnvidaJcs 'rora7>7£n sphc/ivpala/iuuJn Fig. 143. — .\ sagittal sectiun of a vita- small sjihcm lidal sinus from an adult. The inlimatc relations that usualh' exist bet"ween the sijhetioiilal sinus and the hYpoph\'sis eereVjri, the ea\-ernous dural sinus and the related struetures are jirei'ludeel in siieeimens of this stjrt. ( C^e)nipare with V\\i. 197.) to the sphenoidal sinus as early as the third year. The sphenoidal sinus ^'ery common!}- encroaches u])on the confines of the superior orbital (sphenoidal) fissure and because of this establishes intimate topograj^thical .Fossa /^T/pop/f'/scos Siwis sphcnoidali^s Foray "-c^ sphen^opaJj^iinu} i Cc et/imD!xia.Ifs Fig. 144. — A sa«ittal secti'jn cf the body of the sphenoid bone, etc. Note the cxeeplionally small sphenoidal snius and its remote relatir.ns to the hypophyseal fossa. From an adult, aged 50 years. relationships with the structures that are transmitted by it, et cetera (Fig. 139)- Diminutive Sphenoidal Sinuses. — Very small sphenoidal sinuses are now and then encountered. The walls are proportionately thick and pre- 198 THE SIXUS SPHENOID.-VLIS elude the \-ery intimate relations between the sphenoidal sinus and the neighboring structures previously referred to (Figs. 143 and 144). Agenesis of the Sphenoidal Sinus. — Agenesis of the sphenoidal sinus is very uncommon according to the author's observations. Specimens were observed in which posterior ethmoidal cells pneumatized the body M pptixus I U/zde fended or nan- ossiiv.s area. Jffca?udis pteri^^ouleu-s (^Vidii) \ \ B-oiein. canziZis 7r.aso7/xc. Gom^h'oizsphen.opa7Mf:ijzij,m(Neckdu) \ (hone cvt cuuay) Processus imcbuitus Pig. I45--Paranasal chambers exposed from the lateral side. Xotc the projection of a posterior ethmoidal cell over the pterygopalatine fossa. of the sphenoid bone, the sphenoidal sinuses proper being represented by mere rudiments on the ventrocaudal wall of the body of the sphenoid bone. Moreover, a few cases were encountered in Avhich the body of the sphenoid bone was solid and wholly unpneumatized, sa^'e for very slight depressions 199 on the \'entral COXCLUI )IX(;, C'OXSI 1 )KRAT1()XS in wide communication \vith the sj^henoethmoidal recesses or nasal surface of the sphenoidal body. Concluding Considerations.- It is well known that httle, if an)', in- formation of ^-alue regarding the size of the sphenoidal sinus in infancy can be obtained from the skiagram. The solid bod}- of the sphenoid bone throws too dense a shadow at an early postnatal period. Haike, howcA-er, differentiated the sphenoidal sinus in the skiagram at the age of 3I Lhiasm-cr opticu in ^ A^qer 7JXt^i ^ Atniun in^at.ics Wi^iu ^ VcstilnduTr?. nasi FiG- 146. — Photograph of a mid-sayiltal seclion of tlir lioaJ of an adult bcid\ years, the ca\nt}- presenting a brighter area within the dark shadow of the body of the sphenoid. Turner and Porter throw out a caution in the interpretation of skiagrams of the sphenoidal region in \exy A'oung people. They claim that one may be deceived by the lighter shadow jjresented by the cancellous tissue of the bod}' of the sj^henoid l}one. The develo])ment and size of the sj^henoidal sinus is ascertained tc) the best advantage by profile views of the head. A comparison between skiagrams and actual measurements of the .sphenoidal sinus during the childhood period as given in Table I, page ] 78, is helpful in arriving at the size and shape of 200 THE SINUS SPHKXOIDALIS the cavity at a given period. Haike cautions tliat operators must always remain conscious of the limitations of the skiagram, yet owing to the diffi- culty of endonasal investigations in the young child he hopes to obtain conclusi\-e e^'idence from the skiagram alone. However, in older children he believes that one ought always to be guided more by the result of clin- ical examination than by the skiagram. Onodi likewise holds that the clinical signs be considered principally and the skiagram be used only as a secondar}- aid to diagnosis; moreover, believes that while this is true in general in connection with accessory sinus troubles, it is particularly ap- plicable to diseases of the sphenoidal sinus in children. The sphenoidal sinus has been successfully treated by radical operation in children of 6 years of age. Onodi belie\-es that resection of the sphenoidal sinus in the first years of childhood should be performed through the ethmoidal labyrinth. In the adult, skiagraph}- of the sphenoidal sinus is valuable in delineat- ing the \'entrodorsal size of the cavity and the thickness of the sinus walls. Of course, a profile skiagram is desirable. JNIoreover, the skiagram is valuable in diseased conditions, as a means of diagnosis and assistance in determining the anatomical contour and size of the sinus in a particular case. However, it is well known that the skiagram is of less anatomical assistance preliminary to operations in case of the sphenoidal sinus than it is in the frontal and maxillary sinuses. This is, however, not true in the sphenoidal approach of the pituitary body surgically. Roentgenography is indispensable in the estabhshment of the indications and in the operation itself. The radiogram clearly outlines the size of the hypophyseal fossa and its exact relation to the sphenoidal sinus. Moreover, it gives some evidence of the size of the sphenoidal sinus and the distance from the ven- tral surface of the sphenoid bone to the anterior nasal spine. Pfahler^ in 1916 described a new method of study of the paranasal or accessory sinuses with the roentgen rays. He employs a technic where- by a roentgen-ray film is inserted into the mouth and the roentgen-ray tube adjusted over the head so that the rays course more or less at right angles to the film. The method appears to be of especial advantage when skia- grams of the ethmoid labyrinth and sphenoidal sinuses are desired. The several paranasal sinuses appear in the picture in isolated positions with less overlapping than in other methods. This is, of course, of distinct advantage. In disease of the sphenoidal sinus it is well to recall the intimate anatomic relations to important structures. Optic neuritis, even blind- ' Laryngoscope, July, 1916. s COXCLUDTNC; CONSTDERATIOXS 20I ness, may ensue. Infection of the sj^henoidal sinus and the ophthalmic vein may lead to cavernous sinus thrombosis. Certain of the cranial nerves related to the cavernous sinus may be paralyzed. Ventrally the cavernous sinus recei\'es as tributaries the ophthalmic vein and farther dorsad, occasionalh', the basilar \'ein and veins from the related dura mater. Moreover, the two sinuses are interconnected. The blood is carried from the ca\-ernous sinus b>' the two j^etrosal dural sinuses and by veins which lea\-e its caudal surface to jiass extracranially through the foramina in the sphenoid bone, etc. It is well known that the ca\'ernous sinus may become infected from sources other than the sphenoidal sinus, e.g., from foci far removed, especially through the extraorbital anasto- moses of the ophthalmic veins. The anatomy is such that cavernous sinus infection and thrombosis may follow ulceration of the nasal mucosa, alveolo-dental ]:)eriostitis, em])}-ema of other paranasal sinuses, infections of the face, infections of dijiloic tissue in the region of the forehead. Natu- rally, therefore, in obstruction to the blood flow through the cavernous sinus, as in thrombosis, there would be edema of the eyelids and side of the nose and upper face, and an e.\oi)hthalmos; and if the structures that are related to or contained within the caxernous sinus should be invoh-ed, there would be ptosis, ])U])il irregularities, strabismus, pain, etc. In curretting or cleaning pathological tissue from the sphenoidal sinuses, due regard must be had for the very important structures im- mediately ectal to the thin-walled sinus. In extensive pneumatization many or all of the structures mentioned ma)' ha\'e the most intimate anatomic relations to the sinuses. Particularly would the author call attention to the ca\'ernous sinus and internal carotid arter}' as structures readily injured, especially so in those cases where the osseous wall is deficient and the inner wall of the ca\'ernous sinus in direct contact with the mucosa of the sphenoidal sinus. In case of the internal carotid artery the outer (ectal) dural layer alone would intervene between the vessel and the sinus mucosa. This is also frec|uently true for a short segment of the abducens nerve (page 194 and Fig. 197). The \'idian nerve in the floor, the maxfllary nerve as it traverses the foramen rotundum, and the optic nerve in its course through the oj-jfic foramen are the most constant nerves in intimate relationship with the sphenoidal sinus. The auditive tube (tuba auditiva Eustachii) is as a rule too far re- moved from the sphenoidal sinus to become involved in sinus disorders unless the sphenoidal sinus extends its pneumatization extensively into the pterygoid process in the formation of the pterygoid recess (Fig. 139). 202 THE SINUS SPHEXOID.VLIS The latter ma.}' establish intimate anatomic relationships with the auditive tube and be a factor in infecting the mucous membrane of the tube, since the recess is so dependent and far removed from the aperture of the sphenoidal sinus that infectious materials are readily retained within its confines. The auditive or Eustachian tube extends, of course, between the nasopharynx and the tympanic cavity or middle ear. jNIoreover, the pharyngeal ostium of the auditive tube is always in juxtaposition to the dorsal extremity of the inferior nasal meatus and is, therefore, readily involved secondarily in certain disorders of the nasal fossa, since the mu- cous membrane is directly continued from the nasal fossa into the nasopharynx and from there into the auditive tube. VI THE ETHMOIDAL CELLS CHAPTER M THE ETHMOIDAL CELLS The I'^jctal Stacic The ethnaoidal air cells (celluhc ethmoidalcs) are primarily extensions or evaginations of the nasal mucosa from the middle, superior, and lirst supreme nasal meatuses; e.g., from the meatuses directly or from the acces- sory furrows and recesses which configure their lateral walls, particularly the lateral walls of the middle and superior meatuses. The reader is re- ferred to previous paragraphs concerning the early anatom_\- of the major ((irrc-v.vt y r nr/uif^ Jttrf.^//. /I / itv/ Iri/itirJ f/j/y-Dii s ( lliiliif elhmoiilali CflNc/ia //as. //It// r f ///////////// s ' - Ciinr/ia 7ias. 7/ifd. Fig. 147. -.- Fro/i/f/ /'///ro/os /r/ic. /j//r////////\ /////////////. r///. Fii. 14S. Figs 147-14S. — Frontal sectirms through Ihu fr^jiltal recess of a y-iiKintli fetus. Scctir)n Vii^. 147. is farther ventral than is section Fik. 14.S. Xote the blind ventral extremities of the frontal furrov-s in section Fi^. 147. Slrictl\- speaking? these are early cellulae ethmoidales anterior. In section Fi^. 148. some of tlu> furnjA\'s or cells are shown to be in free communication with the frontal recess. Any 'me of these cells may develop suffi- ciently far to become the frontal sinus. Indeed, we see here the potentials foi- niidti]ilc frontal sinuses. The frontal recess prctper also frequently gi^^es rise to the frontal sinus. x 10. {.\ftfr J. P. S.) meatuses and the accessory or secondar}' lurrows and the major and secondary conchee since they play such an im])ortant role in determining the location of the initial ethmoidal cells. The initial ethmoidal out-pouchings arc in evidence as early as the 206 THE KTHMOID.VL CELLS fourth month of fetal hfe. P"or some time the surfaces of the mucous- membrane sacs are in man}' cases in contact and the lumina in a sense mereh' potential, again the early sacs may be mere dimple-like depressions. However, by the seventh month the evaginations have taken shape in the form of hollow tubular-like, blindly ending sacs, with ostia in communi- cation with the points of initial outgrowth. These tubular sacs may now truly said to be ethmoidal cells. Horizontal sections of the nose of IVlfl' FrontaJ fy/rows tec. eth. ant.) Concha ms.mcal ductus ffasoIacrlmaVs si"! Ill/fa/ foids or ^ Y \ \arcessori/ conckiK '■^ I Froc. vncinafus (ace com/iff) Infuiidf/t. /fk _D»r/us riaso/acrimnlis Fig. 149. FiG. j^q. Figs. 149-150. — Drawing,s of frontal seclions through the left nasal fossa in the region of the frontal recess. Note the early frontal furrows, rudiments of anterior ethmoidal cells. Fig. 149, from a term fetus, series D, slide 4; Fig. 150. from a 7-month fetus, series B, slide 31. the term fetus show the ethmoidal cells considerably developed, the anterior group measuring on the aA'erage 5X2X3 mm. and the posterior group 5X4X2 mm. Reconstruction of the "term" ethmoidal labyrinth is a \'aluable method of study of the early stages. The Childhood Stage The lateral masses of the ethmoid bone and its appendages (the major and accessor}' conch;e) are primitively solid structures. Soon, however, ClIILDHOOn STACK 207 the lateral masses become more or less honeycombed or labvrinth-like by the developiiiL,^ ethmoidal cells. In the formation of the ethmoidal lab>-rinth there is no uniformity of development. In a general way the anterior group of the ethmoidal cells develop \-entral to the posterior grouj-i. There is, however, at times considerable o\-erlai)ping of the two groups. Each cell as it grows from a preformed furrow or recess tends more or less toward the cribriform plate of the ethmoid l^one. Even though a certain cell has its anlage-point farther inferior than another cell, it ma}" outgrow its neighbor and force the latter to progress in a direc- tion other than toward which it was primaril}' directed, indeed, dwarf its growth. Later the cells in honcA'combing the lateral ethmoidal masses grow in almost any direction. Cells that arise from unlike me- atuses, ne\"er communicate with each other. Eurthermore, a cell alwa\"S communicates with the meatus from which it develops. There is early a division to])ographically of the ethmoidal field into two grou])s: U) cclliihc cUimoidalcs anterior, (2) ccllulcc cUinioidalcs pos- terior. The anterior group dex'eloj) from points caudal (inferior) to the attached border of the middle nasal concha and the posterior group from points cephalic (suju-rior) to the attached border of the middle nasal con- cha. The so-called eeUiihe elliuioidales Diedice (middle grouj)) are here classed with the anterior group. This is a better classification since the cells which grow from the accessory furrows of the descending ramus of the middle nasal meatus (bullar furrows and infundibulum ethmoidale) are closel}- associated with the cells (the old anterior grouj)) which grow from the ascending ramus (frontal recess and its furrows) of the middle nasal meatus and from the xentral and cephalic extremity of the infundibulum ethmoidale. As stated pre\"iously, the frontal furrows on the lateral wall of the frontal recess var}- in number. There ma}-, indeed, be a total absence (Fig. 40); the frontal recess then appearing as a simi)le, blind outgrowth from the meatus medius. The furrows and recess de\-elo]) variously into anterior ethmoidal cells, and, in addition, the frontal sinus in the majorit}- of cases develops as an outgrowth from this region. Some of the furrows remain e.xtremelv shallow and never reach the dignity of ethmoidal cells. Indeed, regression is operati\-e in some instances and some furrows may disappear altogether, either by a coalescence of bordering folds or other- wise. The agger nasi is verA' commonly pneumatized b}- the most ventral of the ethmoidal cells de\'eloping from the frontal furrows. The infundibulum ethmoidale may terminate \-entrally and superiorly bv dilating into a single ethmoidal ceU lateral to the frontal recess and its 208 THE ETHMOIDAL CELLS derivatives. However, it is not uncommon to find from two to four cells growing out from its ventral extremity- These infundibular cells have varied relationships. Some may grow sufficiently far into the frontal bone to become frontal sinuses. Others may impinge upon the frontal smus and produce buUar-like swellings on the sinus floor. Again, they grow into the agger nasi, the processus uncinatus, etc. The bullar cells (the former middle ethmoidal cells) vary in number from one large cell to five or more smafler ones. In fully 95 per cent, of cases cells arise as extensions from the preformed suprabuflar furrow and Pig. 151. — The paranasal sinuses in a child aged i6 months. The na::ial wall of the maxillary sinus has been removed. Reduced. Rf = recessus frontaUs; SI = sacctis lacrimalis; If = infundibidum ethmoidale; Dn! = ductus nasolacrinialis; Sm = sinus ma.xillaris; 5i = sinus sphcnoidalis; lie = hypophysis cerebri; Tp = tonsilla pharyngea; Ola = ostium tuba auditiva. in 12 per cent, of cases from the infrabullar furrow. Occasionally (8 per cent.) the bullar furrow gives rise to an ethmoidal cell. These cells early hollow out the accessory concha (bulla ethmoidalis) and frequently extend into the supraorbital plate of the frontal bone and into the infra- orbital plate of the maxilla. Their size greatly influences the width of the infundibulum ethmoidale and the hiatus semilunaris, and incidentally the natural drainage channels of the maxillary sinus. During childhood the posterior ethmoidal cells gradually pneumatize and make shell-like the superior and supreme conchae. Even before pubert}' the cells may extend into the supraorbital plate of the frontal CHILDIIOOI) STAOK 2 0Q bone and into the infraorbital i)latc of the maxilla. Indeed, the author has seen as early as tlie tenth A'ear marked extensions into the bod\' of the sphenoid bone and into the maxilla, the latter simulating a duplieatecl maxillary sinus. Such ethmoidal-cell extensions, howe\'er, never normally communicate with either the sphenoidal or maxillary sinuses. iM-en before birth one frequentU' sees extensions into the middle nasal conchie. Growth of a jtosterior ethmoidal cell into the orbital ])rocess of the palate bone is, likewise, encountered (palatal sinus). Fir, 15J —A i.hntMK'raph • .( a dissection of thf paranasal sinuses of a child aged 8 years, 2 months and 10 davs. The msct m the lower right-hand corner illustrates the sphenoidal sinus and its rela- tion to the hypophysis cerebri. (Dissection by Dr. Warren B. Da\-is.) It is well to remember that, owing to the relativeh' narrow nasal fossa, it is difficult to explore the ethmoidal field by the endonasal route in the young child. However, it must not be forgotten that even in early childhood both the anterior and i)osterior groups of ethmoidal cells are fairly well established and subject to diseases. Surgeons have radically operated upon the ethmoidal cells in the child through the maxihary sinus and by way of the frontal sinus. Meyer operated upon the eth- moidal labvrinth by way of the maxillary sinus in a child between 3 and THE ETHilOIDAL CELLS 4 years of age The skiagram is a valuable aid in the delineation of the ethmoidal held in the child, but its limitations must be kept in mind. The earh' frontal sinus may readih' be confused with the ethmoidal cells. Haike, according to Onodi, believes "that a reliable diagnosis of ethmoidal affections in children can only be obtained by skiagraphy." However, he throws out the following caution : " In young children the picture of the ethmoidal cells in the skiagram is so narrow that it is sometimes difficult N. opticus A.carotis into Sulla emmoiclaZis I-nfvnd.ethnwidale Toiisilhi phcai/tt^ea ^ foncha iiasalis iruiA C.pta-ijt/oidev.'ifVidii) Proc. imc7,n(.dns Diic.TJasnlucrbnulis HTa.tv.s stm.iJtmaji.s Fig. 153. — A dissection of the paranasal sinuses and tlie nasolaerinial duct of a male child aged 1 1 years. Note that the degree of pneumatization and the relation of the several paranasal chambers are essentially those of the adult. The Vidian nerve is intimately related to the floor of the sphe- noidal sinus. The arrow in the middle nasal meatus indicates an accessory maxillary ostium. to arrive at a definite diagnosis; thus, even moderate congestion of the mucous membrane may \-eil the lumina of the small ethmoidal cells. With regard to the cjuestion whether the anterior or posterior ethmoidal cells are affected, the skiagram can give no more information in children than in the adult." Table L gives the size of the ethmoidal cells of the childhood period of a series measured b}' the author. Great variation is, of course, en- ADULT STACK 211 countered and is to be expected amon.u; the se\'eral cells com])()sing the ethmoidal lab>T-inth. The great discre])ancy in the size of the cells at a given age is largely due to the great \ariabilit>' in the number of cchs dillerentiated. The fewer the cells the larger will be the se\'eral measure- ments, since the ethmoidal lab_\-rinth will occupy the entire ethmoidal held whether comixised of few or man_\- cells. The author found the number of cells to \-ar\- from llircc to lijlccii. Tm',! 1 r CcphalocauJal, Mediolatera mm. mm. (height) (width) S 2 5 4 2-8 I . s-(5 2-8 1-5-7 i-9 2-ti ,=;-« 3-4 1-^ 5~7 7-» 7-10 8-1 r 7-10 8-1 1 7-10 Q-r 2 8-12 9-14 8-12 g-io 10 Q-i,'? 14 Age Group Newborn ' .-Vnterior Posterior I year 1 1 Anterior Posterior 2 years .\nterior Posterior 5 >-ears f 1 .\ntcrior Posterior 8 years ■ .\nterior Posterior 10 years ) Anterior Posterior 14 \-ears ■ Vnterior Posterior Vcntrodorsa mm. (length) -' 9 2-6 4-6 5-') 6-7 6-7 q-i6 S-io 9-17 8-20 The Adilt Stage General Considerations. — The great complexity' of the adult eth- moidal labyrinth and the \ariations in size, shape and dis])osition of the individual cells composing it are in accord with the earh- anatoni}' and potentialities of development. The fully developed ethmoidal lab)Tinth occupies the lield between the medial surfaces of the bony orbits and, generally speaking, extends between the frontal sinuses ^•entrall^' and the sphenoidal sinuses dorsally. Cephalicalh- (above) the cribriform lamina' serve as the boundary planes, while the uncinate processes represent the caudal limit of the labyrinth. One must, however, bear in mind that almost constantly the ethmoidal labyrinth extends beyond one or more of the true boundaries of the eth- moidal field in the formation of ethmofrontal, ethmolacrimal, ethmomaxil- lary, ethmo,sphenoidal and ethmoi)alatine cells. Moreover, not infre- quently, cellular extensions into the o\'erhanging middle nasal concha (celluhe conchales) extend the ethmoidal labyrinth below the level of tlie uncinate process. 212 THE ETHMOID.VL CELLS The mesethmoid (lamina perpendicularis) divides the ethmoidal labyrinth into two more or less symmetrical and independent lateral halves. Howe^-er, at times one or the other half is markedly enlarged at the expense of its fellow. Classification. — The embryology and adult anatomy of the ethmoidal cells justify the classification appended in Table M. As stated elsewhere the adult ethmoidal cells are seldom wholly con- fined within the ethmoid bone. Their osseous boundaries are variously completed by the articulation of the ethmoid with neighboring bones, t' ._(,'., the frontal, lacrimal, sphenoid, palate, and maxilla. While in many cases related bones merely serve to complete the osseous outlines of eth- moidal cells at the planes of articulation, they not infrequently lodge extensive cellular outgrowths from the ethmoidal labyrinth. These ex- tensions are particularly common into the supraorbital plate of the frontal bone and into the infraorbital plate of the maxilla. Moreover, the ex- tension of posterior ethmoidal cells into the bodies of the sphenoid and maxillar}' bones, there encroaching upon the sphenoidal and maxillar}' sinuses respecti\'ely, must always be kept in mind when dealing with these sinuses. Indeed, the maxillary extension is often mistaken for a super- numerary maxillary sinus (see page 119 and Fig. loi). Extensions into the lacrimal and palate bones are frequent, but of less practical importance. The extension into the palate bone is often referred to as the palatal sinus. This is to be regretted because it implies an individual sinus when in reality it is nothing other than a part of the ethmoidal labyrinth. Very commonly the anterior group of ethmoidal cells encroach upon the frontal sinus, e\en extend into the frontal bone to become topograph- ically frontal sinuses (Fig. 118). Such cells frequently produce bullous- like ele^'ations on the floor of the frontal sinus. They are frequently referred to as frontal bulla; (bullse frontales). Furthermore, cells of the ventral group not infrequently grow into the middle nasal concha, the agger nasi, and the uncinate process. It is impossible in very many instances to judge whether a cell be- longs to the anterior or the posterior ethmoidal group merely from its position. It is the location of the ostium rather than the body of the cell that determines its classification; the anterior group draining into the middle nasal meatus and the posterior group into the superior and first supreme meatuses. Dehiscences. — The osseous boundaries of the ethmoidal cefls are not infrec^uently defective ; particularly are dehiscences common in the orbital plate fos planum, lamina papyracea) of the ethmoid bone. The author CLASSIFICATIOX Taiilk A[. — Ckllvl.e Etiihoidales 213 Primary groups Secondary groups Genetic area^ Cellula- fron- (,/) FnmUil rcce-ss tales ' (!,) Frontal furrows Cellula- ill- Infundihuiluni cthnioidalc f 11 n d i b 11 - lares CMnimunicatinn in adult Frontal recess of meatus nasi mcdius Infundilniluni elhmoidale CelluUe ethmoid- ^ Celhda' l.ul- Hidlar furrou'S, e-speeially Suprabullar furr< ales anterior l-e the supralndlar and the infrabuUar Supra )ullai furrow Infral uUar furrow Bullar furrc w (,«) Meatus nasi mcdius Meatus nasi medius (di- rect 1\- 1 Celluhe con- ih) Infundibulum elhmoidale Infundibulum ethmoidale. chales ((■) ilerely extensions of other Other anterior ethmoidal anterior ethmoidal cells cells CelluUe su- perior (d) X'entral extremity of the meatus nasi superior (A) Recessus superior of me- Meatus nasi superitjr atus nasi superior Cellula; ethmoid- ;; ales posterior = (f) Recessus inferior of the meatus nasi superior (.1) X'entral extremity of the Meatus nasi superior (di- meatus nasi superior recth') Z Celluh'c con- (/)) Recessus inferior of the chales meatus nasi superior (c) Merely extensions of other Other posterior ethmoidal posterior ethmoidal cells cells. C e 1 1 u 1 ;e su- ^Meatus nasi supremus I Aleatus nasi supremus I prenije I (of meatus nasi supremus I) Extraethmoidal Extensions of Celluhe Ethmoidales: (n) h'dhmofrontal, (/)) Ellimo- larrimal, (c) Ethmomaxillary, (<1) FthmosT)henoidal, (c) I'Uhmopalatine 2 14 J-HE MTH.MOIDAL CELLS has likewise obser\-ed a number of s]^ecimens in which the mucous mem- brane of ethmoidal cells was in actual contact wdth the dura mater. The importance of these dehiscences in the spread of infection from the eth- moidal labyrinth to the tissues of the orbit and the meninges must ever be kept in mind by the clinician. Moreover, it is extremely common to find that the osseous wall between certain of the anterior ethmoidal cells and the lacrimal fossa is congenitally deficient, whereby the mucous mem- brane of the cells comes into actual contact with the lacrimal sac. It seems certain from the anatomy of the region that the nasolacrimal pas- sageways must commonly suft'er infection by a direct extension from the ventral ethmoidal labyrinth (see page 255). Size of the Ethmoidal Labyrinth. — The accompanying Table N gives the size of the adult ethmoidal labyrinth and its subgroups as determined by several measurements of a number of specimens selected at random from a larger series. The discrepancy in the ventrodorsal Table X. — The Adult Ethmoidal L.\ba'rixth (All measurements are in millimeters) ber Side -lluUt anten Medio- lateral Cclli la:- poster or Medio- lateral Labyrinth Num Ceptialo- caudal Ventro- dorsal Cephalo- caudal V^entro- dorsal Cephalo- caudal Ventro- dorsal Medio- lateral I \ R L 40 14 13 I 2 3^ 26 -'3 12 13 40 41 34 32 IS 13 / R IQ 10 t) ifi 18 II 17 27 II [ L 15 II 10 17 16 10 17 20 10 3 { R L iH 34 14 -5 8 16 -3 30 26 -5 10 15 30 35 36 35 12 16 4 1 R L 21 16 T7 22 7 9 20 16 28 20 28 10 20 20 36 36 13 13 S { R L I 7 17 3S 3- 10 10 () I 2 1 2 IS 8 8 19 19 40 32 10 12 6 / 1 R L 30 31 20 20 i>S iS -3 -3 20 12 23 3" 36 34 3° 18 18 7 1 R L iS 34 14 26 7 15 -3 31 25 25 10 13 30 30 34 32 10 15 S R L 17 3S ,^ I 9 10 10 I 2 15 8 20 20 48 17 1 17 17 A \-er i<-^e -"3 . 6 22 ,6 HI 20.3 20 . 5 1-3 26.8 32.7 14.0 ANTERIOR EJ'IIMOIDAI. CELLS 215 diameter of the whole ethmoidal lab\Tinth as com]Kire(l with the combined diameters of the anterit)r and jwsterior groui)s of cells, is due to the fact that there is considerable variation at the junction point of the two groups, particularly in the degree of o\erlai)])ing. Usuall_\- the combined ventro- dorsal diameters of the anterior and ])osterior ethmoidal groups exceed Forair/en. cthitwidah M(t. Foran/cn etJ/nwid/iL: jtost. 3/.717J.S sph-dnvuln^.is \FossiL 7/}/pof>hyseos ,' Fossu pu;f//(^opa I^u f/, 7?, /st- L ffia/rjs //u/^l/-l<^ri.5 Spuixx. 7i- \-ar>- in number hom a total absence to three or four. In a large percentage of cases the vminil and cephalic extremity of the ethmoidal infundibulum ends blindly by dilating into an anteri.jr ethmoidal cell (infundibular) lateral to the frontal recess and its related cehs (Fig. 124). Another yery frequent outgrowth from the ethmoidal infundibulum is into the agger nasi which usually more or less oyerlies the lacrimal sac, and in the endonasal surgical ai)proach of the lacrimal sac (dacr>-ocystorhinostomy) it is usually opened into before the lacrimal bone is reached in the operation (Figs. 159 and 175). Infundibular cells fc ra 71/ e 71 optic 11 i/t . __ Sivus splicT/oid/xlis Bl'kssus sphe/7oldalif(^C.,'fh/,/o/dulis post.) TorameJi spl/.anopcila tin 11^777, C.et/imoidahs post. Fig. 155. — A sagittal section through the sphenoidal .sinus anil a posterinr ethmoidal cell. Par- ticularh^ note the extension of the posterir)r ethmoidal cell (recessus sphenoidahsl o^'er llu' sphenoidal sinus into the body rjf the sphenoid bone. The extension of the ethmcjidal cell comes into intimate relationship with the optic foramen and tlie ciaitaincd iifitic ncr\'e, may stop short of the agger nasi and more or less hollow out the base of the ventral portion of the uncinate process, particularly wliere the uncinate process and the ethmoidal bulla are confluent. Additional infundibular cells may grow from the ventral and ce])halic extremity of the ethmoidal infundibulum, but they are, as a rule, small. It has been suggested (^losherj^ that the frontal sinus ma}' be probed with greater ease b\- passing through the larger agger cell instead of going lirst lateral to y\ Method of ObHtcratint; I he Xasofronlal Durt and Cal lieleriziiit; (he Emiilal Sinus, The Laryngoscope, Vol. 21, Septenibcr, 1911. 2 1 8 THE ETHMOID-\L CELLS the middle nasal concha. This would appear correct since not infreciuently this cell is of goodly dimension. The buUar group of the anterior ethmoidal cells arise genetically from the suprabullar, buUar, and infrabuUar furrows. Relatively few cells develop from the infrabuUar furrow, a slightly larger percentage from the buUar furrow, and almost constantly (95 per cent, of cases) from the suprabullar furrow. These cells variously pneumatize the ethmoidal bulla and cause it to be shell-like. Moreover, it is to these cells that the bulla owes it size and shape. Since the larger percentage of bullar cells develop from the suprabullar recess (see page 30), in the adult most of them ha\'e their ostia of communication located between the ethmoidal bulla and the attached border of the middle nasal concha. The number of cells that develop from the suprabullar recess varies from one large cell to four smaller cells. The most ventral of these cells encroach upon cells of the frontal recess, even upon the frontal sinus. Indeed, not infrequently the most ventral bullar cell pneumatizes beyond the ethmoidal field between the two plates of the supraorbital wall, whereof, it is frontal in topography. The most dorsal of the bullar cells very commonly encroach upon certain of the posterior ethmoidal cells; indeed, may topographically be in the position of such cells. Careful dissection, however, shoAvs that they com- municate with the suprabullar furrow of the middle meatus and are, there- fore, cells of the anterior ethmoidal group. As stated elsewhere, it is the point of drainage, e.g., the location of the ostium or aperture, rather than the topographic position of an ethmoidal cell that determines its classifica- tion. The position of a cell is at times very misleading since it may extend far beyond the confines of its allotted field. The frontal bulla (bulla frontalis) is usually an upward bleb-like swell- ing or expansion of one or more cells of the anterior ethmoidal group into the floor of the frontal sinus. Multiple frontal bullcC at times mould the floor of the frontal sinus. The ethmoidal bulla (bulla ethmoidalis) may so extend its boundaries by enlargement of its contained cell or cells that it balloons into the dorsal part of the floor of the frontal sinus and forms a conspicuous frontal bulla; moreover, markedly encroaches upon the con- fines of the frontal sinus. Again the frontal encroaching cells may be outgrowths from the ethmoidal infundibulum (infundibulum ethmoidale), e.g., infundibular cells (see page 213 for their classification). The anterior ethmoidal cells that develop from the frontal recess nearly always encroach upon the frontal sinus or its duct, and at times to such an extent that one or other cell assumes the dignity of a frontal bulla (Figs. 117 and 118). It must not be forgotten, however, in this connection that the balloon- rOSTERIOR ETHMOIDAL CELLS 219 like swelling frequently encountered in the floor of one or the other of the frontal sinuses may pro\'e to be a frontal sinus and, indeed, the only frontal sinus of that side (see page 152 and Fig. 85). The Posterior Ethmoidal Cells (celluke ethmoidales posterior).— The posterior ethmoidal cells genetically arise from the superior and first supreme nasal meatuses and in the adult, therefore, communicate with the nasal fossa above the attached border of the middle nasal concha, either with the superior nasal meatus or with the first supreme nasal meatus. It should be recalled that the first supreme nasal meatus is present in ap- proximately 00 per cent, of adult nasal fossa; and that in 75 per cent, of these cases a posterior ethmoidal cell communicates with it; indi- cating, therefore, that the posterior ethmoidal cell in cpestion arose from the first supreme nasal meatus (see page 23). The superior nasal meatus never fails according to the author's series of specimens to give rise to one or more posterior ethmoidal cells. These cells variously pneumatize and make shell-like the lateral ethmoidal mass above the attached border of the middle nasal concha. Not infrecjuently these cells extend beyond the confines of the ethmoidal field and form ethmomaxillary, ethmo- sphenoidal and ethmofrontal cells. ]\Ioreo\-er, the posterior and anterior groups of ethmoidal ceUs OA'erlap each other's fields as regards topography, but not, as stated elsewhere, as regards the drainage of the two groups. There is no constancy in the number of posterior ethmoidal cells that are dift'erentiated, the author finding them to vary from one to scA'en. Xot infrequently the posterior ethmoidal labyrinth when composed of but one or two cells occupies as much space as when composed of fiA'e, si.v or se\'en cells. It does, however, mean when few cells are present that they are correspondingly much larger than the average. \'er}- commonly the posterior ethmoidal lab}'rinth is, however, not confined to the lateral ethmoidal mass. The extensions of its cells into the ethmoidal appendages (major and minor conch^e or turbinates) will be discussed in subsecpent paragraphs under the caption "conchal ceUs." In the discussion of duplication of the maxillary sinus (page 118) mention was made of the very common extension of a posterior ethmoidal cell into the dorsal and cephalic and medial angle of the body of the maxilla. Such an ethmoidal extension pneumatizes into the body of the maxillary bone at the expense of the maxillary sinus. Moreover, it anatomically simu- lates a duplication of the maxillary sinus. Careful study, howcA'er, indi- cates its true genesis as a posterior ethmoidal cell and that it nearly ahvays communicates with the superior nasal meatus. This ''ethmomaxillary" posterior etkmoielal cell develops variously, at times occui;)ying a relatively 2 20 THK ETH.MOIDAL CELLS small portion of the maxilla where the infraorbital and infratemporal surfaces meet, immediately ventral to the pterygopalatine (pterygomaxil- lar}') fossa. At other times the ethmomaxillary cell may assume large proportions, occupying from a fourth to a half of the body of the maxilla. The maxillary sinus is, of course, proportionately reduced in size (Fig. loi). It is, morcoA'er, obA'ious that an ethmomaxillary cell if of considerable size is, from a clinical -s'iewpoint, more maxillary than ethmoidal despite its origin from the ethmoid bone. The ethmomaxillary cell (or better sinus, if large) has its ostium or aperture located at its most cephalic point, normally in the superior nasal meatus; and, not unlike the ostium of the maxillar}- sinus, is very disadvantageously located for efficient drainage, e.g., gravity drainage is wholly absent in the usual upright posture of the body. In disease, a goodly sized ethmomaxillar}- sinus doubtless behaves like the maxillary sinus proper. The operator must, however, remember that in all likelihood a health}- maxillary sinus proper would be opened into in an empA'ema of the ethmomaxillar}' sinus unless a rhinoscopic and skiagraphic study preceded the operation. In the more usual and moderately sized posterior ethmoidal cells the optic nerve at the optic foramen is separated from the most dorsal and superior of the cells by bone from 2 to 5 mm. in thickness. The ethmoid labyrinth being placed in the sagittal plane, the optic nerve as it courses toward the eyeball diverges more and more from the posterior ethmoidal cells as one passes from the optic foramen toward the eyeball. Not infrequently certain of the posterior ethmoidal cells invade the sphe- noid bone in the formation of ethmosphenoidal cells (Fig. 141). The latter extend ^■ariousl}' dorsal ward into the bod}' and lesser wing of the sphenoid bone over the sphenoidal sinus; indeed, may extend sufhcienth' far to come into very intimate relationships with the optic nerve at the optic foramen and for a considerable distance in front of it. The lamella of bone inter\'ening between the mucous membrane of the ethmosphenoidal cell or sinus and the optic ner\'e is not infrequently reduced to a tissue- paper delicacy. Indeed, the lamella of bone may be deficient at places so that the optic nerve is directly exposed to the mucous membrane of the ethmosphenoidal cell. The importance of this not infrequent A'ery inti- mate relation between certain of the posterior ethmoidal cells and the optic nerve must be thought of in connection with blindness of nasal origin. These sphenoethmoidal cells are at times of such a size that they replace almost entirely the sphenoidal sinuses and, therefore, preclude the sphenoidal sinuses from estabhshing the usual relationships with the optic nerve. Just as the optic nerve at times courses almost within the COXCHAL CELLS 221 lumen of the sphenoidal sinus (Fig. 140), it ma}- be almost entirely sur- rounded by an extensively de\eloi)ed jiosterior ethmoidal cell which has pneumatized into the body and lesser wing of the s])hen(>id (Fig. 155). The extension of jxisterior ethmoidal cells into the frontal bone is extremely common]ilace. The>- usualh- extend dorsal to the frontal sinus proper for a greater or less distance over the orbit and are, therefore, frequenth- called ethmoorbital or ethmofrontal cells. CV'casionalh- the jiosterior ethmoidal cells so dexelo]) and arrange themselves that the>- form the boundaries of the ])terygoi)alatine (pterv- gomaxillar)) fossa and thereby re])lace the more usual maxillarv sinus boundar}- in front and tlie sphenoidal sinus biiundar>- abo\'e and behind (see pages 179, 31S and 319). It is, therefore, wholly jiossible that the sphenojxdatine or nasal ganglion of Meckel be at times exposed to the influ- ences of the posterior ethmoidal lab>-rinth, both in health and disease. The Conchal Cells (celluke conchales).'— Not infref|uentl}- cells of both the anterior and posterior ethmoidal groups grow into the concha nasalis media, the agger nasi, and the processus uncinatus. It is to this group of cells that the name celluhe conchales is appHed.- Such cell ex- tensions ma}- be single or multij^le, both imilateralh- and bilaterallw It must, however, be stated at the outset that these cells do not differ in any manner, sa\'e in tlieir location, from the i)Osterior ethmoidal cells which make shell-like the superior and sui)reme conch;e, and the anterior ethmoidal cells which ])neumatize to a paper}- delicac}- the etJ-imoidal bulla. Since the time of Santorini, who apparenth- was the hrst anatomist to call attention to the ca\-it}' frequentl}- found in the middle nasal concha, many conflicting and erroneous h}-])otheses ha\-e been adxanced as to the nature and origin of these spaces. Many of the theories are from the pens of earlier clinicians who rem(n-ed at o])eration portions of the walls of such cavities that were changed b}- ])athological ])rocesses and attempted to explain the origin of these si)aces by a fault}- interpretation of the al- tered tissue remo\-ed. The ca\-ities have been variously termed c}'sts, abscesses, osseous cysts, exostoses, neoplasms, ectasias of the ethmoid bone, aberrated ethmoidal cells, and when large and occurring in the ventral portion of the concha media, as conch;e bulloscT. ' H. .\. Lothrop, .