ROFESSIQNAl 
 DENTURE 
 SERVICE 
 
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DEDICATION 
 
 To all who seek to place denture service on its 
 proper plane in the esteem of the profession and 
 the public, this work is respectfully dedicated. 
 
Copyrighted, 1918 
 
 BY 
 
 The Dentists' Supply Company 
 New York 
 

 
 
 
 Professional 
 
 
 
 Denture Service 
 
 
 
 BY 
 
 George Wood Clapp, D.D.S. 
 
 and 
 
 Russell Wilford Tench, D.D.S. 
 
 
 
 With an introduction by 
 J. Leon Williams, d.d.s. , p. r.a.s. 
 
 
 
 1918 
 
 
 
 Published by 
 
 The Dentists' Supply Company 
 
 220 West 12d Street 
 New York 
 
 
1^ K U % 
 
 CREDITS 
 
 No claims are made for originality in fundamentals. 
 
 We have gladly taken the best we have been able to 
 find in every line from everyone, have added to it 
 where possible and have harmonized all into a 
 consecutive procedure. 
 
 To all to whom we are indebted we give hearty 
 
 thanks in this way rather than cumber and confuse 
 
 the text with many names of originators of special 
 
 technic. 
 
 The Authors. 
 
THE PI EtPOSE OF THIS BOOK 
 
 is to present every important step in the technic 
 of fitting an edentulous patient with really pro- 
 fessional dentures. 
 
 Professional dentures are distinguished by being 
 stable in all positions of the mouth, comfortable 
 in use, efficient in mastication and natural in 
 appearance. 
 
 The technic employed is that taught in the Labor- 
 atory of the Research Division of The Dentists' 
 Supply Company. It is being used with great satis- 
 faction by dentists in all parts oi the United States. 
 
 The taking of impressions with compound, the 
 use of Williams' methods of selection and Gysi's 
 methods of articulation are taught because the 
 writers believe them to be sufficiently superior to 
 other methods to much more than justify the trouble 
 incident to their mastery. 
 
 Most of the illustrations are original. 
 
 The imperative method has been adopted in the 
 text because it is the natural method in teaching, 
 because it facilitates the mastery of the subject 
 by the student, and because it permits the use 
 of fewer words. 
 
 As far as possible scientific explanation has been 
 omitted because the science has been incorporated 
 in its practice. 
 
 The Authors. 
 
Table of Contents 
 
 PAGE 
 
 Introduction by J. Leon Williams, D.D.S., F.R.A.S. 9 
 
 Part I 
 
 Impressions and Bites 13 
 
 Part II 
 
 Selecting the Size, Form and Shade in Artificial 
 
 Teeth 97 
 
 Part III 
 Measuring Habitual Masticating Movements 124 
 
 Part IV 
 
 Arranging the Teeth 183 
 
 Part V 
 
 Simplex Articulator and Snow Face Bow 211 
 
 Part Vl 
 
 Flasking, Vulcanizing, Finishing and Perfecting the 
 
 Fit 225 
 
Introduction 
 
 A Call to Service 
 
 One of the great merchant princes of America recently 
 said, "The secret of my success is Largely that my business 
 is founded on the principle that service shall have first 
 consideration. Give the public the best possible service 
 and the money returns are certain to follow." 
 
 This idea of "service first" is a comparatively new note 
 in the commercial world. It is a sound financial proposi- 
 tion, and, so far as it is sincerely carried out, represents 
 a great advance in business morality. 
 
 It is sound financially because the wealth of the world 
 is constantly increasing, and, consequently, the standards 
 of everything required in life are always rising. Those 
 who keep abreast of these rising standards, who by superior 
 service build up a reputation for supplying something 
 Keller than the average, will always command first atten- 
 tion from those who want this superior service and have 
 the money to pay for it. 
 
 When T decided, nearly a dozen years ago, that I would 
 devote the remaining years of my life to an etfort to raise 
 the standard of prosthetic dentistry, I saw clearly that 
 three fundamental tilings were necessary. The first and 
 most important tiling was improved forms of artificial 
 teeth: the second requisite was an improved technic in 
 all the processes of the art of making artificial dentures; 
 and the third thing that must be constantly insisted on was 
 an adequate fee to the dentist for greatly improved service. 
 
 Improved service, the best possible service first, and 
 then the demand lor a fee commensurate with that service. 
 T have said that this must be constantly insisted o». and 
 there was a special reason for this, in fact two reasons. 
 The great majority of dentists have always undervalued 
 
their services in this branch of practice. They have not 
 adequately estimated the value of good denture service to 
 their patients and gradually came to relegate as much of 
 the detail of this service as possible to inferior hands. 
 JSTaturally the public came to place on the value of den- 
 ture service the low estimate that corresponded with the 
 dentist's own estimate. To change all this it was there- 
 fore necessary not only to give the dentist materials and 
 methods for a higher form of service but also to encourage 
 him in the effort to educate his patients up to a full ap- 
 preciation of the value of the improved service. 
 
 Almost at the outset of this enterprise 1 insisted that 
 if the dentist would overcome his long cultivated timidity 
 in this matter of fees he would have but little difficulty in 
 this direction. Americans, especially, I felt certain, would 
 be found as willing to pay for value received in denture 
 service as in other less important things. 
 
 During the four years that Trubyte teeth have been in 
 the hands of dentists, the results achieved by those who 
 have adopted their use, in connection with the greatly im- 
 proved technic that has been introduced simultaneously, 
 have fully justified the highest anticipations on the part 
 of those responsible for the introduction of the higher 
 standards of service. Thousands of dentists who have 
 adopted these new methods and higher standards have 
 found such appreciation of their efforts and success on 
 the part of their patients that they have had no difficulty 
 in securing a very substantial advance in fees. 
 
 And this experience is illustrated and confirmed by 
 numberless instances in the history of human progress. 
 QUALITY OF SERVICE FIRST, then make the value 
 of this service clearly seen by the public and the financial 
 rewards are sure to follow. 
 
 One of the greatest weaknesses of human nature, and 
 the one which most seriously interferes with success in 
 life, is lack of faith in oneself and in others. Whatso- 
 ever a man thinketh, that he is and that can he do, and 
 
 10 
 
iii the matter of real achievement the world will, generally 
 speaking, take him at his own estimate. 
 
 A man's occupation or calling fills the larger part of his 
 Life and be should therefore get one of the greatest com- 
 pensations of life out of his calling. And this greatest 
 compensation must be found in the consciousness that: he is 
 rendering the best service that he can to his fellows. 
 
 Nothing is more degrading to all the standards of lifo 
 and the whole moral nature of a man than the ever-present 
 consciousness that he is not doing his best. That way lies 
 the darkest aspect of failure. 
 
 Foremost, among the works which The Dentists' Supply 
 Company has issued with the purpose of assisting dentists 
 in the improvement of their technic in denture service 
 must be placed this little book. 
 
 The authors freely acknowledge that they have gleaned 
 many of the ideas and methods from many sources but I 
 think it is not claiming too much to say that they have 
 added some things of importance out of their own experi- 
 ence and have so simplified, co-ordinated and illustrated 
 every step in the newer methods of denture making as to 
 produce the most valuable work on this subject that has 
 appeared. 
 
 Not a single procedure has been described that has not 
 been successfully tested and practically applied. 
 
 I often heard the late Dr. W. IT. Atkinson say that if the 
 bulky dental text books could be shorn of all their useless 
 trimmings and superfluous verbiage and so reduced to 
 about one-fourth of the usual size their usefulness would 
 be more than doubled. 
 
 This production seems to me to fulfill my old friend's 
 conception of the ideal text book. .May it be to those to 
 whom they have dedicated it an inspiration to establish 
 Ibis necessary and dillicult form of dental service on a 
 plane which commands the respect and even the admira- 
 tion of those who serve and those who are served. 
 
 J. LEOX WILLIAMS. 
 11 
 
The Plan of the Book 
 
 The several steps, from the examination of the month 
 preceding the taking of the impression to the discharge of 
 the patient, are described, as nearly as possible, in the or- 
 der in which they are performed. We hope that dentists 
 who desire to follow this technic may be able to open the 
 book before them and perform the steps in correct order, 
 as they find them illustrated and described. This sep- 
 arates parts of the technic which would otherwise be de- 
 scribed together, but will, we hope, be helpful to students. 
 
 Modelling compound impressions are here accepted as. 
 standard because we believe them to be superior, in prac- 
 tically all cases, to other impressions. We believe that any 
 dentist who will devote to the mastery of compound technic 
 the same attention that he must give to mastering the prin- 
 ciples of inlay making, for instance, can achieve a gratify- 
 ing degree of success. 
 
 Dentists who prefer to use plaster in connection with 
 compound, will find directions for doing so on pages 95 
 and 96. 
 
 The technic of using the Gysi Adaptable Articulator is 
 explained in detail, because an. understanding of its prin- 
 ciples is important to every dentist who wishes to render 
 professional denture service, and certain portions of it 
 may advantageously be used in connection with the Sim- 
 plex Articulator. 
 
 At the date of this writing, it is impossible to obtain 
 Adaptable Articulators from Switzerland, but it is hoped 
 that before long they can be produced in this country, so 
 that they may be placed within the reach of all. 
 
 The Simplex Articulator, when used with proper tech- 
 nic is very satisfactory indeed. The most desirable technic 
 for this articulator is illustrated and described beginning 
 on page 211. 
 
 12 
 
ERRATA 
 
 Owing to unusual condil ions during preparation, certain 
 errors in figure numbers and technical terms have 
 
 occurred, as follows. IT the reader will make the cor- 
 rections on the pages indicated, annoyance will be 
 avoided. 
 
 Page 39, line 13, "D" should be '"A". 
 
 Page 43, line 6, should read "Figure 22" instead of 
 "Figure 20"'. 
 
 Page 73, line 7, "right hand" should read "left hand". 
 
 Page 90, fourth line from bottom of page. "Figure 30" 
 should read "Figure 31". 
 
 Page 126, line is, "Figure 124 "should read "Figure 123". 
 
 Page 147, line 10, "127" should read "126". 
 
 Page 180, line 9, "Figure 150 "should read "Figure 145". 
 
 Page 192, line 4. The sentence beginning "Only the 
 mesio-buccal cusp" etc., should read: "Only 
 the mesio- lingual cusp of this tooth should 
 touch the occlusal surface of the opposing bite, 
 the disto-lingual cusp being slightly raised 
 and the buccal cusps being raised about three- 
 quarters of a millimeter out of contact . as shown 
 in the second diagram of "A". Figure 16*1". 
 
 Page 194, line 9. The sentence beginning "The move- 
 ment" etc., should read "The movement of 
 the teeth on the working side, back to a posi- 
 tion of rest is nearly at right angles to the 
 median line". 
 
 Page 210, line 7. "(b)" refers to solid line "A-P>". 
 "a" refers to upper dotted line. 
 
 Page 213, last line. '137" should read "89" 
 
Part I 
 Impressions and Bites 
 
Merits of Compound Impressions. 
 
 Compound, properly handled, is less objectionable to 
 patients than plaster. 
 
 The impressions can be taken in stages and the adapta- 
 tion of both plates proved before they are made. 
 
 The guesswork and uncertainty as to the height and 
 form of the impression margins common to other methods 
 of impression taking are avoided, and the contour and 
 height of the flanges accurately determined by the actions 
 of the muscles upon the impression material. 
 
 To be successful in mastication, a denture must com- 
 press the soft tissues as described later so that they oppose 
 to the thrust of mastication the same resistance as the hard 
 tissue. Only compound impressions permit proper com- 
 pression of the soft tissues. 
 
 In mouths presenting a relatively large proportion of 
 soft tissue, the correct use of compound insures a greater 
 degree of success than is otherwise obtainable. 
 
 A better degree of success can be achieved in taking 
 lower impressions than we believe to be otherwise possible. 
 
 The finishing of the impression under biting stress is 
 very important. It is possible only when compound is 
 used. 
 
 The use of compound facilitates the taking of impres- 
 sions and bites and records of jaw movements at one sit- 
 ting. The most exact bite relations are obtained and the 
 bites make the most satisfactory bases for taking accurate 
 records of jaw movements. 
 
 The fact that a patient is satisfied with dentures is no 
 indication that they are the best obtainable. Many 
 previously satisfied patients have been astonished and de- 
 lighted with dentures made by the technic described 
 herein. It requires more time and more attention to de- 
 tail than the impression taking methods in general use, 
 but so much time is saved in the later stages of the work, 
 and there are so few make-overs and the results are so 
 much better as to make it really economical. 
 
 14 
 

 ■ ■■••-- 
 
 ffi Vf»Trmaffy-r -iii 
 
 EXTRA DEEP RELIEF 
 FOR BONY PROMINENCE 
 
 SOFT FLABBY R1DGI 
 SPECIAL TECHNIC 
 
 SEE TECHNIC FOR 
 FRENUM NOTCH 
 
 AREA USUALLY 
 RELIEVED 
 
 ANTERIOR LIMIT 
 OF COMPRESSIBLE 
 TISSUE 
 
 HARD, BULBOUS 
 TUBEROSITY 
 REQUIRES SURGICAL 
 REMOVAL 
 
 RELIEVE FOR POSTERIOR 
 PALATINE CANAL 
 
 SPINES BEHIND PALATINE 
 CANALS MAY REQUIRE RELIEF 
 
 TISSUE MOVEMENT BEGINS 
 
 RELIEVE FOR ANTERIOR 
 PALATINE CANAL 
 
 HARD, PROMINENT 
 PROCESS REQUIRES 
 SURGICAL REMOVAL 
 
 RELIEF FOR 
 PALATINE ARTERY 
 SEE FIGURE 62 
 
 THIN. HARD MUCOSA 
 REQUIRES HIGH 
 FLANGE AND CLOSE 
 ADAPTATION 
 
 LIGAMENTOUS 
 ATTACHMENTS 
 SEE FIGURE 23 
 
 RELIEVE FOR POSTERIOR 
 PALATINE CANAL 
 
 EXTREME LENGTH PLATE. 
 FLABBY RIDGE 
 
 Fig. 1 
 
 This illustration summarizes many of the conditions 
 in the mouth which affect the procedure of impression 
 taking, and serves to emphasize certain steps in technic. 
 It is placed here so that when the technic of impression 
 taking' is understood, it may serve as an easily accessible 
 reminder of certain important details. 
 
 15 
 
Classification of Tissue Conditions in 
 Edentulous Mouths. 
 
 It will be found useful to classify the conditions of the 
 tissues in edentulous mouths as a means of determining 
 the procedure most likely to yield satisfactory results. Mr. 
 Supplee's classification, which follows, will be found a 
 valuable aid in the selection of an impression material, in 
 teaching and in the interchange of thought among workers. 
 
 It also helps to understand why dentists who have suc- 
 cessfully made dentures from plaster impressions cannot 
 succeed for the same patient 4 or 5 years later, although 
 they use the same materials and technic. Mouths in 
 Classes 1 and 2 tend to pass into the conditions in Classes 
 3 and 4, especially if the artificial dentures are not well 
 articulated, or when the patient is compelled to masticate 
 on the incisors. 
 