\nnals of Surgery, X'dl. 3S, igo^. George E. Shambaugh, Trans. Amcr. Laryngol. .Vssoc, 1907. J. Parsons Schaeffer, ,\nat. Rec, 1910. Glasmacher, Berliner Klin. Wochenschr., 1MS4. Depuytren, Clinique Paris, Vol. 11, i.S.jo. 2 J. Parsons Schaeffer: On the Genesis of .\ir Cells in the Conchx- Nasales, Anat. Record, N'ol. 4; So. 4, 1910. 222 THE ETHilOIDAL CELLS In order to better understand these cells and to see that they are nothing other than ethmoidal cehs, it is essential that the origin of the ethmoidal labyrinth be kept in mind. The location of these cells appears less abnormal when one recalls that the ethmoidal conchas and the proc- essus uncinatus are merely appendages of the lateral ethmoidal masses. There is no reason, therefore, why ethmoidal cells should not at times in the formation of the ethmoidal labyrinth grow into the appendages just as they grow into the lateral ethmoidal masses proper. According to the author's reconstructions^ of the lateral wall of the nasal cavity of different aged fetuses, the primitive ethmoturbinal fold, with its subsequent modifications, is not concerned only in producing the Fk;. 156. Figs. 150, 157 and 15S Fig. 157. Fig. 158. -Frontal .suctions of the left nasal feissa in the region of the bulla ethnioidalis from a term fetus (series D, slides 5. 6 and 7). Xote the develijpment of ethmciidal eells in the eoncha media and the bulla ethmoidalis. None of the sections is far enough ventrad to pass through the ostium of the ma.xillary sinus. C = cellulEB ethmoidales; M.n.m. = meatus nasi medius; M.n.i. = meatus nasi inferior; C.n.med. = concha nasalis media; B. elh. = bulla ethmoidalis; Inf. elh. = infundibulum ethmoidalc; Proc. nnc. = processus luicinatus; .S. max. = sinus maxillaris; F. cr . ant. = fossa cranii anterior. ethmoidal concha^ and the intervening furrows (meatuses), but also with the structures operculated by the concha nasalis media, e.g., the processus uncinatus, the bulla ethmoidalis, the hiatus semilunaris, and the in- fundibulum ethmoidale. These modifications are all intimately related to the rudiments of the paranasal sinuses. The posterior group of ethmoidal cells are primarily constricted from or are direct extensions of the furrows separating the primitive ethmoidal conchic, and the anterior group of ethmoidal cehs develop from preformed ' Loc. cit. COXCHAI. CELLS 223 accessory furrcws of the middle meatus; therefore, are in relation to the furrows and folds found in this location. In this connecticm it is an in- teresting fact to note that the ostia of conchal cells invariably communicate directl>- or indirectl}- with the points from which ethmoidal cells normally develop. Moreo\-er, a study of a series of specimens pro\-es that conchal cells are either parts of other ethmoidal cells which determine their nasal connection or the>- communicate (a) directl_\- with the superior i>niiii stjfiLnoid i/i -^lui-^tci Siynj.s fro/ifalis Fjvittal cells Seccssii3 fro)/Jalis Aq^er ?iasi cell llnfm/dibular cell) . . Saccus Ictc/rmaJis (dotted outli'ux) \ ...■--- Cc coiichalts ' "" t'Cc.etlimnidales) Ik peru^ cavcrnosi cuncharum. Fig. 159. — The lateral nasal wall with the paranasal sinuses exposed, tlie maxillary sinus exeejited. Especialh' note the extension of posterior ethmoidal cells (Ce. conchales) into the middle nasal concha. Moreover, note how the cell in the agger nasi overlays the lacrimal sac. In the endonasal approach of the lacrimal sac and nasolacrimal duct it is this cell that is opened into first. The condition is common. The erectile character of the mucous membrane is marked o\-er the inferior and miildle conehsE. meatus, ih) with the infundibulum ethmoidale, or (r) directly with the ventral end of the middle meatus. The ostia in the latter case are on the lateral surface of the concha nasalis media. Although the rudiments of the ethmoidal cells are primarily constric- tions or extensions from the nasal fossae, the further extension and develop- ment of these cells depend upon the simultaneous processes of growth (of the sacs) and resorption (of surrounding tissue). In this manner the 224 THE KTHMOIDAL CELLS cells extend farther and farther mto the lateral masses of the ethmoid bone as age ad\-ances, and in the adult are completed by the articulation of the ethmoid bone with the frontal, lacrimal, sphenoid, maxillary, and palate bones. These de\'elopmental processes are not uniform and, doubtless, are carried farther in some cases than in others, hence the extension of ethmoidal cells not only farther into the lateral mass of the ethmoid bone, but also into its appendages, such as the ethmoidal conchas, the processus uncinatus, etc. A reference to Figs. 159 and 160 shows the extension of the inferior ethmoidal groove (superior nasal meatus) not only into the lateral eth- moidal mass, but also into the concha mecha, thus forming conchal cells Co coTjcJialcs ~>^ \ (toTtcha- Tnuifj-^ J Pig. 160. — A frontal section throtii,'h the skull of an adult. Note the stipraorbital extensions of the frontal sinuses and the large ethmoidal cells in the middle nasal conchfe. which are merely parts of the more usual posterior lateral mass cells. At first thought it may seem difficult to account for the conchal cells having their ostia opening inferior to the attachment of the concha media, either into the middle meatus or the ethmoidal infundibulum. However, when one recalls the great modifications of this portion of the middle meatus overhung by the concha media, incident to the formation of the struc- tures found there, and that the anterior group of ethmoidal cells have their origin in this position, it is not difficult to see why some of these cells extend not only into the lateral mass of the ethmoid bone, but also into the processus uncinatus, the concha media, and the agger nasi. In Fig. 158 is represented a photograph of a specimen in which a conchal cell is already present in the concha nasalis media of a fetus at COXCIIAL CELLS 225 term. Of course, most concha! cells must necessarily appear compara- tively late in the formation of the ethmoidal labyrinth, since the positions the>- occup>- with reference to the ethmoidal cell rudiments are relatively far removed. The extensions into the conch;e, etc., would, therefore, m most cases be delayed probably until ])ubert_\-, or e\-en later, when the ethmoidal labyrinth reaches its full development. Knight's statement: F!vrc sst/s tio,-/ta/is Bulla etkmoidaJis CrfrcJ/(.t7faSid(S /ucrh a ' CancJ/a y/(fjsc/2i5 ?/// O^ 7iasalc .* ' P--^^. •Sf-fjlii'^i ?/asi Co I'-n y/aiciJis iiicd/n ^fj/h'a 7/i/5UOS U/7t Nnxillu Fig. 161. — .An enormously developed bulla ethmoidalis as seen (limugh the osseous iiyriform nasal aperture. Xote that the uncinate process is crowded caud')-laterall\' and the concha nasalis media thinned out and crowded against the septum nasi. Obviously the enlar^'ed bulla was the prime factor in the de\'iation of the septum. "Children seem to be exempt. Xone of the patients was under 20 years of age," is misleading. If late fetuses shoAv conchal cells (Fig. 158) surely children are not exempt. Extensions of ethmoidal cells (infundibular) into the agger nasi are not uncommon (Figs. 153 and 159). There is no reason why cells in this location could not extend farther and finally reach and occupy the ventral 15 2 26 THI-; ETHMOID.\L CELLS end of the concha inferior. Such an extension would explain Schaeffer's cell of the ventral end of the inferior nasal concha. The writer finds that cells in the latter position are extremely rare. Careful examination of conchal cells shows that they do not differ in any manner from the ethmoidal cells of the lateral masses. This is true macroscopically and microscopically. The mucous membrane lining conchal cells is extremely thin, but corresponds in its general structure to that lining the other ethmoidal cells, unless changed by a pathological process. It must be remembered that conchal cells, like any of the ethmoidal cells or of the paranasal sinuses, may become the seat of an empyema or a mucocele, and enlarge, because the ostia of these cells are invariably placed at the highest points of the cavity and very disadvan- tageously placed as drainage openings, a fact easily understood when their development is considered. The existence of air cells in the conchas, etc., is certainly not the result of an empyema or rarefying osteitis, but because these cells are normally found in these positions they may become the seat of pathological conditions just as do other cells of the ethmoidal labyrinth. Sex does not have any bearing on the de\'elopment of conchal cells, and the}' are about ecjually di^'ided as to whether the ostia open cephalic or caudal to the attached border of the concha nasalis media. Santorini^ thought conchal cells (referring to the concha media) quite common, but says he should not \-enture to sa}' that the condition was constant. He apparently regarded these cells much more frequent than the}' reall}' are. According to Reardon, Zuckerkandl observed them 8 times in 172 skulls. Knight says that Zuckerkandl "found them 36 times in 200 postmortem examinations." Lothrop found them in 9 per cent, of all cases. The author in an examination of over 200 adult nasal fossae found conchal cells in approximately 12 per cent, of the specimens. The Middle Conchal Sinus. — The so-called middle conchal sinus (a pseudo paranasal sinus), formed by the lateral and superior curling of the free border of the concha media, is not homologous with nor analo- gous to the conchal cells. Nevertheless, in some cases it mav retain fluid in its hammock-like fold; indeed, may become the seat of an empyema or a mucocele. The majority of middle conchcC do not, however, show the sinus and when present it is, as a rule, of minor importance (Fig. 162). Concluding Considerations. — As may be inferred from the foregoing paragrai)hs, it is difficult in skiagrams to distinguish the anterior ethmoidal ' Dominici Joannes Santorini; Observationes Anatomica;, pp. S8-S9, 1739. CONCLUDI.VC CONSIDERATIONS 227 cells from the frontal sinus in the earl\- postnatal period. This is, of course, due to the genetic and earh- intimate to]wgraphic relationships between the most x-entral of the ethmoidal cells and the frontal sinus (Figs. 36 and 37). The fact that the skiagram fails to differentiate the frontal sinus at this early period is of little imixirtance chnically since both the frontal sinus and the anterior ethmoidal cells in diseased states are doubtless conjointh- in\-ol\-ed. The nature of the anatomy of the region Cc.fJ^.m,oidaJes //i/p ophiasis C(i?-(ibri Siruis^:o?'leptiiiii nasi > * ft Siniix niaxiliari!^ '' Meatus nasi s ape J- i or Meat as nasi nicdias Concha iiasalis inferior »#«% *- Fig. 164. — A dissection of the paranasal sinnses. The hning mucous membranes are represented. The cadaver was first formahzed, then the osseous boundaries "were rcmo^'ed piecemeal. upon in children by Ava}' of the nasal ca\'ity, the frontal sinus, the maxil- lary sinus, and the medial side of the orbit (resection of the orbital plate, lamina papATacea). The earh' intimate anatomic relationships between the ethmoidal cells and the orbital ca\'ity must ahva^'s be recalled in ethmoidal affections. Radical operations have been ])erformed on the ethmoidal cells in children as young as 30 months of age' and more fre- 1 E. ilyer, Berliner Klin. Wochenschr,, 1905. 230 THE KTHMOID.U. CI-XLS quently as age ad\-ances and both the ethmoidal labyrinth and nasal fossa assume larger proportions. Transillumination is not to be depended upon as a means of outlining the normal and fully developed ethmoidal labyrinth, and is utterly un- reliable in ethmoidal suppuration in the opinion of many inyestigators. Fig. 165.— Fruntal skiagram of a Jrycd skull of an adult. Note the paranasal sinuses. The prepara- rations shown m Figs. 165, 166, and i66.i were .i--rayed by Prof. Manges. Roentgenography, on the other hand, is of distinct value in the study of the normal ethmoidal labyrinth, despite its limitations. Especially are skiagrams of value in the delineation of the anterior group of ethmoidal cells in their relationships with the lloor of the frontal sinus. Moreover, cox CLV I )L\( ; COXSIl )ERA'riOXS 231 such pictures are desirable wlien the endonasal approach of the frontal sinus is attemjited. Fortunately in the later childhood and adult periods the nasal fossa and meatuses have assumed larger proportions, malting the direct endo- nasal examination of the ethmoidal field possible and feasible. Indeed, some clinicians claim that the presence of pus in the ethmoidal cells can better be determined by direct examination than Ijy roentgenograph)-. Fl(,. l<>iy. — PrMtik- skia^^ram of a ilryed Ho\ve\'er, the skiagram is of real A'alue in the detection of su])])uration and purulent collections. Turner and Porter have been unable in frontal X-ray exposures to satisfy themselves "of the possibility of differentiating between disease of the anterior and posterior grou])s of cells." ^Moreover, it is well known that profile skiagrams not cmh' picture the ethmoidal cells of that side, but also the cells of the op])osite side. This ajipears to interfere with the recognition with certainty of unilateral affections. The experienced roentgenologist, however, not infrequently correctly 232 THE ETHMOIDAL CELLS interprets the ethmoidal field in skiagrams. It is obviousl}' not a work for the no\'ice. To obviate the overlai)ping of ethmoidal cells as occurs in frontal skiagrams and the projection of the opposite ethmoidal labyrinth over the ethmoidal field under investigation as occurs in profile skiagrams, it' would appear that the methods of Pfahler and Pfeifi'er should be of Fig. 166.4.— Profile skiagram nf a sectioned head of an adult negro. The paranasal sinnses are filled with Wood's metal and are indicated by the deep black outhnes. The nasolacrimal duct is shown coursing above and medial to the forepart of the ma.xillarv sinus. The horizontal white lines indicate the planes of section. distinct advantage. Both of the methods take the skiagram through the vertical diameter of the head and picture both the complete ventrodorsal and transverse diameters of the bilateral ethmoidal labyrinth with much less overlapping and superimposing of cells. The anatomy of the eth- moidal labyrinth is, of course, such in very many cases that some over- COXCLUDIXG COXSIDKRATIOXS 233 lapping of cells in X-nu' pictures is inevitable regardless of the exposure. The anatomic ]>osition of the ethmoidal field is of great importance in diseased states of its honeycomb-like structure. Infection may readily extend into the orbit, gi^•ing rise to an orbital cellulitis. .Vt best the orbital plate or lamina jxipNTacea inter\'ening is of extreme dehcacy and not infrequently of a fenestrated nature due to congenital dehiscences. The very intimate relationship between certain of the anterior group of ethmoidal cells and the lacrimal fossa and sac lead to frequent secondary invohement of the lacrimal sac (dacr}-oc}"stitis) in etlimoidal infection (see page 253)- The cranial cavit>' may be in^-olved, the ethmoidal infection extending by wa}' of the ethmoidal veins. The \'ery intimately related ophthalmic ^"ein ma}" carry infection into the dural cavernous sinus. Occasionall}', especial!}' in children, the small vein Avhich traverses the foramen caecum infects the superior sagittal or longitudinal dural sinus. The location of man}' of the anterior group of ethmoidal cells is such that they drain directly orindirecth'intotheinfundibulumethmoidale and from there through the ostium maxillare into the maxillary sinus. The latter maA', therefore, become a cesspool for infectious materials from certain of the cells of the ethmoidal labyrinth (see also frontal sinus, page 172). The A'erv common extensions of the ethmoidal cells into the middle nasal concha, the uncinate ])rocess, the agger nasi, etc., must not be for- gotten in dealing with the bleb-like enlargements of these structures (page 225). Moreover, the extension of certain ethmoidal cells into neighboring bones is of distinct clinical im])ortance, especially those that simulate maxillary and s])henoidal sinuses (see pages 219, 220). It is equally important clinicall}' to recall that many of the ethmoidal cells have no gravity drainage in the more usual ])ostures of the body. In this regard such cells are not unlike the maxillary and sphenoidal sinuses. Some of the ethmoidal cells, however, have dependent or gravity drain- age and are not unlike the frontal sinus in this respect. Vll-THE NASOLACRIMAL PASSAGEWAYS CHAPTER \TI THE NASOLACRIMAL PASSAGHWAYS The lacrimal sac (saccus lacrimalis) and the Jiasolacriiiial duct (ductus nasok\crimalis) are very intimately related to the lateral wall of the nasal fossa and to certain of the paranasal (accessory) sinuses. The lacrimal duels (ductus lacrimales, lacrimal canaliculi) are not intimately related to the parts in ciuestion sa\-e as they near and connect up with the mem- branous lacrimal sac. Moreover, the nasal fossa serves as a drainage chamber for the lacrimal apparatus, receiving the lacrimte or tears in the inferior meatus. The intimate relationship between the nasolacrimal duct and the nasal fossa is taken adxantage of surgically, intranasal dacry- ocystotoni}- (dacryocystorhinostomy) being freriuenth' practised in steno- sis of the nasolacrimal duct. It is, therefore, deemed a])ropos and essential in this connection to anah'ze the regional and topographic anatomy of the lacrimal ducts, the lacrimal sac and the nasolacrimal duct, with especial reference to the nasal fossa and the related paranasal sinuses and to refer to other developmental and anatomical features that are of importance here. Genetic and Developmental Anatomy. — In order that the variations in the topography and anatomy of the fully established nasolacrimal pas- sageways mav be properly interpreted, it is necessary that one recalls the fundamental developmental stages in the formation of the channels. As is well known, at one stage of the human embryo there extends a fissure or furrow, the naso-optic fissure, from the eye to the nasal pit. This fissure is bounded superiorly by the embryonic lateral nasal process and inferiorly by the embryonic maxillary process (see page 4). The naso- optic fissure gradually disappears normall}' by a growth and coalescence of the structures bordering it. The coalescence or fusion of the lateral nasal and maxillary jjrocesses takes place from within outward, thereby "outfolding" the inter\-ening naso-optic fissure (Pig. 167). The strand of thickened epithehum along the floor of the now rudimentar}- naso-optic fissure undergoes further proliferation and sufl'ers absolute and complete detachment from its surface connections and becomes entirely surrounded by the subjacent mesenchymal tissue into which the detached epithelial cord sinks (Fig. 169). The related and surrounding mesenchyme is des- 237 2.38 THE XASOLACRIJIAL PASSAGEWAYS tilled ill part to form the maxilla, the inferior conchal or turbinated bone and the lacrimal bone. The surface-detached and mesenchymal- surrounded solid epithelial cord is the forebear or anlage of the naso- lacrimal passages. The original solid cord grows cephalicalh', giving rise Fig. 167. — Photomicrograph of a frontal section of tire head of a Iruman embryo aged 35 days. Xolc in tlie region of the naso-optic furrow {uof) the nipple-hke thickening (d) of the surface ectoderm in the formation of the rudiment of tlie nasolacrimal passageways. X 7. normally to the cupola of the lacrimal sac and by secondary outgrowths to the tAvo lacrimal ducts. INIoreoA'er, it grows nasalAvard and establishes connections with the epithelium of the inferior nasal meatus. The sohd cord and its secondary outgrowths or sprouts, by a rearrangement of their / Pig. 168. — Photomii rogi iph ( f a frontal section 1 t the head of a human embryo aged 36 days. Note the gro^vth of the rudmicnt ot the nasolaerunal passageuajs (d) and compare with Fig. 167. Nof — remains of naso-optic furrow. X 7. cellular elements, become hollow and form the duct connections between the conjunctival culdesac and the inferior meatus of the nasal fossa. Ossi- fication of the surrounding mesenchyme takes place in the formation of the maxilla, the inferior turbinated and the lacrimal bones, so that ulti- DKVELOPMl'A'T '■39 mately the membranous nasolacrimal duel and the lower ])orUon of f.he membranous lacrimal sac become encased in an osseous canal (canalis nasolacrimalis) formed by the maxilla and the inferior turbinated and the lacrimal bones. The lacrimal ducts and the greater portion of the lacrimal sac do not become encased by bone, the former coursing within the soft tissues of the e>-elids and the latter resting in the shallow lacrimal fossa (Fig. 173). The nasolacrimal passageways, at hrst solid epithelial cords, ulti- mately become canalized in an irregular manner. The canalization is in reality nothing other than a rearrangement of the epithelial cells around a central!}" placed lumen rather than a necrobiosis of central cells. The ocu- lar end of the solid nasolacrimal duct is the first to establish a lumen. The horizontal portions of the lacrimal ducts (canaliculi) estal:)lish lumina be- • // ^^^y» ^''''. ***'«'^^ -x*^ 7.v; '^.^ Fig. 169. — PhotrimiLri>Kraph of a frontal sfitinn nf the head of a human eniljryo aKed 43 days. Xote the complete detachment of the rudimentary nasolacrimal passageways id) from the surface ectoderm. The "passageways" are solid epithelial cords and entirely surrounded by mesenchymal tissue at this time. X 7. fore the vertical portions (Fig. 170). The pointof coalescence between the nasal end of the soHd nasolacrimal duct and the mucous membrane of the inferior nasal meatus is the last point in the entire duct system to become patent. In most instances, canalization here is deferred until the end of fetal life. Indeed, the author has made many obser\-ations in which a membranous barrier between the nasolacrimal duct and the interior meatus existed during the hrst weeks of infancy (Fig. 171). One of the striking features of the nasolacrimal duct at birth is its relatively large diameter and extremeh' irregular Avails. The latter condi- tion gradually disappears to a large degree; some of the recesses, however, developing into diverticula, others remaining as mucosal shelves and so- cahed valves. The nasolacrimal duct at birth averages about 2 mm. in 240 THK XASOLACRIM.\L PASSAGEWAYS diameter. By the third year the diameter has increased to 3 mm. or over, extremes being observed from 1.5 mm. to 6 mm. The latter diameter is, however, ^^ery unusual. A -B Fk;. 170. — Photomicrographs of frontal sections through the nasolacrimal passageways of a human embryo aged 128 days. Note the solid portions of the lacrimal ducts in Fig. .4. In Fig. B, we have a patent section (is) of the ocular end of the nasolacrimal duct and in Fig. C, a section of the mid-por- tion of the nasolacrimal duct still solid {nld). Note the well established lumen {nld) at the nasal end of the nasolacrimal duct in Figs. D and £. Note how extensive the contact point between the naso- lacrimal duct and the inferior nasal meatus wall be (Fig. D). Sid ^ superirir lacrimal duct; ild ^ inferior lacrimal duct; Is = lacrimal sac; nld = nasolacrimal duct; ?'«(■ = inferior nasal concha; hnn ^ inferior nasal meatus. X 19. (AfU'r J. P. S.) The lacrimal sac and the nasolacrimal duct are relatively fixed from the onset as far as position is concerned. The paranasal (accessory) sinuses are, therefore, not as intimately related to the nasolacrimal pas- DJ-A'l'XOPMENT 241 sageways as later when the sinuses assume larger dimensions. Despite the general truth of the foregoing, the maxillary sinus and the nasolacrimal duct bear important and fairly close anatomic relationships e\'en befcjre birth. At birth the nasolacrimal duct lies on the average but 2 mm. YiQ, III, — Photomicr(jKraphs of sections through the nas.iUicrimal duct. .1, from a child at term. Note that the barrier (lacrimonasal membrane) between the nasolacrimal duet and the inferior nasal meatus is still intact. X 3.4. B, from a y-inonth fetus, the lacrimonasal membrane intact. X 6. C. from a term child, the lacrimonasal membrane markedly thinned out but unruptured. Particu- larly note the irregularity of the nasolacrimal duct. D, from an adult, aged 60 years. E, from an adult, aged 65 years. Note the diverticulum (.Y). X 2.0. f, froin an adult, aged 70 years. In the region of the ostium of the common lacrimal duct. directly in front of, or from 1.5 mm. to 2 mm. medial to the ventral end of the maxillary sinus. By the eighteenth month the distance intervening 242 THE XASOLACRIMAL PASSAGEWAYS between the maxillar}' sinus and the nasolacrimal duct is reduced for a limited segment of the duct to an intimacy not unlike in the adult. Of course, only later, when the infraorbital recess assumes goodh' proportions, is the nasolacrimal duct exposed to the surface of the maxillary sinus for a considerable distance. Of the ethmoidal cells, those developing from the frontal recess of the middle nasal meatus are nearest the lacrimal sac at birth. However, the anatomic relationship is not intimate at this time. Indeed, in a child aged from i8 to 24 months from 5 to 7 mm. usually intervene between the lacrimal sac and the nearest ethmoidal cell (Fig. 151). Rarelv a more precocious ethmoidal cell establishes very intimate anatomic relations with the sac at an earlier period of extrauterine life. By the sixth year the maxillary sinus estabhshes fairly intimate relationships with the upper portion of the nasolacrimal duct, and the frontal ethmoidal cells have pneumatized the region formerly existing between the lacrimal sac and the frontal recess. Infundibular cehs like- wise not infrequently early seek lacrimal sac relations. Indeed, the rudi- mentary frontal sinus Neither frontal recess or frontal ethmoidal cell, see page 143) must be thought of in the earh" relationships of the lac- rimal sac. After the eleventh year the anatomic relationships between the para- nasal sinuses and the nasolacrimal passageways are essentially those of the adult (Fig. 153). Variations and Anomalies. — The A-ariations and anomalies in the nasolacrimal passageways as encountered in postfetal life are readily accounted for by the potentialities of development of the anlage of the duct system. Double and triple lacrimal puncta and lacrimal ducts have been observed by the author. Indeed, Majewski found a case of quad- ruple puncta. Should the cephalic end of the solid epithelial cord give rise to more than two lacrimal sprouts, the usual number, either the upper or the lower ej^elid or both might have multiple lacrimal ducts and puncta. Some of the multiple outgrowths fail, however, at times to reach the free border of the eyelid. Moreover, should one or the other of the two usual lacrimal sprouts fail to reach the free border of the eyelid there would, of course, be an absent lacrimal duct and papilla; or should, perchance, the solid lacrimal sprout after reaching the free border of the ej'elid fail to become canalized at that point, a lacrimal papilla with an absent lacri- mal punctum would result. It does not necessaril}' follow that multiple puncta mean a corresponding number of lacrimal ducts; an extensive coalescence of a single lacrimal duct with the free border of the evelid VARTATIOXS AND ANOMALIKS 243 may establish multiple ostia or puncta. Again, a lacrimal jHinctum may be represented b}- a slit-like furrow aloni^^ the edge of the e>-elid. Congenital tistula of the lacrimal sac is occasionally encountered as a unilateral or bilateral defect. It usuall>' means an arrested de^'elop- ment m the obliteration of the ojnical end of the naso-optic furrow. At times it would seem that the defect is due to an attenuation of a di\-erticu- lum of the lacrimal sac. Auxiliary lateral buddings of the solid or uncanalized nasolacrimal duct are ^-ery common at one stage of the human embr>-o (Fig. 17 2). Apparenth-, man>- of these suffer early absori)tion. However, a study Fossa- izasalzs OcvllbS X^'l^f. Ductus ?t4Zsolccc7i?njx2is 2 CoTtcJia, TiasaZis inferior .3 Fig. I 72. — In Xo. i are shown outlines of the hinien of the ductus nasolacrimalis at various Ic^^cls. What appears to be two ductus nasolacrimales lying side by side at one leyel turns out to Ijc the main duct and a diverticulum from it. From an adult. (After J. P. S.) In N'o. 2 is illustrated a frontal section through the nasal fossa of a forty-day human embr>'o. The advanced rudiinent of the nasolacrimal passageways is indicated in solid black. Note the com- plete isolation frr^m the surface and the lacrimal ducts sprouting from the main cord of cells. Lateral auxiliary buds, the rudiments of di\'crticula. arc shriwn protruding from the main cord (">f cells. (Aflt-r J. P. S.] In Xo. 3 is shown the irregular canalization r>f the ductus nasolacrimalis. Frcjm a child aged one day. (After J. P. S.) of much embrA'ologic anrl adult material has con\-inced the author that the very common di\'erticula of the adult nasolacrimal duct have their origin in these embryonic lateral buddings. As the main duct becomes canalized the })rocess is carried into the au.xiliary buds in the formation of dixerticula. Indeed, the case described by (ieddes' in which the naso- lacrimal duct communicated with the middle nasal meatus can be ex- plained by such a lateral bud. These di\erticula ahvays communicate 1 An iVbnormal X'asal Duct, .Vnatom. ,\nz., Bd. 37, X"o. i, Tgio. 244 THE NASOLACRIMAL PASSAGKWAYS with the main nasolacrimal duct and are lined b>' an epithelium not un- like that of the main duct (see page 250).^ The connections of the uncanalized nasolacrimal duct with the epithe- lium of the inferior nasal meatus occurs at various levels. At times the coalescence takes place at the highest point or cupola of the inferior nasal meatus. Again, it may occur at any point on the lateral waU of the in- ferior meatus in the plane of the duct. In the canahzation of the field of union between the nasolacrimal duct and the inferior nasal meatus from one to three ostia are established. The single ostium is, of course, the more usual. The attenuation and rupture of the membranous septum, composed of two layers of abutting epithelium with a limited amount of inter\-ening connecti^'e tissue, located between the lumen of the naso- lacrimal duct and the inferior nasal meatus, is not unlike the rupture of the bucconasal membrane in the estabhshment of the connection be- tween the primiti^'e nasal fossa and the primiti\-e buccal cavity. Should the membranous barrier between the inferior nasal meatus and the naso- lacrimal duct fail of canalization or rupture, atresia of the nasolacrimal duct would, of course, result. The author has encountered atresias in many newborn babies and a few in children that died during the first year of infancy." Doubtless the atresia in the newborn of the naso- lacrimal duct due to a persistent lacrimonasal membrane is in many in- stances short-lived — the already thin membrane soon suffering "rupture." Occasionally, however, surgical intervention is necessary (Fig. 172). The Lacrimal Fossa and the Nasolacrimal Canal. — Before considering the membranous lacrimal ducts and sac and the nasolacrimal duct it is well that one has a clear conception of the osseous relations. The fossa of the lacrimal sac (fossa sacci lacrimalis) is an oblong rounded depression or sulcus located on the ventromedial aspect of the orbit, the frontal process of the maxilla and the lacrimal bone participating more or less equally in its formation. The fossa is limited dorsally by the prominent posterior lacrimal crista (crista lacrimalis posterior) and ventrally by the anterior lacrimal crista (crista lacrimalis anterior), the former a crest on the lacrimal bone and the latter a crest on the frontal process of the maxilla. Cranialward the lacrimal fossa becomes shallower and shallower, ultimately losing its identity at the fronto-lacrimo-maxillary suture line, ' J. Parsons Schaeffer: Nasolacrimal Duct Diverticula and Their Genetic Significance, The Anat. Rec, Vol. 9, 1915. - For a more detailed account of the embryology and development of the nasolacrimal passage- ways in man, the reader is referred to a previous study with an appended bibliography. J. Parsons Schaeffer: The Genesis and Development of the Nasolacrimal Passages in Man, Amer. Jour. Anat., Vol. I ^, IQir. OSSEOUS KASOLACRLMAL CAXAL 24S while nasalward the fossa is direct!}' confluent with the osseous naso- lacrimal canal (Fig. 145). The osseous nasolacrimal canal, the direct continuation of the lacrimal sulcus or fossa, is formed b}' the maxilla, the lacrimal bone and the inferior nasal concha or turbinated bone, the maxilla by its frontal process and body contributing the greater portion of the boundaries. Rarely the Pic 173 —A dissection shdwmi,' the nasolacrimal ijassaue^ays and the relations of the nasolac- rimal duct to the maxillary sinus and the mfenor nasal meatus. The inset is a transection of the nasal fossas, the maxillary sinuses, and the nasolacrimal duels. lacrimal bone fails to participate in the formation of the osseous naso- lacrimal canal, being replaced by an extension of the frontal bone or the maxilla. The canal terminates immediately below the attached border of the inferior nasal concha on the lateral wall and cupola of the inferior nasal meatus in a wide-mouthed ostium. The length of the osseous nasolacrimal canal does not necessarily conform to the enclosed mem- 246 THE NASOLACRI-M.VL PASSAGEWAYS bi-anous nasolacrimal duct, which is frequently longer (vide infra). The osseous canal proper ^'aries in length from 10 to 20 mm. and the lacrimal sulcus or fossa from 10 to 14 mm., making a total length of the osseous channels from 20 to 34 mm. The diameter of the osseous canal measures from 4 to 7 mm. ; however, is seldom uniform throughout. The plane of direction of the osseous nasolacrimal canal must obvi- ously conform to the type of the facial skeleton. Moreover, the breadth of the bridge of the nose, the degree of expansion of the pyriform aperture, and the width of the inferior nasal meatus are extremely variable and necessarily influence the course of the nasolacrimal canal and its contained membranous duct. In a general way one may say that the direction of Lacriinal protiiha aixc ?i7?.7i.5 7naxzif^r7^ Prcc Tjucincttu.s Fig. 174. — A dissection showing excessive pncnniatization or hollowing out of the maxilla by the maxillary sinns. All of the recesses of the sinus are extensively developed; the lacrimal protuberance Ijromincnt. the osseous nasolacrimal canal is caudalward, lateralward and dorsal- ward. As a rule, the osseous nasolacrimal canal is illustrated in text-books as coursing in an almost ^•ertical plane. A study of a large series of speci- mens has convinced the author that the true plane of the canal is seldom, if ever, vertical in the exact coronal plane, but that it is projected in a decidedly oblicjue plane from the lacrimal fossa to a variable point on the medial aspect of the alveolar process of the maxilla, corresponding to the interyal between either the second premolar and the first molar, the first and second molars, or eA'en as far dorsally as the interval between the second and third molar teeth. The osseous nasolacrimal canal courses in the lateral nasal wall between the A-entral j)ortion of the middle nasal meatus and the maxillary LACRI]\r.\L DUCTS 247 sinus, conforming more or less closely to Ihc ^'ertical confines of the middle meatus (Fig. 197). Not infrequently the canal throws a portion of the mesial or nasal wall of the maxillary sinus into a columnar relief (Figs. 102 and 174). The thickness of bone inter\-ening between the maxillary sinus and the osseous nasi)lacrimal canal varies from a pai)erv thinness to 2 or 3 mm. It is especially thin \\-hen the maxillary sinus de\'clops extensively into the frontal process of the maxilla in the formation of the infraorbital or prelacrimal recess. ]Moreover, the nasolacrimal canal and the lacrimal fossa come into intimate relationship with certain anterior ethmoidal cells. The author obser\ed also a number of instances in which the frontal sinus in addition to pneumatizing into the nasal bone extended laterally and caudally into the frontal process of the maxilla, thereb}' establishing most intimate relationships with the lacrimal fossa and its contained lacrimal sac. The Lacrimal Ducts (ductus lacrimales). — The lacrimal ducts or canaliculi begin b}' minute openings, the lacrimal piiiicta, which normally either surmount or are placed on the sides of the conical lacrimal papillcc located on the free borders of the eyelids, the upper about b mm. and the lower about S mm. from the medial palpebral commissure (internal canthus). The lacrimal ducts consist of ^•ertical and horizontal portions with dilatations or ampuUiB at the genua or bends. The ducts average from 8 to 10 mm. in their total length; o.i to 0.2 mm. in diameter at the puncta, I mm. at the genua and 0.5 to 0.8 mm. in the horizontal portions. Irregularities and sacculations are not uncommon (Fig. 178). The in- ferior lacrimal duct is almost invariabl}' longer than the superior duct, with its punctum and papilla farthest remo\ed from the medial j^alpebral commissure. Each lacrimal duct has a lining of stratified squamous cpithehum resting upon a sparse tunica propria rich in elastic fibers. The orbicularis palpebrarum muscle strengthens the ducts. Some of these muscle fibers parahel the horizontal limbs and others encircle sphincterdike the vertical limbs of the ducts. The horizontal portions of the lacrimal ducts communicate Avith the lacrimal sac in A-ar}'ing wa>-s: {a) the ducts may unite into a short, narrow common duct and this in turn establish communication between the lacrimal ducts and the lacrimal sac (the usual way of communication); ih) the ducts may emi)ty separate!}- into an ai)i^arent di\'erticulum of the lacrimal sac— the superior sinus (xAIaier) of the lacrimal sac (this diverticulum may, however, be thought of as a wide common duct of the lacrimal ducts) ; ic) the ducts rarely empty separately into the lacrimal 248 THE XASOLACRBLAI. PASSAGEWAYS sac, ;■.('., there is neither a common duct nor a diverticulum from the lacrimal sac.^ The distal ends of the lacrimal ducts do not bear an intimate relation- ship to the nasal fossa or the paranasal sinuses. The relations of the proximal or terminal ends of the ducts are essentially those of the lacrimal sac which will be discussed in subsequent paragraphs. The Lacrimal Sac (saccus lacrimalis) and the Nasolacrimal Duct (ductus nasolacrimalis).— The membranous lacrimal sac for the most Dnchi'S nasofroj/talis (infundiJ). offronA/l smm) Infundiiiiliun efJunutdale Ac/ffer nasi cell. .^ (C.ethmoi.daJis untj \ ^, Recessv,s prclact /mah s , (SinU'S ?na,Ki/laj is) ' T)vx:tvs 7?asolM^n?KuJi.'. Ostium ductus TtasoIurr/J/ralfi •% I X J)V£t?2b yiasolucj imuh s ^ S7V7j^ yiaiciJIaris, fit m fS. sphenoidali 6 -<^ Fig. 175. — A dissection of the lateral nasal wall with especial reference to the nasolacrimal duct, the lacrimal sac (indicated by dotted outline, in white), the agger nasi cell, and the prelacriinal recess of the sinus maxillaris. The inset is a transection showing the relati'jns of the nasolacrimal duct. Note the extension of the sphenoidal sinus beneath and dorsal to the hypophyseal fossa in the large figure. part occupies the shallow lacrimal fossa, extending, however, for a greater or less distance into the upper end of the lacrimal canal. It may be considered the upper dilated extremity of the nasolacrimal duct and is ^ J. Parsons Schaeffer: Variations in the Anatomy of the Nasolacrimal Passages, Annals of Sur.t^ery, August. 191 1. LACRIMAL SAC AM) XASOLACRL\L\L UUCL 240 bridged over by the palpebral fascia which extends from the anterior to the posterior lacrimal crests. Moreo\-er, it is covered by the medial pali)e- bral ligament, fibers of the orbicularis palpebrarum, and at places merely by skin and subcutaneous tela. The upper rounded extremity or fornix of the lacrimal sac is located at \-arying distances abo^•e the medial ])al- pebral ligament. On the dorsolateral aspect of the sac where the medial palpebral ligament crosses is located the orifice (or orifices) of the united lacrimal ducts. This orifice is usually located from 2 to 5 mm. from the extreme top or fornix of the lacrimal sac. As a rule, the lacrimal sac merges imperceptibly with the naso- lacrimal duct, save for a slight constriction — the ist/ninis. The major portion of the nasolacrimal duct is entirely encased by bone, e.g., the nasolacrimal canal. In many instances the nasal end of the nasolacrimal duct is continued for a considerable distance be^'ond the nasal end of the osseous nasolacrimal canal within the mucous membrane of the lateral wall of the inferior meatus. This extension accounts for the discrepancy in length between the osseous nasolacrimal canal and the membranous nasolacrimal duct : moreover, divides the latter into osseous and pureh- membranous segments. The lacrimal sac measures on the average 12 mm. in its vertical plane and from 2 to 5 mm. in its transverse. Owing to the varied location of the nasolacrimal ostium in the inferior meatus, the length of the nasolacrimal duct is necessarily inconstant, varying from 10 to 2S mm. The diameter of the nasolacrimal duct is not uniform, measuring at the isthmus or point of transition from the sac to the duct but 3 mm.; becoming widet below this point it averages about 5 mm. in its ventrodorsal diameter and 4 mm. in its transverse diameter. . As stated above, the lacrimal sac and the nasolacrimal duct frequently merge in such a manner that the limitations of the sac can only arbitrarily be determined. However, not infrequently the lacrimal sac is very much wider than the nasolacrimal duct at the junction point, making the ex- tent of the sac \-ery ob^•ious. Again, the lacrimal sac and the nasolacri- mal duct instead of merging in a linear fashion are joined side to side in an indirect continuity, the fornix of the nasolacrimal duct appearing dome- like at the side of the lacrimal sac (Fig. 178). It is, of course, obvious that it is utterly impossible in the latter tA-pe to pass a lacrimal probe from the lacrimal sac into the nasolacrimal duct wihout making artificial openings by the advancing probe. On the other hand, the lacrimal probe is passed from the lacrimal sac into the nasolacrimal duct with relati^'e ease when ■they are in direct linear continuity (Fig. 180). The Jibro-elaslic walls of the lacrimal sac partake of the nature of a 25° THE NASOLACRIALVL PASSAGEWAYS lymphoid tissue and are connected with the periosteum by a loose areolar stratum containing a dense plexus of small veins. These anatomic factors account for the ready and marked congestion of the sac following trauma and infection. The lacrimal sac is lined with a double layer of columnar epithelial cells, some of which are ciliated. Here and there branched tubular glands are encountered. The nasolacrimal duct likewise is fibro- elastic and separated from the surrounding periosteum by a loose tissue rich in veins. It is lined by columnar epithelial cells. Small branched tubular glands are found, especially as the duct nears its nasal termination. Nasolacrimal Duct Diverticula and Valves. — It is generally believed that the walls of the nasolacrimal duct are always regular and that the Lateral wall Fi(,. 176.— Photographs of transections of the nasolacrimal duct at the point of communication «-ith the inferior nasal meatus; that is. at the level of the ostium nasohicrimalc (O). The sections are from adults and arc magnified from 2 to 4 times. (Afler J . P. S.) lumen of the duct presents a more or less uniform cjdindrical outline. In- deed, this is what one gathers from many text-books and from the average gross dissection of the channel. However, serial sections of the duct and reconstructions of its lumen at once show the fallacy of this belief. Admittedly, a large number of nasolacrimal ducts have regular and more or less uniform walls. The formation of vah'e-like folds by the mucous membrane of the nasal duct in the upper and middle thirds has been frequently described. Krause and Beraud described a valve at the junction of the lacrimal sac and the lacrimal ducts. Careful study mdicates that in many cases the so-called vah-e is merely a simple elevation of mucous membrane. Howe^-er, the mucous membrane may be suil- ciently reduplicated to form a true valve. The writer agrees with Boch- NASOLACRniAL OS^riUM Fig. 177. — Dravdngs of acUial dissections illustrating various types "f ustia nasi ilacriinalia en- countered in this study. The reader.is referred to the text for a further cunsideratiun 'A them. The concha nasaUs inferior is partly cut away so as to expose for study the manner of communication between the ductus nasolacrimalis and the meatus nasi inferior. 252 THE NASOLACRIlMAL PASSAGIiWAYS dalek that the opening of the lacrimal ducts may be placed in the center of a diaphragm-like lamina of mucous membrane. Again, one encounters many specimens in which there is no evidence whatsoever of mucosal pli- cae or vah-es. Additional valves have been described for the mid-portion of the nasolacrimal duct. These folds of mucous membrane are usually of minor importance and may occur in nasolacrimal ducts presenting regular walls. Recent investigations by the author indicate that many nasolacrimal ducts present lumina of very irregular contour, some even more or less tortuous in course. Minor irregularities, as stated above, are at times due to mere folds in the mucous membrane. In many instances they are of little moment. Again, they may form definite bridges along the walls of the duct. Entirety apart from these minor irregularities, diverticula or direct oittpoucliings of the nasolacrimal duct are not uncommon. They vary from those of insignificant size to those of relatively large dimensions. In studying cross sections of the nasolacrimal duct one is at times puzzled to explain what are apparently two ducts lying side by side. Howe^•er, by following the sections serially one finds that one cavity sooner or later communicates with the other, e.g., one turns out to be the nasolacrimal duct proper and the other a diverticulum from it (Fig. 172). These diverticula must be very important clinically since they are so located that they readily retain infectious material within their confines. Indeed, they may be important factors in the chronicity of pathologic conditions of the nasolacrimal duct. Owing to the irregularity of the lumen of the nasolacrimal duct and the presence of large diverticula, it is obvious that false j)assageways are repeatedly made by operators when they pass the lacrimal probe. The diverticula are lined with a mucous membrane similar to that lining the main duct, and at the ostia of the diverticula the mucous mem- branes of the main duct and diverticula are directly continuous, both grossly and histologically. Genetically, the diverticula are, doubtless, the result of canalization of auxiliary lateral buds which grow from the solid cord of epithelial cells representing the rudiment of the nasolacrimal passageways. It must, therefore, be concluded from the evidence at hand that the diverticula from the nasolacrimal duct are of congenital origin and are not acquired in later life.^ The Nasal and Paranasal Relations of the Membranous Lacrimal Passageways. — The relations between the anterior ethmoidal cells and 'J. Parsons Schaeffer: Xasolacrimal Duct Diverticula and Their Genetic Significance, Tlie Anat. Rec , Vol. g, 1915. RFXATIONS OF PASSAGEWAYS 253 lacrimal sac are more or less variable. Ver>' commonh', howe\-er, two or more anterior ethmoidal cells (frontal and infundibular) immediately adjoin the dorsal and medial aspects of the lacrimal sac. Indeed, the osseous waUs separating the mucous membranes of the ethmoidal cells and the lacrimal sac \-er)- frequenth- under normal conditions show dehiscences. At times ethmoidal cells crowd for a considerable distance forward along the lateral border and over the cupola of the lacrimal sac. Even more common is the extension of anterior ethmoidal cells over the medial or nasal side of the lacrimal sac and the beginning of the nasolacrimal duct. Cells in the latter position usually grow from the infundibulum ethmoidale (infundibular cells). However, at times extensions of ethmoidal ceUs from the frontal recess are found between the lacrimal sac and the middle nasal meatus. When practising endonasal dacr}'ocystotomy these cells must, of course, tirst be ablated before the osseous walls of the lacrimal sac and the ocular end of the nasolacrimal duct can be reached (Fig. 175). Two lamina of bone inter\-ene in such cases between the nasal fossa and the lacrimal sac and duct. Not infrequently, the entire wall of the lacrimal fossa is pneumatized by ethmoidal cells, some of which may extend for a variable distance along the ocular end of the nasolacrimal canal. These cells arise variously from the infundibulum ethmoidale and the frontal recess and extend into the agger nasi, the uncinate process, the frontal process of the maxilla and the lacrimal bone. The nasolacrimal duct lies adjacent to the maxillary sinus and \'ery frequently throws into relief the nasal wall of the sinus in the form of a cord-like swelling which corresponds to the sinus side of the osseous naso- lacrimal canal. It is particularh- the infraorbital or prclacrinial recess of the maxillary sinus that bears the most intimate relationship to the naso- lacrimal duct and lacrimal sac. Unless one bears this extension of the maxillary sinus in mind in endonasal surgical procedures, the maxillary sinus is readily opened into instead of the osseous nasolacrimal canal and the nasolacrimal duct (Fig. 175). As stated elsewhere, the frontal sinus usually does not bear an inti- mate relationship to the nasolac-imal passageways. When, however, the frontal pneumatization extends into the nasal bone, the frontal process of the maxilla and the lacrimal bone beyond the confines of the suture line separating them from the frontal bone, the frontal sinus will bear a direct relationship to the lacrimal fossa with its contained lacrimal sac. The Nasolacrimal Ostium (ostium nasolacrimalis). — The ostium of the nasolacrimal duct is located from 15 to 20 mm. dorsal to the limen nasi and from 30 to 40 mm. from the nares (anterior nares). It is frequently 254 THE XAS()LACR[xA[AL PASSAdKWAVS found at the most ccj)halic point of the inferior nasal meatus, that is, immediateh' caudal to the point of attachment of the inferior nasal concha to the lateral nasal wall. When in this position, the nasolacrimal ostium usually presents a wide open mouth o^ving to the osseous supporting ring. Howe\'er, it is equally common that the ostium of the nasolacrimal duct is located relatively far below the attached point of the inferior concha, the distance varying from o to lo mm. Between these two extremes one encounters ostia at A'arious distances caudal to the attached border of the inferior nasal concha. The nasolacrimal ostium is usually a single opening. However, duplicate and triplicate communications between the inferior nasal meatus and the nasolacrimal duct are not infrecjuently met with. A study of a large series of specimens con\-inces the observer that there is no unvarv- ing typical form of ostium, but that several normal anatomic tjpes are ecjually common. Indeed, it cannot be gainsaid that the notion of an ideal t}'pical form must be abandoned more or less generall}' and in its place substituted the belief and knowledge of normal anatomic types. A reference to Fig. 177, in which are represented actual delineations of human nasolacrimal ostia, will indicate a number of the fundamental anatomic types that are encountered. The belief that all nasolacrimal ostia are provided with a mucosal valve (plica lacrimahs) or the so-called valve of Hasner must be abandoned. When the nasolacrimal duct termi- nates immediately caudal to the attached border of the inferior nasal concha, its ostium almost invariably stands permanently open, wide- mouthed and unguarded by a valve-like structure (see Nos. i, 3, 6 in Fig- 177)- In the tj-pe in which the nasolacrimal duct passes through the nasal mucous membrane rather obliquely, the ostium is slit-like and in a sense merely potential. In these cases the ostium may be said to be guarded by a fold of mucous membrane, that is, a plica lacrimahs of Hasner (Fig- 177. Nos. 5, 10). Occasionally the nasal end of the nasolacrimal duct pushes nipple-Hke into the inferior nasal meatus; surmounting the nipple is located the nasolacrimal ostium (Fig. 177, No. 7). At times the nasolacrimal ostium proper is more or less o])en and somewhat guarded by a plica lacrimahs. Extending from the ostium toward the floor of the nose is a fair!)- deep, gutter-like groo^■e which tends to become deeper and deeper as one approaches its caudal limits (Fig. 177, No. 9). In the t}-pe of ostium shown in No. 5 of Fig. 177 the slit-like aperture becomes shallower and shallower as its caudal hmits are reached and is in this resi)ect unlike No. 9. The nasolacrimal ostium is at times exceedingly small (Fig. 177, Nos. coxcLunrxc; ri:makks 255 4, 10, 11) ami wholh- inadequate as an efficient drainage orifice. 'I'hese stand in marked contrast to the large and e\'er open ostia sliown in Nos. I, 3, of Fig. T77. It is the latter ostia that are S) easily located and probed from the nasal end of the nasolacrimal duct and that escajje collapse from enlargement of the inferior nasal concha. On the other hand, it is the slit-lil^e t^jx- of ostium located in the lateral wall of the inferior nasal meatus that are located and probed Avith difficult}- and readil}- comjiressed b}' enlargement of the inferior nasal concha, occluded by hypertrophy or congestion of the mucous membrane. Indeed, in those cases of persistent nasolacrimal infection des])ite treatment the tv])e of nasolacrimal ostium ma}' be an important factor in the chronicit\' of the ailment. Concluding Remarks. — Xot to minimize the important connecticjns, both anatomical!}- and in disease, between the conjuncti\-a] culdesac and the nasolacrimal passage\\-a}-s, the etiological connections between disease of the latter and the nasal fossa and paranasal sinuses are generally recognized as of jiaramount importance. This is in comformit}- with the very intimate anatomic relationships that exist. At best but pa])ery lamime of bone inter\-ene between the ethmoidal lab}-rinth and tJ-ie orbit and betAveen the Acntral portion of the ethmoidal lab}-rinth and the lacrimal sac and the nasolacrimal duct. This is also ecj^ually true of the maxillar}- sinus in many instances. Indeed, congenital dehiscences in the bonv "party-w-alls" are extremel}- commonplace. Moreover, the abun- dant network of lym])hatic vessels are \-itall}- important in establishing relations between the mucous membranes of the nasal and the nasolacrimal fields. Again, the dense venous plexuses of the nasal mucous men-ibrane establish connections w-ith the venous i)le.\uses of the paranasal sinuses and those surrounding the lacrimal sac and the nasolacrimal duct. The venous plexuses of the nasolacrimal passageways connect also with the facial, infraorbital and ophthalmic veins; and as Zuckerkandl has shown, a lacrimo-facial vein connects with a larger vein emerging from the region of the anterior ethmoidal cells and jjassing through the lacrimal b(me. These anatomic features must be of the greatest importance in thes])read or extension of disease from the nasal fossa and the related ])aranasal sinuses to the lacrimal sac and the nasolacrimal duct and vice \-ersa. The direct communication of the nasolacrimal duct with the inferior nasal meatus and the direct continuit}- of the mucous men-ibranes through the ostium nasolacrimale is of equally great im])ortance in this connection. The ostium is frequently very large, from 5 to 7 mm. in diameter, standing permanently open, thereby inviting infection from the nasal fossa. Again, 2s6 THE NASOLACRIM,\L PASSAGEWAYS the ostium ma}- be so small that adequate drainage of the duct is utterly impossible, or the ostium if located in the mucous membrane of the m- ferior nasal meatus ma>' be readily encroached upon and shut off by pathologic nasal states. In the nasolacrimal ostia which are permanently open and unguarded by true mucosal valves, air and fluids readily find their wav into the nasolacrimal duct. It has been shown that during Fig. 178. Fig. 179. Figs. 178 and 179. — Recon.struction of llie nasolacrimal passagcwa>"S of an adult aged 65 j^ears. Fig. 1 78 represents a medial view and Fig. 179 a lateral view of the model. Especially note the irregularity and the diverticula of the nasolacrimal duct. The inset accompanying Fig. 1 78 shows the details of the side to side union of the lacrimal sac and the nasolacrimal duct ; moreo\-er, illustrates the large bud-like diverticulum from the nasolacrimal duct. X 3.2. SI = Saccus lacrimalis; Dls — Ductus lacrinralis superior; Dli — Ductus lacrimalis inferior; Adl = Ampulla ductus lacrimalis; Dh> = Ductus lacrimalis verticalis; Dili = Ductus lacrimalis horizontalis; Die = Ductus lacrimalis communis; Dyil = Ductus nasolacrimalis; Mni = Meatus nasi inferior; Div'lm ^ Diverticulum (A the nasolacrimal duct; Jc = Junction channel between the lacrimal sac and the nasolacrimal duct. violent blowing of the nose particles of secretion are forced upward through the nasolacrimal duct into the lacrimal sac. Aubaret observed the ascent of ^'ery minute particles of tobacco-snuff as far as the lacrimal puncta. CONCLUDINC; REiMAKKS 257 In some cases true and efficient mucous-membrane valves guard the nasal end of the nasolacrimal duct. It would appear in such cases that the nasolacrimal passageway's would be safeguarded in large measure from the passage of infectious-laden fluids and air into them from the inferior nasal meatus, jiarticularh' in \'iolent blowing of the nose (Fig. 177). Other factors being ecjual, it would seem from an anatomic \-ie\v- point that an infected nasolacrimal duct and lacrimal sac would yield most readily to treatment in those cases in which the nasolacrimal ostium is large, permanenth* o])en- mouthed and unobstructed b}' ana- tomic conditions of the inferitir meatus; moreo^'er, in which the nasolacrimal duct is free of mucosal ledges and diverticula. On the other hand, one would expect infected nasolacrimal passageways to resist treatment and the ailment to enter the stage of chronicity in those anatomic types in which the naso- lacrimal duct contains di\erticula (often without gravity drainage), and nasolacrimal ostia of small and inadequate size for efficient drainage; moreover, a nasal ostium or aperture so located that it is readil_\- in- fluenced b\' conditions of the inferior nasal meatus. The success or failure of non-surgical trealmoit of tit e diseased nasolacrimal passageways is largely dependent upon the anatomic type oj nasolacrimal duct and ostium en- countered. Indeed, here as elsewhere in the body the ''anatomic type" looms up before the physician as an important factor in treatment and prognosis. If one can be guided by clinical reports much success has attended the endonasal operations upon the nasolacrimal duct and lacrimal sac when the caudal portion of the duct is stenosed or its ostium of communication Fi(.. iSu. — Rccrinst.n.K'tiMii (jf the nasolacri- mal iJHSsaKC\\'a\'ti of an aiiulL aged Oo years. Xote the regularity of the nasolacrimal duct and the gradual mergence of the lacrimal sac into the nasolacrimal duct at the constriction or isth- mus. X 3-"- Abbreviations as in Figs. 17S and 179, 258 THE NASOLACRIMAL PASSAGEWAYS with the inferior meatus is blocked by pathologic states or is normally of inadequate size. Toti's endonasal operation on the lacrimal sac and West's endonasal \\'indow resection of the nasolacrimal duct cephalic to the inferior nasal concha are now frecjuently practised. Moreover, new operations or modifications of those of Toti and West have been devised, particularly by HaUe, Polyak, Mosher, Green, Wiener, Yankauer, Beck, etc. The nasolacrimal duct has also been operated upon through the maxillary sinus — the v. Eicken's operation. Exonasal operation, on the lacrimal sac are also frecjuently practised. Probing of the naso- lacrimal passageways would seem ill-ad\'ised from an anatomic viewpoint owing to the ver}- common irregularities and di^•erticula of the nasolacrimal duct, and the occasional side to side union of the lacrimal sac and the nasolacrimal duct. These anatomic conditions preclude the successful passing of the lacrimal probe in A'er}- mam' instances. The ach-ancing probe doubtless leaves the lumen of the sac or duct either to re-enter the more caudal portion of the duct or to course between the membranous duct and the osseous canal. This leads to artilicial openings and passage- ways and leaves the patient in a worse state than before. The successful cases are doubtless those in which the lacrimal sac merges gradualh' with the nasolacrimal duct and the latter is fairly regular in contour. Un- fortunateh' there is no way of knowing what type of duct confronts the operator. VIII-THE NASAL MUCOUS MEMBRANE CHAPTER VHI THE NASAL MUCOUS MEMBRANE Conforming with the anatom>- of the nasal cavit}- and its appendages the lining mucous membrane is di^•ided into three more or less distinct regions, e.g., that of the \'estibule, the nasal fossa, and the paranasal sinu- ses. ^Moreover, the structure of the mucous membrane of the several regions presents characteristics common to the respective fields. In ad- dition, the mucous membrane of the nasal fossa is histologically divided into two unlike portions, conforming thereby to the physiology of the individual parts. The Nasal Vestibule As a sort of an antechamber to the nasal fossa we have the nasal vestibule which corresponds very closely in its extent to the cartilaginous nasal wall. Its lining mucosa is often referred to as the rcgio vestibularis of the nasal mucous membrane. At the naris (nostril) the skin of the upper lip and the wing of the nose passes into the vestibule and for a distance retains its surface characteristics of a stratified flat epithelium with superficial horny cells. The skin characters, however, are lost about the middle of the vestibule, changing here to stratified flat epithelium with an absent horny layer, resting on an underh'ing connective-tissue propria. The epithelium of the forepart of the ^'estibule rests on a con- nective-tissue corium continuous with that of the skin. The fibrous tunica propria is richly pro\"ided with elastic fibrils, coarse, stiff hairs (vibrissa?), and sebaceous and sudoriferous glands. In the deeper part of the a'cs- tibule the connective-tissue propria contains mixed sero-mucous glands which replace the sweat glands. The Nasal Fossa Conforming with the double function of the nasal ca\-ity ])ro})er there are two areas of the lining mucous membrane (Schneiderian or pituitary membrane) that differ in structure — the pars respiratoria and the pars olfactoria. The latter occupies a small portion of each nasal fossa, being confined to the cephalic third of the nasal septum, nearly the whole of the superior concha, a very small portion of the middle concha, and to the 262 THE NASAL MUCOUS MEMBRANE extreme \'entral extremit}- of the supernumerar}' ethmoidal concha that ma>^ exist cephaUc to the superior concha. This dehneation of the olfac- tory area is in close agreement with the extended researches of Read (Figs. 195 and 196), but is more extensive than the long-accepted olfactory area (about 250 sq. mm.) of Briinn. The remaining portion of the mucous membrane is devoid of olfactory elements and is, therefore, classed as respiratory. The Respiratory Portion (pars respiratoria). — The stratiform flat epithelium of the nasal A-estiJDule gradually assumes the characteristics of the respirator)' mucous membrane, c.fi., a stratiform ciliated cylindrical epithelium. This transition in epithelium takes place laterally at the limen nasi (vestibuli), medialh' at the septal tubercle, and caudally (floor) somewhat dorsal to the abo^-e planes. Individual variations as to the exact place of the transition are encountered. The nasal respirator}' mucous membrane varies greath' in thickness in the several parts of the nasal fossa. Over the inferior concha, portions of the middle concha, and adjacent portions of the septum the membrane frecjuently reaches a thickness of several millimeters; elsewhere it may be considerably less than a millimeter. The thickness of the mucous mem- brane over the inferior and middle conchoe, etc., is largely dependent upon the degree of development within the tunica propria of the contained cavernous tissue (vide infra). ^loreover, the membrane is intimatel}' attached to the periosteum and the perichondrium of the bones and cartilages of the nasal fossa. However, considerable variation exists in the degree of the closeness of the connection in the se^'eral parts of the fossa. The respiratory mucous membrane readily thickens under patho- logic conditions, often attaining a thickness from four to six times normal. The stratiform ciliated c}'lindrical epithelium of the nasal respiratory mucosa rests upon a cribriform basement membrane. Ciliated cells ex- tend the entire thickness of the epithelium; the slender ends being deeply placed, resting upon the basal membrane, and the more bulky ends with the attached cilia forming the free surface. The ciha are least developed over the superior and supreme conchc-e. They attain a length of from 5 to 7 microns and produce a definite and characteristic current toward the choanae ^posterior nares). The spaces betAveen the deeper parts of the stratiform cells are filled with irregularh' columnar or conical cells. The latter rest on the basement membrane but never reach the free surface with their pointed apices. Moreover, in addition to the conical cells there are found between the cihated cells, resting on the epithelial floor, KI'SPIRATORY I'OR'I'ION 263 mucous-containing goblet cells. :\Iany cellular elements are encountered that are m the ^-arious stages of conxersion into goblet cells. Cement edges are demn)nstrable bet^veen the more superficial ends of the ciliated and mucous goblet cells. JMigrator}- leukoc\tes are numerous among the eiMthelial elements. The IhiscDiciit Dioiibraiic (memlirana propria) \-aries greatly in thick- ness. For the most part it is dehniteh' de\eloped and fairly well •^^.. '^^m^^%m^' w Fif-.. iSi. — Section rif mucous membrane from the caudal pMrtii.ai of ilic concha nasalis nieili Xote the excessi\-c numliLT of glam:ls. >. (;5. marked; however, at places it is feeble and difficult of demonstration. \\'here best formed it may normalh- attain a thickness of 0.020 mm. or more. It is distinctly cribriform, permitting processes of connecti^•e- tissue cells and leukocytes to pass through the a])ertures into the superim- posed epithelium. The apertures in the basement membrane are often referred to as basal canals, and as Schiefferdecker long since pointed out. 264 THE XAS-VL -MUCOUS ilEJIBRAXE they contain connective-tissue cells and leukocytes, but strangely never blood capillaries. The tunica propria superficial!}- consists of loose fibro-elastic tissue, rich in cells, and here and there collections of lymphoc>'tes, suggestive of a lymphoid tissue (lymphatic nodules), are found. Deeply, as the periosteum and perichondrium are approached, the tunica propria pro- gressiveh- contains more abundant networks of elastic fibers. There is Fig. 1 82. — Section of mucous membrane from concha nasalis inferior. Note the fewer glands as comparccl with Fig. iSl and the large number of ca\'ernous channels (C). X 95. great variation in the amount of elastic fibers that are developed; at times dense, again sparse. One of the characteristics of the nasal respiratory mucous membrane is the extremely rich blood supply of the tunica propria. The arteries of the deeper strata send their branches through the propria to form a capillar}- network beneatli the epithelium and around the neighboring glands. From the arterial network the blood flows into a superficial KlsSriRATOl-iY PORTION 265 venous plexus, thence to a deeper one. Careful study indicates that these venous plexuses or blood-sinuses assume the character and role of an erectile tissue — the plexus cavcniosi conchanim. The latter is especially developed over the inferior concha (Figs. 159 and 183), along the dependent border anci posterior extremity of the middle concha, and along adjacent portions of the nasal septum. In these positions one iinds circular and longitudinal bundles of unstriped muscle embedded in the \\'alls of the \'enous channels Plexus ca.vcmosi coi?xha.TU,j77. / coiic/e^ iiXISClUs i?i-fc7-ior ) ^ ^ v^ wi'2 'jJr " ' /**^> V ^ 'tf? EpiikeliA IMf^, Yeatv^s 7/Msi 7?ffer/or Fig. 1S3. — Surface section of inucous membrane from the eoneha nasalis inferior as seen through the binocular microscope, showing the cavernous and erectile character of the tunica propria. X 12. or vascular areas and the muscle bundles immeshed in a connective-tissue stroma containing elastica. Nerve reflexes control the filling and empty- ing of the cavernous tissue. It is well known that certain stimuli through the reflexes rapidly deplete the thickness of an engorged mucosa and that in certain psychic states similar depletion is experienced, and vice \-ersa. The great masses of blood are doubtless of great importance in w^arming the inspired air. This, indeed, may be the chief function of the erectile tissue. Of course, a possible phylogenetic relationship must be kept in mind. 2 00 THK NASAL JIUCOUS MJiiMBRANE Numerous inlands arc found in the tunica ])ropria of the respiratory mucous membrane. The simplest of these are short di\'erticula of the surface epithehum, dipi)ing into the underl}'ing tunica propria, which are for the most part lined with goblet cells. Moreover, many branched tubo-alveolar glands, resembling the glands of the lips, are found which are of a mixed nature. I'he chief ducts of these open on the free surface by minute orifices. The deeper portions of these glands branch and rebranch to bear the ovoid terminal ah'coli. The latter are lined with mucous-secreting cells between which are groups of serous cells. In addition to these Kallius encountered purely serous glands (Figs. i8i and 1S2). The Olfactory Portion (pars olfactoria). — The olfactory portion of the nasal mucous membrane is limited to a relatively small iield in the 01 facto 7 -IJ cUi'-ci Susteidcuizlar cells- Olfactorij cells "- Olfactm-ij Cflunds - - B^xiod vessel Olfactorif nerves . 'f^v'".- "iM^'^. ''f: ^l , \1>. yOuct of Olf.celPrm^ -ftV^y i^fS-'. - -. '-'»«, ••?,; ^'-^^^K. ,-( V l,ll». i»A*;- ./ :-^j^>/i. Susl.cdJh '^■^jy-- Fig. Fig. 1S4. 1S5. FiG. 184. Sc'Cticin (jf (ilt'actorN- miicrjus memlirane. Isi.ilatC'tl (ilfactory cells, greatly magnified. X 300. (Ajlcr Schulzc.) Fig. i8s nasal fossa as indicated at the beginning of this chapter and delineated in Figs. 195 and 196. It is demarked from the respiratory mucosa of the nasal fossa by its yelloAvish color and greater number of nuclei. Howe^'er, at times the A'elloAvish appearance is ^vanting. The olfactory mucous membrane consists of a surface neuro-epithelium with a subjacent tunica ])ropria. A definite and distinct basal membrane is wanting. The neuro-epithelium is composed of specific sensor}' (olfactory) cells and sustentacular (supporting) and basal cells. Col- lagenous and elastic fibers and tubulo-acinar serous glands (vide infra) are contained in the tunica propria (Figs. 184 and 185). The sustciilaciday cells are tall, columnar, non-ciliated epithelial cells OLFACTORY PORTION 267 and are considerably broader than the ()H"actor\-. Their nuclei contained m the outer and broader ends of the cells are ovoid and form a conspicuous nuclear stratum. There is a clear zone devoid of nuclei beneath the free surface of the epithelium. The deep ends of the su]i])orting cells often termmate by branching into two or more i)r()cesses, in the intervals of which are found basal cells. The cytoi^lasm of the supporting cells is granular and frequently contains a yellow pigment. The basal cells are small, flattened p>-ramidal elements that form the deepest nuclear zone of the olfactory neuro-epithelial layers and are found between the branches of the sustentacular cells. Their nuclei are ovoid and their protoplasm finely granular. They maj- represent younger and additional forms of supporting cells of the olfactory mucosa. The oljactory cells are the ])ercepti\-e elements of the nasal mucosa. While the epithelium of the embryological olfactory pits is, strictly speak- ing, wholly olfactory, the latter designation ultimately applies to relati\-ely few cells since the olfactory function is lost to most of the portions of the nasal fossa\ The cells that retain the olfactory characters and func- tions are known as neuroblasts. The}- remain in the walls of the nasal pits, become bipolar olfactory cells, and by central ])rocesses become connected with the brain. The}- represent morphologicall}- the ganglionic cells on the dorsal (sensory) roots of the spinal nerves, and retain the primiti^-e location of such sensor}- cells in the surface epithelium. The olfactory cells are unique in this regard among neuro-epithelial •elements. The olfactory cell bodies are bipolar, fusiform and contain spherical nuclei located between the deeper parts of the supporting columnar cells. The cells extend through the entire thickness of the neuro-e])ithehum. Their peripheral processes are short and pass to the surface of the mucosa through openings in the olfactor}- limiting membrane, each process giv- ing rise to a hemispherical vesicle which in turn terminates in six to eight minute hair-like processes of fine cilia — the oljactory hairs. Moreover, the olfactory vesicles and processes are surrounded and in a sense supported by a "semi-fluid cuticle" believed to be secreted by the supporting cells. The central processes, slender and often tortuous, become grouped into about twenty bundles, the olfactory nerves, and pass through the foram- ina of the lamina cribrosa of the ethmoid bone into the anterior cerebral fossa, and after piercing the meninges of the brain they enter the olfactory bulb, there to synapse with the dendrites of the mitral cells (see page 332). Embryologically the lateral evagination of the olfactory portion of the fore-brain is correlated with the in\-agination of the olfactory epithe- 268 THE NAS.VL MUCOUS MEMBRANE lium from the ectoderm, and throughout hfe these two parts remain in close anatomical and physiological relationships. The tunica propria is distinct!}' differentiated into a superficial and a deep stratum. The superficial stratum consists of a delicate reticulated tissue contahiing many irregularly round cells resembling lymphocytes. Indeed, the cells are at places so closely packed as to suggest small lymph follicles. On the other hand, the deeper stratum contains relatively few cells, but dense and heavy bundles of connecti^'e tissue, composed of col- lagenous and elastic fibers. The olfactory (Bowman's) glands (glandulse olfactoriae) are contained within the tunica propria of the olfactory mucosa. They are of the branched tubular variety and open on the free surface of the mucosa by very narrow ducts that connect with saccular fusiform ampullae into which the tubular alveoli open. The tubules are lined with cuboidal or conical cells containing many albuminoid secretory granules, not unlike those of the parotid glands. From the evidence at hand, the olfactory glands should be classed as serous, probably elaborating a specific secretion. The ducts of the glands are lined throughout the interepithelial course with independent flattened cells located between the surrounding epithe- lial elements. The Paraxasal Sinuses The paranasal (accessory) sinuses are fined by mucous membrane directly continuous with that of the nasal fossa, including the maxillary, the frontal and the sphenoidal sinuses, and the ethmoid labyrinth. The mucous membrane fining the several paranasal sinuses and cells resembles that of the nasal fossa save that it is much thinner and contains fewer glands. Moreover, it does not assume the characteristics of an erectile tissue (Figs. iS6, 1S7, and 1S8). The mucous membrane of the paranasal sinuses and cells is composed of a stratiform ciliated columnar epithelium, invaded by numerous lymphoid elements, resting on a very delicate basal membrane and tunica propria. Indeed, the latter is firml}- adherent to the underlying perios- teum, especiafiy so in the frontal and maxillary sinuses, less in the ethmoidal labyrinth and still less in the sphenoidal sinus. Unlike the mucous membrane of the nasal fossfe, that of the paranasal sinuses is poorly supplied with elastic fibers. Mo^eo^'er, the glands, mucous in tA'pe, are few and scattered as compared with the glands of the nasal cavity proper. In the maxiUary and sphenoidal sinuses the glands are most plentiful in the vicinity of the ostia of the cavities. PARANASAL SINUSES 269 10 V ^^^ ;§ ^ \ I ■% a <^<5-'^"0 K' V-' \i> ! -^--^^ s 6 d -^ s s (/) ■S.-S a S O) '+3 d '^ rr. 1 .s L '^ 00 _i CO a! M 'ij 'J C g tZ^ r^ X '3 4 ^ ^ ? ^ ''6 mi MS^^ 'ay- e» IT. - - ^ ?-tf^- i I ^ "IS I. p 3 i 2-jo THE NAS.VL MUCOUS JIEilBRANE In spite of the extreme delicacy and thinness of the mucous membrane of the paranasal sinuses and its firm adherence to the periosteum, it is readily influenced and greatly thickened by pathologic processes. It is particularly prone to thickening, rapidly so, in the vicinity of the ostia of the maxillar}' and sphenoidal sinuses owing to the greater looseness of structures at these points. The current produced by the ciha of the epithehum of the paranasal sinuses is toward their respective ostia or apertures of communication with the nasal fossa. As stated elswhere, the current produced by the cilia of the epithelium of the nasal fossa is toward the choana (posterior naris). The Vomeronasal Organ In adult man in the caudo ventral p ortion of the nasal septum slightly cephalic and ventral to the orifice of the nasopalatine canal may occasion- ally be found a small ostium leading into a paired, blindly ending, mucosa- lined tubular sac. The latter courses dorsalward in the septal mucosa for a distance of from 2 to 6 mm., is lined with epithelium continuous with that of the nasal fossa, and has numerous glands opening into its lumen. This rudimentary tubular canal is the homologue of a highly de- veloped tubular organ, the vomeronasal organ (organon vomeronasale Jacobsoni), found in many cjuadrupeds in which the olfactory sense is particularly specialized. In the latter the organ is supported by a carti- lage (Jacobson's cartilage). However, in man the cartilage of Jacobson is represented by a rudimentary strip of cartilage (the ^'omerine cartilage of Huschke) located caudal to both the septal cartilage and the rudi- mentarj- vomeronasal organ and does not gi^•e a supporting framework to the organ as it does in other animals. As stated elsewhere, page 47, the vomeronasal organ in man ap- parently reaches its height of development by the twentieth week of embryonal life; after this retrograde changes in the epithelium occur (Fig. 1 89). In the adult the organ does not function in olfaction; no true olfactory cells are found in its mucosa. Most of the cells are of the sustentacular t}^)^ Some spindle cells (probably homologues of the ol- factory cells) are found between the latter (especially on the medial wall), but do not reach the surface and apparentlj' are not connected with the olfactory nerves in the adult. Read found olfactory connections in the child at birth. In some other animals, e.g., the rabbit, etc., the epithelium of the GEXITAL SPOTS 271 vomeronasal organ is similar in structure to that lining the olfactory mucous membrane of the nose and recei\TS branches of the olfactory ner\-e in addition tt) branches from the terminal and trigeminal nerves. In adult man, on the contrary, the vomeronasal organ seems to have to do wholly with general sensation and is sup])lied b)' the terminal and trigeminal ncr\"es onh'. To ossa izoLsaCis Eth n t o tu.rhincc I Septum itccsi J^[cLxi2loKv/rbijr^C Orqa.riX)n vo/n/^rono^ale Jacoisom Fig. 189.— Frontal section through the nasal fossEe and the nasal septum in the region of the v,jniero- nasal organ of Jacobson. X 133- The So-called Genital Spots Fleiss (189 7) called the attention of rhinologists and gynecologists to what he considered an important relationship between certain areas of the nasal mucous membrane and the genitalia and adnexa. He be- lieved the particular spots in the nasal mucosa to be limited to a very small area on the tuberculum septi, directly opposite the mid-portion 2-] 2 THE NAS.JlL mucous MEMBRANE of the middle nasal concha, and to the ventral portion of the inferior nasal concha. Histologicall)', there is nothing apparently that character- izes these areas in the nasal mucosa, designated by Fleiss "the genital spots." Careful examination by the writer of the erectile portion of the nasal mucosa failed to re^'eal an}' characters common to the areas designated by Fleiss. Further study by a more perfected technic may show a difference in the histology of the so-called genital spots. This is, however, doubtful. If the relationship between the nasal mucous membrane and the genitaha and adnexa becomes established in dysmenorrhea (not taking into consideration the obvious reflex connections between the olfactory and the genital organs), it is more than likely that the genital spots of Fleiss will be found to conform to the extent of the erectile-tissue portion of the nasal mucosa (see page 265). IX-THE BLOOD- AND LYMPH-VASCULAR SYSTEMS OF THE NOSE AND PARANASAL SINUSES CHAPTER IX THE BLOOD- AND LYMPH-VASCULAR SYSTEMS OF THE NOSE AND PARANASAL SINUSES The Arterial Sipply The arterial sui^]ily of the nose and jxiranasal sinuses is derixed from both tlie external and internal carotid SA'stems. Brandies of the ophlhal- uiic from the internal carotid and the cxlrnial maxillary (facial) and the interna' maxillary from the external carotid are concerned in the nasal supply. The final arterial distribution is effected b}- capillar}- plexuses or networks which suj^ply the mucoperiosteum (periosteum, glands and tunica propria); t)ne hdng deej) in the ])eriosteum, a second surrounds and immeshes the glands, and a third forms a network immediately be- neath the epithelium. The Sphenopalatine Artery. — The main arterial suppl_\- to the nasal fossa and its appendages is distributed through the sphenopalatine artery (a. sphenopalatina), the terminal branch of the internal maxillary artery (a. maxillaris interna). The sphenopalatine enters the nasal fossa through the sphenopalatine foramen (foramen sphenopalatinum) which is located on the lateral nasal wall near the dorsal extremity of the superior nasal meatus and is formed b}- the articulation of the perpendicular plate of the palate bone with the caudal surface of the sphenoid bone. In the recent state the foramen is covered over by the nasal mucosa. In the passage of the sphenojmlatine artery through the foramen on the lateral nasal wall it is accompanied by branches of the spheno])alatine nerve, and immediately upon its appearance in the nasal fossa it gives off a small branch which aids in the supph' of the mucous membrane of the sphenoidal sinus, and another variable branch whic at times replaces the pharyngeal artery and has a similar distribution (see pharyngeal artery). The main trunk of the sphenopalatine artery now divides into a large medial and a large lateral branch (Tig. 190). The lateral hraneh of the sphenopalatine artery breaks \i\) into a number of secondary rami, the lateral posterior nasal arteries (aa. nasales pos- teriores lateralesj, which ramify cranial-, caudal-, and ventralward from the choanse to the nares and anastomose with the anterior and posterior ethmoidal arteries and with the lateral nasal branch of the external maxil- 276 THE BLOOD- AND LYMPH-VASCULAR SYSTEMS lary (facial) artery. The group of lateral posterior nasal arteries form a rich plexus in the mucous membrane lining the nasal meatuses and con- cha^, the maxillar}' and frontal sinuses, and the ethmoidal cells. The medial branch of lite sphenopalatine artery, the nasopalatine artery (a. nasopalatina), courses transversely across the roof of the nasal fossa to reach the medial nasal (septal) wall. Here the branch suffers dissociation into_ secondary rami, the posterior nasal septal arteries (aa. A.ethm.oidal.is anterior A.ethmoidalis posterior Si/tas sphenoidodis A. sph.cnopa.Jatina. ApcilatiJta- Ttiinor A.