 UPPERS. 
 
 Class 1. Firm ridges covered with a uniform layer 
 of slightly yielding membrane. Buccal and labial attach- 
 ments connected high on border of ridge. 
 
 If plaster impressions are to be satisfactory anywhere, 
 it will be in this Class and Class 2. Muscle trimmed 
 plaster impressions may be made by the technic described 
 on pages 95 and 96. 
 
 Class 2. Firm ridges and vault covered with tensely 
 drawn membrane. Very small area of soft tissue over 
 the rear third of the hard palate on either side of the 
 median line. Buccal and labial attachments connected 
 close to the crest of the ridge and very definite in move- 
 ment. 
 
 Class 3. Firm ridges. Soft area in the vault, par- 
 ticularly over the rear third of the hard palate on either 
 side of the median line. The buccal and labial attach- 
 ments are connected to the ridge areas of movable soft 
 tissue overlying the buccal and labial surfaces. 
 
 16 
 
Small bony prominences are often hidden under ilic 
 soft membrane and cannot be detected and properly lo 
 cated withoul pressure by ;i ball-end instrument. 
 
 Successful dentures for mouths in Classes 3 and 4 
 arc almost Impossible when plaster is used for impres- 
 sions because localized compression of the soft tissue- is 
 essential. They require the use of compound and the 
 technic described in the following pages. 
 
 ('lass 1. High or low vault. Soft ridges or tuberosities. 
 Buccal and labial attachments cither high or low. Vault 
 either hard or varying in density. 
 
 LOWERS. 
 
 Class 1. The prominent ridge that is hard all over. 
 
 Class 2. The flat, hard ridge with prominent muscles 
 whose hases of attachment are at least V4 inch from the 
 crest of the ridge in the molar region. 
 
 Class 3. The flat or high ridge where the muscular 
 attachments are movable to the crest of the ridge, par- 
 ticularly in the molar region. (In many cases this type 
 has indirect attachment to the top of the ridge through 
 areas of movable soft tissue.) 
 
 Class 4. The flexible or soft ridge. Muscular attach- 
 ments either direct or indirect through soft tissue. 
 
 CLASS 1. 
 
 (supplee) 
 
 LOWER ANTERIOR LOWER POSTERIOR 
 
 EXPLANATION OF MARKS UPPER. 
 
 1. Muscular attachments connected high on labial bor 
 
 der of ridge. 
 
 -. Vault covered with a uniform layer of membrane. 
 
 3. Slight soft areas in rear third of vault. 
 
 17 
 
EXPLANATION OF MARKS — LOWER. 
 
 4-6. Muscular attachments connected low on labial and 
 lingual border of the ridge. 
 
 5. Uniform layer of membrane over a prominent ridge. 
 4a-5a-6a. Same condition in molar region. 
 
 CLASS 2. 
 
 (supplee) 
 
 LOWER ANTERIOR 
 
 LOWER POSTERIOR 
 
 1. 
 
 EXPLANATION OF MARKS UPPER. 
 
 Muscular attachments of labial border connected near 
 
 the crest of ridge. 
 
 2. Vault covered with thin, tensely drawn membrane. 
 
 3. Bony prominence often present in this class of Case. 
 
 4. Small area of soft membrane in rear third vault. 
 
 EXPLANATION OF MARKS LOWER. 
 
 4-6. Labial and lingual attachments connected close to 
 crest of ridge. 
 
 4a-6a. Same condition in molar region. 
 5-5 a. Thin tense membrane covering ridge. 
 
 CLASS 3 
 
 (supplee) 
 
 LOWER ANTERIOR LOWER POSTERIOR 
 
 EXPLANATION OF MARKS UPPER. 
 
 1. Muscular attachment connected to ridge through 
 areas of soft tissue (la). 
 
 18 
 
2. Comparatively deep urea of sofl membrane covering 
 the vault. 
 
 B. A small pronounced bony prominence La often hid- 
 den under the sofl membrane, thai cannol be detected with- 
 out pressure. 
 
 '.'>. Varying depth of movable sofl tissue under the mem- 
 brane covering the rear third of the vault. 
 
 EXPLANATION OF MARKS LOWER. 
 
 l-i;. Buccal and lingual attachments connected to the 
 ridge through an area of soft movable membrane (5). 
 4;H>;t. Same condition in the molar region. 
 
 CLASS 4. 
 
 (5JPPLEE) 
 
 LOWER ANTERIOR 
 
 LOWER POSTERIOR 
 
 EXPLANATION OF MARKS UPPER. 
 
 The predominant characteristics of a Class 4 case is a 
 soft ridge in front ( 3a >, flexible tuberosities, or both. 
 
 1. Labial attachments that may he either high or low, 
 but connected to soft ridge (3a). 
 
 2. The membrane may be thin, heavy, or varying in 
 density. 
 
 3. Movable soft tissue in rear third of vault that may 
 be small and shallow or large and deep. 
 
 li. A bony prominence that is often evident in this class 
 of case. 
 
 EXPLANATION OF MARKS — LOWER. 
 
 4-6. Buccal and lingual attachment connected to soft 
 ridge (7) through the movable membrane (5). 
 
 4a-6a. The same thing in the molar ridge. 
 
 The sofl ridge I 7-7a | as a general rule is thin, ribbon- 
 like, and very flexible. 
 
 19 
 
Fig. 2. 
 
 Locating Compressible Palatal Tissues. 
 
 The posterior margin of the plate is to be located on the 
 soft tissues which overlie the posterior area of the hard 
 palate. These are compressible but do not move much. 
 The ball end of an instrument, pressed against these 
 tissues, can be felt and seen to compress them. Watch the 
 soft palate and with a soft indelible pencil mark the palate 
 14 inch back of where movement in these tissues begins 
 when the patient says "Ah". 
 
 The tray should extend to this point to confine and sup- 
 port the compound and facilitate proper adaptation. 
 
 20 
 
Fis 
 
 Determining Length of Tray. 
 
 The point "A" shows where movement of the soft tis- 
 sue begins when the patient says "Ah". Trim the tray 
 to reach to the line "B", ] t inch behind the point "A". 
 For patients who gag easily, it may he necessary to stop 
 the tray at or y$ inch in front of "A". 
 
 impression 1 rays of thin material are much more 
 easily trimmed and adapted than thick trays. 
 
 Apply cold cream or white vaseline to the corners of 
 the patient's mouth to protect them during impression 
 taking. 
 
Fig. 4. 
 
 Trimming Upper Impression Trays. 
 
 "A" shows a thin aluminum perforated impression 
 tray in the form in which it is received from the maker. 
 
 "B" shows the same tray with the flange cut away in 
 the incisor and bicuspid region to facilitate adapting and 
 trimming the compound. When this tray is in the mouth, 
 it reaches back to the line "B" in Figure 3. 
 
 22 
 

 
 
 
 
 
 BSH 
 
 
 
 
 ^■j^ --*»^ 
 
 
 PV 
 
 li 1 
 
 I w 
 
 
 
 
 •► i * ■ 
 
 \) ^ 3*— "^ 
 
 
 B 
 
 
 
 K- 
 
 
 ?pt- -V 
 
 
 [r^ 
 
 
 
 \l 
 
 
 
 
 — *^ 
 
 
 
 
 
 
 
 Fig. 5. 
 
 A Heater for Impression Compound. 
 
 Compound cannot be properly manipulated for impres- 
 sions and bites unless the heat by which it is softened 
 can be controlled so as to develop the required working 
 qualities. We have found the heater here shown satisfac- 
 tory. Have the water in the vessel about 3 inches deep. 
 Keep the top of the heating ring ] L > inch below the surface 
 and the bulb of the thermometer 1 inch below the surface. 
 
 Immerse three sheets oL : compound in the water to 
 soften for impression work while the tray is being shaped. 
 
 The temperature of the water should be about 150° F., 
 never above L60° F. With the water at this temperature 
 learn to soften compound to the bending stage, the mould- 
 ing stage and the flowing stage. 
 
 23 
 
Fig. C. 
 
 Perfecting the Fit of the Tray, Part I. 
 
 It is often impossible to properly adapt the tray to the 
 tuberosities by sight. Soften two small rolls of compound 
 in water at 150° F. and place on the tray as shown. Carry 
 the tray into the mouth and press carefully upward until 
 the posterior margin of the tray is about % inch from the 
 vault and parallel to it, and the anterior margin is about 
 y s inch below the ridge in front, as here shown. The 
 front margin of the tray should extend forward to a point 
 directly below the most prominent part of the ridge. Re- 
 move the tray from the mouth and chill the compound. 
 
 The compound blocks are called "Adjustment blocks." 
 
 24 
 

 Perfecting the Fit of the Tray, Part II. 
 
 The medial] line of the soft palate is usually clearly pink 
 or white and its location easily seen. Place the tray carry- 
 ing the adjustment blocks in the mouth. When it is in 
 position, make a plainly visible line, with a sharp exca- 
 vator, on the lingua] surface of the tray so that it continues 
 the median line of the soft palate forward, as shown by the 
 black lino on the tray, in- this illustration. Remove the 
 tray and deepen the line. 
 
 When carrying the heel of the tray upward, in begin- 
 ning to take the impression, this line on the tray should 
 be directly below the median line of the soft palate. 
 
 25 
 
Fig. 8. 
 
 Perfecting the Fit or the Tray, Part III. 
 
 The thickness of the adjustment blocks shows whether 
 the tray properly fits the tissues. At the point "1" in "A" 
 the tray was too close to the tissues, as is shown by the 
 compound margin being less than % inch thick. At 
 point a 2" in "A" the compound margin is more than y 8 
 inch thick, showing that the tray was too far from the 
 tissues. 
 
 Cut off the compound projecting through the perfora- 
 tion in the vault of the tray. Remove the adjustment 
 blocks and trim the flanges which are more than Yg inch 
 
 26 
 
Perfecting the Fit or the Tray, Part III. 
 Continued. 
 
 thick, until they are uniformly !y inch thick as shown 
 in "B". 
 
 Reseat each adjustment block in the tray. Grasp tray 
 and block firmly between thumb and lingers at "D" and 
 burnish the flange of the tray against the block. When- 
 ever the compound flange is too thin, as at "1" in "A", 
 insert a knife between block and tray and bend the tray 
 outward. When the tray is properly lined, remove the 
 adjustment blocks. 
 
 Tf the tray is improperly fitted, there may lie too much 
 compound in the impression at the tuberosities. This may 
 interfere with bite taking or the free movement of 
 the mandible and the taking of correct Gysi records. In 
 some cases the mandible moves so close to one or both tuber- 
 osities thai proper records can be taken only by the method 
 described on page 125. 
 
 27 
 
Fig. 10. 
 
 Preparing the Upper Tray eor the Attach- 
 ment or the Compound. 
 
 Grasp the dry tray with pliers and warm it in the flame. 
 Heat the end of a stick of compound in the outer zone 
 of the flame until it sputters and paint the palatal surface 
 of the tray, as shown. Compound applied in this manner 
 will adhere more firmly than if applied to a cold tray and 
 will afford a better attachment for the impression com- 
 pound. 
 
 28 
 
Fig. 11. 
 
 Preparing the Upper Tray for the Attach- 
 
 MKXT OF THE BlTE RlM. 
 
 At this time the under surface of the tray may be pre- 
 pared for the attachmenl of the hire rim in such manner 
 ;i^ in prevent it coming loose from the tray during the sub- 
 sequent manipulation. Heal ;i stick of compound in the 
 outer zone of ;i bunsen flame until it begins to sputter 
 and paint the lingual surface of the ridge portion of the 
 tray ;i< shown here. 
 
 29 
 
Fig. 12. 
 
 A Test for Quantity. 
 
 With the glass spatula, raise from the bottom of the 
 heater, a small mass of compound and form into a sheet 
 3/16 inch thick and of approximately the area of the tray, 
 with enough to turn up for the marginal flanges of required 
 height as here shown. It is usually better to have a slight 
 surplus than not enough. For patients who gag easily, less 
 than enough may be used in the region of the heel, and 
 deficiencies in the impression filled up by additions from a 
 tracing stick later. Shape this test sheet as here shown. 
 Remove it and dip in hot water and knead with the hand 
 till it is of nearly flowing consistency throughout the mass. 
 
 30 
 
Fig. 13. 
 
 Attaching the Impression Compound. 
 
 The tray and the compound already painted upon it 
 should be dried with a towel or bibulous paper. 
 
 Shape the mass of softened compound as shown in this 
 picture and beat the point of it in the bunsen flame until 
 it sputters. Press it quickly upon the compound already 
 mi the palatal surface of the tray and mould it to 
 approximately the shape of the finished impression. 
 
 31 
 
Fig. 14. 
 
 Shaping the Compound in the Tray. 
 
 Shape the compound so that the mass in the center of 
 the vault will be high but the posterior margin of the tray 
 will be free from compound. As this mass touches the 
 palate, it flows to the rear. Form a depression for the 
 alveolar ridge and shape marginal flanges, which will go 
 between the ridge and the cheeks. These flanges should 
 be about 3/10 inch thick. This shaping should be 
 practiced until one acquires skill to finish it while the 
 compound still moulds easily. 
 
 32 
 
Fig. 15. 
 
 Chilling the Compound Next to Tray. 
 
 The tray and about | s inch of the compound next to it 
 are immersed in cold water for about 5 seconds. This 
 hardens the lower pari of the compound, which assists in 
 adapting the softer compound to the tissues, and prevents 
 forcing the tray through the compound and into contact 
 with the tissues. Tip the tray to right and lefl so that the 
 buccal surface of the flanges may he slight lv chilled also. 
 
 33 
 
Fig. 16. 
 
 Softening Palatal Surface of Compound. 
 
 Use an alcohol lamp and a mouth blowpipe. Direct a 
 small blowpipe flame against the compound in the center 
 of the vault and soften it until the surface is smooth and 
 of a flowing consistency. The compound in the center 
 should be heated to a greater depth than that portion of 
 the material which is to come in contact with the crest and 
 sides of the alveolar ridge. When the compound in the 
 center has been sufficiently warmed, direct the flame into 
 the depression for the ridge. Heat until the surface there 
 is smooth. Do not heat the ridge surface of the flanges 
 enough to cause them to fold over on themselves. Do not 
 allow the flame to rest in one place. Keep it moving. 
 
 34 
 
/ 
 
 Fig. 17. 
 
 Chilling the Right Hand Marginal Flange. 
 
 Touch the side of the right hand marginal flange of 
 tho tray and compound to cold water or ice-water, but do 
 not allow the cold water to work over onto the surface 
 heated with the blowpipe. The object is to stiffen the 
 compound flange so that ir will not fold over upon itself 
 when introduced into the mouth. Proper technic will 
 make the bucca 
 inner surface soft and flowing 
 
 urface of the flange hard and leave tho 
 
 35 
 
Fig. 18. 
 
 Equalizing Surface Temperature of 
 Compound. 
 