-paJjitina 7i7.a/or Aa. nasales posteriores latcrales Fig. 190. — The arteries of the lateral wall of the nasal fossa. nasales posteriores septi), which form a rich network beneath and in the septal mucous membrane. These arteries variously anastomose with the anterior and posterior ethmoidal arteries, Avith the septal branch of the superior labial artery, and with the great palatine (anterior branch of the descending palatine) artery near or within the incisive (anterior palatine) foramen. Some of the posterior nasal septal arteries are accompanied by the nasopalatine nerve in its course across the nasal septum to the in- cisive foramen (Fig. 191). arti:ri.\l supply 277 The Anterior and Posterior Ethmoidal Arteries.- The anterior and posterior etlimoidal arteries arise from the ophthalmic artery (a. oi)htlial- mica) as the latter courses along the medial wall of the orbit. Occasion- alh- the posterior ethmoidal arises from the sui)raorbital arter>-. The aiilcrior cUimoidal artery (a. ethmoidalis anterior), accom])anied by the anterior ethmoidal branch of the nasociliar}' ner^•e, ])asses through the anterior ethmoidal foramen on the ^•entromedial as])ect of the orbit mto the anterior cerebral fossa. In its course \-entrahvard along the Aiiasto?ito5is Apalatina, ?!ta/or Fig. igi. — The arteries of the medial or septal wall eif the na,sal fossa. cranial surface of the cribriform plate of the ethmoid bone, the anterior ethmoidal artery supplies branches to the dura mater and to the mucous membrane of the frontal sinuses and the anterior ethmoidal cells, and ulti- mately passes through a .slit-like foramen at the side of the crista galli to reach the mucous membrane of the nasal fossa. Once in the nasal fossa the anterior ethmoidal artery descends, accom])anied by the lateral branch of the nasal ner\-e, in a groove on the dee]) surface of the nasal bone and, finally, courses between the lateral nasal cartilage and the caudal flowerj border of the nasal bone to the tip of the nose. In the 278 THK BLOOD- ANT) LY:\IPH-\'ASCULAR SYSTEMS nose the artery supplies branches to the nasal mucoperiosteum along its course and to the integument on the dorsum of the nose (Figs. 190, 191). The posterior ctlimoidal artery (a. ethmoidalis posterior) is smaller and less constant than the anterior ethmoidal above described. It passes through the posterior ethmoidal foramen on the dorsomedial aspect of the orbit and is distributed to the mucoperiosteum lining the posterior ethmoidal cells and the dorsal and superior portions of the nasal septum and the lateral nasal wall. Here the posterior ethmoidal branch of the ophthalmic artery and the sphenopalatine branch of the internal maxillary artery connect up in a plexiform anastomosis (Figs. 190 and 191). The Descending Palatine Artery. — The descending palatine artery (a. palatina descendens), a branch of the internal maxillary, supplies small branches to the dorsal portion of the nasal fossa and by its direct ventral con- tinuation — the great palatine artery, which courses forward in the roof of the mouth to ascend through the incisive foramen — supplies a portion of the nasal fossa in the neighborhood of the incisi\'e foramen where it anasto- moses with the posterior artery of the septum nasi (the nasopalatine artery). The Pharyngeal Artery. — The pharyngeal artery (a. pharyngea), a small branch of the internal maxillar}-, courses dorsalward, accompanied by the pharyngeal branch of the sphenopalatine ganglion, through the pharyngeal canal (canalis pharA'ngeus) to the roof of the pharynx. From here the artery distributes small branches to the dorsal and superior portions of the nasal fossa, the roof of the pharynx, the sphenoidal sinus and the auditory tube. The Infraorbital Artery.— The maxillary sinus, in addition to the blood supply from the lateral nasal branches of the sphenopalatine artery, receives abundant supply from the branches of the infraorbital artery (a. infraorbitalis). The External Maxillary (Facial) Artery.— The nares (nostrils) of the nose are supplied b}' the latera! nasal J)raneli of the external maxillary (facial) and by the septal hrancJi from the superior labial (a. labialis superior or coronary artery). The external maxillary or facial artery continues along the lateral aspect of the external nose as the angular artery (a. angularis) and anastomoses with the true terminal branch (a. dorsalis nasi) of the ophthalmic artery. This anastomosis supplies the integument oxex the side and dorsum of the external nose. The Venous Supply The veins of the nose form a great network in the deeper parts of the tunica propria of the nasal mucous membrane, which in the respiratory LYMPHATIC SUPPLY 279 region cn-er the middle and inferior nasal concha; and the adjacent por- tions of the nasal septum assumes the character of a dense caYernous plexus. Elsewhere the erectile character of the network is less marked or absent altogether. The Yenous blood is returned from the i)lexiform network b}- three chief pathways: Yentrally into the anterior facial Yein, dorsally into the sphenopalatine Yein, and cranially into the ethmoidal ^■eins. Injections show that the ethmoidal Yeins communicate with the ophthalmic ^■ein and with the \-eins within the dura mate, including the superior sagittal Posterioi ciliary vein Superior ophthalmic vein 1 Supraorbital vein communicatin 7, with nasofrontal Optic nerve " Cavernou sinus„ _ Frontal vein Lacrimal gland Angular vein Inferior oblique muscle Infraorbital \ ^ Maxillary sinus Internal maxil lary vein Posterior facial vein Anterior facial vein Fig. 192. — The veins of the nose and eye and their connections. {Aftfr Qnain.) dural sinus. Moreover, Zuckerkandl found that an anterior ethmoidal vein leads from the nasal mucosa and passes through the cribriform plate to end in the venous plexus of the olfactory bulb or in one of the veins on the orbital aspect of the frontal lobe of the brain. These venous communications must be a factor in the intracranial complications that frequently accompany or follow some cases of inflammation of the nasal cavities and paranasal sinuses (Fig. 19^). The Lymphatic Supply The existence of lymphatics in the nasal mucosa was hrst satis- factorily demonstrated by E. Simon in 1859. He succeeded by puncture injections in demonstrating an extensi\-e network of hmiphatic vessels. 2 8o THE BI.OOD- AXD LY-AIPH-VASCULAR SYSTEMS This network is continuous with the lymphatic vessels of the nasopharynx, the nasal \-estibule and the cephalic and dorsal surfaces of the soft palate. :Moreover, there is a lymphatic connection between the two nasal foss*. The Nasal Cavity.— The lymphatics of the nasal cavity ramify the entire mucoperiosteum, both olfactory and respiratory, including that of the septum. It has also been fairly well established that the lymphatic network extends into the paranasal (accessory) sinuses in communication with the nasal ca^'it^^ The lymphatic vessels are located in the connective tissue of the tunica propria and their richness is in direct proportion to the thickness of the mucosa. At places the mucosa fit A Fig. 193. — The lymphatics of the nasal fossa. (Redrawn frotn Teshit.) At ^ Anterior lymphatic channels; Pi = Posterior lymphatic channels; Sm = Submandibular or submaxillary group of lymphatic nodes; 7^/) = Retropharyngeal group of lymphatic nodes; DC = Deep ceryical group of lymphatic nodes. is iniiltrated with lymphocytes and occasionally very minute solitary nodules are found. In man the main collecting A'essels of the lymphatic network of the nasal fosste form ventral and dorsal groups. The A'entral (anterior) group var}' in number and are found to course in the groove between the triangular cartilage and the bordering bone and between and ectal to the several cartilages of the external nose. In the subcutaneous tela they unite into several large trunks in relation with the facial nerve. These collecting trunks empty into the facial and the submandibular (submaxillary) grou])s of nodes. Furthermore, there is considerable anastomosis Avith the skin lymphatics of the external nose. The l}-mphatic network in the region ventral and caudal to the LYMPHATICS OF NAS.U. CA\TTY 281 pharyngeal ostium of the auditive (Eustachian) tube receives drainage from a considerable portion of the nasal fossa. From this region go forth the largest and most important collecting trunks from the lymphatic network, to terminate in either the deep cer\'ical chain or in the retro- pharyngeal nodes. It has been shown by I\Iost that at whatever point the nasal mucosa is ])unctured, the retroi)haryngeal nodes are colored by the injected material. Sappey long since jiointed out the involvement of the large lateral retropharyngeal nodes \'entrad of the atlas in diseases of both the nose and the pharynx. The frequent infection of the retro- pharyngeal nodes is readily explained when one recalls their extensive lymphatic area. They receive as afferents almost all the collecting vessels from the nasal mucous membrane and from the ca\ities in connection with the nasal fossa?. ^Moreover, afferents from the lymphatic network of the cavity of the tymi)anum, the auditive tube, and the naso])harynx pass to these regional nodes (Fig. 19,^). It would appear established that the subdural space directly com- municates with the extracranial lymj^hatics and the perineural spaces of the olfactorv nerve, etc. Schwalbe, Key and Retzius, and subsecjuently Cuneo, succeeded in injecting the nasal lymjihatics from the subdural spaces. Furthermore, Key and Retzius reported success in injecting the nasal hmrphatics from the subarachnoid spaces at the base of the brain. Confirmation of the latter is, however, lacking at this date and itisprobablc, according to other studies, that the subarachnoid space has no direct lymphatic connections. The perineural sheaths of the olfactory nerves are of interest in this connection. Key and Retzius found that when in- jecting the subarachnoid space the perineural sheaths of the olfactory nerves would frequently be injected. They found, howe\'er, that the true lymphatics did not communicate with these perineural sheaths, but had special passages through the lamina cribrosa and that they were often injected when the perineural sheaths were not injected. ( )n the contrary, the perineural sheaths were at times injected and the h-mphatics not. Flexner, in discussing the mode of infection in epidemic meningitis, states that in all probability the micro-organism passes directly to the nervous system bv wa>' of the hmphatic connections between the naso- phar}'ngeal mucosa and the meninges. The Paranasal Sinuses.— There is little definite knowledge regarding the lymphatics of the paranasal (accessory) sinuses of the nose. Studies of Most indicate that the lymphatic drainage from all the paranasal sinuses and cells is into the retropharyngeal nodes. Clinical evidence bears out this conclusion. 282 THE KLOOD- AND LY.MPH-VASCULAR SYSTE;MS The External Nose. — The h-mphatic network of the external nose is \Tr>' dense over the alae and lobules and as it courses over the dorsum and the root of the organ. There is an anastomosis from side to side. As pointed out before, the lymphatic network of the external nose is con- tinuous with the lymphatics of the nasal vestibule and the mucosa of the nasal fossas. The collecting vessels arise from the cutaneous network in three groups, according to the studies of Kijttner: (a) from the root of the nose the}- pass abo\-e the upper eyelid and terminate in the parotid nodes; (b) from the root and side of the nose they pass across the lower Fi(,. 194. — Schema of the lymphatics of the external nose. [Redrawn from Tcslut, after T. el J.) I = Superior group of lymphatic channels; 2 = Middle group of lymphatic channels; 3 = Inferior group of lymphatic channels; p = Parotid group of lymphatic nodes; sm = Submandibular (sub- maxihary) group of lymphatic nodes. eyehd to the parotid nodes; (c) the third and most important group arise from the entire cutaneous portion of the external nose and terminate in either the facial or submandibular (submaxillary) group of nodes. Klitt- ner was able by puncturing the integument of the external nose to distend the lymphatics of the mucosa of the nasal fossae and to follow the in- jection to the dorsal surface of the soft palate (Fig. 194). Further study of the nasal lymphatics is necessarj' in the light of certain clinical manifestations. X-THE COMMON SENSORY AND THE SYMPA- THETIC NERVES OF THE NOSE AND PARANASAL SINUSES CHAPTER X THE COMMON SENSORY AND THE SYMPATHETIC NERVES OF THE NOSE AND PARANASAL SINUSES A. The Xer\-es of Common Sensation The ner\'es of common sensation of the nose and its appendages are derived from both the ophthahnic and the maxihary di\'isions of the tri- geminal nerve (n. trigeminus), e.g., the ner\-us ophthalmicus and the ner^•us maxillaris, respecti\-eh'. The sensory ner\'es to the nose are in reality peripheral processes of T-hbers which spring from the nerve cell bodies (perikaryons) of the semilunar (Gasserian) ganglion and pass to the nasal organ b}- wa\- of the branches of the ophthalmic and maxillary trunks of the ganglion. The central processes of the T-fibers, on the contrary, pass into the brain stem, there to synapse at the nucleus of termination of the trigeminal ner\-e with neurons of the second order in the common sensory (afferent) pathway- from the nose. The cell bodies of the semilunar gan- glion together with the T-hbers with their central and peripheral processes constitute neurons of the first order in the common sensory pathwa}'. It would appear established that the trigeminal nerve libers rise up between the epithelial cells of the nasal mucous membrane and end free. The "Geruchsknospen" of Blaue and the "Epithelknospen" of Disse need re-investigation. The Central Connections. — The sensory (terminal) nucleus of the trigeminal nerve is located in the pons lateral to the motor one (nucleus of origin of the masticator nerve) and beneath the brachium conjunctivum (superior cerebellar peduncle). It consists of an enlarged upper end, usu- ally referred to as the fuaiii sensory niieleits, and an elongated, slender descending portion — the mieleiis of the spinal traet of the trigeminal nerve. The latter extends through the pons and the medulla and becomes con- tinuous with the dorsal part of the posterior column of gray matter of the spinal cord, particularly the substantia gelatinosa of Rolando. The main sensory nucleus receives the short ascending branches; the descend- ing branches collectively forming the tractus spinalis Avhich ends by termi- nals and collaterals in the several portions of the nucleus of the spinal 28s 286 THE COMMOX SENSORY AND THE SYMPATHETIC NERVES tract, extending through the pons, medulla and spinal cord to the leYcl of the second cervical segment. The ceUs of the sensory or terminal nucleus of the trigeminal nerve together with their processes constitute neurons of the second order in the common sensory pathway from the nose. The centrally directed processes or axons form a distinct bundle, the trigeminothalamic tract, which passes cranialward through the reticular formation and the teg- mentum to end in a special portion of the thalamus by synapsing with the neurons of the third order in the pathway from the nose to the cerebral cortex. For the most part the fibers of the trigeminothalamic or central trigeminal tract decussate or cross to form the opposite paired tract, ascending dorsal to the medial fiUet or lemniscus. A few fibers of the trigeminothalamic tract ascend to the thalamus uncrossed. From the thalamus impulses are carried over neurons of the third order to the somes- thetic area of the cerebral cortex, the axons of which course b}' way of the internal capsule and the corona radiata, mostl}' on the side opposite from which the impulse initially started in the nose. Thus stimulation of the terminal nucleus of the trigeminal nerve leads to conscious sensations, often of a painful character. Some fibers of both the trigeminal nerve direct and from its terminal nucleus pass laterally into the cerebellum. Axons from the nucleus of te'-mination of the trigeminal nerve and collaterals from ihe trigeminothalamic tract in its course through the medulla are given to various motor nuclei, especially the facial, the masti- cator (motor of trigeminal), and the nucleus ambiguus (of the vagus and glossopharyngeal nerves) for simple reflexes. Moreo^'er, some of the reflex or association axons from cells in the nucleus of termination of the trigeminal nerve contribute fibers to the medial longitudinal fasciculus, some of which are long and descend below the level of the second cervical segment, terminating in the gray substance of the spinal cord. Since one of the salient features of the medial longitudinal fasciculus is to associate the oculomotor, trochlear and abducent nuclei, the association axons from the trigeminal terminal nucleus coursing in the bundle doubtless are brought into relationship with the nuclei of the eye-mo^•ing muscles, and since the fasciculus becomes continuous Avith the anterior fasciculus proper of the spinal cord, relationship is also established between the association axons and the A'entral horn cells of the cervical spinal segments. Relations are also established between the central trigeminal fibers and their terminal nucleus and the vasoconstrictor, vasoinhibitor and secretomotor centers. Stimulation of the latter centers leads to un- conscious sensations, resulting in di^'ers reflex i)henomena. SYMPATHETIC NKRVKS 287 The somatic sensory fibers of the \'agus, of the glossopharyngeal and of the pars intermedia of the facial ner\'es terminate in the nucleus of the spinal tract of the trigeminal nerx-e and their cortical impulses follow the trigeminothalamic tract. The descending somatic sensory fibers of the ^•agus, glossopharyngeal and facial (pars intermedia) ner\'es which termi- nate in the spinal tract of the trigeminal ner\-e, doubtless through the medium of associational or connecting neurons, establish relations with the nuclei of the motor cranial ner\-es in the medulla and with the \'entral or motor horn cells of the high spinal cord. B. The Syiipathetic Xerves XerA'c impulses destined to determine the caliber of the blood-\x'ssels and to control the mechanism of secretion in and about the nasal foss;e are transmitted b>' s}'m])athetic efferent nerves. Both the cranial and the thoracolumbar s\'mpathctics ha\"e to do with the nasal supply; the cranial brought about b}' symj^athetic fibers contained in the pars inter- media of the facial nerve and the thoracolumbar by connections between the upper thoracic segments of the medulla spinalis (spinal cord) and the superior cer\ical sym]:)athetic ganglion. Moreover, it is belie\'ed that certain impulses from the nasal mucous membrane reach the cerebro- spinal nerA-ous system o\'er sympathetic afferent nerves. The term "svmpathetic"' is used ad\'isedh' since it is a term generally understood to apph' to that portion of the peripheral ner\-ous sA'stem which inner\"ates the smooth or visceral muscles wherever located, the A-arious glands of the bod^-, and the striated muscle of the heart. It is not deemed profitable nor essential in this connection to discuss the detailed anatomy of the sympathetic ner\-ous sx'stem. The reader is referred to special treatises on the subject. It must, however, be clearh- understcjod that on the eft'erent (motor) side of the s>-mpathetic SA'stem there are two orders of neurons connecting the cerebrospinal a.xis with the tissue or organ sup- plied. The neurons of the first order (preganglionic) have their cell bodies within either the brain or the spinal cord, the peripheral processes (axons) terminating by synapsing in symj^athetic ganglia with the cell bodies of neurons of the second order (postganglionic), whose peripheral processes or axons extend to the parts to be acted upon. This stands in contrast to the single lower motor neurons of the somatic series of nerves in which the cell bodies are also located within the cerebrospinal axis, but whose axons iThe terms autonomic (Langley), vegetative (Myer and Gottlieb) and involuntary (Caskell) are frequently applied to the sympathetic system. Langley limited the term sympathetic to apply to the thoracolumbar outflow. There is, however, no morphologic basis for this distinction. 288 THE COMMON SEXSORY AXD THE SYJIPATHETIC XERVES go directly to the striated or voluntary muscles without further synapse. Furthermore, it is essential to recall that the vast majority of the cell bodies or perikarj'ons of the afferent or sensor}- s}-mpathetic neurons are located in the ganglia on the dorsal roots of the spinal nerves and in homologous ganglia of certain cranial nerves. Cell bodies of a few afferent sympathetic neurons are apparently located in the extra-centrally placed sympathetic ganglia. It is, therefore, obvious tliat the only anatomically independent units of the sympathetic nervous system, so far as a connection with the cerebrospinal nervous system is concerned, are the postganglionic neurons with cell bodies in the sj-mpathetic ganglia and whose axons coUectively course as pure symimthetic ner^•es or as sympathetic components of somatic nerves to the various parts of the body. Moreover, in spite of a certain peripheral autonomy in the physiologic responses of the sympa- thetic nervous system, the latter is in large measure regulated and con- trolled by the cerebrospinal nervous system, a control made possible by the intimate anatomic connections of the two systems. Sympathetic Efferent Neurons. — A. S}'mpathetic efferent or motor libers for the supply of the nasal fossae and sinuses arise from a special nidus of cells located dorsal and medial to the facial nucleus in the reticular formation of the medulla. The prcii^angUonic fibers from this nest of ceUs leave the medulla as constituent elements of the pars intermedia of the facial nerve (the glossopalatine nerve), and are distributed (i) by the chorda tympani and lingual nerAes to the submaxillary ganglion and (2) by the great superlicial ])etrosal nerve to the sphenopalatine (Meckel's, nasal) ganglion. From the cell bodies located in the sympathetic sub- maxillary ganglion go iorih postganglionic fibers, \Si?>od.\\ditor SindsecretOTy in function, to the submaxillary and sublingual sahA-ary glands; and from the cell bodies in the sympathetic sphenopalatine ganghon issue post- ganglionic fibers (in the branches of the si)henopalatine ganglion, see page 307), \asodilator and secretory in function, to the mucous membrane (blood- and lymph-vessels and glands) of the nose and palate, the lacrimal gland, the tonsils, etc. B. Sym])athetic efferent (preganglionic) fibers with cell bodies located in the dorsolateral portion of the \-entral horns of the upper four or five thoracic segments lea\'e the spinal cord by the ventral roots of the cor- responding spinal nerves and reach the ganglionated sympathetic cord by way of white rami communicantes. The axons of most of these preganglionic neurons, destined for the sup])l}- of the A'arious parts of the head, ascend in the cervical sj'mpathetic cord and c SYMPATHETIC AKFKRENT XICUROXS 289 terminate b)- synapsing around Ihe cell bodies of posliiaiiiilioiiic neurons located in the superior cervieul sympatbetie 'ganglion. The latter neu- rons are vat-iously vasodilator, vasoconstrictor, secretory, visceromotor (to the dilator pupilke muscle) in function. The)- ascend b>' way of the ephalic j-ilexiform extension of the superior cerxical sympathetic ganghon and reach their destination b>- way of cranial nerves, especially the branches of the trigeminal. Some of these postganglionic neurons furnish ^'aso- constrictor, and probably additional dilator and secretory fibers, to the nasal mucous membrane. Probably the pars intermedia and the cervical ganglionated cord carry both vasoconstrictor and -s-asodilator preganglionic fibers; but that the \"asodilator fibers are most numerous and active in the pars intermedia and the \-asoconstrictor in the cer\-ical extension from the s^'mj^athetic (at least so far as the nasal mucous membrane is concerned) seems certain. Of ct)urse, when ex])erimentall_\' stimulating these ner\-es the work of the fewer and less acti\'e fibers ma)' be wholly masked by the greater eft'ect and number of antagonistic fibers. In general, throughout the bod>', the vasoconstrictor fibers are the most prominent, exercising a continual tonic effect on blood-vessels. Howe\'er, while vasodilator fibers are fewer and less frequently seen in action, they do exist — striking illustrations are the chorda tympani in its action on the submaxillary gland; the nervi erigentes in the erection of the penis, clitoris, etc.; and the ner\'es to the erectile tissue of the nasal foss;e. Sympathetic Afferent Neurons. — It is known that s>-mpathetic att'erent fibers with their cell bodies located in the geniculate ganglion are constituents of the pars intermedia of the facial ner\e. Doubtless the peripheral processes of some of these neurons accomi)an}- and are a]xirt of the great superficial petrosal nerve and pass through thesplienopalatine or nasal ganglion ot Meckel to be distributed by wa}' ol the branches of the ganglion to the mucous membrane of the nasal fossa, the jmranasal sinuses, and the neighboring ])arts. The central processes of the genic- ulate s\-mpathetic cell bodies follow the trunk ol the pars intermedia of the facial nerve into the medulla oblongata and while their central connections are not clearly established they ])resumably form additional synapse relations, either directly or indirectly, (i) with the vasoconstrictor center in the medulla; (2) with the \-asodilator centers (particular!)- the centers of dilator fibers which accompan}- the pars intermedia of the facial, the glossopharyngeal and the cervical sympathetic), probably located ^■ari- ously in the medulla; (t,) with the cardio-inhibitory center in the medulla; and (4) with somatic eft'erent neurons of the head and cer^■ical regions. 19 290 THE COMMON SENSORY AND THE SYMPATHETIC NERVES Additional sympathetic afferent fibers from the nasal cavity and sinuses seemingly reach the spinal cord by way of the cervical sympathetic cord, with cell bodies located in the ganglia of the dorsal roots of the upper thoracic nerves. The central processes of these cell bodies establish additional synapse relations with eiferent sympathetic (preganglionic) and efferent somatic neurons within the spinal cord. The relations formed between afferent or sensory sympathetic neurons and efferent somatic and sympathetic neurons establish neuron arcs for reflexes. Moreover, afferent sympathetic neurons from the nose synapse either directly or indirectly (by intercalation of additional ele- ments) with the cell bodies of somatic sensory neurons located in the ganglia on the dorsal roots of the upper thoracic spinal ner\-es and in the geniculate ganglion. The synapse relations between afferent sympathetic and afferent somatic neurons pro^'ide the mechanism for the transfer of sym- pathetic sensory impulses to the somatic sensory system (see page 302). The Vasoconstrictor Center. — The vasoconstrictor center is located in the medulla oblongata (bulb) and is always in tonic activity. The cell bodies of the center give oft" axons which descend in the spinal cord and terminate at various levels in the ventral (motor) horn of gray matter, from the first thoracic to the second or third lumbar spinal nerves. Here they s}'napse with tlie cell bodies of the preganglionic^ (efferent) sym- pathetic neurons. The cell bodies of the vasoconstrictor center wdth their axons form, therefore, central or intercalary neurons of the ^'asocon- strictor pathway. The Vasodilator Center.— That \'asodilator fibers exist for the supply of erectile tissue, glands and muscles is established beyond peradventure. These fibers are, however, not connected centrally, so far as the evidence tends to show, Avith a single center. Presumably the dilator libers in the pars intermedia of the facial, the glossopharyngeal, and the cervi- cal S}-mpathetic haA-e their cell bodies located variously in the medulla. Additional vasodilator centers are, doubtless, present in the spinal cord. Pliysiologic evidence tends to show that the A'asodilator fibers are not in tonic activity as are the vasoconstrictor fibers. From the anatomic arrangement of the pale muscle fibers in the walls of blood-A-essels, it would seem that the vasodilators when stimulated bring about turgescence of a vascular area (dilatation of the vessels) by inhibiting the tonic action of the vasoconstrictors. ^ 1 Recent experimentation seems to indicate tliat in tlie thoracic segments of the spinal cord the cell bodies of the prcKanKlionic neurons may under some conditions function as subordinate vasoconstric- tor centers capable of tonic and reflex activitv. RKl'LKX CIRCUITS 2QI C. Rkklex Circuits The anatomic relationshii)s of neurons Avithin the correlation centers mentioned in the foregoing ])aragraphs complete reflex circuits or arcs, composed of rcccf>toi\s, adjiislors, and cjj'cftors. Moreover the circuits provide ajh'rciit (st)malic sensory neurons of trigeminal nerve and sym- pathetic sensory neurons) antl cjfcrcitt (somatic motor neurons of various cranial nerves, somatic motor neurons of the upper spinal nerves, and sympathetic motor neurons of the cranial and thoracolumbar outflows) conductors or pathways, whereby the adjusters or correlation centers are brought into physiologic relations with the receptors (sense organs) and eft'ectors (response organs). These several components of the neuron arc or circuit pro\ ide the anatomic mechanism for reflex phenomena that follow adequate stimulation of the general aft'erent fibers of the trigeminal nerve and seemingh' of sympathetic afferent fibers that borrow the branches of the trigeminal nerve as pathways for a greater or less distance in their course to the central axis. It is not deemed profitable nor essential in this connection to speak of the anatomic arcs for the divers simple and complex reflex acts and plienomena that take })lacc following adequate stimulation^ of the recep- tors or sense organs located within the nasal mucous membrane and re- lated parts. A single reference will suffice to point out the general prin- ciples in\'oh'ed. \M'ien, for example, the normal unanesthetized mucous membrane is stimulated with an ai)])licat()r brush, or an irritant gas is inhaled, there foUows immediately and before consciousness can be a factor a reflex twitching of the facial muscles, mo\-ements of the eyeball, a mo\-ement of the head to one side, and an ele\-ation of the arm in an efl(jrt to remo\e the oft'ending brush or gas. Furthermore, a careful examination will show that the blood-vascular network within the nasal mucous membrane has undergone a dilatation ov turgescence, to be followed by an increased secretion of water}- fluid from the glands of the mucous membrane: indicating a stimulation of the \-asodilator and secretomotor centers, whereby the tonic effect of the A'asoconstrictor center is reflexly inhibited. Sneezing not infrequently follows. The intensity of the reactions is in direct accord with the degree of stimulation. The reflex movements of the striped muscles of the face, neck, arm, etc., are due to the central 1 It must be recalled that receptors respond only when the stimulus is sufficiently strong and of the proper sort— degree of intensity and Icind is, therefore, the adequate stimulus. Arthur F. Hertz has shown that "a nerve-ending maybe sensitive to one form of stimulation— the adequate stimulus— but insensitive to all others." The Sensibility of the Alimentary Canal, London, 1911. 292 THK COMMON SENSORY AND THI-: SVMrATHETIC NERVES connections between the somatic senson' neurons of the trigeminal nerve and the somatic motor neurons' of \-arious cranial and spinal nerves. The reflex movements of these can, of course, be voluntarily inhibited, controlled or modified, since the opposite pyramidal tract (corticopontine, corticobulbar, corticospinal fibers) gives collaterals and terminals to the nuclei of the several motor cranial nerves and to the ventral (motor) horn cells of the spinal cord. The sneezing, howe\'er, cannot be voluntarily controUed, neither can it be voluntarily performed. The afferent channels are the internal nasal branches of the trigeminus and at times the olfactory (the latter in case of intense odors). The efferent or motor paths lie in the nerves of the muscles of expiration. In the correlation center connecting neurons are inter()osed. While sneezing cannot be performed voluntarily, it may be inhibited by compressing the medial nasal nerve below the septum mobile nasi. Here Ave have the operation of antagonistic reflexes — the reflex incident to the compression of the medial nasal nerve (of the ophthal- mic division of the trigeminus) overcoming or inhibiting the reflex of sneezing incident to stimulation of the neives in the interior of the nose (of the maxillary division of the trigeminus). Moreover, the control of the nasal congestion and glandular activity are not under the power of the Avill since unstriped or pale muscle and glands are involved. It is well known that the central processes of the cell bodies of the sympathetic alTerent neurons synapse with either somatic or sympathetic efferent or motor neurons within the central nervous sys- tem in the completion of reflex arcs. Experimental evidence tends also to show that afferent somatic neurons, in addition to completing reflex arcs with eft'erent somatic neurons, participate in the formation of reflex arcs in which the eff'erents are of the sympathetic type. It is, therefore, possible that an impulse from the nasal ca\'it}- meant primarily to bring about reflexly a pure motor response of striated muscles results in a vaso- motor phenomenon as well, t'.,i,'., turgescence of the erectile tissues of the nose. It is obviously difficult to determine whether the afferent impulse from the nose reached the central nervous system by way of sympathetic sensory or somatic sensory neurons, owing to the intimate anatomic rela- 'The efferent neurons of the trigeminal, facial, glossopharyngeal, \-agus and accessory nerves supplying striated muscles in the head and neck are often referred to as special visceral efferent (motor) neurons, since the muscles they supply are derived from the unsegmented mesoderm and not from the early mesodermal segments — the source of the somatic striated muscles. It must; however, be understood that the facial, mandibular, hyoid, laryngeal and phar\-ngeal muscles are striated anrl are under the control of the will and that their ner\-e endings are like those of the striated muscles of the S(jmatic series proper. REFLKX NASAL .AlAXIFESTATIONS 2q3 tionships that arc established, whereb)' transfer of sensor}- impulses from the sympathetic to the somatic s>-stem is continually made. However, the trigeminal ner\e is ob^'iousl^' the imj^ortant afferent pathwa)^ It must, however, be recalled that, e\-en though the turgesccnce and depletion of the nasal muct)sa is commonh' a simple reflex phenomenon, under certain conditions the erectile tissue of the nose is readily influenced b}' psychic states, indicating a connection between the \'asomotor centers and the cerebral cortex. Indeed, intracentral efferent aeurons from the cortex to the \asomotor reflex centers ha^•e been demonstrated. More- over, while it is true that the exteroce])ti\e arcs are most closely connected with the skeletal musculature and the interoceptive with the visceral, and that seemingly some resistance to conduction from one to the other exists, the fact remains, nevertheless, that the unstriped muscle of the blood- vascular areas is readily influenced by stimulating either the interocepti\'e or the exteroceptive flelds.' Turgescence of the cavernous tissue of the nasal mucous membrane is essentially a vasodilator phenomenon, just as Eckhard has shown for the erection of the penis and clitoris, and is due either to a reflex excitation of the A'asodilator centers and libers or to a reflex inhibition of the tonic activitv of the vasoconstrictor center. If the latter, one sees how the nasal mucosa would become depleted after a temporary congestion, b}- a removal of the inhibition and an assertion of the tonic action of the vasoconstrictor center and fibers, whereby the size of the vascular areas becomes lessened. It is ob\'ious that ])sychic states pla}' an important role in the stimulation of the vasodilator centers — blushing of the face from emotions, congestion of the sali\ary glands on thinking of an apj)e- tizing food, the erection of the cax'ernous tissues of the male and female genitaha in erotic states of mind are common examples. Reflex Nasal Manifestations Incident to Nasal Disease and Dis- orders. — The reflex circuits or arcs ])ro\ide also the anatomic and physio- logic mechanisms for the man>- and varied reflex manifestations that are encountered clinicaH}- in diseases oi the nose and paranasal (accessory) sinuses and in mal])ositions of nasal jiarts. Pure nasal neuroses are not as common as one time behe\-ed. Careful study and examination in many instances reveal the source (jf the reflex. It is, oi course, ob\-ious that adeciuate and suitable stimulation of the sense organs of the normal nasal fossje and sinuses will, in some instances at least, result in reflex nasal manifestations not unlike those encountered in nasal disease, etc. Some of the so-called reflex nasal manifestations incident to nasal dis- ' Charles S. Sherrington: The Integrative .\etii)n of the Nervous System, New Haven, iqid. 294 THE CO.M-MON SEXSORV AND THE SYMPATHETIC NERVES orders and those of neighboring parts are in reality of a referred nature and should not be thought of as reflexes (pages 302 and 305). Many of the reflex nasal manifestations are puzzling from an anatomico-physiological view^point and much work needs to be done to clear the obscure horizon. Indeed, further study may shoAv that anatomy and physiology have no adequate explanation for some of them. However, in spite of some obscure conditions, there are many reflex and referred nasal manifestations that occur in nasal diseases that can be accounted for b}' the anatomic arrangements and relations of neurons composing neuron circuits, and unless these pathways are kept in mind and clearly understood faulty interpretations will be gi^'en many of these reflex and referred phenomena Avhich emanate from the nose, the paranasal sinuses and the related parts. It is not the province here to enter into a discussion of the many reflex nasal manifestations and neuroses. The reader is referred to treatises on clinical neurolog}' and rhinology for detailed expositions concerning them. The reflex and referred manifestations encountered in nasal disease can in a general way be di^'ided into motor, sensory, trophic, and vasomotor. In relation with the respiratory tract one meets with such important conditions as sneezing, coughing and asthma, which are directly traceable to nasal disorders. Reflex phenomena in the ear referable to nasal disease are not uncommon. Lacrimation due to tur- gescence of the inferior nasal concha has been reported. Migraine and neuralgias may be referred manifestations due to conchal lesions, sinus disease, septal spurs, etc. Gastralgia, indigestion and vomiting have been recorded as produced reflexly by intranasal disease. Alteration of the cardiac rhythm and numerous sexual phenomena frequently have a definite nasal reference. The reverse ma}- also be true, e.g., nasal phe- nomena have a definite sexual origin. One naturally wonders how, for example, the cardiac rhythm can be affected by nasal disease and by suitable or adequate stimulation other- wise applied to the interior of the nose. It has been demonstrated that experimental irritation of certain portions of the nasal mucous membrane resuhs in an alteration of the heart beat. Moreover, it has been reported that some typical cases of so-called cardiac neuroses and arhythmias were cured by the treatment of hypertrophied nasal concha; and deflected nasal septa. It is necessary in this connection to recall (i) that afferent impulses from the nose pass over the trigeminal fibers (somatic sensory neurons) to the terminal trigeminal nucleus, thence by wav of the centrally directed trigeminothalamic tract to the thalamus and from there to the KEKLl'X PATHS 29s somesthetic area of the cortex lor the conscious recognition of such impulses (some impulses may pass via sympathetic afferent fibers o\er the peripheral branches of the trigeminal, the great superficial petrosal and the pars intermedia of the facial), and (2) that nasal impulses may follow reffex axons from the nucleus of terminaticm of the trigeminal nerve and coUaterals f'-om the trigeminothalamic tract to the dorsal nucleus of the vagus nerve ( nucleus of the ala cinerea) located in the medulla and which contains the cardio-inhibitory center. In all probability connec- tions are also established with the predominant cardio-accelerator center located in the medulla and secondar}' cardio-accelerator centers of the high thoracic cord. The inhibitory preganglionic neurons (sympathetic motor) to the heart represent a component part of the outflow of the medulla or bulbar symjiathetic flbers, the cell bodies of which are located, as stated above, in the dorsal nucleus of the vagus nerve, and the ])eripheral libers (axons) are distributed by way of the trunk of the vagus. The peripheral flbers end by synapsing with sympathetic ganglion cells, located within or near the heart, of cardio-inhibitory postganglionic neurons destined for the supph" of the heart muscle. The preganglionic accelerator neurons to the heart emerge from the spinal cord in the ventral roots of the flrst, second, third and fourth thoracic spinal nerves. The cardio-accelerator center, probabh' located in the medulla, establishes synapse relationships with the cell bodies of the preganglionic accelerator fibers located in the ventral horn of the spinal cord. It is, therefore, obvious that the heart beat which is inhibited by the bulbar s}'mpathetic (\isceral) system through the \'agus nerve and accelerated by the thoracolumbar sym])athetic system through certain thoracic spinal ner\es, can be refle.xly influenced by adequate afferent stimuli of nasal origin. This, since neuron pathway's are pro^'ided not only for the possible conscious recognition of the sensory impulses, but also pathways whereby the somatic sensor}' and the synii^athetic aft'erent impulses are carried to the correlation or adjustor centers and from there svmpathetic efferent impulses to the heart muscle. Since the nucleus ambiguus contains the cell bodies of origin of the somatic efferent or motor fibers of the \'agus nerve' which supply the cross striated muscles of the pharA'nx and lar\nx there is a reason for the so- caUed nasal cough (reflex cough) in disorders of the nasal fossa, and since the opposite p\Tamidal tract gives terminals and collaterals to the nucleus ' Probably the glossopharyngeal nerve receives efferent fibers from the nucleus ambiguus. Cunningham, however, questions whether this nerve contains any motor fillers at all, there being paths by which the fibers of its so-called motor branch to the stylo[)har\ngeus muscle might enter the nerve from sources other than the nucleus ambiguus. 