 The hardening of the buccal surface of the marginal 
 flange should have occupied not more than three seconds 
 and the surface of the rest of the compound should still 
 be too hot to permit introducing into the mouth without 
 burning. Invert the tray and compound over the hot 
 water as shown here, dip the blowpipe heated surface in- 
 to the hot water and immediately withdraw it with a 
 jerking motion. This operation must be very quickly per- 
 formed, or the hard layer next to the tray and the flanges 
 will be unduly softened. 
 
 36 
 
Fig. 10. 
 
 Introducing Compound for Upper Impression. 
 
 Part I. 
 
 Support the tray on the middle finger, guiding it side- 
 ways with the thumh and forefinger. Hold the right side 
 of the impression toward the patient. Carry the right side 
 of the impression into the month and against the right 
 corner of the month. Distend the left side of the mouth 
 with the left forefinger. Tfotate the tray quickly so that 
 the left heel passes the left corner of mouth. The left 
 forefinger protects the left flange from being bent by lip 
 pressure. 
 
 37 
 
Fig. 20. 
 
 Introducing Compound for Upper Impression, 
 
 Part II. 
 
 With the finger of the left hand, pull the cheek out- 
 ward to protect the marginal flange on left side. At the 
 same time, pull the traj and compound a little to the 
 right and drop the left flange. The right buccal flange 
 may have been bent slightly and this procedure assists in 
 passing it upward between the ridge and the cheek. Move 
 the tray upward and a little to the left to offset the 
 previous pull to the right and the tilting. Hold the tray 
 in this position with the compound lightly in contact with 
 the tissues, and make sure that the front and back portions 
 of the tray bear the relation to the ridge shown in Figures 
 6 and 7. !STow press the tray about half-way home and 
 hold it in this position during the manipulation described 
 for Figure 21. 
 
 38 
 
Carrying the Compound Flanges IIkjtt. 
 
 W'iih the Left index finger press the lefl buccal flange 
 
 upward and inward between cheek and ridge, from tuber- 
 osity to cuspid as shown at ".V". 
 
 Withdraw the left index finger with a sliding motion 
 upward and forward until it is in the position shown at 
 ■•J)". This stretches the lip and check muscles and places 
 the labial and buccal soft tissues in a favorable position 
 for taking the impression. Tat the compound from cuspid 
 to cuspid lightly upward and toward the ridge. 
 
 Substitute the left middle finger for the right middle 
 finger supporting the tray as shown at "C". 
 
 Manipulate the right buccal flange with the right index 
 finger as the left buccal flange was manipulated in "D". 
 
 Return the index and middle fingers to the position 
 shown at "C" and press the tray home. 
 
 Ivclease the right hand and hold the tray firmly in po- 
 sition with the left. With the index finger of the free 
 hand, make pressure on the outside of the cheeks opposito 
 the vertical center of the compound flange and force the 
 compound gently upward and inward against the ridge. 
 
 ('hill the compound by means of \U inch cotton rolls 
 wrung out of ice-water, or with low pressure air. Do not 
 remove the impression until it is absolutely hard. 
 
 'The impression will now usually show marked suction. 
 
 Extreme caution should be employed in removing tho 
 impression. Many impressions are spoiled in removal by 
 faulty technic. Insert an index linger between the cold 
 compound flange and the cheek and lift the tissues some- 
 what as shown at "A" to admit air between the ridge ami 
 flange. Work impression gently downward and forward 
 in such way as to drop the lefl heel ami side until the air 
 works freely under the impression, when it will release. 
 
 If the patienl can close the lips and distend tin 1 cheeks 
 with air, the impression will be dislodged with a minimum 
 danger of distortion. Immerse impression in cold water 
 and allow to remain 1 - minute. 
 
 ■:.\) 
 
Fig. 21. 
 
 40 
 
Fig. 22. 
 
 Trimming the Surplus from Upper Impression. 
 
 The manipulation described lias turned over the sur- 
 plus material shown at "A", leaving the impression upon 
 which the final muscle trimming will be done in the area 
 within the dotted line. With a sharp knife cut away the 
 surplus material in such way as to leave the margin of the 
 flange not less than 1/g inch thick, which is less liable to 
 be distorted by the rapid absorption of heat than a thin- 
 ner flange. It will be safer for a beginner to leave the 
 flange a little more than y$ inch thick. 
 
 As a thick flange can be less rapidly muscle trimmed 
 than a thin one, one or two more heatings may be neces- 
 sary, but tli is is compensated for by the reduced danger of 
 flange distortion. 
 
 The impression, after the removal of the surplus, is 
 shown at "B", 
 
 41 
 
mmm 
 
 Fis 
 
 Trimming the Impression for Length. 
 
 Trim the tray and impression in normal cases, to reach 
 back to the point where movement of the soft tissues be- 
 gins, when the patient says "Ah". To do this, trace a line 
 at this point on the soft palate and transfer it to the im- 
 pression. The ends of this line should rest on the com- 
 pressible but non-moving tissue in the depression behind 
 each tuberosity, and the line should cross the vault where 
 movement in the tissues commences. 
 
 Koll a swab of cotton tightly on an instrument, and 
 with the application of firm pressure, wipe the tissues of 
 the posterior part of the vault free from mucin. 
 
 42 
 
Moisten the point of a soft indelible pencil in water 
 ;mk1 draw this line. Slightly moisten the impression, place 
 ii in the month, press it firmly againsl the vault, and 
 rotate it a little, if possible, thereby transferring the lino 
 from the tissues to the impression as shown a1 "B" in Fig 
 ure 20. Too much moisture on the impression will make 
 the line indefinite. 
 
 liemove th< 1 impression and trim the tray and impression 
 to the line, cutting so as to hold the tray against the 
 compound. 
 
 [f there is cloubt as to where the line should rest, it is 
 better to leave the impression a little too long and trim the 
 plate it' irritation makes it necessary. 
 
 In some mouths the area of compressible hut non-mov- 
 ing tissue behind the tuberosities is very narrow because 
 of unusual ligamentous attachments. To determine tbo 
 character of these attachments, have the patient open the 
 mouth as wide as possible and watch the tissues. Make 
 a dot on each side where movement commences when the 
 ligament becomes tense. If the denture is finished to rest 
 upon the point of attachment of this ligament, it will be 
 pulled loose whenever the mandible is dropped, by the 
 action of the ligament. 
 
 In cases where the mouth presents a soft, flabby ridge 
 in front, tbe plates must be made longer than in normal 
 cases, to prevent breaking the valve fit in the back by the 
 unavoidable excessive movement of the plate in speech, 
 swallowing and mastication. In extreme cases ir may be 
 necessary to extend the plates * \ inch beyond the point 
 where movement commences when the patient says "Ah*'. 
 
 [f the impression does not show suction, add black wax 
 as shown in Figure 64. If the addition of the wax docs 
 not produce the desired result repeal the impression tech- 
 nic, beginning at Figure 10. 
 
 In very difficult cases a beginner may find it accessary 
 to follow the alternative technic under the title "Com- 
 pound-Plaster 1 mpressions." 
 
 43 
 

 Fig. 24. 
 
 Attaching the Upper Bite Rim, Part I. 
 
 Take from the hot water enough compound to form a 
 roll ^2 inch in diameter and 3 or 4 inches long. Heat in 
 the flame, until it sputters, enough of one side to reach 
 from the first molar to the median line. Attach the 
 heated portion to the previously prepared ridge area of 
 the tray so that the end of the roll will he about where 
 the distal side of the first molar is expected to come. 
 
 If this bite rim is left too long, it may interfere with 
 equalizing the bite pressure or the free movement of the 
 mandible and the taking of correct records of jaw move- 
 ments. 
 
 44 
 
Fit 
 
 Attaching the Uppee Bite Rim, Pakt II. 
 
 The tray is here shown hold in the left hand, with the 
 unattached portion of the roll forming the bite rim in the 
 right hand. Direct a bunsen flame against that portion 
 of the hito rim which will be attached to the tray, taking 
 care not to heat the tray or the impression. When the 
 compound sputters, withdraw from contact with the flame 
 and press it against the tray. This heating should com- 
 plete the attachment of the rim to the tray. 
 
 45 
 
Fig. 26. 
 
 Attaching the Upper Bite Rim, Part III. 
 
 While the bite rim is still soft, cut off the surplus ma- 
 terial about where the distal side of the first molar will 
 come. Invert the impression as shown, and immerse tray 
 and impression in cold water up to the point of the at- 
 tachment of the bite rim to the tray. This is to prevent 
 the heat in the bite rim softening the impression. 
 
 The bite rim is trimmed shorter than has been custom- 
 ary, to bring the stress in bite taking forward of the up- 
 ward incline on the rear portions of the lower ridge. 
 
 46 
 
What the Occlusal Plane Is. 
 
 It is :m arbitrary plane which has generally been ac- 
 cepted because it is useful in arranging artificial teeth. 
 
 This plane is generally parallel to a line on the outside of 
 the cheek from the upper margin of the external auditory 
 meatus to the lowest point of the wing of the nose. If, in 
 edentulous cases, the occlusal surface of the hire rims be 
 made parallel to it. and on a level slightly below the upper 
 lip at rest, the most advantageous position for the arrange- 
 ment of the teevh will he established. 
 
 The practical value of the occlusal plane is about as 
 follows : 
 
 It estahlishes a generally accepted starting point for 
 the arrangement of artificial teeth. 
 
 It is of value in mounting models in articulators, 
 whether or not the face bow is used. 
 
 Its use facilitates the achievement of pleasing esthetic 
 effects. 
 
 The cusps of Trubyte teeth can be set against this 
 plane, as will be shown, to easily and quickly establish 
 approximately correct compensating and lateral curves. 
 
 47 
 

 Fis. 27 
 
 Establishing the Plane of Occlusion, 
 Part I. 
 
 Dip the bite rim in hot water until it is plastic, which 
 requires, usually, about 10 seconds. Put the impression 
 with bite rim attached into the mouth. Mould the bite 
 rim in the labial and buccal regions to about the contour 
 the teeth are to take. 
 
 Make sure that when the moulding of the bite rim is 
 completed it is directly above the lower ridge. This will 
 prove to be important in later stages of the work. 
 
 48 
 
Fig. 2S. 
 
 Establishing the Plane of Occlusion, 
 
 Part II. 
 
 When the contour of the bite rim has been satisfactorily 
 established, press the occlusal surface of the bite rim in the 
 fnmt of the mouth upward with the finger, as shown, push- 
 ing the surplus toward the center of the mouth, until. 
 when the patient raises the lip as in smiling, the bite rim is 
 exposed about as the teeth arc to be. 
 
 Press the sides of the occlusal surface of the bite rim 
 upward in the same manner until they are approximately 
 parallel to the occlusal plane. "When the patient raises the 
 lip, it should he possible to see more of the compound in the 
 incisor region than in the posterior region. 
 
 49 
 
Fig. 29. 
 
 The Plane of Occlusion, Front View. 
 
 The horizontal position of the occlusal plane, when seen 
 from the "front, should be parallel to a line through the 
 pupils of the eyes. 
 
 After the occlusal surface of the upper bite rim has been 
 made approximately parallel with the occlusal plane, lay 
 a ruler across the anterior section, as here shown, and test 
 the parallelism with the line through the eyes. 
 
 Tf one side of the bite rim is too deep, whittle it until 
 the plane is established. 
 
 In cases where the lip is habitually raised unevenly, 
 giving the mouth a crooked appearance, the best esthetic 
 results will be obtained by setting the edges of the teeth 
 pretty closely to the plane here described. 
 
 50 
 
Fiff. 30. 
 
 The Plane oe Occlusion, Side View. 
 
 Tn edentulous cases, establish the antero-posterior level 
 of the occlusal plane by drawing a line on the face from 
 the upper margin of the external auditory meatus to the 
 lowest pari of the wing of the nose, by means of a ruler, a 
 Strip of celluloid or a cord. Parallel the occlusal surface 
 of the bite rim to this line and test the parallelism by hold- 
 ing a ruler againsl the occlusal surface of the bite rim as 
 shown above, and observing the projecting portion. Cut 
 away the occlusal surface or add to it at the heel as may 
 he necessary to establish the plane. 
 
 In the preceding illustration and this, the ruler is shown 
 supported in position, with the operator out of view, for 
 photographic reasons. 
 
 51 
 
Fig. 31. 
 CORRECTING ERRORS IN BlTE RlM DEPTH, 
 
 Part I. 
 
 The edges of the upper centrals are usually exposed 
 when the lips are slightly parted. The upper lip is usually 
 raised, in smiling, to the necks of the upper centrals. Trim 
 the upper bite rim so that it is exposed from 1/16 to 1/8 of 
 an inch when the lips are slightly parted. 
 
 Stand several feet in front of the patient. Have her 
 smile. Decide whether the depth of rim exposed is greater 
 than the length of the teeth suitable for the face. If it is, 
 trace a line on the labial surface, as here shown, and re- 
 establish the plane of occlusion at this level. 
 
 52 
 

 
 Fig. .°.2. 
 
 Correcting Errors in Bite Rim Depth, 
 Part II. 
 
 If it is necessary to trim the surface of the lute rim, 
 pass the surface to be trimmed through the side of the 
 bunsen flame and heal it to a depth of not more than 1/16 
 inch. Cut with a cold, very sharp knife. It' much is to 
 he cut away, make several shallow heatings rather than one 
 deep heal ing. 
 
 The patient is here shown with the Into rim trimmed to 
 the proper vertical depth and with the occlusal plane paral- 
 lel to the line through the pupils of the eyes. 
 
 53 
 
Fig. 33 
 
 Completing the Upper Bite Rim. 
 
 Fill in any serious irregularities in the occlusal surface 
 of the bite rim by tracing on soft compound. Heat the 
 entire occlusal surface to a shallow depth in the side of the 
 bunsen flame and press upon a moist glass surface to make 
 it flat and smooth, but do not change the vertical height 
 or occlusal plane. 
 
 Cut notches like those shown at "B". These should be 
 wide and flaring, irregular in shape, about l/g inch deep 
 and inclined toward the median line at different angles. 
 These will insure proper locking of the lower bite rim. 
 
 54 
 
Fig. 34. 
 
 Lower Trays. 
 
 Tt is advantageous to select one of the larger sizes of 
 lower impression trays and shorten it to fit the case, be- 
 cause the larger size has a wide flange in the bicuspid and 
 molar region, which will better support the compound. 
 
 A thin metal, lower impression tray as received from 
 the maker is shown at "A". At "B" is shown the same 
 tray with the labial flange cut away from cuspid around 
 to cuspid and the lingual flange partly cut away in the 
 same region to avoid pressure on the frenum. 
 
 55 
 
Fig. 35. 
 
 Shaping the Lower Tray. 
 
 With contouring pliers spread the flanges of the tray 
 in the bicuspid and molar region so that the lateral con- 
 tour is flatter than that of the ridge. Bend the tray to fit 
 the curvature of the ridge in the incisor region and con- 
 tinue the bending so that the tray follows the curvature of 
 the ridge in the bicuspid and molar region, as it does on 
 the model, which is shown here purely for purposes of 
 illustration. 
 
 56 
 
Fig. 3G. 
 
 Guide Rimming the Lower Tray. 
 