2q6 THE COMMON SENSORY AND THE SYMPATHETIC NERVES ambiguus for the mo\'ements of the lan'nx and pharynx the cough may be voluntarily controlled unless the nasal stimulation, owing to diseased states, is excessive and the resultant reflex cough beyond the control of the will. Most of the cerebrospinal control of the visceral reactions is effected from the sympathetic centers located in the medulla by way of the vagus nerve. Sympathetic efferent (preganghonic) fibers with cell bodies located in the dorsal nucleus of the vagus are distributed by the \'agus to various sympathetic ganglia. From the latter go forth postganglionic neurons for the supph' of such organs as the esophagus, the stomach, the small intestines, the lungs, the heart (inhibitory, referred to above), etc. Tliese connections account for such reflex manifestations as asthma, gastralgia and \-omiting in nasal diseases. It is well known, for example, that the remo^•al of nasal polypi or the exenteration of the eth- moid labyrinth in severe ethmoiditis have eft'ected cures of troublesome and vague asthmas. Moreover, the relationship between the nose and attacks of bronchial asthma has also been established experimentalh'. Weak electrical currents applied to the nasal mucous membrane increase the intrabronchial pressure (Lazarus).^ Stimulation of the nasal septum produces spasm of the muscular walls of the smaller bronchioles (Brodie and Dixie ).'- Naso-sexual Relations.— The wide connections between the cortical olfactory centers and other parts of the cerebrum pro\'ide anatomic and physiologic mechanisms for the many associations connected with odors. Moreover, it is ob\'ious from daily observations and experiences that in many animals (man included, although to a less degree) the olfactory sense is very intimately connected with sexual reflexes. Apart from the peripheral and central olfactor}- organs there appears to exist a definite physiologic and pathologic relationship between the nose and paranasal sinuses and the sexual organs. Certain sexual condi- tions seem to have a nasal reference and vice versa, e.g., some nasal dis- orders seemingly are the result of sexual irritation or disease. Indeed, there are some striking anatomic and physiologic analogies between cer- tain portions of the sexual organs and the nose. Menstrual life may be estabhshed by the occurrence of nasal bleeding. Turgescence of the erectile tissue of the nasal fossje may regularly accompany menstruation in women with normal nasal mucous membranes. Nose-bleed is frequent in bo}-s at the age of puberty. The symptoms of nasal diseases are not in- ' IJeut- -Aled. Woch., XVH, iSqi. - Trans, Path. Soc, London, EIV, 1903. NASO-SICXUAL RFXATIONS 297 frequenth- aggra\-atecl during the menstrual period and following sexual excesses. Indeed, sexual excesses in some instances appear to be the cause of certain nasal disorders. Moreover, reflex sneezing, engorgement of the nasal erectile tissue, coryza, hypertrophic changes in the nasal fossa^ ha\-e been reix)rted as concomitants of sexual excesses. Elsberg some >-ears ago suggested that arrested sexual de\'elo])ment might be due to nasal disease. Schift" stimulated the noses of female dogs and found that in 7 out of 15 animals experimented upcm contractions of the uterus followed the nasal irritation. Control stimulations of the sciatic nerve gave feeble uterine resi)onses. Priapism due to nasal disorders is not un- known, cures ha^•ing followed nasal treatment. Certain dysmenorrheas are belie\-ed by some clinicians to ha\"e a definite nasal reference. Many of the so-called naso-sexual relations are obscure. Probabh^ some ha^■e a phylogenetic bearing. Others may be merely the expression of a more or less uniform reaction of anatomically similar tissues, c.;^., erectile or ca^"ernous tissues. Pure neuroses are doubtless encountered. However, certain of the naso-sexual relations, when carefully studied, seem to be of a reflex nature with the source of the reflexes located either in the genital a])paratus or in the nasal ca\'ity. The cause of such reflexes may be due to diseased states or adequate stimuli otherwise ap])lied. In this connection a knowledge of the established neuron arcs or circuits is essential. As stated pre\-iously, asthmas, coughs, vomiting, alterations of cardiac rhythm, etc., are frequently reflex ex])ressi(ms of nasal stimu- lation incident to disease, etc. P\)r these manifestations the neuron pathwavs are more or less definite and established. It is, therefore, plausible and indeed i)robable that nasal stimulation if of the proper sort wfll reflexly influence the sexual apparatus (exclusi^•e of the ob\'ious influ- ence of the olfactory sense on the sexual reflexes). Indeed, laboratory experimentation and clinical evidence lend supjwrt to the thesis. Un- fortunately the neuron arcs or circuits are not as well known in this con- nection as elsewhere. Howe\er, some outstanding facts are unmistak- able. It is ob\-ioush' difticult to establish certain links in some neuron circuits (reflex circuits) and until this is done it is justifiable and projier to assume tentatively certain facts based on established related lacts and clinical e\-idence and exi)erience. One must, however, remember that some of the reported cures of reflex manifestations in j^atients following treatment of the nose or sexual ap])aratus mean nothing more nor less than suggestion and mental influence on the part of the patient and want of discriminate judgment on the part of the ph}-sician. It is not deemed profitable in this connection to discuss the many and \-aried observations 298 THE CO.AOION SENSORY AND THE SYiMPATHETIC NERVES reported in the literature, suffice it to spealv of a few conditions in wliich nasal irritation seemingly gives rise to reflex genital expression, with spe- cial reference to probable neuron circuits. Priapism is according to some apparently authentic cases occasionally caused refiexly by nasal disease. The removal of the nasal irritant with a concomitant cure of the priapism seems to establish the nasal source of the reflex. In this connection one must, however, always bear in mind that intermittent priapism is not infrequently seen in neurasthenic men subjected to prolonged mental strain and that the cure of the priapism following nasal treatment may be merely a mental suggestion. In spite of the fact that in the vast majority of cases priapism is an expression of spinal lesions, etc. (see proper treatises on the subject), the nasal fossa; as a possible source of the reffex seems estabhshed. One naturally wonders, howcA'er, what the possible underlying anatomic and physio- logic mechanism of the relationship can be. Despite the relative un- imjwrtance of this relationship, it may not be amiss to briefly survey neuron pathways and centers that may possibly be invoh'ed in this and other connections. Persistent abnormal erection of the penis, usually without sexual desire (priapism), like the nomial erection of the penis is a vasodilator phenomenon. Normal erection is a reflex act effected through a secondary center in the lumbar cord. This center may be aroused by psychic impulses descending from the brain (erotic sensations, for example) or reflexly by sensory (aft'erent) impulses arising in the genital tract and elsewhere. Persistent (at times intermittent) abnormal erection or priapism is likewise clearly a reflex act and doubtless eft'ected through the same secondary erector center in the lower portion of the spinal cord. The center may be aroused by afferent impulses incident to pathologic conditions of the genital tract — for example, gonorrhea; or by afferent impulses arising from pathologic states in more remote parts of the body — for example, the nasal fossae (priapism due to spinal cord and blood conditions do not concern us here). The sacral efferent sympathetic fibers (preganglionic) make their exit from the spinal cord with the ventral roots of the second, third and fourth sacral nerves. These sympathetic fibers become massed in the pelvis and form the nervus erigens (pelvic nerve), which terminates about cell bodies of sympathetic ganglia located in the h}'pogastric or pelvic plexuses. F"rom the cell bodies of these ganglia go forth fibers (post- ganglionic) for the supply of the peh'ic viscera. Some of these fibers are \'asodilator in function to the vessels of the pelvic organs and the external XASO-SKXUAL RELATIONS 299 genitalia. Stimulation of the pudendal nerve or of the nervus erigens results in a turgescence or erection of the erectile tissues of the penis, clitoris, etc.; seemingly by inhibiting the vasoconstrictor iibers which arise from the second to the fifth lumbar segments of the spinal cord and pass as preganglionic fibers to the inferior mesenteric ganglion. P>om the latter issue, among others, i)ostganglionic vasoconstrictor iibers which course b}- wa}- of the h>-pogastric (sympathetic nerve) and ]>lexus and the pudendal nerve (internal pudic nerve) to the erectile tissues of the penis, clitoris, etc. There is strong evidence that the dominating vasodilator center is located in the medulla with subordinate centers in the spinal cord; for example, the erection center in the lumbar region. The dominating vasodilator center is connected by descending iibers with the cell bodies of preganglionic neurons issuing from the subordinate erection center. As stated before, stimulation of the ner\-i erigentes leads to erection of the penis, and the erectile genital tissues of the female. Moreo\-er, ir- ritation of the glans penis, clitoris, etc., leads to erection even after the lumbar cord is se\"ered from the remaining portion of the cerebrospinal axis. This indicates that the afferent impulses pass over the pudendal nerve, moreover, that the subordinate center can function independently of the dominating center. Eckhard' found that erection of the penis can be produced by stimulation of the spinal cord, of the medulla, and of the pons as far as the peduncles. This ma}' ex])lain the i)henomenon of priapism in spinal cord and brain stem lesions. It has been shown also that the psychical activity of the cerebral cortex has a i)rofound influence on the vasodilator nerves of the sexual apparatus. Indeed, Pussep- has shown that electrical stimulation of a dehnite field of the cerebral cortex leads to penile erection and ejaculation in dogs. It is, therefore, obvious that the subordinate ^•asodilator (erection) center in the lumbar region can be directly stimulated reflexly by irritation of the genital svstem. Moreover, it is eriually clear that the dominant vasocHlator center exercises some sort of control over the subordinate center b)' way of the neuron connections. Since the trigeminal nerve (carrying afferent impulses from the nose, etc.) establishes relationships through inter- calated neurons with somatic and sympathetic elTerent neurons (of various motor cranial nerves and of the upper spinal ner\-es), it is highh' probable that similar relationships are established with the dominant \asodilator center probably located in the medulla. And, as stated above, the domi- ^ Kckhard, Beitrage zur .\nat(imie unrl Pliysiclogic, iX(,^ and iSdy. - Hermann's JahresberichI Her Ph\'si(jliigie, \'ol. XL, 1003. 3O0 THK CO.M.MOX Si;XSORV AXI) THK SYMPATHETIC NKRVES nant and subordinate xasodilator (erection) centers are connected. This would establish a complete neuron arc (or better, circuit) from the nasal ca\'ity to the erectile tissue of the genital apparatus, thereby providing an anatomic mechanism for the causation of priapism incident to nasal disorders. Fleiss in 1S95 ^'^d 1897^ called the attention of rhinologists and gyne- cologists to what he considered an important relationship between certain areas of the nasal mucous membrane and the female genitalia and adnexa. He found when applying a 20 per cent, solution of cocaine to an exceed- ingh" small area of mucous membrane on the tuberculum septi, directly opposite the mid-portion of the middle nasal concha, and to the mucous membrane over the ventral portion of the inferior nasal concha that pains in the back and abdomen incident to dysmenorrhea ceased after ti\'e- to eight-minute applications and did not return until the effect of the drug had disappeared. Moreover, Fleiss claimed that if the anterior portion of the inferior concha on either side of the nose was touched the headache ceased, but had no eft'ect on the abdominal pains. If one side of the nose was treated with a 20 per cent, solution of cocaine, applied to both of the spots, the headache and the pain on the opposite side of the abdomen was re- lieved. To obtain a deiinite cure of the dysmenorrhea it sufficed, according to Fleiss, to destroy the nasal areas in question with the galvano-cautery. Because of their apparent connection with the genitalia and adnexa Fleiss designated these areas of the nasal mucosa the genital spots. Since the initial reports by Fleiss a number of rhinologists and gyne- cologists ha\'e treated dysmenorrhea with cocaine, trichloracetic acid, menthol and the actual cautery by way of the so-called genital spots, with very divergent results. Some confirm the findings of Fleiss, others find the treatment efficacious in a selected type of cases, while a third group of clinicians consider the treatment of dysmenorrhea by way of the nasal mucosa irrational, and when found "effective" to be merely the imagina- tion of the patient and the phj'sician. Anatomically, as stated elsewhere, the nasal mucous membrane is di\-ided into the olfactory and the respiratory portions, the former con- taining the perceptive olfactory elements. The respiratory portion over the inferior nasal concha, a goodly portion of the middle nasal concha and the adjacent portion of the nasal septum is distinctly cavernous in its structure and assumes the role of an erectile tissue. Further study may point to the erectile-tissue portion of the nasal mucous membrane as most 'Wicn. Klin. Rundschau, 1X05. The Relation of the Nose and Female Genitalia, Lcipsig, \'ienna, 1897. XAS()-S1''.XUAL RELATIONS 301 intimately related with the ii;enitalia and adnexa. This area of the nasal mucosa is, ho^ve^'er, much more extensive than the genital spots of Meiss. As stated on page 272, the "genital s]iots" do not present histologic char- acteristics that particularize them from the erectile-tissue portion of the nasal mucous membrane. It would a])pear fr(un \arious experiments and observations that the peh'ic sexual organs are retlexly influenced from di\"ers sources. I'hc uterus, for example, contracts reflexly on stimulating the central end of the sciatic ner\'e (Basch and Hofmann), the central end of the brachial plexus (Schlesinger), the nose (Schiff), the nipple (Scanzoni). Linder in a number of kqxirotomies obser\-ed contraction of the uterus following irritation of the nasal mucosa corresponding essentially to the distribution of the nasal cavernous tissue. Spiegelberg found that stimulation of the lumbar and sacral parts of the spinal cord caused powerful uterine movements. The obser\-ation has also been made that stimulation of the sciatic ner\'e results in reflex stimulation of the A'asoconstrictor fibers of the uterus. Now comes the contention that certain types of dysmenor- rhea, doubtless meaning more than merely a uterine congestion, have a nasal reference. In general, the pelvic field is supplied by vasoconstrictor ner\-es by Ava}' of the h>'iX3gastric ner\-e and plexus (pre- and postganglionic neurons) from the last thoracic and upper lumbar segments of the cord and by vasodilator fibers through the nervi erigentes and their postgan- glionic connections. Stevens in French's Index of Differential Diagnosis classes dysmenor- rheas into three basic types— spasmodic, congestive and membranous — and gives a number of causes fo^ the several types. He holds that spas- modic cases are practical!}- ahva>-s ])rimar}-, that is, they commence with the onset of menstruation; while congestive and membranous tyjies are secondarv, that is, acquired as a result of some definite lesion. There is, howcA-er, no conformit>- in treatises on g>mecolog\- on the subject of d}-s- menorrhea, this applying equally to classification, etiology and treatment. The relation of the nose to d_\-smenorrhea is extremely obseiire and ccrtaitilv nol eslablislieil at the present time despite the tact that many verv suo-gestive clinical obser\ations have been made. In some of the congestive types of dysmenorrhea, if there be such, nasal disease or dis- orders may possibh' be a hictor in reflexh' stimulating the vasodilator centers of the genital apparatus, and at the time of menstruation (indeed, for some time before) lead to a h>-])ercongestion of the extensive vascular netAVork of the pelvic genitalia. It is, likewise, possible to conceive that nasal treatment might reflexly stimulate the vasoconstrictor center, thus 302 THE COMMON SENSORV AND THE SYMPATHETIC NERVES leading to a general lessening of the congestion by a constriction of the blood-vessels. Depletion of the congested areas would lessen the pressure on the nerves, thereby influencing the pain. Moreover, the permanent remo^•al of the pathologic state in the nose, which reflexly resulted in pelvic congestion by inhibiting the peripheral tonic activity of the vaso- constrictor ner^'es, would permit the vasoconstrictor mechanism to assume its usual and normal tonic activity; whereby, owing to the reduced caliber of the blood-vessels, the amount of blood in the vascular channels would be lessened. If the trigeminus nerve, through reflex neurons in the medulla, estab- lishes synapse relations with the vasoconstrictor and the vasodflator centers, thereby bringing about reflex nasal phenomena, etc., one naturally wonders why adefjuate stimulation of the trigeminal nerve should not at times result in reflex pelvic phenomena, since the connections of the vaso- motor centers in the medufla with related secondary centers in the lower portions of the spinal cord are fairly weU established. The connections of the secondary vasoconstrictor centers (lumbar cord) and the vasodilator centers (sacral cord) with the intrapelvic and extrapelvic genitals are discussed elscAvhere. The Transference and Reference of Afferent (Sensory) Impxolses.— The class of so-called reflex pains are, correctly speaking, transferred and referred sensations since there is no reflex action involved in the process. So far as the transference and reference of pain is concerned in which the nose, paranasal sinuses and related parts are at fault, two sets of nerves recjuire attention: (i) the aft'erent nasal distribution of the trigeminal nerve and (2) the afferent nasal sympathetics. I . One or other of the divisions of the trigeminal ner\'e is commonly involved in referred pain. Indeed, such pains may include the entire distribution of the ner^'e. In general, diffusion of pain o^'er the sensory trigeminal system is at first confined to the division suppl}'ing the ofiend- ing or diseased area, and as the pain impulse gains in severity there is an o^•erflow and reference along the other main divisions of the nerve. Dental caries, for example, while at first giving rise to a more or less local pain, may, if a marked case of nerve exposure and irritation exists, lead to such general reference of pain along the various branches of the trigeminal nerve that it is impossible for the patient to locate the source of the trouble. Extraction of a wrong and healthy tooth is a well-known error of commission in such cases. Pain in the ear due to a carious tooth of the mandible or lower jaw is of frec|uent occurrence and for its proper interpretation a knoAvledge of the composition and distribution of the rRAXSFKRRF.I^ AXf) REFKRRKI) IMPULSES 30.^ mandibular ner\-e (n. mandibularis, inferior maxillary nerve) is essential. It is of interest in this connection to note the anatomic communication between the inferior alveolar (dental) nerve and the auriculotemporal nerve. The auriculotemporal ner\'e of the mandibular di^'ision frequentlv refers a pain impulse coming over the lingual ner\'e of the same division to the ear and the temporal fossa. This is particularly true in ulceration and cancer of the tongue. Indeed, in the latter malady such reference of pain ma}- precede the appreciation of local ])ain. Neuralgias of the maxillary nerve (n. maxillaris) are common in connection with caries of the upper teeth, maxillary sinus disease, medial and lateral nasal wall disorders. Some of the worst sujn-aorbital ]:iains are due to disease of the frontal sinus and the ethmoid lab>Tinth and are referred along branches of the ophthalmic nerve (n. ophthalmicus). It should also be recalled that the ])ars intermedia of the facial ner\-e contains a number of somatic sensor}' neurons, some of which are for gen- eral sensation and course by wa}* of the great superficial petrosal nerve, the ner\e of the pter>-goid canal (Vidian ner\'e), the si)henopalatine gang- lion and the small and middle palatine nerves to be distributed to the soft palate and adjacent portions of the pharynx. It is conceivable that these nerves (peripheral processes) with cell bodies in the geniculate ganglion in their wa}' centrally through or around the spheno])alatine ganglion would be irritated in disease of the latter and thereb}' account for the referred pharxngeal pain (sore throat) in ])ure sphenopalati\'e involvement. 2. SA'mpathetic afferent (sensory) libers from the environs of the nose seemingly synapse, as stated elsewhere, either directly by collaterals or indirecth- bv intercalation of an additional neuron with the cell bodies of the somatic sensory neurons located in the ganglia of the dorsal roots of the upper thoracic spinal nerves. Similar relationships of s^'myjathetic and somatic sensory paths are also probably estabhshed within the genic- ulate ganglion. Such synapse relations are well established for the dorsal gangha of typical spinal nerves. ^Moreover, Herrick believes that colloca- tions of sympathetic and somatic sensory paths similar to those in the ganglia of the dorsal roots of the spinal ner\-es exist within the spinal cord and brain. By such anatomic arrangement or mechanism, sym- pathetic sensory impulses from the nasal mucous membrane would be transferred from the sympathetic sensory system to the related somatic sensory system for sensorial (cortical) stimulation; and since the functions of the sympathetic nerves in general do not come into consciousness the 304 THE COMMON' SKXSORV AND THE SYMPATHETIC NERVES transferred SA'mpathetic sensory impulses may be referred by the brain as pain to the peripheral field of distribution of the associated somatic nerves and thus brought into consciousness. It is well known that pathologic conditions of certain organs or areas may be accompanied not by pain at the site of the disease, but by cutaneous pain and tenderness in more remote parts of the body (Fig. 194.4). Indeed, such ^"eference of pain occurs in some nasal disorders. A striking example apparentl}' is found in an in\'olvement of the spheno- palatine or nasal ganglion of jMeckel. Sluder^ has reported that in these cases there is pain in the root of the nose and in and about the eye, the upper jaw and teeth, sometimes the lower jaw and teeth, the mastoid re- gion, the ear, and in severe cases pain extending to the neck, shoulder, breast, arm, forearm, hand and fingers; also a sense of sore throat on the same side. In this connection one must recall the distribution of the cranial nerves coming from the medulla and the pons and the composition and distribution of the brachial and cervical plexuses in order that trans- ferred and referred manifestations may be properlv interpreted. It is obviously ditficult to determine in disease of the sphenopalatine ganglion whether the aft'erent impulses to the central nervous system are by way of afferent sympathetic or afferent somatic neurons. Since the peripheral processes of both the sympathetic and somatic sensory neurons utilize the ganglion in cjuestion as a pathway, it would seem plausible that both systems of ner^-es must be in\'olved and convey impulses from the diseased ganglion. In all probability, Jwwevcr, mosl of the pains mentioned above assoeiated ivitli disease of the sphenopalatine gang- lion are in reality an expression of irritation of peripheral fibers of the tri- geminal nerve which pass via the ganglion in their course centrallv. 0\-erflow of the afferent sensations would cause them to be referred along certain other peripheral trigeminal fibers and probabh' along other ner\'es with which the latter establish peripheral communications. There are, hoAvever, according to Sluder, pains referred to regions far removed from the field of distribution of the trigeminal nerve and remote from the nasal foss;e and paranasal sinuses in some of the severer cases of sphenopalatine ganglion involvement. This would appear to indicate that both sympathetic and somatic afferents were inA'oh-ed in the mechan- ism of some of the referred pains in question. 'Oreenhcld Sluder: Further Clinical ObserN-ations on the Sphenopalatine GanRlion (Motor Sensory, Gustatory), New York Med. Jour., igio. The Syndrome of the Sphenopalatine Ganglion Neurosis, Tr. Am. Laryngol. Assn., iqio. The Sympathetic Syndrome of Sphenopalatine (Nasal) Ganglion Neurosis, Together ^vith the Consideration of the Neuralgic Syndrome and Their Treatment, Tr. Am. Lar^-ngol. .\ssn loi ^ TRAXSl'l'.RRKI) AXl) R |;|-|:RRK1 ) LMTULSRS 305 It IS well known that s_\mpathetic ailercnt neurons are among the constituents of the pars intermedia of the facial ner\e. The ])eripheral processes of some of these follow the great superiicial i)etrosal ner\e, the nerve of the pterygoid canal (Mdian ner\-c) to the sphenoi)alatine ganglion. They pass either around or through the latter to be distributed with the ganglionic branches. ]\Ioreo\er, somatic alTerents are likewise found in the pars mtermedia, some of which follow the same course mentioned for the s>-mpathetic afferents. In both instances the cell bodies of the neurons are located in the geniculate ganglion where s^aiapse relations by collaterals are presumabh' established between the sympathetic and somatic elements. The transferred im])ulse nia>- then be referred to the .'- P" Fig. 194.4. — A schematic rcjire.'Jent.'iliMn nf the synapse relations in a spinal ganj,'Hiin whereby afferent \'isceral sensations are transferreil from tile SA-mpat}:etic s\-steni to tlie srjmatic sensor\- system. The afferent visceral sensatiims do not eume into e- .nseiousness as such but pass to the brain o\-er afferent somatic piaths; the brain not infre( leiinlK- intLTjircting them as pain and referring them to the pierifiheral field 'if distrilnition of tlie related somatic ncr\-es. ^..d^'in^f rise to referred pain. I = Cell of DriKiel; 2 = Afferent sumalic neui-ons; 3 = .Vffcrcnt s\-miiathctic neuron with cell body located -^^dthin the .spinal ^..'ancdiMn; 4 = Aff<.'rcTU symp)athL4 ii.' neuron \\\{h cell body locatcii in a sympathetic ganKdion;g. = sjjinal ganKli"n ; /)», = peripheral nerve; re, = ramus c immunicans. peripheral endings of the somatic sensory neurons b}- the brain and inter- preted as pain. This may ex])lain certain pharyngeal pains in inA'oh'e- ment of the sphenopalatine ganglion (see also page 315). It is also ])robable, from the clinical e^'idence at hand, that sympa- thetic afferent neurons with cell bodies located in the ganglia on the dorsal roots of the upper four thoracic spinal nerves send some of their peripheral processes (in a sense dendrites) to the nasal and adjacent lields Ijy Avay of the cer\'ical sympathetic cord, the great dec]) petrosal nerve, the ner\e of the pterygoid canal (Vichan ner\x'), tlie spheno])alatine ganglion and its branches. In these .spinal ganglia sxnapse relations ,^o6 THE COMMON SEXSORV AND THE SYMPATHETIC NERVES are presumably established between the sympathetic afferent neurons and the somatic sensory neurons, and doubtless here some transfer of sym- pathetic impulses is made to the somatic sensory neurons as well as some impulses carried into the cord over the axonic processes of the sympa- thetic cell bodies of the dorsal spinal ganglia for reflex arc connections with both sympathetic and somatic efferents (Fig. 194^). Since the first and second thoracic nerves participate in the formation of the brachial plexus and the latter distributed to the shoulder, upper extremitv, etc.; moreoA'er, since sympathetic afferent impulses do not come into consciousness, save possibly in an extremely vague fashion, the brain naturally refers or interprets the sympathetic sensory impulses as pain and coming from the somatic sensory nerves of the fingers, hand, arm, shoulder, etc., to Avhich the initial impulses from the diseased spheno- palatine ganghon have been transferred.^ Herrick's observation,- that collocations similar to those occurring in the spinal ganglia between the sympathetic and somatic sensor}' paths are undoubted]}' established within the spinal cord and brain, probably oft'ers the solution for referred pains in those regions where the necessary peripheral anatomic mechanisms for the transfer of sympathetic afferent impulses to the somatic afferent pathways are wanting or, if existent, are unknown. D. The Peripheral Nerves and the Sphenopalatine Ganglion The Maxillary Division of the Trigeminal Nerve in its Nasal Dis- tribution. — The maxillary nerve (n. maxillaris) leaves the cranial cavity through the foramen rotundum, traverses the pterygopalatine (spheno- maxillary) fossa and enters the orbital cavity by way of the inferior orbital fsphenomaxillary) fissure. Once in the orbit the maxillary nerve is known as the infraorbital nerve and courses ventralward in the floor oi the orbital cavity, traversing the infraorbital sulcus and the infra- orbital canal, finally emerging on the face through the infraorbital foramen. In its course through the infraorbital sulcus and canal, the infraorbital nerve comes into intimate relationship with the roof or orbital wall of the maxillary sinus (Fig. 198). Indeed, there may be dehiscences in the cau- dal surface of the sulcus and the canal so that the nerve comes into actual ' Postscript : Since tlie completion of the manuscript of tire foregoing discussions, Dr. Green- field Sluder's book on " Headaches and Eye Disorders of Nasal Origin," St. Louis, 191S, has appeared. The reader is referred to this splendid work for many anatomico-clinical observations on the spheno- palatine ganglion and the paranasal sinuses, - Loc. cit. MAXILLARY XKR\'E L\ LPS NASAL SUIM'LV 307 contact with the mucous membrane of the sinus for a greater or less distance. The sphenopalatine nerves (nn. spheno])ahitini) or the so-called sen- sory roots to the si)heno])alatine Kanj^dion of .Meckel leave the maxillary nerve in the iUer>-go])alatine fossa as two or three short, stout trunks. r(m- trary to what one is led to believe from a gross dissection, an exceedingly small portion of the sphenopalatine ner^■es enter the sphenopalatine gang- lion, the larger portion jxissing on the lateral or \-entral surface of the gang- Bulbils o/factorius Met/imoida/h ant. I Nn.nasalei ant.kU. posteriores mfericres lot. ^ J- 1 J ■ ' ^^^- ^^^^'^5 post^z-iores si//?eri'ores lot. Gu/ylu>fi sp/>e7to/paJ,a/inum / ; i JV. palatums anterior jY/i. pa/Mtijii ; ^ palalii/as medius M^paJaUnijyS fiost/frior Fig. 195. — The nerves of the lateral wall of the nasal fussa. The ner\'es of both the olfaetory and respiratory portions of the fossa are shown. Note the Vidian iier\'e in the floor of the sphenoidal sinus and the osseous dehiscence at y with exposure of the maxillary nerve to the sinus mucosa. An- other osseous dehiscence at .v exposes the internal carotid artery, which forms a serpentine-like mound on the lateral wall of the spthenoidal sinus. The inset shows the dissection of the cavernous dural sinus with contained structures. lion to continue as the greater bulk of the fibers of the so-called branches of the ganglion. The few sensory or sphenopalatine nerve fibers that termi- nate in the ganglion supply the capsule of the latter and con\-ey im|)ulses of general sensibility from the ganglion in question to the central ner\-ous system (Fig. 201, neuron No. 3). The bulk of the fibers that do enter and 3o8 THE COMJION SENSORY AND THE SYMPATHETIC NERVES terminate in the sphenopalatine ganghon are the axons of the pre- ganghonic (s}-mpathetic) neurons (motor and secretory) contributed by various ner-\'es and Avhich synapse with (arborize with) postgangHonic (sympathetic) neurons within the ganglion, and which latter are destined for the suppl}' of unstriped or iuA'oluntary muscle and glands located in the nose and related parts. The axons of the latter neurons, together with the sphenopalatine nerve fibers which pass on the surface of the spheno- Nn.v/f sales ant.7/?&dia],KS Szni/s spheno/^^Mlis N.e.thjn.oidctJib cintmorls .. :' Chias^mu opt7,cu,»e, \ \ Jhi. olfactorii ; ; Hz/pap/z/ysis cejebii. Fi jVeruus na&opalatiTiv^JScarpiuiJ 19''--- The nerves of the medial ur septal wall of the nasal fossa. palatine ganglion, conjointly form the conventional branches of the sphe- nopalatine ganglion; the branches containing a few fibers of ceU bodies located in jMeckel's ganglion and a far greater number with cell bodies located in the (iasserian ganglion. A \-ariable number of nerve fibers whose cell bodies are located in the geniculate ganglion likewise course b>- Ava}- of the sphenopalatine ganglion and certain of its distributing branches. Strictly speaking, therefore, the "branches" of :Meckers MAXILLARY \1';R\-K IN ITS NASAL SU1'P1>V ^09 ganglion are direct continuations of the sphenopalatine branches of the maxillary nerve, augmented by a variable number of peripheral processes (axons) of postganglionic (sympathetic) neurons with cell bodies located within the sphenopalatine ganglion and of peri])heral i)rocesses of afferent sympathetic and somatic neurons with cell bodies located in the geniculate ganglion, etc. Cc.efJimoidales ant ^ Cc. etktrwi dales post . ^ N^. opticus , A.cai-otis 7,nter>iii \ N, ocvlo m.ptorms Maidzu:ens^ N.tri^eminus '~^ Sinus frontalis Proc ii?2cinuiv-s ; ,.- C.iitfiindibula,7-/S ' ^])v£ 7tasofMcrl?naIis Jvfiznfii.b. em?tw7xlal(t- : linwK mstihuli % * V *-?» N.canalis ptcri/f^oLdei ( i/idii) \ Hecessws p//Mr/ynqeij:i f HosefLi/iiudler-i) Fi< ■ Siri)j^ sphe!ujuZaJ,7, s Ost.pTiavyn.ti'-bae au^itivae n..lc the -A regional dissection of a midsagittal section of an ailiilt head. I^articul nerve relations of the sphenoidal sinus. The following nerves, usualh' mentioned as branches of the si^heno- palatine ganglion, supph' both the medial and lateral walls of the nasal fossa from a line erected from the incisi\e foramen to the dorsal third of the cribriform plate dorsalward to the choame: The orbital rami (ramiorbitales) are two or three threaddike ascending branches which ])ass into the orbit through the inferior orbital fissure (sphenomaxillary ffssure) into the orbital cavity and after tra\-ersing the posterior ethmoidal foramen, or a special foramen, are distributed to the posterior ethmoidal cells and the sphen(.>idal sinus. 310 THE COMMOX SENSORY AND THE SYMPATHETIC NERVES The palatine nerves (nei-\'i palatini) are descending branches and are usually described under three heads : (a) The anterior palatine nerve (nervus palatinus anterior, the large posterior palatine nerve) passes through the large posterior palatine foramen to reach the inferior surface of the hard palate, then courses forward in a groove' in the hard palate and arborizes with the nasopalatine nerve (which see). Moreover, the anterior palatine nerve, in its course through the large posterior palatine foramen, gives off a ^'ariable number of posterior inferior nasal rami (rr. nasales posteriores inferiores). The latter pass through the small apertures in the perpendicular plate of the palate bone and supply the mucoperiosteum of the dorsal half of the inferior nasal concha and the adjacent portions of the middle and inferior nasal meatuses, (b) The middle palatine nerves {ner\-i palatini media^, the accessory posterior palatine nerves) pass through the small palatine foramen and supply the mucosa of the soft palate and the faucial tonsiUar region, (c) 77/f />05/n'z"or /)a/a//«f ;;fnr (nervus palatinus posterior, the small posterior palatine nerve) descends in a small posterior palatine foramen to supply the inferior surface of the soft palate. Probably the facial nerve sends aberrant libers over the posterior palatine nerve for the motor supply of the levator palati and the azygos uvulae muscles (P'ig. 95). The posterior superior nasal rami (rami nasales posteriores superiores) are internal branches from the sphenopalatine ganglion. They pass from the pterygopalatine (sphenomaxillary) fossa through the spheno- palatine foramen into the nasal fossa. Once in the nasal fossa the fila- ments comi)osing the ner\-es assemble themselves into two groups: (a) rami laterales, (b) rami mediales. The lateral rami (the posterior superior nasal nerve) supply the mucous membrane of all the structures entering into the dorsocephalic portion of the lateral wall of the nasal fossa. The medial rami cross the dorsal portion of the roof of the nasal fossa to reach the mucosa of the septal wall which they supply. Once in the septal mucosa the main trunk of the medial rami (nervus nasopalatinus, Scarpae) passes ^-entrocaudalward in a groove in the vomer and septal cartilage to reach the Y-shaped incisive or anterior palatine foramen through which Avith its fellow of the opposite side it passes and forms a fine plexus. On the caudal surface the nasopalatine ner\'es arborize with the anterior palatine nerves (vide supra). The nasopalatine nerve and the related medial rami supph' branches to the dorsal portion of the nasal roof, the nasal septum, and the portion of the hard palate derived from the pal- atine processes of the maxillae (Figs. 195 and 196). The posterior superior alveolar rami (posterior superior dental nerves), usually two, arise from the maxillary nerve before the latter be- -MAXILLARY XERVE IX ITS XASAL SUPPLY 311 comes the infraorbital, pass caudally and \'entralh- upon the infratemporal surface of the maxilla, sooner or later entering the ah'eolar canals to pass to the molar teeth and to participate in the formation of the superior dental plexus. In some cases the nerYes i)ass under cover of the mucosa of the maxiUary sinus (Fig. iq8). The middle superior alveolar ramus (middle superior dental nerve) arises Irom the infraorbital ner\-e in the proximal part of the infraorbital canal. It courses caudalward in a canal in the lateral wall of the maxil- ^n. cdi'colarei supcizofes pvsterwrcs N. IJifraorbitalis '^ N. alveolaris supcrwr metiiii^s , Min/raorbUaJis I ]^fi . alvcolan'i ^upcriores Uiz/erwrcs V; // '/' /' ¥ VJiiii|iiiii'„/V '", Fig. 198. — A dissection showing the maxillary and infraoilnUil nerves and branches as related to the maxillar}' sinus. lary sinus and after entering into the formation of the superior dental plexus supphes the premolar teeth . It ma_\' arise from the anterior superior alveolar nerve (xide infra) (Fig. 198J. The anterior superior alveolar ramus (anterior superior dental nerve) arises from the infraorbital nerve immediately proximal to the infra- orbital foramen. The nerve usually descends in a canal in the ventral or facial surface of the maxillary sinus. It aids in the formation of the su- 312 THE COMiMOX SENSORY AND THE SYMPATHETIC NERYES perior dental plexus and supplies the canine and incisor teeth. Occasion- ally the anterior superior ah'eolar arises from the infraorbital nerve farther dorsad than usual, passes through the caudal wall of the infraorbital canal and courses diagonalh' from the roof to the ventral wall of the maxillar}' sinus under cover of the mucous membrane. Indeed, at times the mucosa is drawn away from the bone so that the ner\'e is suspended by mucous membrane and in a sense is in the maxillary sinus (Figs. 19S and 199). The anterior superior alveolar nerve gives off a nasal branch which enters the nasal fossa through a small canal in the lateral wall of the in- ferior nasal meatus to supply the mucojieriosteum of the ventral portion Fig. 199. — A dissection showing the anterior superior alveolar nerve (N) issuing from the infra- orbital nerve some distance behind the infraorbital foramen and coursing under cover of the mucous membrane of the maxillary sinus (see text). JV = N. alveolar su]ierioris anterioris; Nni = Nn. infraorbitales; i?