 Heat aboul ! ^> inch of a tracing stick in the top of tho 
 bunsen llanie and trace compound on the fitted tray, as 
 shown. This compound should be a little over y% inch 
 in depth and several tracings will be required. If there 
 is any tendency for the first tracing to run when the later 
 tracings are made, chill in cold water. Xote that the 
 guide-rims are confined to the margins of the tray and do 
 not touch the center. 
 
 To prepare the guide rims to go into the month, dip 
 them into hot water until they are of a consistency which 
 will require a slight pressure, but not a severe pressure, 
 to mould. This will require from 2 to 4 seconds. 
 
 57 
 
-' 
 
 Fi?. 37. 
 
 Inserting the Lower Tray. 
 
 Have the patient open the month wide enough to admit 
 the tray but not to tighten the cheek muscles. 
 
 Stand in front of the patient. Carry the left side of the 
 tray toward and into the month until the center, which is 
 grasped between the thumb and finger, touches the left 
 corner of the mouth. Distend the right corner of the 
 mouth with the index finger of the left hand. Rotate the 
 tray until the left side touches the. cheek and the right end 
 passes into the mouth. Continue the rotation until the 
 tray is approximately centered. Release the tray and let 
 it settle. 
 
 58 
 
Fig. 38. 
 
 Seating the Lower Tray. 
 
 Make sure thai the anterior margin of the tray does not 
 extend forward beyond the labial surface of the Lower 
 ridge. This will bring the lower tray in the same relation 
 in the lower ridge thai the upper tray is to the upper ridge 
 in Figure 6. 
 
 Make lighl pressure over the parts of the tray to which 
 the compound is attached. When this pressure is properly 
 made the tray will nol be forced down into contacl with 
 the ridge anywhere but will remain about 1/16 inch above 
 it all around. 
 
 Remove the tray Immediately from the mouth and chill 
 the compound in cold water. 
 
 59 
 
Fig. 39. 
 
 Seating the Lower Tray, Continued. 
 
 The guide rims at U A" show the result of the techuic iu 
 Figure 38. The tray has since been dried and soft model- 
 ling compound traced in the hollow of the incisor region. 
 Place the tray in the mouth. Make light pressure over 
 the guide rims as in Figure 38. This accurately reseats 
 the tray and takes an impression of the ridge in the in- 
 cisor region. Do not apply pressure in the incisor region 
 as it may tilt the heels of the tray upward and establish 
 wrong relations. 
 
 Withdraw the tray ; chill the compound ; replace the 
 tray and test for stability. If it is not stable, repeat the 
 operation until it is. 
 
 Paint hot compound from a tracing stick upon the lin- 
 gual side of the tray, as it was painted upon the upper in 
 Figure 11. 
 
 60 
 
Pig. 40. 
 
 Forming the Lower Bite Rim. 
 
 Soften compound and form a roll as described for Figure 
 24. Bend the roll to lit the curve of the tray and cut it 
 short enough so that it does not extend onto the upward 
 incline at the heels. 
 
 Have the compound in an easily moulding stage but not 
 soft, and press the roll against the tray so that it takes the 
 imprint of the tray. 
 
 This bite rim should ho made very shallow vertically and 
 should permit the ridges to come too close together for 
 crood esthetic results. The height will be corrected later. 
 
 61 
 
Fig. 41. 
 
 Attaching the Lower Bite Rim. 
 
 Remove the roll and dry it and the tray. Grasp the 
 bent roll at the bicuspid region on the left side. Bring 
 the left heel of the tray side of the roll against the base 
 of the bunsen flame, as shown. Heat the compound until 
 it sputters. Slowly rotate the roll toward the left, keeping 
 the compound and name in contact until the compound has 
 been heated to a sputtering condition the full length of 
 the roll. 
 
 Place the roll in position on the dry tray and press home. 
 This makes the bite rim. Chill the tray to prevent the 
 heat in the rim softening or changing the guide rims. In- 
 vert the tray and dip the occlusal surface of the bite rim 
 in hot water to a depth of *4 inch until it can be easily 
 moulded. 
 
 62 
 
-4 
 
 Fig. 42. 
 
 Carrying the Bite Rimmed Lower Tray Into 
 the Mouth. 
 
 Grease the occlusal surface of the upper bite rim with 
 cocoa-butter and place the upper impression in the mouth. 
 ( rrasp the hard portion of the lower liitc rim as shown and 
 carry the left heel into the mouth and sideways against the 
 left cheek, at the same time distending the righl corner 
 of the mouth with the left index finger. Carry the righl 
 heel inward past the finger and release the tray. 
 
 G3 
 
Fig. 43. 
 
 Placing the Bite Rimmed Lower Tray. 
 
 Stand in front of the patient. Place both index fingers 
 against the buccal surfaces of the lower bite rim in the 
 bicuspid region, as shown at "B" and make pressure 
 inward and downward. Ask the patient to touch the tip 
 of the tongue to the center of the vault, as far back as 
 possible. This is usually near the heel of the upper im- 
 pression. While the tongue is in this position, direct the 
 patient to close the jaw as far as possible. 
 
 Chill the bite rim with l/o inch cotton rolls wrung from 
 ice water, or with low pressure air, and remove it from 
 the mouth. 
 
 64 
 
B 
 
 "> 
 
 1 
 
 w~ 
 
 Pig. 44. 
 
 Trimming the Lower Bite Rim. 
 
 Figure "A" shows the upper bite rim in place on the 
 lower as they were closed together in the mouth. The 
 occlusal surface of the lower bite rim is shown at "B". 
 The wedges of compound which filled the notches in the 
 occlusal surface of the upper rim can lie seen. 
 
 Trim away the excess compound on the buccal and lin- 
 gual surfaces until the edges of the impression of the 
 upper rim are reached. Do no1 trim oft the wedges on 
 the occlusal surface. Dry the ridge surface of the tray 
 and guide rims. Replace the upper impression in the 
 mouth. 
 
Fig. 45. 
 
 Shaping the Compound foe the Lower 
 Impression. 
 
 Shape a roll of compound % inch in diameter and as 
 long as around the tray from heel to heel. Heat one side 
 of the roll in the bunsen flame until it sputters and attach 
 it to the ridge side of the tray. Mould the compound so 
 that it will be narrow and relatively deep at the median 
 line, and wide and relatively shallow at the heels, as shown 
 here. It should be concave on the ridge side. 
 
 Heat the ridge side of this compound to a flowing con- 
 dition with the mouth blowpipe as shown in Figure 16. 
 The central depression of the compound should be softened 
 to a greater depth than are the margins. To equalize the 
 temperature and prevent burning the patient, carry the 
 ridge surface into the hot water and remove with a quick, 
 jerking motion. 
 
 66 
 
Pig. 4G. 
 
 Inserting the Tray for the Lower Impression. 
 
 The lips and corners of the patient's month have been 
 lightly coated with white vaseline. Carry the lower tray 
 into the month as described for Figure 37. 
 
 As soon as it is in the month release it. Place 
 the index fingers on the buccal surfaces of the bite rim in 
 the bicuspid region as in Figure 43 and hold the bite rim 
 off the ridge by pressing the index fingers toward each 
 other against the buccal surfaces. This method of holding 
 permits the dentist to move it or rotate it as desired. 
 Request the patient to tonch the tongue to the vault of the 
 mouth. Guide the wedges on the lower bite rim into the 
 notches in the upper bite rim. Have the patient close as 
 far as possible and proceed as in the following illustration. 
 
 G7 
 
Fig. 47. 
 
 Turning Up the Surplus Compound on Buccal 
 and Labial Surfaces. 
 
 Instruct the patient to make a steady suction or negative 
 pressure in the mouth. While this suction exists, uncler 
 biting pressure, place the thumbs on the side of the face, 
 as shown here, and press upward and inward against the 
 lower margin of the compound, which can be felt toover- 
 liang the border of the jaw, forcing the compound against 
 the buccal and labial surfaces of the ridge. 
 
 Part the lips but not the jaws and chill the compound 
 with cotton rolls wrung out of ice-water, or with low 
 pressure air. 
 
 When thoroughly chilled, carefully remove both impres- 
 sions from the mouth and immerse in cold water. 
 
 68 
 
Fig. 48. 
 
 The Incomplete Lower Impression. 
 
 This illustration shows the lower impression as ir results 
 from the manipulation illustrated in the two figures im- 
 mediately preceding. 
 
 Ohscrve that the wedges on the occlusal surface of the 
 lower bite rim fit into the grooves in the occlusal surface 
 of the upper hite rim and maintain correct relations be- 
 tween the upper and lower. This automatically holds the 
 lower tray in correct relation to the lower ridge as the 
 patient bites into the soft compound and insures the taking 
 of the impression under biting stress and negative pressure. 
 These are the most favorable conditions for taking a lower 
 impression. 
 
 This method of forming the two bite rims and of holding 
 the lower in a fixed relation to the upper while the lower 
 ridge is closed into the soft compound to take the impres- 
 sion is a complete reversal of the methods common for 
 many years past. This method, once mastered, will he 
 found very satisfactory. 
 
 69 
 
Fig. 49. 
 
 Trimming the Surplus From the Lower 
 Impression. 
 
 "A" shows che ridge surface of a lower impression as it 
 is at the end of the manipulation described in Figures 
 46 and 47. 
 
 "B" shows the same view of this impression after the 
 manipulation described in Figures 51 to 54 inclusive was 
 completed. 
 
 Trim away the surplus which is shown outside the white 
 line in "A". This will leave the flange about % inch 
 thick. 
 
 The impression in "B" is smaller in ridge area than 
 that in "A". This is due to the "trimming" described 
 in the steps to follow. A "trimmed" impression is less 
 liable to interfere with the movements of the buccal and 
 lingual groups of muscles and hence is more stable and 
 comfortable. 
 
 70 
 
Fig. 50. 
 
 Technic for Heating Flange for Muscle 
 Trimming. 
 
 In heating the flanges for muscle trimming, allow the 
 heat to strike only the compound to he softened. Invert 
 the lower to heat, but do not invert the upper. Hold the 
 edge of the flange to be heated for muscle trimming against 
 the side of the base of the flame, where the heat is less 
 intense than at the top. In this position the heat is not 
 deflected to soften the compound elsewhere. 
 
 Heat only the edge of the flange to a depth of Yg inch 
 or as deep as judgment indicates to be necessary and skill 
 in handling permits. 
 
 Heat the flanges of each impression in three sections, 
 one from cuspid to cuspid, one from each cuspid to each 
 heel. When one becomes expert, it may be possible to 
 include two or more sections in each heating. 
 
 Dip the heated flange in hot water. Instantly remove 
 with a jerking motion and quickly place the impression in 
 the mouth. 
 
Fig. 51. 
 
 Trimming Lower Labial Flange- 
 Cuspid. 
 
 -Cuspid to 
 
 Leave out the upper impression. Heat the lower labial 
 flange from cuspid to cuspid. Place the lower quickly in 
 the mouth and press on the occlusal surface in the bi- 
 cuspid region, until the impression' is properly and firmly 
 seated. Have the patient draw the lip upward and in- 
 ward over the bite rim. Massage the compound by thumb 
 pressure upward and inward on the outside of the lower 
 lip, beginning a little below the heated margin. 
 
 Hold the impression firmly in place until the flange has 
 been chilled or is hard. 
 
 Tf only a little surplus is turned up, it may not be 
 necessary to repeat. A beginner should repeat until an 
 upward pull on the relaxed lip in this region will not 
 raise the impression. 
 
 72 
 
Fig. 52. 
 
 Trimming the Lower Buccal Flange. 
 
 Hear the buccal flange from cuspid to heel. Place the 
 impression in the mouth and hold in place by pressing 
 downward with the first and second fingers of the right 
 hand in the bicuspid region. Make heavier pressure on the 
 side which has not been heated than on the heated side. 
 
 Stand in front of the patient. Grasp the right check be- 
 tween the index and middle fingers of the right hand and 
 pull it gently upward and inward againsl the margin of the 
 softened flange. At the same time the thumb may pat the 
 heated margin gently upward and inward, through the 
 cheek. This position cannot be photographed. The illus- 
 tration shows the action bul not the position. Employ only 
 gentle pressure. Trim the left llanire in ;i similar manner. 
 
 The buccal margin may be regarded as trimmed when 
 the pull of the muscles in this region will not dislodge the 
 denture, or when the margin of the impression does not 
 extend below the external oblique line. 
 
Fig. 53. 
 
 Muscle Trimming the Lower Lingual Flange 
 
 Part 1. 
 
 Heat the edge of the lingual flange from cuspid to 
 cuspid in the manner illustrated in Figure 50. 
 
 Place the impression in the mouth and make pressure 
 on the occlusal surface of the bite rim with the index 
 fingers of both hands. Note that the thumbs, as shown 
 here and in Figure 52, are pressed upward below the 
 mandible to assist in making this pressure. 
 
 Cause the patient to place the tongue either between the 
 upper ridge and the upper lip or outside the upper lip, at 
 the same time moving it from side to side. 
 
 74 
 
Fig. 54. 
 
 Muscle Trimming the Lower Lingual Flange 
 
 Part 2. 
 
 Heat the edii'c of the left flange from cuspid to heel, 
 in I he manner descrihed. Place the lower impression in 
 the mouth, the upper being out, and hold in place as de- 
 scribed for Figure 53. 
 
 Cause the patienl to open the mouth ;is wide as pos- 
 sible and to then try to lick with the tongue between the 
 right cheek and the righl upper and lower alveolar ridges, 
 in the region of the second molar. 
 
Fit 
 
 Trimming the Buccal Flange. 
 
 The white line in "A" shows a foreshortened view of 
 the white line in "B" and the area marked "C" is the 
 same in both figures. The margin of the compound to the 
 left of the white line in "A" shows first a depression and 
 then a mound. This mound is composed of the compound 
 which has been forced downward so that it bears too heavily 
 upon the muscles and if reproduced in the denture would 
 cause irritation, when the muscles on which it rests come 
 into play. The compound outside the white line in "B" 
 should be trimmed to the contour of the dotted line "C" 
 in U A". The section of the flange here shown at "C" 
 corresponds to the section of the flange represented as 
 extending below the external oblique line in the next 
 illustration. 
 
 All denture margins should be rounded and pulley like, 
 rather than sharp. This form permits the muscles to play 
 over them without irritation. 
 
SPINE AT 
 
 MYLOHYOID 
 
 LINE 
 
 COMPOUND 
 FLANGE 
 
 Fig. 50. 
 
 The Relation of the Lower to the Ridge 
 
 The diagram above shows a section through a flat lower 
 jaw, the impression, the tray and the bite rim in the region 
 of the second molar. The flanges here shown extend 
 below the external oblique line and the mylo-hyoid line, 
 as they arc sometimes Left after mnscle trimming. It' the 
 plate is made with the flanges in this position, the muscles 
 which were easily depressed in muscle trimming may prove 
 active enough to develop considerable irritation at the 
 point where the tissues chafe against the flange. 
 
 The buccal and lingual flanges should not extend below 
 the level of muscle attachment at the external oblique and 
 mylo-hyoid lines respectively unless a slight extension is 
 necessary to develop "suction." 
 