^ = Recessus prelacrimalis (sinus ma.xillaris). of the under surface of the inferior concha, also the corresponding portion of the inferior meatus and the fossal floor. The maxillary floor receives filaments from the superior alveolar (dental) nerves in their course and additional filaments from the superior dental ])lexus. The infraorbital nerve after its emergence from the infraorbital canal breaks up into a large tuft-like mass of terminal branches; the external nasal rami (rami nasales externi), some of Avhich supply the lateral sur- face of the external nose, ]:)articularh' the ala nasi; and the internal nasal rami (rami nasales interni), some of which supply the septum mobflenasi. ui'H riiAL-Mu; xi;r\ K rx rrs xasal suim-ln' 313 The Ophthalmic Division of the Trigeminal Nerve in its Nasal Distribution. -The nasociliary (nasal) iiltnc, one nf the three main branches of the ophthah-nic nerxe, originalh- erroneously sujjposed by ]\lagendie to be the ner\-e of smell, but subsequentl}' accurateh' interpreted by Ksehricht, enters the orbit through the superior orbital (sphenoidal) hssure, between the lieads of llie lateral rectus muscle and between the two di\isions ol the oculomotor ner\-e. The ner\e then courses obliquely across the orbital ca\it_\- to reach tlie anterior ethmoidal foramen located on the \-entromedial surface of the orbit. The main portion of the naso- ciHary ner\"e trax'erses the foramen as the aiilrrior ct/n)ioitlal iicivc inervus ethmoidalis anterior) and i)asses into the cranial ca\'ity, then courses forward along the cranial surface of the cribriform plate of the ethmoid bone to the nasal fissure at the side of the crista galli through wliich it passes into the nasal fossa. Cel/ in crista, galli , Sij7M^ frordfdi s Bul,hus olFadoriurS ' ' Jfccess expansion of S.fronUdrs Fig. 200. — A tranM--ction through the frontal sinus and the crista galli. Xute the cell in the latter and the eneroachment of the frontal sinuses on the confines of the olfactory bulbs. Before the nasociliary nerve reaches the anterior ethmoidal foramen, it frequenth- gives off a branch, the posterior ctlimoidal nerve, which traverses the posterior ethmoidal foramen on the dorsomedial aspect of the orbital cavitA' to supph' the mucous membrane of the posterior eth- moidal cells and the sphenoidal sinus. Moreover, the anterior ethmoidal nerve gives off filaments as it traverses the anterior ethmoidal foramen for the supph- of the anterior ethmoidal cells and the frontal sinus. Once in the nasal fossa the anterior ethmoidal ner\e terminates as such by dividing into the medial and lateral nasal branches — the rami iiasales meeliales and the rami iiasales laterales, res])ecti\-ely. The medial rami (septal branches) sup])ly the mucous membrane of the ventral portion of the nasal septum nearly as far as the naris. The la I era! rami (lateral nasal nerve) are represented 1)>- two or three filaments and are distributed to the mucous membrane of the ventral portion of the lateral wall of the 314 THE COMMON SENSORY AND THE SYMPATHETIC NERVES nasal fossa, including the ^•entral portions of the middle and inferior nasal conchse. Moreover, a branch of the lateral rami or lateral nasal nerve continues as the ramus uasalis cxtcnius (external nasal branch) by groo\-- ing the deep surface of the nasal bone and issuing from between the nasal bone and the lateral cartilage of the nose. It then courses caudahvard under cover of the compressor naris muscle to the tip of the nose and supplies the integument over the lower half and tip of the external nose. As the nasociliary nerve nears the anterior ethmoidal foramen, it gives off the infratrochlear nerve (n. infratrochlearis) which passes forward along the medial wall of the orbital cavity below the superior oblique muscle to the m^edial commissure of the palpebral fissure where it ends in filaments which supply the conjunctiva, the lacrimal sac and caruncle, the integu- ment of the upper eyelid, and the root and lateral aspect of the nose as far as the lateral nasal cartilage (Figs. 195 and 196). The Sphenopalatine Ganglion. — The s])henopalatine ganglion (g. sphenopalatinum), also known as jNIeckel's, the nasal or the sphenomaxil- lary ganghon, is a small triangular, reddish-gray (in the fresh state) bod}' and is a component of the group of sympathetic ganglia found in the head region of the bod}-. It is located in the sphenopalatine fossa and ver"\' close to the sphenopalatine foramen and is suspended from the maxillar\' division of the trigeminal ner\-e. The sphenopalatine ganglion is, there- fore, more or less intimately related topographical!)- with the lateral wall of the nasal fossa, the sphenoidal sinus and certain of the posterior eth- moidal cells. In its histologic make-up it consists of an interlacement of nerve fibers and stellate nerve cell bodies. The nerve fibers, forming the ganglionic branches (see pages 306 to 30), participate in supplying the nasal fossa and the related parts. In conformit}- with the other s}-mpathetic ganglia of the head the sphenopalatine or nasal ganglion has three so-called roots Avhich convey nerve fibers to and from the ganglion; e.g., motor (visceral motor), sensory and sympathetic. Strictly speaking, it is a mere convention to designate the roots as motor, sensory and sympathetic respecti\'ely since they usually are of a mixed character as regards the physiology of their component ner\'e fibers. HowcA-er, one or other type of libers usually predominates m the several roots, a fact that probabl}- justifies the naming of the roots as has been done. The motor root of the sphenopalatine ganglion in its major part con- sists of visceral (s>'mpathetic) motor fibers (preganglionic) of the pars in- termedia of the facial ncr\& (n. intermedins, n. glossopalatinus). These fibers arise in the medulla oblongata from a group of cehs in the reticular SPHEXOrALATINE GANCLION AND ITS CONNKCTKJXS 315 formation dorsal and medial to the facial nucleus, pass through the genicu- late ganglion and become component fibers of the great superficial petrosal nerve (n. petrosus superficialis major) and the nerve of the pterygoid canal (n. canalis pterygoidei Vidii, Vidian nerve) and reach their termi- nation in the sphenopalatine ganglion b)' arborizing or s}'napsing there ^^•ith the cell bodies of postganglionic neurons (see neurons numbered 6 in the diagram, Fig. 201). A few of the visceral motor fibers (pregan- glionic) arising within the medulla oblongata terminate Avithin the genicu- late ganglion b}' synapsing Avith the cell bodies of postganglionic neurons. Pj(-^ ,f)j — Schema showing the connections of the sphenopalatine (Meclfel's, nasal) ganghon. 4 '= Sensory root; B = Motor root; C = Sympathetic root. See text, pages 314 to 317, for a consideration of the component fibers of the so-called roots of the ganglion. The reference numbers are explained in the text. The peripheral processes of some of the latter neurons follow the great superficial petrosal nerve and the nerve of the pterj-goid canal of Vidian, pass through the sphenopalatine ganglion without interruption to be dis- tributed via the ganglionic branches (see neuron numbered 7 in the diagram, Fig. 201). It is also estabbshed that a number of somatic sensory neurons with cell bodies located in the geniculate ganglion are associated with or rather 3l6 THE CUM.MOX SEXSORV AXD THE SYMPATHETIC NERVES are a part of the so-called motor root of the sphenopalatine ganglion. The peripheral processes of these somatic sensory neurons follow the great superficial petrosal and the Vidian nerves, pass through the spheno- palatine ganglion uninterrupted and descend in the small palatine nerve to the soft palate and adjacent parts of the pharynx where some are seemingly concerned with the gustator}' function and others with general sensation. The central processes of these somatic sensory neurons termi- nate about cells at the upper pole of the nucleus of the alar cinerea in the medulla (see neuron numbered 13 in the diagram, Fig. 201). Moreover, there is supporting evidence that there are sympathetic afferent neurons associated with the motor root of the sphenopalatine ganglion. The cell bodies of these neurons are located in the geniculate ganglion, the peripheral processes of which follow the same course as the somatic sensory neurons, above referred to, save that the sympathetic afferents enjoy a wider distribution, including among other parts the nasal cavity. The central connections of the sympathetic afferents are not definitely es- tablished (see neurons numbered 9 in the diagram, Fig. 201). The great superficial petrosal nerve is usually spoken of as the motor root of the sphenopalatine ganglion. It is, however, obvious from the foregoing that the nerve is not merely motor in its composition, but that in addition to the motor and most numerous fibers, it contains sensor)- (somatic and sympathetic) fibers. The great superficial petrosal arises from the geniculate ganglion of the pars intermedia of the facial nerve in the facial canal (canalis facialis), passes through the hiatus of the facial canal (hiatus canalis facialis, hiatus Fallopii) and a groove in the petrous portion of the temporal bone in the middle cerebral fossa. It now courses under the semilunar (Gasserian) ganglion to the position of the middle lacerated foramen (foramen lacerum) where it is joined by the great deep petrosal in. petrosus profundus major) or the so-called svmpathetic root of the sphenopalatine ganglion. The great superficial and the great deep petrosal nerves merge o\'er the cepahlic surface of the cartilage of the middle lacerated foramen in the formation of the nerve of tlie pterygoid canal of Vidian. The latter with accompanying blood-vessels traverses the pterygoid canal in the root of the pterygoid process of the sphenoid bone, enters the sphenopalatine (sphenomaxillary) fossa, there to connect with the sphenopalatine ganglion located on the lateral side of the spheno- palatine foramen (Fig. 145). The sympathetic root of the sphenopalatine ganglion is the great deep petrosal nerve (n. petrosus profundus major) which is, in a sense, a direct extension of the carotid plexus. Indeed, the great deep petrosal nerve SPHKXOrALATIXE OAXCLIOX AN'I) ITS CONXECTIONS 317 may be considered the connecting or association fasciculus betAveen the superior cervical sympathetic ganglion and the si)henopalatine sympathetic ganglion. Most of its fibers are the peripheral processes (axons) of postganglionic neurons arising from cell bodies located in the superior cervical sympathetic ganghon. These postganglionic libers pass through the sphenopalatine ganglion uninterrupted for distribution by way of the ganglionic branches (see neurons numbered 2 in the diagram, Fig. 201). AIoreo\-er, a few of the fibers contained in the great deep petrosal nerve are seemingly the peri])heral processes of preganglionic neurons arising from cell bodies located in the A-entral horns of the upper thoracic spinal cord segments. These j^reganglionic fibers end in arborizations or synapses around the stellate cell bodies of postganglionic neurons located in the sphenopalatine ganglion (see neurons numbered i in the diagram, Fig. 201 ). In addition to the motor elements the great deep petrosal nerve apparentl}' contains sympathetic aft'erent fibers, the cell bodies of which are located in the ganglia of the dorsal roots of the upper thoracic spinal ner\'es. Further stud}' is necessary to definitely establish these afferent sym- pathetic elements. Certain laboratory experiences and clinical evidence tend to support the existence of sympathetic afferent elements in the great deep petrosal ner\-e (see neurons numbered 'goid process (base and laminre) of the sphenoid and into the orbital process of the ])alate bone and occasionally into the ethmoid bone by encroachment on posterior ethmoidal cells or by replac- ing them that the very intimate ganglionic relationships are established. The intimacy of the relationship is, of course, dependent upon the direc- tion and degree of the pneumatization (Figs. 145 and 139). At times a pos- terior ethmoidal cell (or cehs) replaces the extension of the sphenoidal sinus into the orbital process of the palate bone. Indeed, ethmoidal extensions may take place into the sphenoid bone, e\'en pneumatizing into the root of the pterygoid process. In such cases the sphenopalatine ganglion bears a much more intimate relationship to the posterior ethmoidal cell or cells than it does to the sphenoidal sinus. Witness, for example, the dissection represented in Fig. 135. Here .^20 THE COMMON SENSORY AND THE SYJIPATHETIC NERVES the sphenoidal sinus on the right side of the body shows extensive pneu- matization extending to the left beyond the mid-sagittal plane at the expense of its fellow. The right sinus has pneumatized into the basilar process of the occipital bone, the pterygoid process of the sphenoid bone, the orbital process of the palate bone, and has actually extended forward into the dorsal extremity of the ethmoid bone. The sphenoidal extension into the orbital process of the palate bone (the palatine recess of the sphenoidal sinus) is separated from the dorsocephalic extension of the maxillary sinus by a mere film of bone. A large posterior ethmoidal cell has likewise pneumatized into the orbital process of the palate bone and is throughout separated from the sphenoidal sinus by an extremely thin lamella of bone. It is ob^•ious in such specimens that involvement of the sphenoidal sinus or of the posterior ethmoidal cell may readily in- fluence the maxillarv sinus and \'ice versa. ^Ioreo\-er, these several sinuses, due to the extreme pneumatization, establish the most intimate relationship with the sphenopalatine foramen and the sphenopalatine ganglion. Sometimes posterior ethmoidal cells are superimposed, one over the other; the more caudally placed of which is the more intimately related to the sphenopalatine ganglion. Again, a posterior ethmoidal cell may extend its pneumatization into the bod}' of the sphenoid bone and replace the ventrosuperior portion of the sphenoidal sinus. This does, howe\-er, not preclude the extension of the sphenoidal sinus into the root of the pterygoid process and its encroachment upon the pterygopalatine fossa with its contained sphenopalatine ganghon (Tig. 155). Anatomical Relations of the Nerve of the Pterygoid Canal.— In a study dating from 1907^ the author has had opportunity to observe the relations of the nerve of the pterygoid canal (Vidian nerve) in an extremelv large number of cadavers. These obser^'ations were made in regular dissections and in sections through the various planes and at different ages. In many of the specimens studied the floor of the sphenoidal sinus is separated from the pterygoid (Vidian canal) by a fairly thick layer of compact bone. However, there are a large percentage of specimens in which the sphenoidal sinus extends its pneumatization caudally and ventrally into the root of the pterygoid process (Fig. 139). Indeed, the extension may pass beA'ond this, either mediallv or laterally or both, into the plates of the pterygoid process. In such instances the pterygoid canal with its contained Vidian ner\-e and \-essels is at best merel}- sepa- rated from the mucous membrane of the sphenoidal sinus by an extremely 1 Tlic first reference by the author concerning these observations was macJe at an Anatomical Seminar at Cornell University in rgog. TOPOGRAniV OF VIDIAN XKR\'E 321 delicate la>-er of bone. Indeed, in tl/e majority of such cases the canal is thrown into marked relief in the jloor of the sphenoidal sinus so that it forms a distuict -ccatersJied dividing a lateral from a medial pterygoid diverticulum or recess oj the splienoidal sinus. Again, it is not an unusual condition to tind pterA'goid canals in \vhich the thin la}-er of bone is actually want- ing (dehiscences), thereby exposing the contained Vidian nerve and accompanying blood-^•essels to the influences of the outside atmosj)here or of an infected sphenoidal sinus. The mucous membrane of the sphenoidal sinus alone is interposed between the sinus cavity and the Vidian nerve, etc. Witness, for example. Figs. 133, 139, 195 and 197 in which the ner^•e of the pterA'goid canal courses across the cavity of the sphenoidal sinus at a considerable distance above the sinus floor proper, thereby throwing the mucous membrane into marked relief.^ ' See also Greenfield Sluder, .\rchi\'. f. Laryngol. u. Rhin., Bd. 27, Heft. 3, 1Q13; Annals Otol., Rhin. and Laryngol., 1Q13, 1014, and Ladislaus Onodi, Jour. Laryng., Rhin. and Otol., 1014, for in- structi\"e and valuable anatomico-clinical considerations of the Vidian and other nerves. 21 XI-THE OLFACTORY APPARATUS PROPER CHAPTER XI THE OLFACTORY APPARATUS PROPER The olfactory apparatus proper may, for convenience of description, be dix'idecl into a ecu I nil origan and a peripheral organ, the former extra- nasal in position and the latter intranasal. The ])erii)heral organ especially concerns us in this A\'ork and some phases of its anatoni}- \\ere pre\-ioush' considered in connection Avith the nasal mucous membrane. The central organ Avill be but briefly alluded to, and it will suflice in subsequent para- graphs to point out the general features of the olfactory brain and to refer to the more im])ortant pathways inA'ohx-d in olfactor\- reflexes and those which serve in carrying afferent olfactor}' impulses to the cerebral cortex and efferent voluntary impulses of cortical origin in which the olfactory element predominates. A. The Peripheral Organ The peripheral organ of smell in adult man is the specific sensors- epithelium within the nasal foss;e — the extent of which was discussed previouslv under the caption "nasal mucous membrane." The perceptive elements (the olfactory recei)tors, the olfactory cells) of the nasal mucosa are bipolar, with short peripheral and long central processes — the latter the olfactorA- nerves. The peripheral olfactor}- tract extends from the olfactorA- portion of the nasal mucous membrane to the intracranial ol- factory bulb, and its elements are neurons of the first order. The impulse is conducted bv the peripheral ])rocesses (dendrites) to the bipolar cell bodies, thence by the central processes (axons) to the olfactory bulb. In some of the lower \-ertebrates, and in mammals with a highly de- veloped sense of smell, three ner\-es are apparenth- concerned with the peripheral olfactory organ: (i) the olfactory nerve proper, (2) the termi- nal nerve, and ("3) the vomeronasal ner\-e. In man the latter is absent owing to the rudimentar}- state of the A'omeronasal organ of Jacobson. Moreover, the terminal ma>- not be a special sense nerve, but i)rove to consist of postganglionic neurons, with cell bodies located in the terminal ganglion for the supply of unstriped muscle and glands (motor and secre- toryj, thus conforming to the postganglionic fibers distributed to the nasal 32s 326 THE OLFACTORY APPARATUS PROPER cavity, e.g., the fibers from the sphenopalatine ganghon (Meckel's), etc. (see page 306). The Olfactory Nerve (Nervus olfactorius).— In man approximately twenty non-medullated olfactory ner\'e filaments (the axons or central processes of the bipolar olfactory cells) issue from the olfactory mucosa near the lamina cribrosa of the ethmoid bone. These filaments (the ol- factory nerves, collectively the olfactory nerve) pass at once through the foramina of the cribriform lamina in two rows, medial and lateral. After entering the anterior cerebral fossa the olfactory filaments pierce the cerebral meninges and enter the olfactoiy bulb, there to synapse with the dendrites of the mitral cells in formations known as the olfactory glomeruli. The latter contain the first synapse in the olfactory pathway (Fig. 202). Since the days of Scarpa anatomists considered the olfactory nerves as forming a plexus in their passage from the olfactory ceUs to the olfac- tory bulb. Figures from the writings of Scarpa and Leveille, the latter doubtless influenced by the former, were freciuently copied into text-books. Even to-day new books appear with adaptations from the illustrations of the above authors. However, the researches of Miss Read^ show that, instead of a plexiform arrangement, the olfactory nerves "extend in non- anastomosing bundles to the olfactory bulb ; all appearance of anastomo- sis being due (a) to a crossing of the bundle of nerves or (b) to a net-like arrangement of the connective tissue or blood-vessels." The Terminal Nerve (Ner^'us terminalis). — The terminal nerve is a slender and variably plexiform nerve. It contains both medullated and non-medullated fibers (the latter predominate), and unlike the ol- factory and vomeronasal nerves is ganghonated. The terminal nerve is found in many classes of vertebrates from fishes to man. In man it has been satisfactorily demonstrated in fetuses and infants. The author has dissected the nerve in a number of infants. Her- rick states that the nerve is present also in the adult. Its peripheral twigs are found distributed to the mucous membrane of the nasal septum and to the mucosa joining the olfactory region proper. Furthermore, it has been shown that the terminal ner^'e accompanies and shares the distri- bution of the vomeronasal nerve when the latter is present. The exact ending of the peripheral twigs of the terminal nerve is unknown. Cen- trally the nerve passes through the cribriform plate of the ethmoid bone in company with the olfactory nerve (or nerves) in the form of two or three small roots mesial to the vomeronasal nerve. The roots of the terminal nerve pass over the inferior mesial aspect of the olfactory bulb, here leave ' The American Journal of Anatomy, Vol. 8, igoS. TERMINAL XKRVE 327 the olfactory libers, continue dorsally to enter the brain in the region of the olfactory trigone. The function of the terminal ner\-e is obscure. It may contain both afferent and efferent fibers (Johnson). It is well known that grou])s of ganglion cells are found along the extra- and intracranial courses of the ner\-e. Some describe the ganglion cells and the libers as having the characteristics of the sympathetic neurons. Hardesty suggests that, in- stead of being an independent ner\-e as now claimed, the ncrvus terminalis may be a part of the forward extensit)n of the cephalic sympathetic and that its neurons recei^•e and con\'ey im])ulses to the gland cells of the nasal mucosa and to the unstriped muscles of the blood-\-essels of the nasal mucosa and those supi:)lying the inf eromesial part of the frontal end of the cerebrum. Others believe that the hbers of the terminal nerve may be followed through the length of the olfactory area and hyjiothalamus, ad- mitting ignorance, however, of the exact cerebral connection. Herrick states:' "The problem of the functional and morphological relationshi])s of the ner\"us terminalis must be soh'ed before a complete understanding of the olfactory nerve itself is possible. It may be that the ncrvus termi- nalis is a remnant of a ner^"e of general chemical sensibility of the nose region which has been largeh' supplanted b}- the more highly developed chemical receptors of the specitic olfactory s}'stem. On the other hand, it mav be a nerve of general visceral efferent tA-pe, the cells of the ganglion terminale being postganglionic sympathetic neurons." Brookover,- in a discussion of "the peripheral distribution of the nervus terminalis in an infant," summarizes briefly b>- saying that the peripheral nervus terminalis is so large in man that it may be said to be hypertrophied as compared to the known deA'elopment in other mammals, without especially increasing its central root. In addition to man}- cells in the ganglion terminale, it contains about fifteen hundred cells periph- erallv under the nasal mucosa. Though disposed in three or four chief rami emerging from the lamina cribrosa, there is a vast network of inter- lacing bundles deep to the main arteries. Some of the hbers trail over the walls of the arteries, but the method of treatment by the silver technic does not re\-eal ultimate endings. The Vomeronasal Nerve (Nervus A-omeronasalis). — The \-omeronasal nerve is composed of central processes of nerve cells located in the mucosa of the vomeronasal organ (of Jacobson). Since the latter is rudimentary and probably functionless as an olfactory organ in adult man, the vomero- ' Introduction to XeuroloKV, Philadcl[)hia, iqiO. - The Journal of Comparative XeuroloKV, \'ol. -'.'^, 191 7- 328 THE OLFACTORY APPARATUS PROPER nasal nerve is absent. In those forms in which the vomeronasal organ functions in olfaction, c.^t^., in the dog, cat, rabbit, etc., the vomeronasal nerve passes into the submucosa and joins the filaments of the olfactory ner^•e proper. The nerve fibers terminate in the accessory olfactor}- bulb on the posteromedian aspect of the olfactory bulb proper. In am- phibia the \omeronasal organ is supplied by fibers from the vomeronasal, terminal and olfactory nerves. Read' has also shown that in man a branch of the olfactory nerve passes to the vomeronasal organ, at least at the time of birth. Some would consider the \'omeronasal nerve as a special slip of the olfactory nerve and as terminating in a specially differentiated portion of the olfactory bulb — the formatio vomeronasalis of McCotter. In adult man the ^•omeronasal region seems to be for general sensation only and is, therefore, supplied by the trigeminus nerve and by the cephalic sympathetic fibers common to the mucosa of the general nasal fossa. B. The Central Organ The olfactor_v region of the telencephalon or end brain is usually referred to as the rhinencephalon, a term of doubtful utihty owing to its varied application by anatomists. It is a well established fact that the olfactory brain is ph}'logenetically the oldest part of the cerebral hemisphere and that it is early differentiated ontogenetically. Owing to the fact that it is the oldest part of the cerebral hemisphere in vertebrate evolution, it is often termed the archipallium as distinguished from the greater por- tion of the remainder of the hemisphere — the neopalHum (the corpus striatum is not a portion of the latter). The rhinencephalon is reduced to a comparatively rudimentary state in man and primates generalh-, being greatly overshadowed by the non-olfactory portion of the cerebral hemisphere. This reduction is, doubtless, due to the relatively feeble olfactory sense in these forms. The archipallium reaches its highest development in the lowest mammals and the neoi)allium attams its maximum size in man. The Olfactory Brain. — The portions of the human brain connected with the olfactor)- apparatus may be said to include the \-ery rudimentary olfactory lobe, the hippocampus and the uncus and certain accessory parts. Hiese structures are either wholly or partly associated with the function of smell. From the A-iewpoint of morphology the olfactory bram or rhinencephalcm may be divided into an anterior and a. posterior division. The former consists of the several portions of the olfactory lobe and the latter of certain other parts (Fig 20,^: ' The American Journal of Anatomy, \'ol. S, looS. OLFACTORY BR.MX 329 Olfacti.rv Lolx Olfactory Oortex and .-Vccessorv Parts (a) Olfactory bulb (6) Olfactory tract I (c) Olfactory- triiioiu- I (d) Anterior perforated substance I ((■) Parolfactory area (of liroca) 10) Subcallosal ^,'yrus (peduncle of corpus callosum) ' (a) Uncus (gyrus uncinatus) (b) Hippocampus (hippocampus major) if) Amygdaloid nucleus (d) Supracallosal gyrus, including Ihe medial and lateral stria? (gyrus epicallosus, indusium griseum) (c) Dentate fascia (gyrus dentatus) (j) Septum lucidum (septum pellucidum) (g) Fornix (// 1 I''imbria (/) Mammillary body (j) Habenular nucleus (/;) Thalamus (optic thalamus) (/) Anterior cerebral commissure (m) i\Iedullar\- stria of thalamus (;;) Mammillo-lhalamic fasciculus (0) Jlammillo-peduncular fasciculus (/>) Terminal stria of thalamus (t;enia semicircularis) (q) Habenulo-pedinicular fasciculus (;•) I';tc. The InppoaDupus (the curve(d eminence which extends throughout the floor of the inferior cornu of the lateral ventricle) and the uncus, while chiefly functioning as the olfactor}- cortex, gi\'e off many association path- ways for connection Avith other parts of the cerebral cortex. The liip- pocampal }• the optic chiasma and tract and the olfactory trigone and in large part belongs to the rhinencei:ihalon. The fissura prima separates the olfactorv' trigone fr(im the anterior per- forated substance. Ventrally and medially the anterior perforated substance is confluent with the subcallosal gyrus, and lateralh' is found the lateral olfactory stria on its way into the uncus and the limen insula. Moreover, the gray matter of the anterior perforated substance is con- fluent with the corpus striatum. Numerous blood vessesls enter the sub- stance giving it the perforated ap])earance. Some fibers from the ol- factory tract end about cell bodies located witliin the anterior perforated substance ix'vlt supraj. The parolfactory area of Broca (area parolfactoria) is ])articularly related to the medial stria of the olfact(jry tract, since many of the latter fibers terminate in it. It is a small, more or less triangular field located on the medial surface of the cerebral hemisphere immediately 332 THE OLFACTORY APPARATUS PROPER ^ ^ ^ id V- rn u :3 o y in ^ o (Tl "a) -d 4-> ^( ':r rt "- 'J, tin ^ Cj ^ t- ^ 03 ■*^ ^.' o tt, O !■' d aj d o rt II •-' C S rf O j:: •— ' II a a " ;^ 1) u o C £ ri o *V- .^11 S £ oj " a '^ rt ^ -^ '-' ^ ;■: 'r- ^ '^ '^^ (H II r- & 5 W5 :3 Gg-3 ^ P o ■ - a-c _o ni in 'rus, ci^., the medial and lateral longitudinal striw. Dorsally the thin supracallosal lamina with its stria; passes around the splenium of the corpus callosum and continues bilaterall}' as the faseiola cinerea, then as ihit fascia dciitala liippoeanipi (Fig. 205). Some of the component fibers of the supracallosal gyrus arise from cell bodies located within the subcallosal gyrus, the parol- factor}' area of Broca, and the anterior perforated substance. These fibers assume a dorsal course within the longitudinal stride and terminate in the dentate fascia and the hippocampal field. Other fibers leave the o-rav matter of the su])racallosal g>TUS and enter the longitudinal stria;, coursing both forward and backward. A few of the comi)onent fibers of the stria- are known to pierce the corpus callosum to join the fornix (see page ,3,32). The fascia dentata hippocampi (g>'rus dentatus) is prolonged from the faseiola cinerea caudoventrahvard above the hippocampal gyrus 334 THE OLFACTORY APPARATUS PROriiR into the depression of the uncus where it forms an acute bend and is continued over the surface of the uncus for a greater or less distance as the hand of Giacomini. The identity of the latter is ultimately lost on the lateral surface of the uncus. The free edge of the dentate fascia or gyrus is overlapped by the fimbria, the fimbriodentate fissure inter\'ening, and presents a characteristic notched appearance, the result of many parallel grooves partially cutting it at right angles (Fig. 203). Below the dentate fascia or gyrus is the extremely rudimentary or in most cases obliterated hippocampal or dentate fissure. The latter is not a factor in the produc- tion of the hippocampus in man (vide infra). The hippocampus (hippocampus major) is the cur^'ed, sickle-shaped ventricular eminence, about 5 cm. long, which courses throughout the length of the floor of the inferior cornu of the lateral ventricle. It begins as a narrow, low ridge dorsally at the termination of the body of the lateral ventricle where it is confluent with the posterior pillar of the fornix. Ventrally and interiorly the hippocampus undergoes enlarge- ment forming the ventricular surface of the uncus and presents from two to three secondary elevations, the hippocampal digitations. This causes a paw-like conformation, the pes Jdppocampi. The hippocampus is covered by a thick layer of white substance — the alvciis — which arises from deeper parts and is continued mediallv to become confluent with the fimbria hippocampi. The latter is folded, audits margin — the tcciiia Jimbricr, lies in a sense in the cavity of the inferior cornu and attached to the choroid plexus and the extremely dehcate non-ner\-ous floor of the choroidal fissure. It should, however, be recafled that the immediate boundary of the inferior cornu of the lateral \-entricle is epithelium (ependyma) and that, strictl}- speaking, the onh- thing in the ventricular system is the cerebrospinal fluid. The ventricular eminence (hippocampus) in man is formed by the hippocampal and dentate columns of cells pushing the ventricular sur- face into relief rather than b}' an in\-agination of the surface, usually referred to as the fissura hippocampi. Elhot Smith sa3's: "There is no fissura hippocampi in the human brain." While this is true in the ma- jority of specimens there are occasional partial hippocampal fissures en- countered but seldom of suflicient depth to be a factor in the molding of the hippocampus. The uncus appears as the thickened ventral extremity of the hippo- campal gA-rus, and \entraUy and caudally is separated from the adjacent temporal lobe by the rhinal sulcus. Deeply the uncus is in juxtaposition to the anterior perforated substance, and as stated elsewhere, is connected ul.^Ac■^()R^• hkaix 335 dorsally and medially witli the fascia dentata hipiM)campi and the fimbria hippocampi. :Moreo\-er, the lateral olfactory stria in large measure ends in the uncus {vide sui)ra). Despite the fact that the uncus is seemingly a part of the limbic lobe, in continuity with the hippocam])al g>'rus, Turner and Elliot Smith have established its relation with the rhinencephalon. The fornix is the great bilateral association pathwa}', arched beneath the corpus callosum and confluent with the septum lucidum. Tt is concerned almost wholh- with the rhinencephalon. It ma}' be considered the chief liber-pathwa>- connecting the olfactory cortex located within the uncus and hippocampus with the habenular body of the epithalamus, the mammillary body of the h^'pothalamus, and secondarily with the thalamus and mid-brain. ]\Ioreo\-er, the angle formed by the diverging i:)OSterior pillars (crura fornices) with the body of the fornix is crossed by the trans\-erse fibers — the transverse fornix or the liippoeauipal eom- ijiissiire — whereby the right and left hippocampal regions are intercon- nected. Xot infreciuently the dorsal part of the bod}' of the fornix and the trans^•erse fornix are adherent to the under surface of the corpus callosum; again, a horizontal cleft, the so-called ventricle of the fornix (Verga's ventricle), may intervene. The crura or posterior pillars of the fornix are continued into the inferior cornua of the lateral ventricle as the limbria hippocampi (see page 334). The anterior pillars end as such in the mammillar}- bodies of the liA'pothalamus, howe\'er, man}- of the iibers pass througli them without termination in synapses, decussate to the opposite side, turn into the reticular formation and course to the mid-brain, pons, and probably to lower levels (see also, the tractus mammillopeduncularis, page 342). It is not deemed profitable in this connection to enter into a detailed description of the fornix. The fore- going will sufike to indicate the connections of the fornix as an important association pathway in the olfactory apparatus. The septum pellucidum (septum lucidum) is the thin, vertical bi- laminar partition between the anterior cornua of the lateral ventricles. It is attached above to the under surface of the corpus callosum, below and dorsallv to the fornix, and ventrally to the reflected portion of the corpus callosum (Fig. 203). The septum pellucidum contains between its lamince the cavnni septi peUucidi — the so-called fifth ventricle. Each lamina of the septum consists of a stratum of degenerated gray matter next the cavity of the septum and a stratum of white matter next the ependyma of the anterior cornu of the lateral ventricle. The septum pellucidum is in part concerned with the olfactory organ. 336 THE OLFACTORY APPARATUS PROPER Some of the fibers of the supracallosal gyrus join the fornix ventrally b}- passing through the ventral and inferior part of the septum pellucidum. Moreover, a few fibers from the medial olfactory stria pass into the septum pellucidum and course b>' wa}- of the fornix to the hippocampus. It appears that the posterior angle of the septum pehucidum contains a few commissural fibers which leave the body of the fornix and a few perforating fibers which come from higher le^'els, e.g., from the stratum griseum and fasciculus cinguli.' The habenular triangle (trigonum habenute) is the small triangular area delimited by the superior collicular body, the peduncle of the pineal bod}-, and the puhinar of the thalamus. This triangle contains the habenular iianglion (ganglion habenula;)— an important olfactory reflex center. About the cell bodies terminate the fibers of the medullary stria; of the thalami of the same and opposite sides, the decussation taking place by way of the habenular commissure. The axons of the cefls of the habenular ganglion are collected on the \-entral aspect of the ganglion and gi^'e rise to the fasciculus retroflexus of Mcynert which courses down- ward and forward in the tegmentum of the mid-brain, medial to the red nucleus, and ends as such by synapsing with cell bodies Avithin the inter- peduncular ganglion. The axons of the cell bodies of the latter ganglion form the tegmental bundle of Ciudden which parti}' ends in the dorsal tegmental nucleus. The fibers of the bundle also establish relationships with Schutz's dorsal longitudinal bundle and with other association neur- ons in the neighborhood. The medullary stria of the thalamus (stria medullaris thalami) is a bilateral band of nerve fibers which courses along the superomedial aspect of the thalamus subjacent to the cpendymal ridge — the tcsnia thalami. ]\Ian}' of the fibers of the medullar}' stria end by synapsing with cell bodies within the habenular ganglion of the same side, others decussate in the habenular commissure and end by S}'napsing Avith cell bodies within the habenular ganglion of the opposite side. jNIoreover, it is believed that a few component fibers of the medullary stria fail of termi- nation within the habenuke and pass as such into the superior colliculus of the mid-brain, others into the posterior longitudinal bundle. Relation- ships are also established Avith association neurons of the midbrain. ' The cinKulum (fasciculus cingulij is an association pathway which begins in front in the \icinity of the anterior perforated substance, arches in front of, then over the corpus callosum to the splenium of the latter, where it curves forward and downward in relation with the hippocampal gyrus, the uncus, and the temporal lobe. The cingulum is contained within the basal part of the cingulate gyrus and is composed of a number of short tracts, which enter and leave it at short intervals. It is estaljlished that no long association fibers coursing the entire extent of the cingulum are present. OLFACTORY HRAIX 337 The majority of the component fibers of the medullary stria of the thalamus belong to the olfactory apparatus and are derived from three important sources: (a) fibers from the anterior perforated substance and the parolfactor)' area of Broca ]iass to the medullary stria and form a rather direct olfacto-habenular tract: (b) fibers from cell bodies within the anterior nucleus of the thalamus bend into the medullar}' stria, forming a thalamo-habenular pathway: and (c) fibers lea\-e the fornix and recurve into the medullary stria. These fibers are axons of ncr\e cell bodies within Gi/ras suprucallusus Fascwlu ctnereoccifiita2ii , Fimbria Bulbus CorpjjS ?nn mTnillare 3ni/ei or Giacommi Hippocamfjii.-> Fasciix (Je/dtjjM Aippocumpi Fig. 21J3. — A dissection sho\\ing the rhinencc]ilialon or olfactory brain in color. A goodly portion of the thalamus is removed and other fKjrtions of the brain drawn aside so as to ex])osc (he fimbria, hipi.tocampus, etc. Ca — Commissiira anterior; Smi = Stria medullaris thalami; F ml - Fasci(.'ulus mammillo- thalamieus (\'ieq d' Azyr). The inset in the lower right hand corner is a frontal section from the lower end of the inferior horn of the lateral ventricle and related structures. I ^ Choroidal fissure; 2 ^ Fiinbria; 3 ^ Fimlirio-dentate fissure; 4 = Rudimentary hi])pocampal fissure: 3 ^ Dentate gyrus; 6 ^ Hipjiocampus; 7 = Inferior horn of lateral \'cnlricle; S = Tenia semicircularis ; 9 — Tail cjf caudate nucleus; ro - Choroid ])le.\us ; 11 - lipcndymal lining in^■^.