 Tf the ridge is flat, it may be necessary to trim the 
 flanges to the form of dotted outline. The impression 
 should he trimmed so thai when the finger is passed 
 downward across its lingual surfaces the flanges will 
 appear to he continuous with the hard tissues ol the man 
 dible at the level of the mylo-hyoid line. 
 
 When the teeth occupy the relation to the rfdge shown 
 by the dotted tooth outline, the muscular action of the 
 cheek and tongue will balance each other and the denture 
 will have maximum stability. 
 
 77 
 
Fig. 57. 
 
 Stabilizing the Lower Impression. 
 
 The lower impression should now exhibit "suction'' and 
 be stable on the ridge against direct vertical pressure on 
 the occlusal surface at any point between the first molar 
 locations: or against a rocking pressure applied in the 
 bicuspid region. If it is not stable, some error has 
 occurred in manipulation. 
 
 Place the upper impression in the mouth. To correct 
 the error in the lower, hold the impression as shown and 
 direct a sharp-pointed, mouth blow-pipe alcohol flame 
 against the compound which lies in contact with the crest 
 of the ridge. Avoid overheating the compound or deflect- 
 ing the heat against the flanges. Apply the flame first at 
 the top of the left heel, and move it evenly along the bottom 
 of the valley of the impression, so as to reach the other 
 heel in about one second. Have the flame make a return 
 trip from heel to heel. Repeat this three times. Dip the 
 lower, thus heated, into hot water. Instantly remove it 
 with a jerking motion and place in the mouth. . Cause the 
 patient to place the tip of the tongue in the rear of the 
 center of the vault and close the mouth, swallow and suck, 
 while holding the bite rims in contact. Allow the impres- 
 sion to harden thoroughly, remove ; chill in cold water and 
 test for stability. 
 
 78 
 
Pig. 
 
 Heating the Upper Buccal Flaxge for Muscle 
 Trimming. 
 
 The upper impression is to be muscle trimmed under 
 biting pressure with the mouth closed. This is opposite 
 to the practice for the Lower, which was trimmed with the 
 mouth open. 
 
 Hold the right buccal flange of the upper in contact with 
 the side of the bunsen flame, near its base, as shown, with 
 the impression tilted to the inclination shown. 
 
 Soften the edge of the flange from cuspid to tuberosity 
 to a vortical depth of Yg inch. 
 
 The first heating should be from heel to cuspid. 
 
 Dip in hot water, remove as quickly as possible and 
 carry to the mouth. 
 
 79 
 
59. 
 
 Muscle Trimming the Upper Buccal Flanges 
 
 The trimmed lower impression is in the month. Stand 
 in front of the patient and place the upper impression in 
 the mouth, left side first. Protect the softened right flange 
 while entering, by distending the right corner of the 
 mouth with the left index finger. Seat the impression by 
 upward ancl backward pressure with the right index finger 
 in the center of the vault. Cause the patient to close, 
 swallow and suck with the bite rims in contact. 
 
 Soften the edge of the left buccal flange. Stand be- 
 hind the patient, distend the left corner of the mouth 
 with the left index finger, enter the impression right heel 
 first, rotate to position and have the patient close and 
 swallow. 
 
 80 
 
Fig. 60. 
 
 Muscle Trimming the Labial Flange oe the 
 [Jppek Impression, Part l. 
 
 Heal the margin of the flange Prom the firsl bicuspid on 
 one side to the firsl bicuspid on the other, using the technic 
 described for Figure 58. Equalize the temperature in hoi 
 water, place in the mouth in the same manner as before. 
 Cause the patienl to close upon the bite vims and to 
 throw the lips forward as here shown and backward as in 
 Figure 61. 
 
 SI 
 
^•OB 1 
 
 Fig. 61. 
 
 Muscle Tkimming the Labial Flange or the 
 Upper Impression, Part 2. 
 
 Before causing the patient to make the forward and 
 backward lip movements, the dentist should demonstrate 
 these movements by performing them himself and then 
 give the patient a mirror and cause her to practice. 
 
 It is sometimes advisable to stand behind the patient and 
 place the index fingers on the upper lip and when the for- 
 ward movement is to be made, push the lip forward, and 
 when the backward movement is to be made, pull it back. 
 These movements should be deliberate and rhythmical. 
 
 The result of muscle trimming is to provide a Avorking 
 space for the muscles in contact with the upper denture, 
 so that ordinary movements will not destroy its stability. 
 
 82 
 
Fig. G2. 
 
 Outlining Areas for Compression and Relief. 
 
 Locate first the posterior palatine foramina, marked 
 "A A" in this illustration. Those can best he located by 
 pressing a ball ended instrument against the tissues over- 
 lying the palatine artery commencing at the first molar, 
 and moving it backward, with pressure upward and out- 
 ward, until it tits into the depression over the foramen. 
 Roll cotton tightly on pliers or a match, moisten ir with 
 water and wipe the mucin from the tissues in this region. 
 With a soft indelible pencil, mark a circle about 3/16 inch 
 in diameter, enclosing the area over the foramen. It is 
 no1 uncommon for the hard palate to present a spine jusl 
 posterior to the foramen. Such a spine can lie detected 
 with the ball end instrument and the area it occupies 
 should bo included within the circle. Make the same 
 examination and mark over the opposite foramen. 
 
 To provide relief over the anterior palatine foramen, 
 also marked "A", draw a circle about the base of the most 
 anterior papilla of the rugae. 
 
 83 
 
The dotted lines "B-B" show how far forward the soft 
 tissue may extend in some cases. No compression of 
 these tissues should be made anterior to the palatine fora- 
 mina nor over them, for fear of shutting off the circulation 
 in the vessels which emerge here. 
 
 The area of soft tissues which may properly be com- 
 pressed to perfect the fit of the posterior part of the denture 
 to the vault, is bounded by the solid black line "C". Draw 
 the crescent shaped lines "C" by starting at the bottom 
 of the notch behind either tuberosity and moving the 
 pencil inward and forward to the posterior margin of the 
 circle around the palatine foramen and the spine, if pres- 
 ent, and then to the anterior margin of the compressible 
 soft tissue at the median line. 
 
 The hard unyielding tissues in the center of the mouth 
 are usually located within the area marked "D". Deter- 
 mine the form and extent of this area in each case with 
 the ball end instrument and mark the boundaries on the 
 tissues. 
 
 Relief Over the Course of the Palatine 
 Artery. 
 
 It sometimes happens that an upper impression prop- 
 erly taken and trimmed will have stability and fit tightly 
 but after a minute or more will be forced out of place 
 without muscular movement by the patient. In such cases 
 examine the impression for" air leaks at the margins. Make 
 sure that muscle trimming is complete. When satisfied 
 that there are no air leaks and no muscle strain, relieve the 
 impression over the palatine foramina and along the course 
 of the palatine artery. This usually results in the reten- 
 tion of the impression. 
 
 In some mouths the rami pass so close to the tuberosity, 
 in the opening movement, that one of them may thrust 
 the impression downward and forward. In such cases 
 trim the impression material over the tuberosity very thin. 
 
 84 
 
Fig. 63. 
 
 Transferring Markings to Impression. 
 
 Press the dried impression against the roof of the month 
 for a second or two, hold with a slight rotary motion. 
 Remove. This should transfer to the impression the bine 
 lines made in the mouth. Engrave these lines into the 
 Impression with a pointed instrument. It is not desirable 
 to CU1 the relief ;it this time if records are to be taken for 
 the Adaptable Articulator, because the creating of the 
 proper relief mighl allow the impression to move slightly 
 during lateral movements of (lie mandible. 
 
 Those who are nol to employ that articulator and de- 
 sire In make the relief QOW, ;ire referred to Figure oO. 
 
 85 
 
Fig. G4. 
 
 Impression Marked for Relief. 
 
 The area "A" is the location of the relief over the hard 
 tissues of the median suture. "B" "B" a B" are located 
 over the palatine foramina. The area "C" is that of 
 the compressible soft tissues, over which material may be 
 added to the impression with the idea of compressing these 
 tissues more than they otherwise would be. The right 
 side of this area is here shown with wax added. This is 
 the black wax on which Trubyte teeth are carded. Boll a 
 small portion between the fingers until it is soft and 
 mould over the area to present a thin edge in front and a 
 rounded edge at the rear. Have the wax thin at the 
 median line and the tuberosities and gradually thicken to 
 about % millimeter, half way between the two. 
 
 The lower impression is in the mouth. Place the upper 
 immediately in the mouth and cause the patient to close 
 and swallow several times. This moulds the wax to a pres- 
 sure fit with the soft tissues, 
 
 86 
 
Fig. G5. 
 
 Trimming the Upper Impression at the 
 Frenum. 
 
 Note whether a slight downward pull on the upper lip 
 causes the frenum to pull too strongly against the flange of 
 the impression. If it does, heat the bottom of the frenum 
 notch to a depth of ahout y s inch, using a mouth blow- 
 pipe and nn alcohol flame. Dip in hot water, quickly 
 place in I lie mouth and hold as shown and have the pa- 
 tient move the lip downward as illustrated. 
 
 When the ridge is very hard and the frenum active and 
 attached near the crest of the ridge, only a slight downward 
 lip movement is permitted, since "suction" may be lost 
 if heating or lip action is carried too far. 
 
 Thorough! v chil! the impression and test for "suction" 
 by causing the patient to perform the lip movements in 
 Figures 60 and 61 while pronouncing such words as 
 "W-h-a-t". 
 
 87 
 
Fig. GG. 
 
 Perfecting Adaptation of the Upper Flange 
 to the Ridge. 
 
 If, following the foregoing manipulation, the upper im- 
 pression is stable on the ridge, but is easily dislodged by lip 
 or cheek movements, as in pronouncing the word "when," 
 and it is known that the posterior margin has been post- 
 dammed so that no leak exists there, the fault will be found 
 in imperfect adaptation of the buccal and labial flanges to 
 the ridges. It may be corrected as follows : 
 
 Place the lower impression in the mouth. Dip the buc- 
 cal flange of one side, from cuspid to heel, in water of a 
 temperature of 115° or 120° F., for about 10 seconds, or 
 
until it is softened to the bending stage. Place the upper 
 impression carefully in the mouth, entering the softened 
 flange last, and have the patienl close. By very lighl 
 finger pressure directly on the flange, bend il to adaptation 
 to the ridge and theu have the patienl suck. Adapt the 
 oilier buccal flange in the same way. 
 
 The labial section of the flange, after softening, may be 
 adapted by drawing the lip tightly down upon ii with the 
 thumbs, or by drawing a towel tightly across it while the 
 pal ient sucks. 
 
 Tf muscle trimming has been properly performed, the 
 impression should now be well retained against all lip and 
 cheek movements. 
 
 The Heights of the Bite Rims. 
 
 It is important to the stability of the lower denture and 
 to the patient's comfort to trim the lower bite rim to the 
 proper fullness and height. 
 
 First trim the labial flange of the impression thin 
 enough to prevent the lip exerting any backward pressure 
 and forcing the impression off the ridge, a condition 
 which causes the failure of many lowers. The flange 
 should not he thinner than 1/16 inch, except in some 
 recent extraction or undercut cases, where it is entirely cut 
 away. 
 
 Trim the labial surface of the bile rim to the exact po- 
 sition desired for the labial surfaces of the lower an- 
 teriors. This should be such that the incisors will rest 
 upon the ridge, rather than in front of it, and the centers 
 of gravity of the teeth will he directly over the crest of the 
 ridge. 
 
 Bring the occlusal surface of the lower bite rim. from 
 cuspid to cuspid, six to eight millimeters above the crest 
 of the lower ridge, by trimming or adding compound. If 
 the sections from cuspids to heels are too high, soften the 
 
 89 
 
occlusal surface in the bunsen flame, dip in hot water, place 
 in the mouth, the upper being in place, and have the pa- 
 tient close until the rims come together in front. If the 
 sections from cuspids to heels are too low, add soft com- 
 pound until they are a little too high and have the patient 
 close the bite rims together in front. 
 
 To enable the patient to drink comfortably, the lower 
 incisors must not extend above the relaxed lower lip. The 
 lip and tongue can then easily rise above them and form 
 a joint with the glass or cup and prevent fluid from getting 
 between the lip and teeth. If the teeth are too high to 
 permit forming this joint, fluid will go down inside the 
 lip and under the plate. 
 
 Trim the upper bite rim to, such a height that when the 
 mouth is at rest there will be an open space of about 3/16 
 inch between the upper and lower rims in front. 
 
 When the jaw is at rest the lower teeth are out of con- 
 tact with the uppers sufficiently to allow the tongue to 
 spread between the sets and partly over the occlusal sur- 
 faces of the lower bicuspids and molars. The face ex- 
 hibits its normal expression when it is at rest with the 
 lips closed and the teeth thus out of contact. If the height 
 of the bite rims provides for this habit, the dentures will 
 be more comfortable and stable, the teeth will not click in 
 speech and they will be more efficient in mastication than 
 if the rims are so high as to prevent the teeth dropping out 
 of contact. 
 
 To determine the height of the upper bite rim, stand in 
 front of the patient and cause her to pronounce such 
 words as "Mississippi" or "When". Watch the lower bite 
 rim. If it approaches the upper to within less than 3/16 
 inch, trim the upper until this amount of separation is 
 established. To do this, mark the upper rim as in Figure 
 30 and with a sharp knife trim to the line. Slightly soften 
 the trimmed surface in the flame, dip in hot water, place 
 in the mouth and have the patient close it against the 
 lower rim.. This will remove slight irregularities. 
 
 90 
 
l^^fl 
 
 4-\ 
 
 Fig. G7. 
 
 If the separation exceeds 3/16 inch, add compound and 
 have t lie patient close with biting pressure. Repeat until 
 the desired separation is secured. 
 
 In cases where the teeth have been recently extracted, 
 and rather rapid settling is expected, it is advisable to re- 
 duce the amount of separation between the bite rims in 
 pronouncing these words, to y$ inch or less. This will 
 cause some discomfort at first but the settling -will soon 
 produce the required space. 
 
 In Figure CT both bite rims have boon trimmed :i> di- 
 rected above and the tongue shows in the space between 
 them. 
 
 91 
 
Fig. 08. 
 
 Restoring Facial Expression, Part 1. 
 
 The changes in the expression of the face about the 
 mouth following the loss of the teeth are well shown in this 
 illustration. The upper lip has fallen backward so that 
 its margin is actually behind the margin of the lower, 
 which has also fallen. The corners of the mouth have sunk 
 inward and drooped vertically. 
 
 These conditions offer dentists opportunities for the 
 exercise of a high degree of artistic skill in making den- 
 tures which support the jaw in correct vertical position 
 and carry the soft tissues back to approximately the posi- 
 tions they formerly occupied. 
 
 These conditions also offer unexcelled opportunities to 
 interest patients in the operations involved in professional 
 denture service. 
 
 92 
 
PWe 
 
 ^2 
 
 Fis;. G9. 
 
 Restoring Facial Expression, Part 2. 
 