■sting the choroid plexus and lining the horn of the ventriide. the hippocampus and uncus. They are often referred to as the cortico- habenular tract fFig. 202). The mammillary bodies (coi:iora mamnnllaria) are the round, ^\•hite bodies which lie side by side in the interpeduncular fossa, behind the stalk ,,g THE OLFACTORY APPARATUS PROPER of the In-pophysis and immediately in front of the posterior perforated substance. The bodies have an ectal co^■ering of white substance largely derived from the columns of the fornix, and their interiors contain gray nuclei with man)- cells. The mammillary bodies have important olfac- tory connections; e.g., the columns of the fornix, the fasciculus mammiho- thalamicus and the fasciculus mammiUopeduncularis. Through some of these paths olfactory impulses reach the brain stem and probably the spinal cord, thereby influencing the skeletal muscles. The stria terminalis (ttenia semicircularis) is a bilateral narrow, ribbon-like band of white substance located in the sulcus between the caudate nucleus and the thalamus and according to Dejerine is connected with the oKactory sense. ^ Both the anterior perforated space and the septum pellucidum yield libers to the stria. It is also believed that the anterior cerebral commissure adds a few components to it from the opposite olfactorv lobe. Most of the fibers of the stria terminalis continue dor- sally in the interval between the caudate nucleus and the thalamus, leave the bodv of the lateral ventricle and descend within the roof of the inferior cornu of the same and in intimate topographic relationship with the tail of the caudate nucleus to terminate in the amygdaloid nucleus (nucleus amygdalcT). :\Ioreover, the stria terminalis contains fibers which arise from cell bodies located within the amygdaloid nucleus. These fibers oppose the others as regards direction, and after coursing for a greater or less distance as components of the stria they pass (a) to the thalamus and (b) to the internal capsule and cerebral cortex. The amygdaloid nucleus is located in the ventral portion of the tem- poral lobe and in most intimate topographic relationship with the uncus. Indeed, the nucleus appears to be a detached portion of the uncus. Olfactory Reflex and Cortical Connections. — As previously stated the cell bodies of the olfactory neurons of the first order are located in a small area of the nasal mucous membrane. The axons or central processes of these neurons pass through the cribriform plate of the ethmoid bone in approximately twenty bundles (the olfactory nerves, collectively the ol- factory nerve), and terminate by free arborizations in the primarj' ol- factory center (reception nucleus) within the olfactory bulb. As a rule, several olfactor}' ner^'e fibers and one or more dendrites of the mitral cells form entanglements of fibers known as the olfactory glomeruli. Here the first s}'napse in the olfactory pathway occurs (Fig. 202). The arrangement of the neurons and their mode of s>'napse within the olfactor}- bulb may lead to strong excitations in the olfactory centers ' The stria terminalis is not infrequently referred to purely as an association pathway. OLFACTORY Rl'FLI'X .VXD CORTICAL CONNECTIONS 339 even though the peripheral oh'actory stimukition be feeble. As shown in the diagram (Fig. 202), two or more olfactory nerve libers may synapse with the dendrites of a single mitral cell, thus ])ro\'iding for the summation of stimuli in a single mitral cell. Furthermore, in addition to forming component fibers of the olfactory tract, the axons of the mitral ceHs give olf collateral branches which synapse with the granule cells (small neurons of the olfactor}' bulb), A\'hich granule cells discharge among the dendrites of the mitral cells. This arrangement causes the discharge from the mitral cells to be enhanced. Ihe mitral cells are of the second order in the olfactory neuron chain, and, as stated above, their central processes (axons) collectively form the olfactory tract. The latter extends dorsally and divides into three dis- tinct paths, the medial, intermediate, and lateral olfactory stria\ to terminate in various portions of the olfactory area or the secondary ol- lactory center and at points beyond. The Dicdial olfactory stria cur\'es medialh' and most of its component fibers terminate about cell bodies located Avithin the parolfactory area of Broca. Relatively few fibers are found to end within the substance of the anterior i^erforated space and the related portions of the septum pellucidum. ^loreover, it is well estabhshed that the right and left olfactory bulbs are connected, the fibers of communication coursing by way of the medial olfactory stria and decussating in the anterior cerebral commissure, forming its pars olfactoria (see also page 34,3). The lateral olfactory stria is the particularly prominent root of the olfactory tract, receiving most of its fibers. This stria is not infrecjuently referred to as the lateral olfactory gyrus. It curves dorsolateralward and its component fibers cross the anterolateral portion ot the anterior perforated space into Avhich a few fibers sink to terminate about its cell bodies. Ecjually few fibers find their termination in the olfactory tri- gone. The vast majorit}- of the fibers of the lateral olfactory stria, how- ever, pass beyond and penetrate the uncus to establish synapse relations with cell bodies found Avithin this complicated and chief olfactor}' cortical region. Moreover, the component fibers of the lateral olfactory stria in coursing oA'er the subfrontal region on their wa>' to the uncus, giA'c off collaterals which establish synapse relations Avith cells of the related frontal cortex. The latter cells give off axons to the medullar}- stria of the thalamus and to the thalamus. Some of these fibers ma}' reach the brain stem (pons and medulla). The intermediate olfactory stria is the most indefinite of the roots of the olfactor)' tract. Most of its comjxment fibers terminate within the 340 THE OLFACTORY APPARATUS PROPER anterior perforated substance, while a few are doubtless prolonged beyond into the olfactory cortex (uncus). The several nuclei of the secondary olfactory center (the primary ol- factory center is located in the oHactory bulb) are (i) important reflex centers ivhere olfactory and otiier sensory impnises are correlated and (2) centers for tlie dischariie of olfactory impidses into the olfactory cerebral cortex. It is beheved that each nucleus of the olfactory area has an individual ph)-siologic pattern complex. Ludwig Edinger believes that the inter- mediate nucleus, for example, especially in some mammals, is concerned with the feeding reflexes of the muzzle or snout; including, therefore, touch, smell, taste, and muscle and tendon sensibility. To this function complex Edinger has applied the term "oral sense." The reader is referred to the appended works by Edinger' for full discussions. It would lead us too far afield to consider them here. From the several portions of the secondary olfactory center go forth neuron pathways of the third order, some more or less direct, others tor- tuous, in\'olved in olfactory reflexes and in carrying impulses destined to reach the olfactory cortical centers. Moreover, many fibers of the ol- factory tract pass the secondary olfactory center without suffering termi- nation in synapses, particularly those coursing via the lateral olfactory stria. The reflex pathways from the secondary olfactory centers within the olfactory area, etc., pass in large measure to the mammillary bodies of tlic liypothalamus and the liabenular bodies of the cpithalamns. From these bodies issue neurons of the fourth order to connect with the motor centers of the brain stem, which in turn establish relations with the nuclei of origin of cranial nerves and seemingly with the \'entral horn cells of the upper spinal cord as well. Through these relations the most ^'aried reflex movements are accomplished following olfactory excitation. The studies of Herrick- ha\-e led him to belie\'e that in the epithalamus the olfactory nervous impulses are correlated with those of the somatic sensory centers of the thalamus (optic thalamus), especially the optic and the tactual systems; while in the hypothalamus they are correlated with the gustatory and the A'arious visceral (sympathetic) sensory systems. Moreover, as 1 \'orlesungen uber Bau der ner\-osen Zentralorgane Vergleichende Analomie des Gehirns, Leipzig, Bd. 2, 1908. Tlie Relations of Comparali\-e Anatomy to Comparati\-e Psychology, Journal Comparative Neurology, Vol. XVIII, pp. 437-457, 1908. Ueber die Oralsinne dienenden Apparate am Gehirn der Sauger, Deutsch. Zeits. f. Nerven- heilkunde, Bd. 36, 1908. \'orlesungen uber den Bau der Xer\-osen Zentralorgane Des Menschen und der Tiere, Leipzig, 1911. - Litroduction to Xcurology, Philadelphia, 1916. IMPORTANT OLFACTORY PATHWAYS 341 stated above, the secondary olfacton- center discharges also into the ol- factory cerebral cortex, the hippocampus and uncus. The oljactory cortical centers give off association i)ath\vays for connec- tion with other parts of the cerbral cortex, thus bringing the \aried func- tional systems into interrelation with olfaction. j\Ioreover, from the olfac- tory cortex, especially the hippocami)us, issues a motor (efferent) pathway which courses by way of the hmbria, the seYcral portions of the fornix and the stri;e medullares thalami to reach both the hyi)othalamus and the epithalamus. From the latter points connections are established with the motor center in the cerebral jx-duncles, etc., by the same pathwavs that are involved in olfactory reflexes. Efferent or motor impulses (of cortical origin) in which the olfactor}- element prevails follow the efferent neuron pathway from the olfactory cortex abo\'e referred to, and by ])rojection and association pathways reach the motor centers in the cerebral j^eduncles within the mid-brain, the nuclei of origin of the several cranial nerves, and the cell bodies of the motor spinal ner^•es located in the ventral horns. Such acts as motions of the ahe of the nose, sniffing, turning the head and bodv aside when breathing unpleasant and irritating odors may be ex- plained by such neuron pathways. Ob\'iously, it is at times diflicult to separate actions which are the result of olfactory reflexes from volun- tarv motor actions resulting from efferent impulses in which the olfactory element predominates. Olfactory Pathways. — The more imj^ortant connections of the ol- factory apparatus may be briefly summed up as follows (Fig. 202): (A) An aft'erent conduction path con\'eys olfactory impulses from the olfactor}' mucous membrane to the primary olfactor}- center located within the olfactory' bulb. From here the im])ulses follow the olfactory tract and either pass directly to the ohactory cortical centers or are transferred, within the secondary olfactor}-- center, to neurons of the third order, the axons of which likewise terminate in the olfactory cortex. It will be re- called that the greater number of the axons of the mitral cells after cours- ing in the olfactory tract are prolonged into the lateral olfactor}' stria and terminate in the uncus, a few axons terminating within the olfactory trigone and the anterior perforated substance. While the uncus and the hippocampus contain the important cortical centers for smell, the amygda- loid nucleus also is belie\'ed to be ])art of the olfactory cortex. It is con- nected with the secondar}' olfactory center b}- the tract known as the stria terminalis or taenia semicircularis (see page 338). (B) The several portions of the secondary olfactory center are im- portant olfactory reflex stations. Tracts arising from the secondary ,42 THE OLFACTORY APPARATUS PROPIiR center pass directly to the tuber cinereum, the mammillary body, the habenular gangUon, the brain stem, and in all probability the spinal cord. \¥liile the reflex paths from the secondary olfactor}' center to the lower portions of the brain stem and spinal cord are but partially known, the following tracts appear established: 1. The direct tr actus olfactotegmcntalis (tractus olfactomesencephali- cus, basal olfactory bundle of Wallenburg) arises from cell bodies located within the anterior perforated substance, the olfactory trigone, the cortex of the ohactory tract, and the septum pellucidum. The tract courses more or less direct to the tuber cinereum, the mammillary body, the motor centers of the brain stem, and, according to some investigators, to the spinal cord. Some of the hbers of the olfactotegmental tract penetrate the mammillary body and are believed to establish relationships with the contained nerve cell bodies, the latter gi^'ing rise to the tractus mammillopeduncularis. 2. The tractus mammillopeduncularis (fasciculus mammillotegmen- talis, the mammiUotegmental bundle of Gudden) connects the mammillary bod)- with the motor centers of the mid-brain within the cerebral peduncles and the gra>' substance of the cerebral aqueduct. Moreover, a few fibers of the mammillopeduncular tract are believed to enter the posterior longitudinal bundle. 3. The tractus olfactoliabcuularis arises from cell bodies located within the parolfactoT-y area and the anterior perforated substance and passes through the inferior segment of the septum pellucidum, and with other fibers (tractus corticohabenularis, etc.) forms the stria medullaris thalami (see page 337 for the component fibers of this stria). The medullary stria of the thalamus terminates b}' synapses in the habenular nucleus of the same and opposite sides (see page 336). Moreover, it is known that a few fibers of the medullary stria fail of termination within the habenular nucleus and continue beyond into the superior coUicular (c|uadrigeminal) body and the association and projection pathways of the mid-brain, in- cluding the posterior longitudinal bundle. 4. The tractus liahcnulopcduncularis (fasciculus retroflexus, Meynert's bundle) issues from the cell bodies of the habenular nucleus and connects the latter Avith the interpeduncular ganglion located within the posterior perforated substance in front of the pons between the cerebral peduncles. 5. The tractus tcgmentaJis (tegmental bundle of Gudden) arises from the cell bodies of the interpeduncular nucleus, courses dorsocaudalward and some of its fibers end in tlie red nucleus, others come into relationship with Schutz's dorsal longitudinal bundle and other association neurons of the tegmentum of the mid-brain. IMPORTANT OLKACTOm- PATJIWAYS 343 6. The tractus mammillothalamicus (tract of Vicq d'Azyr) connects the mammillar}' bod>' with the anterior nucleus of the thalamus for the correlation of the olfactor}' with the general somatic reactions. The tract of \'icq d'Az}'r is formed b}' axons arising from the cell bodies of the medial and lateral nuclei of the mammillar_\- bod)- and Ijy some of the fibers con- tinued from the anterior pillar of the fornix which fail to suffer synapse terminations within the mammillar^' bod^^ (C) Efferent fibers, the axons of the p>Tamidal cells of the uncus and the hippocam]uis and the \-ariously shaped cells of the related dentate fascia of the hippocam])us, lea\'e the cortical olfactory centers by wa)^ of the fimbria. Approximately twenty-five per cent, of these eft'erent fibers are continued into the fornix pro])er, for distribution to the habenular ganglion, the mammillary bod}-, the brain stem, and points below. ^lore- o^-er, axons arising from ner\-e cell bodies within the amygdaloid nucleus course via the stria terminalis (taenia semicircularis), opposing in direction the afferent components of this stria, and enter the thalamus, others pass into the internal capsule and to the cerebral cortex above (see page 338). The eft'erent fibers from the olfactory- cortex are to be thought of as olfactory associational and ])rojection fibers. Of those that enter the for- nix proper, some leave the latter and join the stria meduUaris thalami (see page 337) for the habenular nuclei and the mid-brain, others pass to the mammillary body via the corresponding anterior pillar of the fornix, either to terminate in this body or to pass through it.' The fibers that fail to terminate in the mammillary body either cross to the opposite side and be- come component fibers of the tractus mammillopeduncularis or enter the tract of Viccj d'Azyr (probably of both sides). It will be recalled that the former passes in the reticular formation to the mid-brain, ])ons and prob- ably to points at lower levels. (Dj Commissural tracts connect the two sides of the olfactor}- appa- ratus. Approximatel}' seventy-fi\'e per cent, of the fibers which leave the uncus, the hippocampus and the related dentate fascia by way of the fim- bria (see above) are distinctly smaller than the remaining association and projection fibers, and are commissural in character. The}- course in the fimbria, but instead of being continued into the fornix proper i)ass by way of the hippocampaJ commissure (transverse fornix, lyre, ventral psalterium) to the fimbria and hij)pocampus of the opposite side, thereby connecting the olfactorv cortices of the two sides. i\Ioreo\'er, the anterior cerebral commissure contains a small oljaclory fasciculus which connects the ol- ' Despite the fact that man\- filjcrs pass tlirough the manimiUar\' hmly, synapse relations arc established with the cells in loco by collaterals from the libers. 344 THK OLIWCTORY APPARATUS PROPER factory bulbs of the two sides— true commissural fibers— and the olfactory bulb of one side with the uncus of the other side. According to Van Ge- huchten,' however, none of the fibers of the anterior commissure arise from the ner^'e cells located within the olfactory bulb. He believes that the ohactory portion of the commissure is an association system connecting the olfactory cortex of one side with the olfactory bulb of the other. The Relations of the Brain to the Walls of the Nasal Fossae and the Paranasal Sinuses. — But brief mention of the anatomic naso-encephalic relations need be made here since reference to the relationships is made in the foregoing chapters. This is especially true for the meningeal relations, the hypophj-sis cerebri and the ca\'ernous sinus. The olfactory bulb and tract lie in very close relation with the roof of the nasal cavity. While the olfactor}' bulb usually rests more or less freely upon the cranial surface of the lamina cribrosa of the ethmoid bone, it is at times markedly encroached upon by the dorsomedial extension of the frontal sinus, by a cell in the crista galli, or by ethmoidal cells. Frequentlv such encroachments merely lead to a crowding of the olfactory bulb in one direction or another. When, however, these sinus and cell extensions occur simultaneously the olfactory bulb may be pinched upon to a marked degree (Fig. 200). The author is unable to say whether this has any bearing upon atroph}- of the olfactory bulb or upon the physiology of smell. The frontal sinuses come into relationship with the brain cortex in the neighborhood of the pole of the frontal lobe. It is essential in this connection to recall the extensive pneumatizations of the frontal sinus that are not infrec^uently encountered (Figs. 113 and 114). Naturally, the brain exposure is in accord with the size of the frontal sinus. The ethmoidal cells lie opposite the gyrus rectus and usually come into relationship with the basal cortex for a goodly distance lateral to the gyrus rectus. Dorsally the sphenoidal sinus replaces the ethmoidal cells in this relationship. While the sphenoidal sinus is usually separated laterally from the brain cortex by the inter\'ening cavernous sinus, it occasionally pneumatizes beneath and lateral to the cavernous sinus and comes into most intimate relationship with the temporal lobe of the brain (Fig. 142). It is, therefore, possible for an abscess of the temporal lobe to arise from a diseased state of the sphenoidal sinus. An appreciation and knowledge of the relations and variations of the ])aranasal sinuses are alone of value in the localization of rhinogenic brain abscesses of paranasal origin. ' Lc Xevraxe, 1Q04. XII-PHYSIOLOGICAL ADDENDA CHAPTER XTI PHYSIOLOGICAL ADDENDA The Nose Proper. — The functions of the nose proper are of di\-ers sorts. Only small portions of the definitive or adult nasal fossa- are spe- cifically olfactory in function (see the peripheral olfactory organ, page 325). The remaining and greater portions of the nasal fosste conjointh' ser\-e the role of an adjunct respiratory organ despite the fact that the primitive or primary nasal fossiv and their derivatives are whohy olfactory in their ph}.'siolog>-. The respirator}' role is purely secondary as is evidenced by the embryology and comparati\-e anatomy of the nose (see Chapter I). The nasal ca\'it\- ser\-es ancillar}- roles in connection with audition, taste, and the proper ])roduction of ^'oice; moreo\-er, serves as a drainage cavity for the paranasal sinuses and the nasolacrimal apparatus. The nasal mucous membrane in its normal condition is supposed to ha\T certain bactericidal properties, whereby the nasal fossa; become defensive organs against the in\"asion of bacteria by wa}' of the inspired air. The external nose very frequently reproduces to a marked degree family and racial characteristics and through the attachment of facial muscles modifies facial expression. It is generalh' belie\'ed that the current of air in passing through the nasal fosScT does not pursue a straight course, but passes in curves and eddies. This leads to a prolonged sta}' of the air within the nasal cavity; moreover, aids in the dissemination of the air into the various recesses, etc., of the \-ery irregularh' configured lateral nasal walls. The fore- going are important factors in warming and moistening the air before it passes into the nasopharynx. The great ^'ascularity of the nasal mucous membrane and the secretions of the nasal glands are the prime factors in supplying heat and moisture to the inspired air. By the time the air has reached the larynx it is normally warmed to blood temperature and laden with moisture. The erectile tissue of the nose is especially active and un- dergoes engorgement when the air is dry, thereby providing the neces- sary moisture. When the inhaled air is humid the erectile tissue is less active. It has been estimated that in twenty-four hours over a liter of water is normally supplied by the nose and that when the functions of the 347 :;4S rHYSIOLUGIC.U. ADDENDA latter are impaired there is a dryness and tendency to catarrh in the nose, phar>'nx, trachea, etc. (Figs. 159, 181 and 183). The nose normally acts as a filter for particles of dust and bacteria with which the inhaled air is laden. The vibrissas located in the nasal vestibules entangle many of these and keep them from reaching the nasal mucous membrane proper. The A'estibules are always laden with mi- croorganisms (mostl)' non-pathogenic); fewer are found in the nasal fossse and fewer still in the nasopharynx. Dust particles and microorganisms which reach the nasal fossae and paranasal sinuses are normally expelled by the action of the ciliated epithelium and the secretion of the nasal glands. The activity of phagocytes is, doubtless, also a factor. The cur- rent produced b}' the ciliated ei:)ithelium of the nasal fossae is toward the nasopharA-nx and that of the paranasal sinuses is toward the ostia of the sinuses, therefore, toward the nasal fossae. This was confirmed by the author by placing powdered carbon on the mucous membranes of the paranasal sinuses in a number of animals. The observation showed that the carbon particles were carried into the nasal fossa; and from there into the nasophar}'nx. While the acti\-e bactericidal property of the secretion of the nasal glands is cjuestioned by some, it is doubtless established that it has at least a marked inhibitor}- influence on the growth of microorganisms. This is ec|ualh' true of the paranasal sinuses. Thomson and Hewlet found when cultures of non-pathogenic organisms are artificially introduced into the nose they disappear rapidly.^ This probabl}' accounts for the great abundance of microorganisms in the nasal vestibules and for their relative scantiness in the interior of the nasal fossae and their almost total disap- pearance in the upper portions of the pharynx. BertarelH and Calamida- claim that the paranasal (accessory) sinuses, in animals at least, are always sterile. Torne'' found the paranasal sinuses of human bodies just dead to be sterile. In a later obser\'ation-' he, however, found bacteria present, indicating that the inspired air carries microorganisms into the paranasal sinuses. It is, however, definitely known that the paranasal sinuses are not the conspicuous habitat for microorganisms as was one time gen- eralh- belie\'ed. Two prominent physiologic factors come into play in ridding the nasal fossa; and its related paranasal sinuses of bacteria: first, the action of the ciliated epithelium and second, the apparent bactericidal or surely inhibitory properties of the nasal mucus. Should these defensive 1 Mcd.-Chir. Trans., Vol. 7.8, 1805. ^ Archivio Itilano di Otologica, Vol. 13. 'Nord. Med. Arkiv., H. i, IQ04. ^ Central, f. Bakteriolo^;ie. Ed. 3,3, IQ03. NASAL FOSS_E 349 mechanisms be overcome b}' in\-ading bacteria, infection of the nose and paranasal smuses is, of course, inevitable. Phagocytes and solitary h-mph nodes of the nasal mucosa may be additional i^-otectix-e agencies. St. Clair Thomson in commenting uj)on the bactericidal functions of the secretion of the nasal glands emphasizes the importance of respecting the erectile tissue portions of the nasal mucous membrane; arguing that "it is better to be a partial mouth-breather than to have free nasal passages with their protecti\-e mechanisms seriouslv damaged." The nasal cavities exert a profound influence upon vocalization. The sound-^-ibrations which arise in the lar>-nx and ascend in the pharynx require a resonating chamber for the realization of a full and clear sonorous tone of the human voice; for some sounds this chamber is found in the e\-er open nasophar^mx and the nasal fossa; with their posterior and an- terior apertures. If the nasal fossa^ or their apertures are blocked bypatho- logic conditions, marked changes in some of the fundamental sounds are encountered. The soft palate likewise is of importance in this connec- tion — its mo\-ements must be free and unimpeded. The voice of every indi^-idual has a peculiar qualit}-, clang or timber. This is dependent upon the shape, size and health of the ca\-ities connected with the larynx. In nasal tones the air in the nasal fossa' vibrates freeh', necessitating, there- fore, free nasal foss;c and apertures. The nasal timber is produced by the soft palate (palatum molle) not shutting off completely the nasal fossae, happening when pure \-o\vels are sounded with a resultant s}-mpathetic A-ibration of the air in the nasal fossa\ It has been shown that "when a A"owel is spoken with a nasal timber, air passes out of the nose and mouth simultaneously, while with a pure vowel sound, it passes out onlv through the mouth." Hartmann has demonstrated that it requires an artificial pressure of 30 to 100 mm. of mercury to o\'ercome the soft palate Avhen sounding a pure or non-nasal vowel, so complete is the ph}'siologic occlu- sion between the oropharynx and the naso])har}'nx. The vowels, a, a (a'), 6 foe), o, e, are used with a nasal timber. Strictly s])eaking a nasal i does not occur in any language since it is next impossible to sound it as such under normal conditions, since the h)ulk of the air passes out through the nasal fossfe and their apertures. According to their mechanism of forma- tion consonants may be di\'ided into explosi\'es, vil)ratives, aspirates, and resonants. In the sounding of the latter grou]) the nasal fossie are en- tirely free, while the oral aperture is shut off; therefore, the)' are frecjuently called nasals or semi-vowels. In the former three grou])s the nasal ca\'ity is entirely shut oft". The foregoing will sufiice to show the imj)ortance of health)- and nor- 3SO PHYSIOLOtllCAL ADDENDA mal nasal fossa? in vocalization. The reader is referred to the special treatises on \-oice and sounds for more detailed discussions. It would lead us too far afield to undertake it here. The Paranasal Sinuses. — Various functions have been ascribed the paranasal sinuses, some of which are unwarranted, others purely hypothetical, while a third group are suggestive and within the field of probabihty. It is not profitable, however, in this connection to speak of the many theories that have been advanced, suffice it to speak of those that appear tenable. The author is of the firm opinion that until the phylogenic beginning of the paranasal (accessory) sinuses is more definitely established the functions of the ca\'ities must necessarily remain more or less obscure. Indeed, the initial functions of the sinuses may have been entirely replaced by secondary functions in man. Comparative anatomy has, of course, given some light and further study in this direction is essential. It is not an easy task to map out accurately the olfactory field in a large series of mammals. The embryolog}- or ontogenetic history of the paranasal sinuses is well known for a number of forms (see Chapter I for man), but what is especialh' wanted now is the phylogenetic histor}'. It would appear certain that the paranasal sinuses are old in their phylogeny since the}- begin their ontogenetic de\'elopment relati\-ely early in the human embryo (see pages 36 to 37). This behef is supported by the recent observations of Moodie^ who had the opportunitA' of studying the casts of the paranasal sinuses of two early tertiary mammals — oreo- dont- (Merycochoerus) and an early bear-dog (Daphaenus). The casts made b}' nature and preser\'ed in fossil form indicated an enormous de- velopment of the frontal and maxillary sinuses. A stud}- of the casts leads ]Moodie to belie\'e that the origin of the paranasal chambers "is to be found, not in the early mammals, but in their ancestors, and probably their remote ancestors." Descrii)ti\-e paleontology may indeed prove a valuable supplement to comparati\-e embryolog}', anatomy and physiology in an effort to solve the real meaning of the paranasal sinuses, both primi- tive and recent. Smell is e^-identl}- the dominant sense in very manv of the lower vertebrates. This is e\-idenced by the great development of the ohactory brain and the beha\-ior of such animals. In man and other primates the olfactory organ is much reduced and the olfactory sense relatively very rudimentary (see page 328). As stated elsewhere, in accordance with the 1 On the Sinus Paranasales of Two Early Tertiary Mammals. Jour. Morph., Vol. 28, 1916. = Leidy speaks of the genera of the Oreodontida; as "ruminatinp; hoRS.'' PARANAS.U. SINUSKS 351 degree of ckn'elopment of the olfactory a]:)paratus, one may distinguish between mammals which are macrosmatic (most of the mammalian orders), microsmatic (seals, whalebone-whales, and primates, including man), and anosmatic (most toothed-whales). In Mammaha, except in Mono- tremala, the nasal fossiv communicate \\'ith one or more paranasal cham- bers; c.t,'., the maxillary, frontal, and sphenoidal sinuses (the three sinuses are not necessarih- i)resent in all forms). In some forms that have been careluU}' studied oljaclory folds are enclosed in the paranasal sinuses men- tioned, especialh- the frontal and sphenoidal. With the reduction of the olfactory sense in other forms there is a resultant loss of the primary olfac- tory function of the sinuses — a pneumatic and purely secondar}' role being assumed. Indeed, the sinuses may disappear altogether; witness, for example, Pinnipedia (seals, walruses). The maxillary is the most constant of the sinuses, being typical for Euthcria, and the only sinus present in Insectivora and bats. The author is of the opinion that the j^aranasal sinuses of man no longer till the role initially set for them in their phylogenetic history. There is considerable exidence that the olfactory mucous membrane was much more extensive at one time. Indeed, as indicated above, it is more extensi\"e in many of the lower mammals. The fact that the entire embr}-onic nasal foss;r of man (see page 47) arc iinliaJly olfac- tor}" in their character, e.g., in their embrAonic de\-elopmcnt, would seem to indicate that phylogenetically the olfactor}- nasal mucosa was more extensi\'e than it is in the post-embr\-onic human nose. The respiratory role of the human nasal cavity is clearh' secondary. In all likelihood, therefore, in the phylogeny of the human nose, the olfactory mucosa pri- marily extended into the derivatives of the nasal fossae, e.g., certain of the paranasal sinuses; this in order that the area of the olfactro}' mucosa be increased and a correspondingly more acute, sense of smell pro\'ided. i\Ian and the anthropoids not ^er|uiring the strong sense of smell for their existence and sur\'ival became macrosmatic (possessing .smeh in a com- paratively feeble degree); the respiratory field of the nasal mucous mem- brane gradually encroaching upon the olfactory field and reducing it to the limited area in the upper portion of the nasal fossa; moreover, the olfactory- elements becoming completely lost to the paranasal sinuses. Strictly speaking, the olfactor)' nature of the ethmoid cells cannot be argued since the ethmoid labyrinth is not present as such in most macrosmatic or acutely smelling animals. In these forms the ethmoid field assumes a great complexity and maze of endo- and ectoturbinals, enclosing within their scroll-like folds portions of the nasal fossa. These 3152 1>IIV,S1()].(X;[C.U. AUJ)EXIJA fossa-inclusions can, liowever, not be spoken of as "ethmoid cells," since the latter designation connotes an entirely erroneous conception of these structures both as to their genesis and real anatomy. The ethmoid labyrinth, composed of sinuses or cells not unlike the frontal, maxillary and sphenoidal sinuses, reaches its perfection as such in some of the an- thropoids and man. Despite the phylogenetically late appearance of true ethmoidal cells, the ethmoidal labyrinth as found in man simulates in a measure the A^ery complex field of ecto- and endoturbinals with nasal- cavity inclusions of acutely smelling or macrosmatic animals. The scroll- like inclusions of the turbinal field of macrosmatics are in a sense analogous to the cells of the ethmoidal lab^Tinth of man and certain anthropoids. However, it must be strictly understood that they are not morphologically homologous. The great reduction of the ethmoidal field in man naturally precludes the formation of inclusions of the nasal fossa save to a limited extent (see the furrows of the middle meatus, pages 28-35). The direct outgro\\th of the nasal mucosa in the formation of the ethmoidal cells and the pneumatizaton of the ethmoid and neighboring bones is the nearest approach to the complicated scroll-like formations of macrosmatic animals. Since smeh is a chemically excited sense requiring a solution of the gaseous odoriferous substances in the moisture of the olfactory mucous membrane before the olfactor}- receiptors are stimulated, it was obviously necessary from the phylogenetic beginning of the paranasal chambers that air passes into them in order that the olfactory elements might be stimulated. It is, therefore, clear that, while the olfactory function of the sinuses ma}' have been primary, the role as pneumatic cavities and adjuncts to respiration was perforce equahy primitive. With the withdrawal of the olfactory functions in the phylogenetic de\-elopment of the sinuses in man, the one conspicuous and probably dominant function remaining is that as an adjunct to respiration, parti- cularly to aid in humidifying and warming the inspired air. It has been definitely established, especially by Braune and Clasen, that during respiration there is a certain amount of air change in the paranasal sinuses. The degree of interchange of air is obviously more or less dependent upon the size and freedom of the ostia of the respective sinuses and the amount of air inspired. Good ventilation of the paranasal sinuses is essential to health and is normally maintained. Pathologic states in the nasal fossa; may seriously block the interchange of air by encroachment on the ostia of communication between the sinuses and the nasal fossae. A number of in\-estigators support the theory that in order to ha^•e proper equipoise of the head it is necessarv that some of PARANASAL ST^'USES 353 its bones be pneumatizcd. Such pneumatization is found in the paranasal sinuses and from this is inferred that tlie main function of the sinuses is to ligliten tlie bones of the skull. Braune and Clasen^ particular!}' ha\'e opposed such function in \-iew of the fact that, according to their studies, but one ]^er cent, would be added to the weight of the skull should the pneumatic ca\-ities be replaced b}' spongy bone. Their contention would merit more support if the pneumatization of the head bones should be eciualh' distributed. It, however, happens that practically the entire system of pneumatic cavities is located in the ventral portion of the head. It appears ])lausible, therefore, should the paranasal sinuses be replaced by solid bone, that the poise and ec^uipoise of the head would be markedly interfered with, since the head with the contained sinuses is \'er}' e\'enh- balanced. The argument, that the theory of light- ness and balance of the skull as related to the paranasal sinuses fails be- cause children have no sinuses yet are able to balance their heads, is not permissible, since children do have fairly well developed sinuses even at birth. It is \'er}' unlikely that the paranasal sinuses exert any influence upon \-ocalization. The ostia of the sinuses are so small and not infrequently encroached upon b}' neighboring parts that one naturalh* wonders how the chambers can have any modifying influence on the sound Ava^•es. JNIore- o\xr, the great variations in the size and arrangement of the sinuses would preclude any constanc}' of influence. The theory that the paranasal sin- uses impart resonance to the voice must, doubtless, be abandoned In view of the fact that the mucous membranes of the paranasal sin- uses are very sparsely supplied with glands, the theory that the dominant function of the sinuses is to supph' moisture in the form of mucus to the nasal fossae is archaic and unwarranted, since a very limited amount of moisture is thus suppHed. Under normal conditions the paranasal sinuses are capable of self-drain- age. .\11 of them are lined b)' a ciliated epithelium, Avith a wave-like ciliar}' motion directed toward the ostia of the sinuses. It must, however, be recalled that in the human nose the maxihary and sphenoidal sinuses and certain of the ethmoidal and conchal cells have no gra\-ity drainage. Most of the ethmoidal ceUs and the frontal sinuses h&ve their ostia so located that gravity itself is a material factor in freeing the sinuses of accumulated mucus. Of course, when the position of the bod}' is changed from the erect posture to the horizontal, or better Avhen the head is placed with its vertex downward, the maxillary, sphenoidal and conchal cells likewise 1 Zeit. f, Anat., Bel. 2, 1877. 23 354 I'HYSIOLOGICAL ADDP:NDA have a gra^-ity drain. This discrepancy in the location and relations of the ostia of the several sinuses accounts for the dissimilarity of the sub- jective symptoms (other things being ecjual) in diseased states of the indi- vidual sinuses. Olfactory Sensation. — The development and complexity of the ol- factory lobes of the cerebrum and the nasal fossa? in mammals vary greatly and are in accord with the degree of acuity of the sense of smell. Of course, the immediate intensity of the olfactory sensation depends on the size of the olfactory fields in the nasal fossae, the concentration of the odor- iferous substance and the frequency of the conduction of the substance by sniffing to the olfactory receptors. Certain animals have no sense of smell (anosmatic) including certain cetaceous mammals like the porpoise and toothed whale, the olfactor}' nerve being absent. Rarely there is congenital anosmia in man. In other mammals the sense of smell is remarkably acute (macrosmatic) , including rodents, carnivora, marsupials and other mammals. ]Moreo\'er, there is an intermediate group of animals which possess smell in a comparatively feeble degree (microsmatic) , including most primates, monotremes, some cetacea and man. Since the olfactory function warns the indi\-idual of offending gases, the olfactory organ assumes the additional role of a protectiA'e organ. In spite of the fact that man is microsmatic his sense of smell is nor- mally aroused b_v inconceivably dilute solutions of odoriferous substances — one part of mercaptan to thirty billions of air being detectible. Valentin reports that "^ of a grain of musk canbe distinctly smelled. Cam- 100,000,000 phor is perceived in a dilution of i part to 400,000. It is known that the acuteness of the sense of smell can be greatly improved by practice. The case of James Mitchell, who though deaf, dumb and blind, distinguished persons and objects b}' his acutely trained sense of smeh, is often re- ferred to in this connection. The delicacy of the sense of smeU varies normally in dift'erent individuals. The threshold of excitation is much lower for smell than it is for taste owing to the suppression of a synapse in the peripheral olfactory receptors in the nasal mucosa and to peculiari- ties in the neuron synapses in the olfactory bulb (page 338). The olfac- tory organ responds to a much larger range of chemical stimuli and to greater dilutions than does the gustatory organ. Parker and Stabler^ have shown that the human olfactory organ responds to alcohol at a dilu- tion 24,000 times greater than that necessary to activate the organ of 1 On Certain Distinctions between Taste and Smell, Amer. Jour. Physiol., Vol. XXII, pp. 230 to 240. OLFACTORY SENSATIOiN 355 taste. The interrelations between taste and smell are, however, very important (vide infra). Strangely the olfactory receptors are almost as readily fatigued as they are excited and the sense of smell soon becomes untrustworthy as an organ for the detection of odoriferous substances. Many inhaled substances after a brief period cease to ])roduce a detectible sensation. The normal indi\idual readily notices the unpleasant odor upon entering an ill-^■entilated room, yet after the lapse of a few minutes ceases to perceive it because of the fatigue of his olfactory apparatus. A complete!