 If, when the impressions are in place, the expression of 
 the lips seen full front and iu profile is not pleasing, 
 modify the Labial surface of the upper bite rim. If the 
 upper lip is not sufficiently prominent, add to the labial 
 surface, from cuspid to cuspid, a layer of softened com- 
 pound slightly in excess of the amount likely to be re- 
 quired. Mould il to be thicker iu the median line than 
 elsewhere, and place in the mouth while it is soft. By 
 pressure on the outside of the lip. mould il until the lip 
 assumes the desired contour. 
 
 The excess compound will be forced downward and 
 should be trimmed off level with the piano of occlusion. 
 
 93 
 
Fig. 70. 
 
 Restoring Facial Expression, Part 3. 
 
 In the ideal Caucasian profile the upper lip overhangs 
 the lower about as shown in this figure. When trimming 
 for expression is finished, the incisal edge of the upper 
 bite rim should project about 2y 2 millimeters (a little 
 less than % inch) in advance of the incisal edge of the 
 lower bite rim. If this projection of the upper bite rim 
 is not sufficient to establish the profile about as here 
 shown, add more compound. 
 
 This projection of the upper bite rim also turns the 
 edge of the lower lip outward and assists in giving it a 
 pleasing expression. 
 
 94 
 
Fie. 71. 
 
 Compound-Plaster Impressions. 
 
 For dentists who feel that the use of plaster in finish- 
 ing upper impressions is a short cut in time and for those 
 who find difficulty in mastering the technic for full com- 
 pound impressions, the following directions will be help- 
 ful. In many mouths in Class 2 and practically all mouths 
 in Classes 3 and 4, the results obtained with proper com- 
 pound technic are probably impossible with plaster, even 
 when it is supported by compound, unless the soft tissues 
 of the ridge have been surgically removed. 
 
 To use plaster for the complete upper impression to the 
 best advantage the technic for compound impressions 
 should be followed until muscle trimming has been com- 
 pleted, as described for Figure GO. After that, place the 
 lower impression in the mouth. Coat the upper impres- 
 sion with a thin layer of quick setting impression plaster 
 mixed to a creamy consistency. Place the impression in 
 the mouth and cause the patient to hold it in position by 
 biting pressure. When the plaster is hard, remove the 
 impression and trim away the compound wherever it shows 
 through the plaster. Remove all the plaster from the im- 
 pression and with a tracing wheel roughen the palatal 
 surface of the impression as shown above. Coat the rough- 
 ened surface with a uniform layer of quick setting model 
 plaster of a creamy consistency, and again place the im- 
 pression in the mouth; the lower being out of the mouth. 
 
 9o 
 
With a rocking motion press the upper firmly against 
 the upper ridge and hold it there exerting pressure upward 
 and backward npon the centre of the palate portion of the 
 impression. When a test mass of plaster is hard, remove 
 the impression from the month and immerse in cold water 
 until it is set. Soften the occlusal surface of the upper 
 bite rim and equalize the biting pressure by having the 
 patient close the lower against the upper. 
 
 The outline of the areas to be relieved may be marked 
 on the palate and transferred to the impression as they 
 were on the compound impression. The lines may then 
 be graven slightly in the plaster and relief established by 
 adding thin air chamber metal to the cast before form- 
 ing the base plate. 
 
 Wax may be added to the back of the impression to 
 compress soft tissue if desired. 
 
 This method may be extended to the lower impression, 
 but we believe it more difficult to employ it successfully 
 than to employ the method described for compound lowers. 
 
 Plaster Upper Compound Lower. 
 
 Dentists who desire to employ full plaster impressions 
 for upper combined with compound lowers may do so by 
 taking an upper plaster impression and shaping a base- 
 plate over the cast made from it and attaching a bite rim 
 to the baseplate. Notches should be cut in the occlusal 
 surface of this bite rim in the manner described for 
 Figure 33. The technic for the lower may then be fol- 
 lowed. After the lower impression is complete, the upper 
 baseplate may be examined and its margins trimmed with 
 a knife until the action of the muscles cannot displace it. 
 Quick setting model plaster may then be flowed into the 
 baseplate and a new upper impression taken, which will 
 probably be more accurate than the first impression. 
 
 96 
 
Part II 
 
 Selecting The 
 Size, Form and Shade 
 
 In 
 
 Artificial Teeth 
 
Fig. 72. 
 
 Marking the Median Line. 
 
 It is important to esthetic effects to correctly locate the 
 median line on both bite rims. This can be done by using 
 as guides a point half-way between the eyes on the bridge 
 of the nose and one in the center of the chin, dis- 
 regarding the deflection to which the tip of the nose is 
 subject. 
 
 Extend the median line the full width of the upper and 
 lower bite rim and cut a notch at its upper end to preserve 
 its location during the use of the Incisor Path Marker. 
 
 98 
 
Fi.L 
 
 Locating the Distal Sides of the Cuspids. 
 
 There is no fixed rale for determining the positions of 
 the cuspids which will be mosl pleasing. The following 
 plan is satisfactory. 
 
 Stand at one side of the patient. With the bite rims 
 closed together, have the patienl raise the lip as high as 
 possible in the median Line and over the cuspids. Assisl in 
 the raising by lightly tapping the edge of the Lip upward. 
 
 Marl? the upper bite rim 3/16 inch in front of the corner 
 of the orifice on each side, when the lip is raised as di- 
 rected. These marks will satisfactorilv locate the distal 
 
 99 
 
Fig. 74. 
 
 angles of the upper cuspids in any mouths save the very 
 large and the very small. If the mouth is large and the 
 lips thin and active, locate the marks 5/16 inch in front 
 of the corners of the orifice. If the mouth is small and the 
 lips inactive, locate the marks directly at the corners of 
 the orifice. 
 
 Have the patient smile. Decide whether anteriors as 
 wide as between the marks will appear well. If necessary, 
 move the marks. The average person exposes all of the 
 first bicuspids in smiling and laughing. 
 
 Make a vertical mark across both bite rims Vo inch back 
 of the cuspid on each side. 
 
 100 
 
■ 
 
 Fig. 
 
 Measuring fob Width of Uppek Anteriors. 
 
 Remove the upper impression from the month and place 
 the edge of a Twentieth Century .Millimeter Measure par- 
 allel to the incisa] edge and about Yg iuch above it, as shown 
 here. Place the 20 mm mark on the location for the righl 
 cuspid, hold the celluloid in contact with the bite from 
 cuspid to cuspid and nolo the reading at the left cuspid 
 location, and subtract 20 from it. This will give the com 
 bined width of the upper six anteriors which will set up to 
 the fullness of the bite and bring the cuspids in correct 
 positions. This information is of special value to the 
 careful worker, since, when used in connection with the 
 tables of dimensions on page 114. it facilitates rapid and 
 sal isfactory select ion. 
 
 When upper and lower dentures are being made to 
 gether, there is no need to take measurements of the 
 lowers. 
 
 101 
 
Fig. TG. 
 
 Fig. 77. 
 
 IIARMONY OF FORM ILLUSTRATED 
 The face in repose is of square form an 
 medium proportions. The upper centrals arc 
 of similar form and proportions. 
 
 Figure 78 shows the shadow of the natural 
 upper central, enlarged to the width of the 
 face between the condyles and imposed on the 
 face. It follows the facial outline perfectly. 
 Figure 79 shows the shadow of the Trubyte 
 upper central indicated for the case mould 
 2E, which is fully as harmonious with the 
 face as tiie natural central. 
 
 Fig. 78. 
 
 102 
 
Harmony of Form in Faces and Teeth. 
 
 I>r. Williams has demonstrated a striking relation be- 
 tween the outline forms of- faces and outline forms of 
 upper central incisors in enough cases and under enough 
 conditions to permil the formulation of the following 
 law: I" it'* 1 lines! natural dentures, the outline form of 
 the upper central is identical with the outline of certain 
 port ions of the face. 
 
 This law is. capable of exhaustive proof. Select a 
 natural denture which is pleasing when critically studied 
 in relation to the face as in Figure 77. Photograph the 
 upper central and enlarge it to he as wide as the face at 
 the condyles. Impose the photograph of the tooth on a 
 photograph of the face, with the neck of the tooth at the 
 chin margin as in Figure 78. The photograph of the tooth 
 will uniformly extend to the brow line, two-thirds way 
 from the root of the nose to the normal hair line. The 
 inverted tooth outline will follow the face outline in a 
 striking manner. 
 
 Nature evidently desires that the outline form of the 
 face and of the upper centrals shall he identical. She 
 achieves this result in a comparatively small percentage of 
 people; these furnish our finest examples and maintain 
 our inspiration and furnish the basis for our laws. In the 
 great majority of people the outlines of the face and teeth 
 are approximately alike and the teeth are pleasing when 
 not too critically studied. Tn some people the face outline 
 and tooth outline are visibly unlike and the teeth are not 
 pleasing.* 
 
 There is no relation between the color of the complexion 
 and the outline form of the teeth, as was claimed by the 
 temperamental theory. 
 
 Those desiring further illustrations of this form of proof are 
 referred to the book, "Trubyte Teeth for Vulcanite Plates," pub- 
 lished by The Dentists' Supply Co., and sent free on request. 
 
 L03 
 
When selecting for edentulous cases, pay no attention 
 to the form of the lost natural teeth, but select an arti- 
 ficial form which harmonizes with the facial outline. This 
 will insure the selection of long teeth for long faces, short 
 teeth for short faces, narrow teeth for narrow faces, and 
 wide teeth for wide faces, together with the proper 
 straightness or convexity of outline form. If the natural 
 teeth were harmonious with the face, this method will re- 
 produce them; if they were inharmonious, artificial teeth 
 selected in this way will improve upon them. 
 
 Figure 79 shows a photograph of the Trubyte upper 
 central indicated for this face, enlarged and inverted as 
 the natural central is in Figure 78. When subjected to 
 this, the most exhaustive test so far devised, the artificial 
 form is seen to be quite as harmonious with the face as 
 the natural form in Figure 78. 
 
 Trubyte teeth are offered in graded sizes and selection 
 of the desired size can be best effected by the marks of the 
 lip positions on the compound as already described. 
 
 The selection for both form and size can be most 
 quickly and satisfactorily completed by the use of a Mould 
 Guide. While a Mould Guide can be used by one who 
 knows nothing about face forms, it can be more quickly 
 and satisfactorily used if one will master at least the 
 elements of face and tooth form as summarized in the 
 following pages. 
 
 Anterior Tooth Forms In Partial Cases. 
 
 When selecting teeth for a partial case in which natural 
 centrals remain, select a form of artificial teeth which 
 duplicates the remaining central, without regard to the 
 face form. If only the natural laterals remain, the central 
 may be selected to harmonize with the face form. 
 
 104 
 
Brow line 
 
 Fig. SO. 
 
 Harmony of Form in Faces and Teeth, 
 Continued. 
 
 The continuous Mack outline encloses the areas of the 
 face with which the ideal central will harmonize. 
 
 Starting with the neck of the inverted upper central at 
 the margin of the chin, the cervical third of the tooth out- 
 line will follow the outline of the lower margin of tin 1 
 jaw; the outline of the middle third of the tooth will fol- 
 low the outline of the cheeks; and the incisal edge will he 
 at the brow line, about two-thirds distance from the root 
 of the nose to the normal hair line. 
 
 Selection for lull cases may he confined to the form and 
 size of the centrals, because in properly formed teeth, they 
 host express the character of the set and are well sup- 
 ported by the same character in the laterals and cuspids. 
 
 105 
 
Wide forehead 
 Sides of head 
 
 Fig. 81. 
 
 Typal Square Faces. 
 
 There are only three typal forms in faces and teeth, 
 the typal square, illustrated and described above, the typal 
 tapering and the typal ovoid. All other forms have been 
 made by Mendings of these three. There are thousands of 
 such Mendings, each with its individual characteristics, 
 but if only the more important elements of form be con- 
 sidered, such as general outline form and proportions of 
 width to length, there are probably not more than 15 or 
 16 important forms in faces and teeth. Fourteen of these 
 have been isolated and Trubyte teeth harmonious with 
 them haA^e been produced. They meet the requirements 
 of the most exacting practice. 
 
 There are five distinct forms of the square type of face. 
 They are shown on page 107. 
 
 106 . 
 
Face Forms and Tooth Forms, Square Type 
 
 Fie;. 83. 
 
 The Long Square 
 
 Narrow in proportion to length. Nearly 
 
 straight and nearly parallel sides. 
 
 Moulds 1C— ID— IE— IF— III. 
 
 The Medium Square 
 
 Medium proportions. Nearly straight and 
 
 nearly parallel sides. 
 
 Moulds 2C— 2D— 2E— 2F. 
 
 The Short Square 
 
 Short in proportion to length. Nearly straighl 
 
 and nearly parallel sides. 
 
 Moulds 3B—3C— 3D. 
 
 The Intermediate Square 
 
 Wide in proportion to length and with very 
 
 slightly rounding outlines. Rectangular 
 
 in appearance. 
 
 Moulds 4B— 40— 4E—4H. 
 
 The Oval 
 
 Long and relatively narrow. Check and jaw 
 
 lines in long sweeping curves. Pleasing 
 
 [aces and beautiful teeth. 
 
 Moulds 50— 5D— 5E— 6F— 61 1 . 
 
 107 
 
Pig. 87. 
 
 The Typal Tapering Face. 
 
 This form of face, illustrated and described above, is 
 distinguished from the typal square and typal ovoid faces 
 by the more rapid convergence downward of the cheek 
 lines and their occasional concavity.' 
 
 This frequently seen form of face appears to have been 
 unrecognized in dentistry until Dr. Williams discovered 
 it. Certainly no forms of teeth harmonious with it and 
 its modifications and expressive of the character of taper- 
 ing teeth were produced. 
 
 The five forms of the tapering type are among the most 
 frequently seen forms of faces and teeth and certainly 
 among the most pleasing. The faces are shown on page 
 109. 
 
 108 
 
Face Forms and Tooth Forms, Tapering Type 
 
 i i 
 
 Fig. SO. 
 
 The Typal Tapering 
 
 Medium wideormore in proportion to length. 
 
 Nearly straight, converging sides. 
 
 Moulds iM— IN— IP— 1R. 
 
 _- - - .. ^-^\ J 
 
 The Second Tapering 
 
 Narrower in proportion to length than the typal 
 
 form. Slightly more rounding outlines. 
 
 Moulds 2M—2N—2P. 
 
 ( \ ' 
 
 Third Tapering 
 
 Wide in proportion to length. Noticeablj 
 
 rounding, converging sides. 
 
 Moulds 3M— 3N— 3P. 
 
 Fiu. !H). 
 
 O 
 
 J 
 
 ForiMii Tapehixi; 
 
 Like third tapering but narrower in proportion 
 
 to length. 
 
 Moulds 4M— 4N— 4P. 
 
 Fig. 91. 
 
 IJ 
 
 Fig. 02 
 
 Fifth Tapering 
 
 A combination of the medium Bquarc and 
 
 typal tapering. 
 
 Moulds 5M 5N 5P— 5R. 
 
 L09 
 
Mediui 
 forehead 
 
 sides of head 
 
 Fig. 93. 
 
 The Typal Ovoid Face. 
 
 This face is entirely unlike either of the other types, 
 being wider in proportion to its length and bounded 
 wholly by segments of circles. There is a characteristic 
 double curve in the chin margin, which is reproduced, in a 
 remarkable way, in the mesial surfaces of the upper 
 laterals and the distal surfaces of the upper centrals. 
 
 Like the tapering type, this type appears to have been 
 unknown to dentistry until discovered by Dr. Williams. 
 
 Faces of the four forms in this type, shown on page 111, 
 are probably not as numerous as those of the other types, 
 but they are often distinctive or pleasing and require 
 suitable forms in artificial teeth. 
 
 no 
 
Face Forms and Tooth Forms, < >void Type 
 
 Tyiwi. Ovoid 
 
 Medium wide in proportion to length. Outlines 
 
 in segments of circles. 
 
 Moulds LW— IX— 1Y. 
 
 Pig. 04. 
 
 Second Ovoid 
 
 Like the typal ovoid but narrower in proportion 
 
 to length. 
 
 Moulds 2U— 2X— 2Y. 
 
 Fig. 95. 
 
 Fig. 90. 
 
 Third Ovoid 
 
 More than medium vide in proportion t< 
 length, with converging convex sides. 
 
 Moulds 3U— 3W— 3X— 3Y. 
 
 MUM 
 
 Forum Ovoid 
 
 .ike the third ovoid bu1 narrower in proportion 
 
 to length. 
 
 Moulds 4U—4W—4X—4Y. 
 
 Fie. 97. 
 
 ill 
 
kkkkkkkkai 
 
 rig. os. 
 
 Typal Forms in Natural Teeth. 
 
 Tt can be shown that three typal forms of upper centrals 
 have been common to all' races from which we have even a 
 dozen skulls showing anterior teeth, and this without 
 relation to the time in history, the stature, the color or the 
 intelligence of the race. 
 
 One type is square with nearly straight and nearly 
 parallel sides ; the second is tapering with nearly straight 
 sides rapidly diverging downward ; the third is ovoid with 
 all its outlines in segments of circles. 
 
 The typal forms of teeth are so identical in outline and 
 proportions with typal faces as to preclude any idea of 
 rare and accidental occurrence, and to amply support the 
 deduction of the law on pages 102 and 103. This law of 
 identity of form holds good in fine specimens of the modi- 
 fications of the typal forms. 
 
 Every other form of teeth can be shown to be a com- 
 bination of these forms. 
 
 ISTo other typal form has been found and no form which 
 requires another type to account for it. 
 
 112 
 
Determining the Type of Face. 
 
 If straighl edges are laid against the cheeks, from the 
 condyles to the angles of the jaw, the type of face can be 
 easily determined and the harmonious form of tooth 
 selected. Tf the straight edges are nearly parallel, the 
 face is of the square type (Class 1. Trubyte classification). 
 Tf the rulers converge noticeably downward, as here, the 
 face is (it* the tapering type (Class II, Trubyte classifica- 
 tion). If the rulers diverge downward from the condyles, 
 the face is ovoid (('lass III, Trubyte classification), 
 
 113 
 
Dimensions Trubyte Moulds— UPPERS 
 
 
 
 
 Length Cen- 
 
 Width 
 
 Width 
 
 Combined 
 
 
 
 Mould 
 
 tral Without 
 
 6 Anteriors 
 
 Full 14 
 
 Bite and Shut 
 
 Width of 
 
 
 
 Wo. 
 
 Collar 
 
 Set up 
 
 Set up 
 
 of Central 
 
 Central 
 
 
 
 
 1C 
 
 9.5 
 
 42. 
 
 100. 
 
 8. 
 
 6.75 
 
 
 
 
 ID 
 
 ]0.5 
 
 46. 
 
 108. 
 
 8. 
 
 7.25 
 
 
 
 e\ 
 
 IE 
 
 11. 
 
 48. 
 
 113. 
 
 9. 
 
 7.75 
 
 
 
 £ 
 
 IF 
 
 11.25 
 
 52. 
 
 117. 
 
 9.5 
 
 8. 
 
 ul 
 
 
 
 . 1H 
 
 12.25 
 
 57. 
 
 120. 
 
 9.5 
 
 8.5 
 
 Du 
 
 
 CM 
 
 " 2C 
 
 9.25 
 
 46. 
 
 108. 
 
 8. 
 
 7.25 
 
 
 E 
 
 2D 
 
 9.75 
 
 49. 
 
 111. 
 
 8.5 
 
 7.75 
 
 >" 
 
 
 r 
 
 2E 
 
 10.5 
 
 50. 
 
 115. 
 
 9.5 
 
 8. 
 
 H 
 
 ~^ 
 
 "- 
 
 . 2F 
 
 11.25 
 
 52. 
 
 127. 
 
 9.5 
 
 8.25 . 
 
 
 CO 
 
 CO 1 
 
 3B 
 
 8. 
 
 45. 
 
 107. 
 
 7.5 
 
 7.25 
 
 U 
 
 t/1 
 
 E . 
 
 3C 
 
 8.75 
 
 49. 
 
 111. 
 
 8. 
 
 7.75 
 
 OS 
 
 < " 
 
 LL. 1 
 
 3D 
 
 9.5 
 
 48. 
 
 113. 
 
 8. 
 
 8.8 
 
 < 
 
 J 
 
 * 
 
 ' 4B 
 
 8.5 
 
 47. 
 
 113. 
 
 6.5 
 
 7.5 
 
 
 U 
 
 E 
 
 4C 
 
 9.25 
 
 49. 
 
 117. 
 
 7. 
 
 8. 
 
 D 
 
 
 = 
 
 4E 
 
 10. 
 
 50. 
 
 118. 
 
 7. 
 
 8.25 
 
 a 
 
 
 "■ 
 
 . 4H 
 
 10.25 
 
 52. 
 
 120. 
 
 7. 
 
 8.5 
 
 Crt 
 
 
 
 " 5C 
 
 9. 
 
 34. 
 
 96. 
 
 8. 
 
 6.5 
 
 
 
 » 
 
 5D 
 
 9.5 
 
 37. 
 
 101. 
 
 8. 
 
 7. 
 
 
 
 i- 
 
 5E 
 
 10. 
 
 39. 
 
 106. 
 
 8.5 
 
 7.25 
 
 
 
 £ 
 
 5F 
 
 11. 
 
 48. 
 
 110. 
 
 9. 
 
 7.75 
 
 
 
 
 . 5H 
 
 11.5 
 
 52. 
 
 117. 
 
 9. 
 
 8.5 
 
 
 
 
 r 1M 
 
 9. 
 
 45. 
 
 107. 
 
 8.5 
 
 7.5 
 
 
 
 eJ 
 
 IN 
 
 9.75 
 
 48. 
 
 110. 
 
 9.5 
 
 8.25 
 
 
 
 s" 
 
 IP 
 
 10.5 
 
 52. 
 
 117. 
 
 9.5 
 
 8.5 
 
 Qu 
 > 
 
 
 
 l 1R 
 
 11. 
 
 54. 
 
 125. 
 
 9.5 
 
 8.75 
 
 
 CM 
 
 2M 
 
 9.5 
 
 45. 
 
 107. 
 
 8.5 
 
 7. 
 
 
 E . 
 
 2N 
 
 10. 
 
 46. 
 
 108. 
 
 8.5 
 
 7.5 
 
 H 
 
 — 
 
 £ 
 
 . 2P 
 
 10.75 
 
 51. 
 
 116. 
 
 9. 
 
 8. 
 
 
 
 CO 
 
 CO 
 
 3M 
 
 9.5 
 
 45. 
 
 103. 
 
 8.5 
 
 7. 
 
 2 
 
 en - 
 
 E - 
 
 3N 
 
 10.25 
 
 48. 
 
 110. 
 
 8.5 
 
 8. 
 
 < 
 
 u. 
 
 3P 
 
 11. 
 
 54. 
 
 125. 
 
 8.5 
 
 8.5 
 
 s 
 
 J 
 
 * 
 
 4M 
 
 9.5 
 
 44. 
 
 102. 
 
 8.5 
 
 7.25 
 
 Hi 
 
 u 
 
 g. 
 
 4N 
 
 10.5 
 
 49. 
 
 111. 
 
 9. 
 
 7.75 
 
 cu 
 
 
 £ 
 
 4P 
 
 10.75 
 
 52. 
 
 114. 
 
 9. 
 
 8.25 
 
 < 
 
 
 LO 
 
 r 5M 
 
 9. 
 
 45. 
 
 103. 
 
 7.5 
 
 7.25 
 
 H 
 
 
 E . 
 
 5N 
 
 9.5 
 
 46. 
 
 108. 
 
 7. 
 
 7.5 
 
 
 
 1 
 
 5P 
 
 10.25 
 
 49. 
 
 111. 
 
 8. 
 
 8. 
 
 
 
 
 , 5R 
 
 11. 
 
 53. 
 
 118. 
 
 8.5 
 
 8.75 
 
 
 
 ' ^ 
 
 1W 
 
 9.75 
 
 46. 
 
 108. 
 
 8. 
 
 7.5 
 
 
 
 E . 
 
 IX 
 
 10.25 
 
 48. 
 
 110. 
 
 8 
 
 
 8. 
 
 
 
 1 
 
 1Y 
 
 11. 
 
 52. 
 
 117. 
 
 8 
 
 
 8.5 
 
 UJ 
 
 
 CM 
 
 2U 
 
 10. 
 
 42. 
 
 100. 
 
 7 
 
 5 
 
 7. 
 
 Du 
 
 
 E , 
 
 2X 
 
 10 25 
 
 46. 
 
 111. 
 
 8 
 
 
 7.75 
 
 > 
 
 ~ 
 
 £ 
 
 2Y 
 
 10.5 
 
 48. 
 
 113. 
 
 8 
 
 
 8. 
 
 H 
 
 en 
 
 
 r 3u 
 
 9.25 
 
 48. 
 
 110. 
 
 8 
 
 
 7.5 
 
 Q 
 
 en 
 
 
 3W 
 
 10. 
 
 50. 
 
 115. 
 
 9 
 
 
 8. 
 
 < 
 
 EH 
 
 o 
 
 3X 
 
 10.5 
 
 54. 
 
 119. 
 
 8 
 
 5 
 
 8.5 
 
 o 
 
 J 
 
 £ 
 
 L 3Y 
 
 11. 
 
 55. 
 
 120. 
 
 9 
 
 
 9. 
 
 > 
 
 
 
 O 
 
 « 
 
 r 4U 
 
 9.25 
 
 46. 
 
 104. 
 
 8 
 
 
 7.25 
 
 
 E 
 
 4W- 
 
 9.75 
 
 48. 
 
 110. 
 
 8 
 
 
 7.75 
 
 
 i" 
 
 4X 
 
 10.5 
 
 50. 
 
 112. 
 
 8 
 
 
 7.75 
 
 
 
 "• 
 
 l 4Y 
 
 11. 
 
 52. 
 
 117. 
 
 9 
 
 
 8.5 
 
 114 
 
Dimensions Trubyte Moulds — LOWERS 
 
 
 Length Cen- 
 
 Width 
 
 Width 
 
 Combined 
 
 
 Mould 
 
 tral \\ itboul 
 
 (. Vnteriors 
 
 hull 14 
 
 Bite and Shut 
 
 Width of 
 
 No. 
 
 Cellar 
 
 Set up 
 
 Sri up 
 
 of Central 
 
 Central 
 
 
 f !C 
 
 ~ .5 
 
 31. 
 
 it.".. 
 
 ' .5 
 
 18.5 
 
 
 - id 
 
 9. 
 
 35. 
 
 104. 
 
 9. 
 
 19.5 
 
 
 ii ie 
 
 ;i ."> 
 
 38. 
 
 108. 
 
 it .". 
 
 • ■•> 
 
 
 -I IF 
 
 it ."> 
 
 39. 
 
 109. 
 
 9, 
 
 21.' 5 
 
 
 I 1H 
 
 i l. 
 
 19. 
 
 L25. 
 
 9.7 5 
 
 2 1 . 5 
 
 UJ 
 
 CM f 2C 
 
 8.5 
 
 35. 
 
 104. 
 
 8. 
 
 lit :, 
 
 0. 
 
 E 1 2D 
 
 it 
 
 36. 
 
 Kir. 
 
 8.5 
 
 20. 
 
 > 
 
 11 2E 
 - [ 2F 
 
 9.75 
 
 38. 
 
 108. 
 
 9. 
 
 ■'. l . 5 
 
 H 
 
 lit.:, 
 
 10. 
 
 1 10. 
 
 10. 
 
 2 2..", 
 
 n in 
 
 " i :5B 
 
 7 
 
 34. 
 
 103. 
 
 '. 5 
 
 19.5 
 
 UJ «J ■ 
 
 8*. 
 
 37. 
 
 106. 
 
 8. 
 
 2 1..". 
 
 < u 
 
 3 
 
 £t 3D 
 
 8.5 
 
 39. 
 
 109. 
 
 8. 
 
 22. 
 
 rr I 4B 
 
 7 
 
 36. 
 
 109. 
 
 6. 
 
 22. 
 
 E I 4C 
 
 8! 
 
 37. 
 
 1 1 1. 
 
 <;.•"> 
 
 23. 
 
 a 
 
 CO 
 
 5 1 4E 
 
 8. 
 
 37. 
 
 110. 
 
 7 
 
 22. 
 
 "■ I 4H 
 
 9. 
 
 40. 
 
 115. 
 
 7. 
 
 25. 
 
 
 f 5C 
 
 8.5 
 
 30. 
 
 94. 
 
 8.5 
 
 17. 
 
 
 10 5D 
 
 8.5 
 
 33. 
 
 97. 
 
 8. 
 
 18. 
 
 
 ij 5E 
 
 8.5 
 
 34. 
 
 103. 
 
 
 19. 
 
 
 «2| 5F 
 
 9. 
 
 35. 
 
 104 
 
 8 5 
 
 19. 
 
 
 , L 5H 
 
 10. 
 
 42. 
 
 1 1 2. 
 
 8. 
 
 22. 
 
 
 - f 1M 
 
 S.5 
 
 35. 
 
 104. 
 
 8. 
 
 19. 
 
 
 E 1 IN 
 
 9. 
 
 38. 
 
 107. 
 
 8.5 
 
 2 1 . •"> 
 
 
 Si IP 
 
 10. 
 
 41. 
 
 111. 
 
 8.5 
 
 22.5 
 
 Ld 
 
 I 1R 
 
 10. 
 
 42.5 
 
 128.5 
 
 it..". 
 
 23. 
 
 DU 
 
 = (, 2M 
 
 s. 
 
 33.5 
 
 102.5 
 
 8. 
 
 19. 
 
 > . 
 
 li 2N 
 
 9. 
 
 30. 
 
 105. 
 
 9. 
 
 21. 
 
 H - 
 
 £ / 2P 
 
 10. 
 
 39. 
 
 109. 
 
 9 5 
 
 21.5 
 
 
 « ( 3M 
 
 8.5 
 
 34. 
 