}- fatigued apparatus recovers, however, in a \'ery short time, provided the environment is suitable. It would appear established that smell in man, as probably in all present vertebrates, has both exteroceptive and interoceptive qualities. Despite the fact that primitively smell was an interoceptive sense it is now dominated by the exterocepti\'e ciualit}-. Howe\-er, some of its initial cjualit}' persists. As Herrick states, the somatic reactions are obviously more important than the \'isceral responses. Smell like taste is a chemically excited sense. It requires a solution of the gaseous odoriferous substances in the moisture of the olfactory mucous membrane before the olfactory receptors are stimulated. The mucous membrane must be neither too moist nor too dry for the most favorable reaction. Strangely all gaseous substances do not stimulate the olfactory receptors, and it is assumed according to Howell and others that there are certain odoriphore groups which are characteristic of all odoriferous substances and by virtue of which these substances react with the special form of protoplasm found in the olfactory hair cells. Halli- burton savs that generally the odors of homologous series of compounds increase in intensity with increase of molecular weight, but bodies of ^'ery low molecular weight are odorless, while \-apors of \-erA- high molecular weight, which escape and diffuse slowly, hsLve little or no smell. The passage of odoriferous substances to the olfactory recei)tors is accomplished by mere diffusion or by the act of sniffing which i^roduces currents of air and intensifies the sensation. The peripheral localization is very imperfect since individuals confound many smells with tastes. Many flavors (tastes) are reah}' smells, the odoriferous substances which are being eaten in all probabiht}- reaching the peripheral olfactory organ through the choaaae, and since they accompany the presence of food or other particles in the mouth are interpreted as gustatory sensations rather than olfactory. Indeed, it is well known to e^'eryone that blocking of the choanal (posterior nares) b>' a nasopharyngeal pathology and the nares and nasal fossa; by a coryza loses much flavor value of foods to the in- ,-K rHVSIOLOCaCAL ADDENDA dixidual. Physicians and mothers weU know that compressing the nares (nostrils) of the httle rebellious patient makes easier the administration of certain drugs by mouth— much of the so-called "taste" of the medicine is destroyed thereby. :\Iany attempts ha\-e been made to disco\-er the fundamental or elementar}' sensations of smell as has been satisfactorily done for taste (sour, salty, sweet, bitter). Ordinarily individuals are content to speak of olfactory sensations as agreeable or pleasant and disagreeable or repul- sive. In addition to these Haller suggested a third— the mixed. It is held by some that the agreeable or disagreeableness of the olfactor}' sen- sations (odors or smells) is in many instances dependent upon the olfactory associations connected Avith them, i.e., if the associative memories aroused are unpleasant the odor is repulsive or disagreeable and vice versa. One of the most complete classifications of odors is given by Zwarrdemaker.' He classifies them into ( i ) pure odors, {2) odors confused with taste and (3) odors mixed with common sensibilit)' of the mucous membrane of the nose. These primary- groups are subdivided into secondary groups. It is weh known, for example, that ammonia a pungent substance, stimulates the endings of the trigeminal nerve as well as those of the olfactory nerve. The so-called taste of spices is not i:)erceived Avhen the nose is compressed and the nares closed off, a certain pungency alone being experienced, due to a stimulation of the nerves of general sensation. If, however, the nose is freely open "taste" is experienced which is m ''eality smell. When two odoriferous substances are simultaneously inhaled, one ma}' be dominant and the other secondar}' or entirely suppressed in the consciousness. On the other hand, one of the odors may be percei\'ed and after a ver_\- brief i)ause the other, or the two odors may be perceiA'ed as a mixed odor and be unlike either of the elementary odors. Some odorifer- ous substances readil}' fatigue the olfactory receptors in the nasal mucosa. However, the receptors may be fatigued by one substance, yet be acutely sensitive and active to others. This leads one to think of either a selective power of the units composing the peripheral olfactory organ or that some substances affect some portion of the olfactory mucosa, while others affect other parts. It is, of course, Avell known that the organ is A-ariously sensi- tive to different odoriferous substances. As stated elsewhere the cortical olfactory center located in the hippo- campus and the uncus is widely connected with other parts of the cerebrum. These connections serve as an anatomic basis for the extensive association connected with the odors. Olfactory sensations often awaken powerful ' Die I'hysioloRie des Cicruchs, Leipsig, 1895. ixhi;ritaxck and sMa':j.L 357 multitudinous associations of memory and as Howell^ aptly says, "our olfactory memories are good." It has long been obser\-ed that ob\-ious important relationshii)s exist between the olfactor>- and the sexual organs. In animals with highly developed olfactory organs, both vertebrate and invertebrate, the olfactor)' sense is intimateh- connected with the sexual reflexes (see also page 296). ;Moreo\-er, a reinnant of such relationships is \-er}- apj^arent among human beings. Howell' rightly states that "among the so-called special senses that of smell is the one most closel}- connected with the bodih' a])])etites, and o^•er-gratihcation or over-indulgence of this sense, according to histor- ical evidence, has at least been associated with periods of marked de- cadence of ^-irtue among civilized nations." There exists also apparenth' a physiologic and pathologic relationship between the non-olfactor}- nasal mucosa and the sexual organs. It is said that inflammations of the nasal fossa; and the paranasal sinuses ex- ercise a marked influence o^•er the sexual functions. (See Cha])ter X for a fufler discussion.) The author recenth- learned of a few indixiduals in whom during e\"ery sexual excitement the glands of the nasal mucous membrane jjour forth a A'oluminous amount of mucous which subsides at once with the completion of the sexual act. lliis is, of course, a psychic condition, supporting the thesis that there is a cortical center which acts on the glandulosecretory and vasodilator centers (see page 293). Little is known on the heritability of differences in the sense of smell. Blakeslee' has shown that two indi\'iduals may exhibit marked degrees of sensiti\it}- to the fragrance of \'erbena flowers. He found in tests that one individual not infrequently would declare one of two blossoms emit- ting a fragrant odor and the other not, while a second indixidual on judging of the same blossoms would declare the exact o]iposites as regards the fragrance of the blossoms. (Uaser' recenth' observed an indi\'idual, A, who was quite uaable to distinguish odors in the usual wa}' and whose histor\' showed among his immediate sibs two sisters normal as regards olfaction, one brother the exact counteri)art of A, and another with but slight capacity for the detection of odors. The mother of A was unable to detect odors and her father was similarly deficient. A careful study indicated that there were certain resemblances to sex-linked inheritance. The fact that the trait has appeared in one collateral (A's cousin is defec- ti^•e in the sense of smell and is the daughter of a ])aterna] aunt who is ' Textbook of PhysioloRV. Philadelphiii, 1014. - Loc. cit. ■' Science, N. S,, Vol. 48, igiX. * Science, X. S., Wjl. 48, 1918. 358 PHVSIOLOGIC.VL ADDENDA anosmatic) and two direct generations, is believed by Glaser to be suf- iiciently frequent to warrant the assumption that anosmia is heritable. Moreover, he belie^■es that anosmia is probably to be placed in the list of sex-linked characters since two sisters of A are reported to be normal as regards olfaction. It is reasonably certain that defects in the sense of smell are inherited in human beings, especially so since the function of olfaction is degenerate and ^■estigial as compared with other forms. Not infrequently there is a striking difference in the sense of smell on the two sides of the same in- di\'idual. Again, the function may be entirely suppressed. While anosmia is, doubtless, inherited at times, one must ever be cautious not to confuse anosmia due to diseased states of the olfactory mucosa, the ol- factory bulb and tract or of the olfactory cortex Avith a truly congenital anosmia. Careful examination of the nasal fossae by a trained rhinolo- gist, including both macroscopic and microscopic studies, is essential in anosmatics. In many instances such study will place pre\'iously believed congenital anosmatics on the side of the acquired type and the result of nasal disease. Strangely the condition of anosmia seems to be inbred in some locali- ties which suggests that certain nasal disorders are especially prevalent, leading to diseased olfactory mucosa; Avith a resultant suspension of smell. The author doubts that anosmia is sex-linked in inheritance since it occurs in both Avomen and men. It Avould, hoAA^eA^er, seem that congenital anosmia is mare frequenth' encountered in males. The reason for this is unknoAvn. HoAveA'er, until the records of a large series of cases shoAA^ a decided adA-antage in faA'or of men, it is unwise to assume that anosmia is sex-linked in inheritance. Functional anosmia is occasionally encountered. Wheeler in the Bulletin of the Canadian Army Medical Corps, records an interesting case of complete functional loss of smell in a soldier Avho Avas buried bv an explosiA-e shell, April, 1917. The soldier recoA^ered Avith the gustatory sense normal for the four primary tastes. He Avas incapable, hoAvever, of recognizing his food, haA'ing lost that fine discrimination Avith Avhich taste and not smell has usuahy but erroneously been credited. FoUoAAang electrical treatments the olfactory function returned and the patient Avas again able to recognize odors. His foods once more "tasted" normal and appetizing. INDEX no, I20 QtJ A Abducens nerve, 170, 103, 104, 105, 196, 201 relations of, to ca\-frnoas sinus, 104 to internal carotid artery, 104 to sphenoidal sinus, 105 Aberrant posterior ethmoidal cells, Accessor_\' nasal concha", 2;, 28, furrows, 30 bullar furrow, 30 infrabuUar furrow, 30 infundibulum ethmoidale, ^o suprabullar recess, 30 meatuses, 27,28 sinuses (paranasal sinuses) ostium of the maxillary sinus, 92, 130, 131, 132, 133 rudiments of, 36 Allerent neurons, 291 sympathetic neurons, 2S9, 290 Agenesis of frontal sinus, 146, 157, 158, 159, 160, 1 70 of sphenoidal sinus, 19S Agger cells, 97, 141 nasi, 18, 2I1, 34, 87, 97, 207 development of, 18 Alffi nasi, 68 Alar cartilages, greater, 68 crura of, 69 development of, 40 lesser, 70 Alveolar processes, 55 Amydaloid nucleus, 33S Anatomical relations, ner\-e of pterygoid canal, 320, .3 -'I Anosmia, 334, 358 Antagonistic reflexes, 292 Anterior cerebral commissure, 343, 344 ethmoidal cells, 34, 35, 141, 151, 152, 153, 154, 135, 162, 163, 164, 165, 166, 167, 170, 171, 172, 207, 2r2, 214, 215, 216, 217, 2i8, 233 bullar group of, 218 communication of, 216 extension into the frontal sinus, 212 into the middle nasal concha, 212 frontal group of, 216 infundibular group of, 216, 217 Anterior ethmoidal ner\e, 313 nares (sec Nares) 7, 10, 11, O3, 71, 72, 8g nasal spine, 66 palatine canal, 76 foramen, 76, 276 nerve, 310 perforated substance, :i:i,i superior alveolar ramus, 3ri dental nerve, 311 Antrum of Ilighmore (see Maxillary sinus), 101-133 .\[ierlura piriformis, 66 Apex nasi, 63 Arcus superciliaris, 146, 169 Area parolfactoria, 329, 33r, 333 Artery or arteries angularis, 278 dorsalis nasi, 278 ethmoidalis anterior, 277, 278 posterior, 278 external maxillary Cfacial), 275 infraorbital, 278 internal carotid, 273 maxillary, 273 labialis superior, 278 nasalis posterior lateralis, 275 septi, 276 nasopalatine, 276 ophthalmic, 275, 277 palatina descendens, 27S pharyngeal, 278 sphenopalatine, 273, 276 Ascending palatine artery, 182 Asymmetr>' of the nasal septum, S3, 171 Atresia of the choana, 10, 74 Atrium meatus medii, 88, 97 nasi, 88 Auditive tube, 201 pharyngeal ostium of, 202 Auriculotemporal nerve, 303 B Basal cells (nasal mucous membrane), 26,7 [irocess of the occi[iital bone, 189 Blood \-essels of the nose and paranasal sinuses, 273, 276, 277, 278, 270 Bones of the external nose, 63 Bowman's glands (see Olfactory glands), 2O8 359 360 IXDKX Hi'dca, (lia'^'uiial hand of, 533 parolfact(]ry area of, 331, 333, 337, 33q Buccal cavity, 55 Bucconasa) membranes (Hoclistetlcr), q, 10 rupture of, 10, 48 Bulbar sympathetic system, 295 Bulbous olfactorius, 330 Bulla ethmoidalis, ;q, 31, 32, ^^j. 94, 127,128, 129. 140, 152, 1(15, 172, 208 frontalis, r32, 153, 154, 212, 218 Bullar cells, 208 folds, 29, 30. 31, ,5-', 33. 34 inferior, 32 superior, 30, 32 furrows, 31, 208 ,t^roup of anterior ethmoidal cells, 218 Canal of .Stenson, 70 Canalis incisi\'us, 7(1 nasc)lacrinialis. 244 pharyngeus, 278 Canine fossa, no, 114 Cardio-accclerator center, 295 -inhibitory center, 289 postganglionic neurons, 295 Carotid canal, 196 plexus, 310, 31 7 Cartilage of tlie nasal septum, 39, 40, 81, 82 Cartilages of the external nose, 39, 40, b6 Cartilagincs alares minores, 70 sesamoidete nasi, 70 vomeronasales, 82 Cartilaginous nasal capsule, 38, 43, 88, 175 septum, 81 Cartilago alaris major, 68, 82 nasi lateralis, 99, 70 septi nasi, 64, 8r, 82 Ca\-ernous sinus, 181. 182, 1S9, 193, 104, 195, ig6 relation of, to sphenoidal sinus, etc., 19^, IQ4, 105, 196 thrimibosis of, 201 tissue, 295, 292. 203, 2Q7 Ca\-um nasi, 71 scpti pellucidi, 335 Celluls conchales, 211, 213, 221 ethmoidales, 37, 87, 139, 20^ anterior. 207, 215, 21Q bullar, 208, 218 frontal, 207, 2i() infundibular, 213, 219 jiosterior, 207, 210 Cephalometric nasal index, 92 Cer\-ical .ganglionated cord, 289 Ciioauc-e (posterior iiares), 9, 10, 14, 15, jj^ y^ Chorda tympani nerve, 288 Cli\-us blunienbachii, 105, 196 Commissural tracts of olfactory apparatus, 343 344 Comparati\-e anatomy of the olfactory organ, 351 of the paranasal sinuses, 350, 35 1 Compressor narium, 70 Concha nasalis inferior, 19, 20, 21, 22, 32, 39, 42, 87, 88 media, 26, 34, 90, qr, 172 superior, 95 suprema I, 96 Concha' nasales supremic 11 et III, 97 sphenoidales, 43, 175 Conchal cells (see celluhe conchales), 141, 221, 222,223,224,225,226 empyema of, 226 frec|uency of, 226 ostia of, 226 Congenital defects of the nose, 51 hstula of the lacrimal sac, 243 occlusion of choanal, 57 of nares, 57 Coronarv" artery (A. labialis superior), 278 Corpora mammillaria, 337, 338 Corticobulbar libers, 292 Corticopontine fibers, 292 Corticospinal fibers, 202 Cribriform plate of the ethmoid, 47, 95 Crista C(mchalis, 88, 89 lacrimalis, anterior, 244 posterior, 244 lateralis, 84 nasalis, O4, 81 suprema, 35, 91 D Dacryocystitis, 233 Dacryocystorhinostomy, 237 Dacryocystotomy, 253 Deficiencies of the osseous walls of ethmoidal cells, 212 of frontal sinus, 169 of maxillary sinus, 132 of sphenoidal sinus, 201 Definitive hard palate, r2, 13, 14 nasal fossre, 17, 18 septum, 37, 38 Deflections of the nasal septum, 83, 84, 85. 86 Depressor ala; nasi, 71 septi nasi, 71 Dermoids, 57 Descending palatine artery, 278 Diagcmal band of Broca, 333 INDEX 361 DiaphruKma sella-, iSg Dilatou's narif, 70 Diminutive sphenoidal sinuses, 197, iqS Disease of the nose, relation to bronchial asthma, jqh Di\-erticula of the frontal sinus, 154, 155, 150, 157 of the lacrimal sac, 043 ol the nasolacrimal duct, 243, 250, 2^1, 252 of the sphenoidal sinus, 1S4 Dorsal longitudinal bundle (Schutz's), 342 Ductus nasofrontalis, ih2. 163, 164, lOo, 1O7, i6,S Utcrimales, 237, 247 nasolacrimalis, oo, 237, 24S Duplication of the frontal sinus, 150-152 of the maxillary ostium, 120, 130 of the maxillary sinus, nS, iig, 121, 122 Dura mater, 1.S4, 1,85, iSq, 193, 214 Ectoturbinals, 27, 2,S Eiterent neurons, 291 Endonasal dacr_\-ocvstotomy, 253 Endoturbinals, iS Erectile tissue, 2(15, 202, 203, 207 Ethraofrontal cells, 211, 21O. 219, 221 f-^thmoid bone, 40 articulations of, 212 cribriform [date of, 40 development of, 40, 41 orbital plate of, 40 perpendicular plate of. So held, extensions of, infection in, 233 notch, 63 Ethmoidal arteries, 277 bulla, 29, 31, ,]2, 92, 94, 127 cells. 40, 94, 205, 20O, 20S, 242. 351 adult stage, 205, 211-233 classification of, 212, Table .1/, 213 dehiscences of, 212 extensions of, 207, 20S, 209, 224, 225, 2,^^, practical considerations of, 226, 227, 22,S, 229 roent<,'eno<,'rai)hy, 230, 231, 232, 2,^-,i, anterior, ^,2. 34, 207, 200 childhood stage of, 206, 207, 20S, 209, 210, 211 operations during, 229, 230 size of, 21 r, Table L skiagrams of, 2ro drainage of, 2^,^ fetal stage of, 205 posterior, 35, 36, 207, 209, 219 conchic (see conchxj, 22, 23, 24, 25 fissure, 99 Ethmoidal fold, 2r, 22 infundibulum (see iiiliiinliliiiliiiii rllnnoujijlf), 2,S, 30, 31, 35,91, lOi, 103, 119, 12S, 129, 140, 141, 142, 143, 152 lal)\Tinth, 159, 207, 2ir, 220, 352 boundaries of, 211 development of, 40, 41 extension of, 2-11, 212 mucous membrane of, 2(18, 270 size of. Table jV, 214 Ethmolacrimal cells, 211 EthmomaxiUary cells, 211, 210, 220 sinus, 220 I'Jthmopalatine cells, 211 Ethmosphenoidal cells, 2LI, 219, 220 Ethmoturbinal fold, 20, 222 Ethmoturbinals (see concha.'), 21 Eustachian tube, 72, 201, 202 External maxillarv artery, 275, 27.S nasal rami, 312 nose, 61, 62 bones of, 63 congenital absence of, 5(1 embryonic, 48 lymphatics of, 282 muscles of, 70 I]\terocepti\e arcs, 293 Facial artery (see External nuixiUnry aiicry), 275, -78 canal, 310 ner\-e, 28(1, 287, 2,So nucleus, 315 Eascia dentata hippocampi, 333 Eascicidus mammillotegmentalis, 342 retrollexus of i\[e\nert, :,;^i', 342 Fasciola cinerea, m Eimbria hippocampi, 334 First supreme nasal concha and meatus, 96 EistuUe, congenital dermoids, 57 E'oramen lacerum medium, iqd o\'ale, 1 78 rotundum, 178, 201, 318 sjdienopalatinum, 275 P'ornix, 335 Fossa canina (see canine fossa), no hypophyseos, 189 nasalis, yr prenasalis, 66 pterygopalatina (s|)henomaxillary), 179 sacci lacrimalis, 244 F'rontal bone, 45, 63, 66, 141, 144, 146, 148, 150, 158, 1 09 bulla, 152, 153, 154, 218, 210 3(32 INDIiX Frontal bone cell?, 140, 216 concha; (sec frontal folds), 34 ethmoidal cells, 21O folds, 33, 35, 161 furrows, 31, 33, 34. 14°, Ui, 142, 161, 162, 163, 164, 165, 166, 207, 216 lobe of brain, relation to frontal sinus, 146 process, 48 recess, 35, 140, 141, 166, 168, 207, 242 sinus (see Simis frontalis), 32, 34, 93, 95, 20S, 216, 218, 242 adult stage of , 146-170 agenesis of, 146, 157, 158, 159, 160, 170 childhood stage of, 143, 144, 14S. 146 measurements of, 145, Table F clinical considerations of, i 68-t 7 2 deficiencies of osseous walls of, 169 diverticula of, 154-157 extensive pneumatizations of, 147-150 fetal stage of, 139-143 frontal bulla of, 152, 153 mucous membrane of, 268, 270 nasofrontal connections of, 160-166 duct of, 166, 167,168 referred pain, disease of, 303 relation of, frontal lobe of brain, 146 optic ner\'e, 193 septum of, 169 size of, 147, Tables C, // skiagrams of, 1 70-172, 227, 228 supernumerary frontal sinuses, 150-152, 159, 169, 170 topography of, 151 variations of, 146, 147, 157, 169 Fronto-lacrimo-maxillary suture line, 244 Frontonasal process, 4, 37, 38 G Ganglion, geniculate, 2S9, 305, 316 habenula?, 336 semilunar (Gasscri), 2S5, 308, 316, 317 sphenopalatine, 314 Gasserian ganglion, 285, 308, 316, 317 Geniculate ganglion, 289, 305, 316 Genital spots of Fleiss, 271, 272, 300, 301 Giacomoni, band of, 334 Globular process, 4 Glossopharyngeal nerve, 286, 287 Gnathnic index, 74 Great deep petrosal nerse, 306, 31O, 317 palatine artery, 278 superficial petrosal ner\-e, 288, 289, 2c 5, 303, 3i5> 31'' Greater alar cartilage, 68, 6g, 82 Gyrus dentatus, 333, 334 epicallosus, 329, 333 subcallosus, ^^t, H Habenular bodies (see Habeniilar ganglion), 340 ganglion, 336, 340 triangle, 336 Harelip, 51, 53, 54, 55 Hiatus of the maxillary sinus, in semilunaris, 93, 127, 128, 129, 166 Hippocampal commissure, 335 digitations, 334 Hippocampus (hippocampus major), 329, 334 Huschke, vomerine cartilages of, 270 Flypophyseal fossa, i8g, 195 Hypophysis cerebri, 180, 182, iSS, 1S9, 190 relations of, to basilar arter_v, 189 to cavernous sinus, 189 to internal carotid artery, 189 to optic commissure, 189 to pons, 189 to sphenoidal sinus, 1 89 tumors of, 190 I Incisive foramen, 55, 76 Incisor teeth, 53, 54, 55 Inferior buUar fold, 32 nasal concha (turbinate), 20, 88, 238, 255, 262, nasal meatus, 20, 89, 107, 202, 239, 245, 246, 254 InfrabuUar furrow, 31, 94 Intranasal area, 48 Infraorbital artery, 278 canal, 45, 105, 108, 31S nerve, 312 Infratemporal fossa, no Infundibular cells, 141, 142, 152, 208, 216, 242 fold, 29, 30, 31, ii group of anterior ethmoidal cells, 216, 217 Infundibulum ethmoidale, 28, 30, 31, 35, 92, 93, 119, 128, 129, 140, 141, 142, 143, 152,155, 162, 163, 164, 165, 166, 167, 168, 171, 172, 207, 225, 233, 253 of the frontal sinus, 93, 166, 167, 168 of the hypophysis cerebri, 188 Inhibitory preganglionic neurons, 295 Intermaxillary mass, 48 process, 14, 16 Intermediate olfactory stria, 339, 340 INDEX 363 Internal carotid artery, io6, 275 relations to abducens nerve, 196 cavernous sinus, ig6 hypophyseal fossa, 196 sphenoidal sinus, 196 nasal rami, 312 nose, 71 Internasal bones, 66 suture, 64, 60 Interpeduncular ganglion, 336 Intranasal dacryocystotomy, 237 Jacobson's organ (see ]'omcronasa! (>)-ga)i), 9, iS, 47, 4S, 270, 271, 325, 327, 32S cartilage (see ]'omcronasal carlilagc), 68, 82 L Lacrimal bone, 42, 43, 238, 239, 244, 245 canal, 24S canaliculi, 237 ducts, 237, 239, 242 orifices of, 249 sacculations of, 247 variations of, 242, 243 fossa, 244, 245, =47 papilla, 242, 247 process, 88 puncta, 242, 247 sac, 237, 239, 240, 242, 243, 247, 248, 249, 250, 252, 253 congenital fistula of, 243 diverticula of, 243 embrj'ology of, 49, 50 Lacrimonasal membrane, 244 Lamina cribrosa, 40 papyracea, 40, 233 perpendicularis, 64, 80 rostralis, 333 terminalis, 243 Lateral ethmoid mass, 219, 222 nasal cartilage, 39, 40, 64, 6g processes, 4, 11, 237 wall, 18, 86, 87 olfactory stria, 339 Levator labii superioris alfeque nasi, 70 Limen nasi, 73, 262 vestibuli, 73 Lingual nerve, 288 Longitudinal stria, 333 Lymphatics of external nose, 282 of the nasal cavity, 280, 281 of the nose and paranasal sinuses, 279, 280, 281, 282 Lyre (transverse fornix), 343 M Major nasal concha;, 18 meatuses, 18 Mammillary bodies, 337, 338, 340 JMammillotegmental bundle of Gudden, 342 Mandibular nerve, 196 Maxilla, 44, 23S frontal processes of, 65, 66 ossification of, 44 Maxillary fold, 22 nerve, 197, 201, 285, 306, 307 relation to maxillary sinus, 306 ostium, 103, 127, 128, I2g pouches, 103 processes, 4, 5, 11, 51, 55, 88, 237 fusion of, 48 sinus, 76, loi, 164, 166, 179, 220, 233, 241, 242, 247, 353 adult stage of, 109-134 boundaries of, 109, no, in communication with the superior nasal meatus, 102, 118, iig, 120 decrease in size of, 122, 123 duplication of, lor, 118, 119, 120, t2i, 122 enlargement of, 122 location of, 109 relation of the sinus floor to the nasal floor, III canine fossa, 114 teeth, 112 to the inferior nasal meatus, in, 114 ridges, crescentic projections and septa on walls of, 116, 117, 118 size of, see tables C, D, and E, 122, 123, 124, 125, 126, 127 variations of, 126 childhood stage of, 104, 105, io6, 107, 108, 109 dimensions of (Table B), 104, 105, 106, 107, 108 endonasal procedures during, 107 relations to dentition, 106 infraorbital canal, 106, loS size of (Table 73), 108 skiagraphy of, loS, 109 communication with the inferior nasal meatus, 102 fetal stage of, 36, loi, 103, 104 size of (Table A), 104 infraorbital recess of, 253 mucous membrane of, 268, 270 openings of, oatia, 129 practical considerations of, 133, 134, 135 radiography of, 133, 134, 135 Maxilloturbinal, 19, 42, 87, 88 .. - Meatus nasi, 71 . , ■ 364 INDEX Meatus nasi, inferior, 87, So medius, 2S, 33, 87, 91, 92, 95, 96, 127 superior, 95, 96 supremus, 87, 96 Meckel's nasal ganglion, 221, 28S, 314 Medial lemniscus, 286 longitudinal fasciculus, 2S6 olfactory stria, 339 Median subcallosal sulcus of Retzius, 333 Medulla, 285, 286 Medullary stria of the thalamus, 336, 337 Membranous conchal folds, ig lacrimal ducts, 247 passageways, nasal and paranasal relations of, 252, 253 sac, 239, 248 nasal capsule, 38 nasolacrimal duct, 239 portion of the nasal septum, 82, S3 Metopic suture, 45, 145 fontanelle, 45 Middle conchal sinus, 226 nasal concha, 90, 171, 271 meatus, 20, 25, 91, 92, 107, 141, 162, 163, 166, 168, 171, 172, 243 palatine nerve, 310 superior alveolar ramus (dental nerve), 3ri Minor conchje, descending ramus of middle meatus, 30 nasal concha;, 27, 28 Mitral cells, 339 Molar, third, impaction of, 116 Motor nuclei of, 116 facial, 286 trigeminal, 286 Mucosal diverticula, of the sphenoid sinus, 184, 185, 186 relations to the dura, 185, 186, 187 Mucous membrane of, ethmoidal labjTinth, 268, 270 frontal sinus, 268, 270 maxillary sinus, 268, 270 nasal fossa;, 261 sphenoidal sinus, 268, 270 Muscles of the external nose, 70 compressor narium, 70 depressor alae nasi, 71 septi nasi, 71 dilatores nans, 71 levator labii superioris ateque nasi, 70 quadratus labii superioris, 70 N Nares, 10, 62, 72 anterior, 10, 14, 62 Nares, congenital occlusion of, 57 posterior, 14, rj Nasal atrium, 88, 97 bones, 42, 65, 66 bridge, 63, 66 capsule, 38, 176 cartilages, greater alar, 68, 70, 82 lateral, 69 lesser alar, 70 septal, 8r, 82 sesamoid, 70 vomeronasal, 68, 82 cavity, 71, 76 lymphatics, 2S0 conchic, 18, 19, 27, 28, 71 disorders, relation to asthma, 296 to dj'smenorrhea, 297, 301, 302 to menses, 297 to priapism, 298 distribution, maxillary division trigeminal nerve, 306 fossse, 16, 45, 66, 71 apertures of, 66 dimensions of, 72 floor of, 72 lateral wall of, 72, 86, 87 medial wall of, 77 mucous membrane of, pars respiratoria, 261, 262, 263, 264, 265, 266 olfactoria, 261, 267, 268 primitive, 37 relation to the brain, 344 roof of, 77 furrows, accessory, 27-35 glands, 47 index, 62 meatuses, 71 accessory, 27, 28 development of, 19, 27 inferior, 20, 8g middle, 20, gr superior, 21, 95 ist supreme, 21, 96 2d supreme, 21 3cl supreme, 21 mucous membrane, 261 erectile portion of, 272 muscles, 70, 71 neuroses, 294 ostium of the frontal sinus, 172 processes, 4 lateral, 4, 37, 48 maxillary, 4, 53, 55 , INDEX 365 Nasal processes, media!, 4, 37, 55 and paranasal relations of the membranous lacrimal passageways, 252, 253 olfactory mucous membrane, 261, 267, 26S pyramid, 63 referred pains, 302, 303, 304, 305, 306 respiratory mucous membrane, 2(33, 264, 265 cavernous tissue of, 265, 202, 203-297 ciliated cells of, 262, 263 septum, 3S buccal border of, 55 cartilaginous. Si definitive, 37 deviations of, S3 mobile, S3 mucous membrane of, 3S, 261 osseous, 7S primiti\'e, i6 secondary, 16, 37 steleton, 38 spine of the frontal bone, Si turbinates (see Conclm) vestibule, 261 Nasociliary nerve, 277 Nasoencephalic relations, 344 Nasofacial angles, 63 Nasofrontal connections, 160, 161, 162, 163 duct, 93, 142, 143, 153, 162, 163, 164, 16s, 166, 167, 16S, 216 Nasolabial sulcus, 63 Nasolacrimal canal, 241, 244, 245 ostium of, 245 duct, 239, 240, 241, 242, 244, 24S, 249, -5° communication with the middle nasal meatus, 243 diverticula of, 250, 251, 252 embryology of, 50, 31 isthmus of, 249 membranous, 239, 249 nasal end of, 255 relation to the maxillary sinus, 253 uncanalization of, 243, 244 valves of, 250, 251, 252 ostium, 89, 90, 241, 249, 251, 253 location of, 253, 254 number of, 254 types of, 251, 254, 255 passageways, 237 canalization of, 239 clinical remarks, 255, 256, 257, 258 development, 49, 237, 238, 239, 240, 241, 242 lymphatics of, 255 relations of, to conjunctival culdesac, 238 to nasal meatuses, 23S to paranasal sinuses, 240, 241, 242, 253 Nasolacrimal passageways, variations and ano- malies, 242, 243, 244 venous plexuses of, 255 sac, 49, so, 23/, 24S Naso-ojitic fissure, 48, 50, 237, 243 Nasopalatine artery, 276, 278 canal, 76, 121, 122 Nasoscxual relations, 296, 297, 298, 299, 300, 301, 302 Nasoturbinal (agger nasi), 18, 26, 87, 97 Nasus externus, 71 internus, 61, 71 Nerve or nerves (nervus or nervi), abduccns, 194 canalis pterygoidei Vidii, 177, 179, 183, 201, 315, 320, 321 ethmoidalis anterior, 313 glossopalatinus, 314 intermedins, 288, 2S9, 303, 314 maxillaris, 177, 197, 285, 303, 306, 307 nasociliary, 277, 313 olfactorius, 47, 325, 326, 338 ophthalmicus, 177, 179, 1S5, 2S5, 303 palatini, 310, 311 petrosus profundus major, 316 superficiahs major, 316 sphenopalatini, 275, 307, 308, 309 terminahs, 325, 326, 327 trigeminal, 177, 285, 286, 287, 306-318 vomeronasalis, 327 Neuron arcs, 291 Nose, 49, 61, 63 congenital defects of, 51 development, 3, 4, 13, 14 erectile tissue of, 265, 292, 296, 297 nomenclature, 27, 28 and paranasal sinuses, arterial supply of, 275 lymphatic supply of, 279 sensory nerves of, 285 sympathetic nerves of, 285 physiology of, 347, 348, 349, 350 Schaeffer's types of, 62 sympathetic fibers of, 302, 303, 304, 305, 306 Topinard's types of, 62 Nucleus, ala cinerea, 316 ambiguus, 286, 295 amygdalie, 338 oculomotor, 2S6 trigeminus, 285, 286, 287 relation to nuclei of, 286 abducent, 286 centers of, 2S6 oculomotor, 286 secretomotor, 286 366 INDEX Nucleus, trigeminus, relation to trochlear, 286 vasoconstrictor, 286 vasoinhibitor, 286 sensory nucleus of, 2S5, 286 O Oculomotor nerve, 179 Odors, classiiication of, 356 Olfactory apparatus, 325 bulb, 328, 329, 330, 354, 356 bundle of Wallenburg, 342 cells, 271, 323, 326, 327 central organ of, 328-341 anterior perforated substance, 331 fascia dentata hippocampi, 333, 334 fornix, 335 habenular triangle, 336 hippocampus, 334, 349 longitudinal stria;, 333 mammillary bodies, 338 medullary stria of the thalamus, 336, 337 olfactory brain, 32S bulb, 330 lobe, 329 tract, 330, 331 trigone, 331 parolfactory area of Broca, 331, 332 septum pellucidum, 335, 336 stria terminalis, 338 subcallosal gyrus, 333 supracallosal gyrus, 333 uncus, 334, 335 cortical centers, 341 fissure, ro? fossa;, 38 glands, 268 glomeruh, 326, 338 hairs, 267 lobes, 354 nasal mucosa, phylogeny of, 351 nerves, 47, 325, 326, 338 neurons, 338, 339, 340 pathways, afferent fibers of, 34r, 342, 343, 344 commissural fibers of, 343, 344 efferent fibers of, 343 peripheral organ of, 325-328 olfactory nerve, 325, 326 terminal nerve, 325, 326, 327 vomeronasal nerve, 325, 326, 327 pit, 47, 48, 35 7 portion of the nasal mucous membrane, 266, 267, 268 receptors, 355 refiex and cortical connections,338, 339, 340, 341 Olfactory apparatus, sensation, 354, 355, 356, 3S7, 358 relation to sexual organs, 357 to sexual reflexes, 296, 297 sensation, 350, 351, 352, 354 strife, 331 sulcus, 88, 97, 98 tract, 329, 330, 331 trigone, 33 r ' ' _ Ophthalmic artery, 275, 277 nerve, 179, 180, rSr, 182, 183, 184, 185 vein, 201 Optic chiasm, 191 commissure, r8o, 189, r9r relations of, to the paranasal sinuses, 190, 191, 192, 193 to the posterior ethmoidal cells, igi, 192, 193 to the sphenoidal sinus, 191, 192 Optic nerve, 177, 179-185, 2S5, 303 relations of, to frontal sinus, 193 to maxillary sinus, 193 to ostium sphenoidale, 192 to sphenoidal sinus, 191, 192, r93 neuritis, 190, igr, 200 tracts, 189 Orbital rami, 309 Organon vomeronasale Jacobsonii, 9, 18, 47, 48, 270, 271, 325, 328 Os frontale, 45 lacrimale, 42 ■ , nasale, 63 palatinum, 42 sphenoidale, 40, 43 Osseous framework of the lateral nasal wall, 87, 88 nasolacrimal canal, 245, 246, 247, 253 relation to, anterior ethmoidal cells, 247 maxillary sinus, 247 Ossiculum Bertiri, 43, 175 Ostium of the frontal sinus, r66, 167, r68 maxillare, 93, 94, 127, 128, i2q, 164, 166, 172 dimensions of, 103 duplication of, no, 129, 130 location of, 127, 129, 134 relation to infundibulum ethmoidale, iir accessorium, 92, ro3, rii, 130, 131, r32, 133 genesis of, 131, r32 location of, 130 -< nasolacrimale, 51, 89, 90, 253 types of, 90, 249 sphenoidale, 98, 175, 180, 181, 184, 192 deviations from the usual location, measure- ments, Table /, 188 INDEX 367 Ostium sphenoidale, location ot, 187 primitive, 176 size of, 177 Palatal processes, i2-:5 sinus, 17S Palate, bipartite, 55 definitive, 12, 13 hard (palatum durum), 55 ossification of, 42 primitive, ii secondary, 15 soft (palatum molle'), 13, 55 tripartite, 55 . , ■ Palatine nerves, 310 Papillae palatina, 76 Paranasal sinuses (see jrontal, maxillary, sphe- noidal, ctlimoidal) blood vessels of, 275-279 cilia of, 270 comparative anatomy of, 350-352 functions of, 350-353 lymphatics of, 2S1, 282 mucous membrane of, 26S-270 phylogeny of, 350-352 referred pains of, 302, 304, 305 relations of, to brain, 344 rudiments of, 36, 37, 71 Parolfactory area, Broca, 329, 331, 339 Pars olfactoria, nasal mucous membrane, 266- 268 intermedia, 288, 2S9, 305 respiratoria, nasal mucous membrane, 262-266 Partes laterales nasi, 63 Partial osseous septa, frontal sinus, i6g maxillary sinus, 116 sphenoidal sinus, 183 Peduncle of corpus callosum, ^j,t, Perforation, nasal septum, 86 Perpendicular plate, palate bone, 179 Pes hippocampi, 334 Pharyngeal artery, 275, 278 canal, 180, 318 Physiological addenda, 347-358 Physiology of the nose, 347-35° Pituitary body (see hypophysis cerebri), 188, 189 Plexus cavernosi concharum, 89, 265 Plica lacrimalis, 254 Plicte septi, 37, 38, 78 Pneumatization, of frontal bone, 147-150 of maxilla, 122, 123 Pneumatization, of sphenoid bone, 178, 179, 180 Posterior ethmoidal arteries, 278 cells, 179, 180, 198, 207, 208, 219 communications of, 219 extensions of, 212, 219, 221 genesis of, 219 relations of, to optic nerve, igi-193, 220, 221 to sphenopalatine ganglion, 221 foramen, 278 nerve, 313 longitudinal bundle, 336 nares (see Clioana), 38, 46, 71, 73, 355 nasal septal arteries, 276 palatine nerves, 310 superior alveolar rami, 310, 311 dental nerves, 310, 311 nasal rami, 310 Postganglionic neurons, 287, 288, 289 Pre-ethmoidal recess, 216 Preganglionic neurons, 287-289, 295, 296 Premaxilla;, 53 Premaxillary process, 37 Primary choana; (posterior nares), 9 nasal fossa;, 7, 47 septum, 15, 37 Primitive sphenoidal ostium, 176 Processus alveolaris, no, in, 112 ethmoidalis, 88 lacrimalis, 89 paranasalis, 39, 44 sphenoidalis septi cartilaginei, 82 uncinatus, 28, 29, 33, 34, 93, 94, 127, 128, 129, 140, 165, 172, 222 Projecting nose, 56 Pterygoid canal, 177, 320, 321 Pterygopalatine fossa (see also Sphenomaxillary fossa) J no, 179, 318 canal, 180, 318 Pyriforra aperture, 66, 246 Q Quadratus labii superioris, 70 R Radix nasi, 63 Rami nasales laterales, 313 mediales, 313 orbitales, 309 posteriores superiores, 310 inferiores, 108 Ramus nasalis externus, 314 Recessus alveolaris, 108 aoicis, 73 368 INDEX Recessus, frontalis, 33, 139, 140, 141, 143, I44, 152, 155, IS7, 158, 161, 162, 163, 164, 172 palatinus, 120 sphenoethmoidalis, 95, 97 Referred nasal manifestations, 294, 295, 296 Reflex circuits, 291, 292, 293 antagonistic, 292 inhibiting, 292 nasal manifestations, 293 nasal pains, so-called, 302, 303, 304, 305, 306 olfactory pathways, 341 centers, 340 sympathetic neurons, 291, 292 Regio vestibularis, 261 olfactoria, 261, 266, 267, 268 respiratoria, 261, 262, 263, 264, 265, 266 Relation, brain to nails of nasal fossa: and para- nasal sinuses, 344 Respiratory portion, nasal mucous membrane, 262, 263, 264, 265, 266, 307 Ridges on wall, maxillary sinus, 117, 118 Saccus lacrimalis, 49, 50, 237, 240-253 Second and third supreme nasal concha; and the related meatuses, 97, 98 Secondary nasal fossre, 17, 18 septum, 16, 38 olfactory centre, 340, 341 Sella turcica, 189 Semilunar ganglion, 285, 308, 316, 317 hiatus, 03, 127, 162, 171, 216 Sensory nerves of the nose and paranasal sinuses, 28s Septa on the walls of the maxillary sinus, 116, 117, 118 Septal cartilage, 38, 64, 81, 82 folds (seePliccE), 38, 78 Septum lucidum, 335 mobile nasi, 83 nasi cartilagineum, 81 membranaceum, 83 osseum, 78 plicae, 38, 78 sinuum frontaHum, 145, 146, 169 sinuum sphenoidalium, 187 Sesamoid nasal cartilages, 68, 70 Sinus frontalis (see Frontal sinus), 139 adult stage of, 146, 147, 148, 149, 150, 151, 152, 153, IS4, 155, 156, IS7, 158, 159. 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170 childhood stage of, 143, 144, 145, 146 fetal stage of, 139, 140, 141, 142, 143 maxillaris (see Maxillary sinus), loi Sinus maxillaris, adult stage of, iog-135 childhood stage of, 104, 105, 106, 107, 108 109 fetal stage of, 36, loi, 103, 104 pseudo paranasal, 226 sphenoidalis {see Sphenoidal sinus), 175 adult stage of, 178-202 childhood stage of, 176, 177, 178 fetal stage of, 175, 176 superior sagittal, 279 terminalis, 17s, 176 Skeleton changes incident to growth, 45 Solid nasolacrimal duct, 239 Somatic sensory fibers of, glossopharyngeal, 286 pars intermedia, 286 . . vagus, 286 Sphenoethmoidal cells, 220, 221 recess, 96, 97, 180, 187 Sphenoid bone, 43 Sphenoidal concha;, 43, 175 fissure, 195 sinus, 17s adult stage of, 178 agenesis of, 198 anlage of, 36 caudal wall of, 182, 183 relation, to posterior nares, 182 to Vidian nerve, 183, 320, 321 cephalic wall of, relation, to hypophysis cerebri, 182, 189 to optic commissure, 182, 189 childhood stage of, 176, 177, 178 growth of. Table /, 178 relation, to trigeminal nerve, 177 To Vidian nerve, 177 curetting of, 201 disease of, 199, 200, 201 diverticula of, 184, 185, 186 mucosal, relation of, to dura, 185, 186, 187 dorsal wall of, 182 relation of, to basilar arterjr, 182 to pons, 182 fetal stage of, 175, 176 size of, 176 lateral wall of, 181, 182 location of, 178 medial wall of, 183 nerves of, 309 ostium of, 43, 187 INDEX 369 Sphenoidal sinus, partial osseous septa of, 18,5, 184 pneumatization of, 178, 170, 184, 189 primary ostium of, 187 recesses of, 178 relations of, to basilar artery, 182 to cavernous sinus, 181, rS:, 103-1Q6 to ethmoidal conchie, i8t to foramen ovale, 178 to foramen rotundum, 17S to Gasserian ganglion, 106, 107 to M-pophysis cerebri, 182, 188, 180 to mandibular nerve, 106 to maxillary sinus, 170 to optic nerve, 179, T07 to sphenopalatine ganglion, iSo to Vidian nerve, 177, 320, 321 septum of, 187 size of. Table K, 1S8 topography of, iSo, 181 ventral wall of, 181 X-rays of, 199, 200, 201 in infants, 199, 200 Sphenomaxillary fissure, 309 fossa (see Ptcrygopalalinc fossa), iro, 179, 31S ganglion, 314 Sphenopalatine artery, 275, 276 foramen, r79, 180, 275, 318 ganglion (^Meckel's ganglion), 180, 221, 28S, 289, 303, 30s, 306, 307, 308, 310, 314 anatomic relations of, 318, 319, 320 disease of, 304 fibers of, 307, 308, 309 location of, 314, 318 motor root of, 314 sensory root of, 317, 318 somatic sensory neurons of, 315 sympathetic afferent neurons of, 316 root of, 316, 317 nerve, 275, 307, 308, 309 Sphenoturbinals (see Sphenoidal coiiihx), 41, 43, 17s Stratum griseum, :}_^^ Stris longitudinales, $i^ meduUaris thalami, 336, 339, 342 terminalis, 338 Subcallosal gyrus, 329, ^:}3 Substantia gelatinosa of Rolando, 285 perforata anterior, 329, 331 Sulcus ethmoidalis, 64 nasalis posterior, 72 olfactorius, 88, 97, 98 Superciliary ridges, 146, 169 Superior buUar fold, 32 cervical sympathetic ganglion, 287, 289, 317 24 Superior dental plexus, 3r:, 312 dural sinus, 279 labial artery, 276 nasal concha, 32, 95 meatus, 95, 96, 220, 224, 275 orbital fissure, 179, 195, 313 Supernumerary frontal sinuses, 150, 131, 152, 169, 170 Supraoullar furrow, 30, 92, 141 recess, 30, 32, 95 Supracallosal gyrus, ^^^ Sustentacular cells (see Nasal miuoiis memhraiie), 266, 267 Sympathetic afferent neurons, 289 efferent neurons. 289, 29S postganglionic, 288 preganglionic, 288 fibers, 287, 288 nerves of the nose and paranasal sinuses, 285, 287 sacral efferent fibers, 298 system, bulbar, 29s T^nia fimbria;, 334 semicircularis (slria Icrmhialis), 338 thalami, 336 Tegmental bundle of Gudden, 342 Terminal nerve, 271, 325, 326, 327 sinus (nasal), 43, 44, 173 stria, 338 Thoracolumbar sympathetic, 287, 295 Topinard's nasal types, 62 Tract of Vicq d'.\zyr, 343 Tractus habenulopeduncularis, 342 mammillopeduncularis, 342 mammillothalamicus (Vicq d'Azyr), 343 olfactohabenularis, 342 olfactomesencephalicus, 342 olfactorius, 329, 330, 331 olfactotegmentalis, 342 tegmentalis, 342 Transference and reference, afferent impulses, 3°^. 303, 305, 306 Transillumination, 228, 230 Triangular area of His, 48 Trigeminal nerve, 271, 3:3 central connections of, 285, 286, 287 divisions of, 285 nasal distribution of, 306-318 terminal nucleus of, 285, 286 Trigeminothalamic tract, 286, 287, 294 Trigonum habenul*, 336 olfactorium, 331 Trochlear nerve, 179 Tuba auditiva Eustachii, 72, 201, 202 370 INDEX Tuberculum septi, 78, 271 Turbinate crest (crista conchalis), SS Turoinated bones (see Concha nasalcs) U Uncinate process (see Processus imcinaliis), 34, 9^, 93, 211 Uncus, 334, 335, 33S, 356 V Vagus nerve, 286, 287 Valve of Hasner, 90, 254 Valves of nasolacrimal duct, 250, 251, 252 Vasoconstrictor center, 289, 290 fibers, 288, 289 Vasodilator center, 288, 289, 290, 293, 299, 357 Veins, anterior facial, 279 etlimoidal, 279 Veins, splienopalatine, 279 Venous supply, nose and paranasal sinuses, 279 Ventral psalterium, 343 wall, sphenoidal sinus, 181 Ventricle of the fornix (Verga), 335 Ventriculus bulbi oltactorii, 330 Verga's ventricle, 335 Vestibulum nasi, 73 Vicq d'Azyr, tract of, 343 Vidian canal, 177, 179, 180, 318 dehiscences of, 305, 306, 315, 316 relation to sphenoidal sinus, 320, 321 Vidian nerve, 177, 179, 183, 201, 320, 321 relation to splienoidal sinus, 320, 321 Vomer, 41, 42, 79 Vomerine cartilage (Huschke), 270 Vomeronasal cartilage (Jacobson), 68, 82, 270 organ (Jacobson), 9, 18, 47, 48, 325, 327, 328 mucous membrane of, 270, 271 nerve, 327 , " _' -5p^»