 98. 
 
 7.5 
 
 19. 
 
 §} 3N 
 
 9.6 
 
 38. 
 
 107. 
 
 8. 
 
 21. 
 
 5 < 
 
 £/ 3P 
 
 10. 
 
 4 2. 
 
 128. 
 
 7.5 
 
 23. 
 
 a: J 
 
 ■* i 1M 
 
 
 :;:; .". 
 
 it:..". 
 
 8. 
 
 19. 
 
 
 £-, -IN 
 
 9.5 
 
 37. 
 
 106. 
 
 9. 
 
 20. 
 
 £/ 4P 
 
 10. 
 
 39. 
 
 108. 
 
 9.5 
 
 22.25 
 
 < 
 
 u> (' 5M 
 
 7.5 
 
 34. 
 
 98. 
 
 7. 
 
 19. 
 
 E J 5N 
 
 5 1 nP 
 
 8. 
 
 35. 
 
 10 l 
 
 7.25 
 
 20. 
 
 f- 
 
 8.5 
 
 38. 
 
 107. 
 
 8.5 
 
 21.5 
 
 
 . £ l 5R 
 
 9. 
 
 39. 
 
 . L09. 
 
 8.5 
 
 22.5 
 
 - ( 1W 
 
 8 5 
 
 34. 
 
 103. 
 
 7 
 
 18.75 
 
 
 E\ IX 
 
 9. 
 
 36. 
 
 K)5. 
 
 8! 
 
 20.5 
 
 UJ 
 
 £ ( 1Y 
 
 8.75 
 
 38. 
 
 108. 
 
 8. 
 
 '.' '.' 
 
 a. _; 
 
 « ( 2U 
 
 s :.».-> 
 
 32. 
 
 90. 
 
 '■ .5 
 
 i: S 
 
 >- s 
 
 H l/l 
 
 en 
 
 §1 2X 
 £ '. 2Y 
 « 1 3U 
 
 !i 50 
 
 35. 
 
 L04. 
 
 8. 
 
 20. 
 
 9.25 
 
 8 
 
 35. 
 35. 
 
 105. 
 104. 
 
 8. 
 
 19.5 
 
 i ;>.:.". 
 
 Q < 
 
 o J 
 
 E 1 3W 
 
 8 5 
 
 39. 
 
 11)9. 
 
 s. 
 
 21. 
 
 "■ I 3Y 
 
 9 5 
 
 12. 
 
 I L2 
 
 it 
 
 23. 
 
 10. 
 
 42. 
 
 1 14. 
 
 9.5 
 
 23. 
 
 E 1W 
 
 8. 
 
 ::.'.. 
 
 99. 
 
 7 5 
 
 19 
 
 
 
 
 37. 
 
 106. 
 
 - 
 
 2"'. 
 
 
 L"- 1 JY 
 
 9.5 
 
 39. 
 
 L08 
 
 - • 
 
 2 1 5 
 
 
 9.5 
 
 :••'.'. 
 
 L09 
 
 it. 
 
 
 115 
 
TRUBYTE 
 
 A^.. TEETH 
 
 TRUBYTE TEETH 
 
 yyy | ^ vUUi 
 
 * A *A.A* 
 
 
 
 
 UUU ^itu« ^ 3Y ilUii : "JLkiiii 
 
 THE DENTISTS' SUPPLY COMPANY, 220 WEST 4 2 nd STREET. NEW YORK, U.S.A. 
 
 Fig. 100. 
 
 116 
 
Fig. 101. 
 
 The Use or a Mould Guide 
 
 enables the dentist to compare the ontline form and pro- 
 portions of the entire line of artificial upper centrals with 
 the ontline form of the face, and in connection with the 
 Selection Rim described on page 118, to try the teeth 
 in the mouth and observe the effect. 
 
 If the dentist is ahle to determine the Type and Form 
 of the face, he can proceed to select immediately from the 
 required type of teeth. Otherwise he may simply invert 
 the centrals and ohserve which is most like the face 
 
 Tn extensively modified faces, where selection is more 
 difficult, lie may compare the two or three forms available 
 and choose the mosl pleasing. 
 
 Tie may then order teeth or select from his stock by 
 mould number. 
 
 117 
 
Fig. 102. 
 
 The Tbubyte Selection Rim. 
 
 When the teeth have been selected, the choice should 
 be confirmed by trying them in the mouth to judge of the 
 harmony of form, size, and, if the desired shade is at 
 hand, the color. 
 
 Trying-in is greatly facilitated by the use of the Selec- 
 tion Rim here shown in use. It is heavily nickeled and 
 may be sterilized and filled with fresh wax for each 
 patient. 
 
 When natural lower teeth are in place, the appearance 
 of the uppers may be contrasted with them by mounting 
 a roll of wax on the back of the Rim and setting it, with the 
 teeth, immediately upon the lowers, with the uppers in 
 the desired position. 
 
 118 
 
Fig. 103. 
 
 Shading in Artificial Teeth. 
 
 It is impossible to make natural looking dentures if 
 the artificial anterior teeth are all of one shade, or have 
 beeii shaded without a knowledge of the methods used by 
 nature to achieve her finest esthetic effects. 
 
 In Figure 103A good natural denture? are illustrated. 
 In Figure 103B, the same dentures are shown, bul made 
 all of one shade, as must artificial teeth are. The uniform 
 shading makes the teeth appear larger and more promi- 
 nent, especially in the hack of the mouth. This effect is 
 unavoidable with most artificial teeth. 
 
 In line natural sets the lower anteriors arc deeper in 
 shade than the uppers. This is to emphasize the per- 
 spective. The laterals are generally a trifle darker than 
 
 119 
 
*v- '.;';;!" 
 
 Fig. 104. 
 
 Diagram of the incisal view of upper and lower anteriors. 
 Outside the teeth, bands of color showing the relative depths 
 of color of the upper and lower anteriors in one fine natural 
 set. This variation in color contributes greatly to the 
 beauty of the teeth. 
 
 the centrals and the lower cuspids, the darkest of all the 
 anterior teeth. 
 
 The incisal halves of the upper centrals present the 
 lightest spot in both sets. The upper laterals are more 
 uniform in color than the centrals and the cuspids darker 
 still, especially at the necks. The effect of this shading 
 is to greatly emphasize the perspective of the rounding 
 form of the tooth row. 
 
 Artificial teeth can be esthetically successful only when 
 the shading in a set is varied as it is in fine natural teeth. 
 The effort to make up sets by taking different shades is 
 only partly satisfactory because the shades are of unlike 
 characters and were not meant to be arranged in that way. 
 
 When artificial sets are properly shaded in the set, the 
 underbite of the lower anterior is properly emphasized, 
 the perspective of the rounding form of the tooth row is 
 enhanced as nature intended it to be, the band of color 
 shown by the exposed anterior teeth is more natural in 
 appearance, the bicuspids and molars are reduced in prom- 
 inence and any slight error in selection of shade is greatly 
 minimized. 
 
 120 
 
Suggestions for the Selection of Shades. 
 
 la ;i general why ii may be said thai the besl time to 
 select tooth colors is between 9 A. M. and 3 P. M. The 
 lighting of i In- room should be good but not brilliant. 
 Brightly colored office furnishings or decorations make 
 accurate matching impossible. The besl color for sur- 
 rounding objects when matching shades is a Light tone of 
 warm gray or brown. 
 
 For edentulous patients select a color which will har- 
 monize with the color of the skin around the orifice of the 
 mouth. When natural teeth are in the mouth these should 
 he matched rather than the face. 
 
 Fair or white skinned people will require much less 
 depth of color in the tooth to balance the depth of color 
 in the face than persons whose complexion is naturally 
 highly modified by red or yellow or darkened by exposure 
 to the sun or weather. 
 
 The skin of most people will he found to exhibit a 
 surprising amount of red if examined under a separate 
 light, through a paper tube 10 inches long and % inch in 
 diameter held to the eve to exclude side lights. For such 
 faces teeth of suitable depth of yellow to harmonize with 
 the face will be more satisfactory than any others. 
 
 A face with clear or brilliant red coloring will require 
 teeth of clear yellow, while faces which have bilious, muddy 
 yellow skin will require teeth thai are a yellow muddy hue. 
 
 "Red and yellow or their combinations are the basis of 
 color of the skin of most light-skinned people. 
 
 Dentists who are not color experts, will do well to 
 choose teeth, for edentulous patients, in which the domi- 
 nant color is yellow, ^r yellow modified by red. Teeth 
 in which the dominant color is blue, green or gray art 1 
 very likely to produce a disharmony unless selected by 
 an expert ami in any case are rarely indicated for eden- 
 tulous pal ielits. 
 
 121 
 
A Table of the Colors in the Twentieth 
 Century Shade Guide 
 
 Shade No. 1. Lightest shade in use. No coloring. 
 
 Shade No. 2. Trace of purple. 
 
 Shade No. 3. Trace of blue. Trace of yellow. Lightest blue. 
 
 Shade No. 4. Trace of yellow. Lightest yellow. 
 
 Shade No. 5. Trifle of gray and trace of yellow. Point same 
 as No. 4. Neck darker. 
 
 Shade No. 6. Same as No. 4, with a little gray in the tip. 
 Neck not so bright a yellow as No. 5. Lightest gray. 
 
 Shade No. 7. Light yellow. Darker than No. 5, with color 
 decidedly stronger in neck. 
 
 Shade No. 8. Light yellow. Tip darker than No. 5 or No. 7. 
 Neck lighter than No. 7, and makes tooth look a straw color. 
 More uniform than No. 7. Yellow is the only color present. 
 
 Shade No. 9. A little yellow, a little gray, a little pink. Light 
 brown yellow neck. Tip pink gray, follows No. 11. 
 
 Shade No. 10. Gray. Lighter than No. 9. Darker than No. 6. 
 
 Shade No. 11. Uniform gray throughout. Neck grayish yel- 
 low slightly darker than 10, which it follows. 
 
 Shade No. 12. Grayish blue. Follows No. 3 in the blues. 
 
 Shade No. 13. Grayish blue. Follows No. 9. 
 
 Shade No. 14. Yellowish gray. Gray yellow neck. Follows 
 No. 13. 
 
 Shade No. 15. Pinkish gray. Decidedly darker and shows 
 more pink than No. 9. The other grays are bluish grays. This 
 follows No. 14. 
 
 Shade No. 16. Yellow. Follows No. 8. 
 
 Shade No. 17. Greenish yellow. Green tip and yellow neck. 
 
 Shade No. 18. Dark yellowish gray. Follows No. 14. 
 
 Shade No. 19. Dark greenish yellow. Follows No. 17. 
 
 Shade No. 20. Brownish yellow. Follows No. 16. 
 
 Shade No. 21. Dark brown yellow. Follows No. 20, which it 
 is like, only darker. 
 
 Shade No. 22. Dark gray. Follows No. 18. 
 
 Shade No. 23. Darkest brown yellow. Follows No. 21. 
 . Shade No. 24. Dark grayish brown. Follows No. 22. 
 
 Shade No. 25. Dark yellowish brown. Follows No. 23. 
 Shades in order of depth from light to dark. 
 Light Shades, 1-2. Yellows, 4-5-7-8-16-17-19-20-21-23-25. 
 Grays, 6-10-11-9-13-14-15-18-2-24. Blues, 3-12. 
 
 122 
 
Surface Texture and Tooth Shades. 
 
 Dentists who wish to make fine prosthetic restorations 
 should avoid using teeth with such smooth labial surfaces 
 thai they look glassy. While the labial surfaces of many 
 natural teeth have been worn smooth by lip action, the 
 finest teeth present labial surfaces with slighl irregulari- 
 ties, as though the enamel had been deposited in waves. 
 These irregularities diffuse the light reflected by the 
 teeth and soften both the high lights and the shadows. The 
 result is that the entire tooth has a soft and pleasing 
 color. 
 
 The artificial teeth of the past have presented either 
 very smooth labial surfaces or depressions like those re- 
 sulting from defective calcification. The smooth surfaces 
 have collected light rather than diffused it and have ex- 
 hibited small, localized strong high lights and deep 
 shadows. The high lights being brighter than the color 
 of the tooth, and the shadows deeper than that color, have 
 made it impossible, in certain cases or certain lights, to 
 place artificial teeth beside natural teeth and have them 
 indistinguishable, however carefully the shade was chosen. 
 
 When Trubyte teeth were produced, this subject of dif- 
 fusion of light was given very careful consideration, and 
 after much experimenting to develop a method of mould- 
 making which permitted the production of labial surfaces 
 with satisfactory irregularities to diffuse the light, Tru- 
 byte teeth were brought out with such surfaces. 
 
 Three of the great factors in shade selection are thus 
 placed in a favorable position before the dentist, satis- 
 factory shades from which to select; a variation of shade 
 in the set and between uppers and lowers which achieves 
 the proper perspectives; and tooth surfaces which diffuse 
 the light as do the tinest natural teeth. 
 
 123 
 
Part III 
 
 Measuring Habitual 
 Masticating Movements 
 
Why It Is Worth While to Reproduce Jaw 
 Movements. 
 
 Because if the dentist can foresee the conditions under 
 which the dentures will operate in any mouth, he can 
 achieve stability, comforl and efficiency in those dentures. 
 
 It is probable that the permanent natural teeth deter- 
 mine the habitual movements of the jaw, and there can he 
 no question that these movements determine the bony 
 formations in the fossae and condyles and often alter them 
 extensively. 
 
 The natural teeth are rarely lost all at once or evenly 
 on both sides or both jaws. With the uneven loss of teeth 
 the jaw movements on the two sides change, sometimes in 
 great degree. The jaw is often incapable of movements on 
 one side which it habitually performs on the other. 
 
 When all the natural teeth are lost, the only guides as 
 to what the habitual movements were, are the records of the 
 habitual jaw movements. If these can be recorded and re- 
 produced in an articulator, the teeth can be so arranged 
 that when they are placed in the mouth, the jaw can go 
 right on with the movements to which it is accustomed!, the 
 dentures will not lie dislodged, and the teeth will oppose 
 each oilier in the manner essential to trituration. 
 
 Any other course requires the adoption of an arbitrary 
 set of movements for the jaw, the arrangement of teeth 
 to harmonize with them, and the error! to force the jaw to 
 adopt 1 1 10 arbitrary movements, with the necessary changes 
 in bony formation and muscular action, which in advanced 
 age is impossible. 
 
 "Custom-made" dentures, that is. those made to fit the 
 individual patient as clothes fit the individual form, are 
 so much move satisfactory to patients and dentists as to 
 fully justify the necessary procedure. 
 
 125 
 
Interferences that Prevent Correct Records. 
 
 It is impossible to take correct records of the habitual 
 jaw movements, if the heel of either impression is so 
 bulky as to interfere with natural free movements of the 
 jaw. 
 
 If the impression material over the upward inclines of 
 the lower ridge is too thick, it may come into contact with 
 the material over the tuberosities of the upper jaw which 
 may also be too bulky. These improper contacts may 
 cause pain. The patient should be instructed to report 
 even slight sensations of pain or any feeling that the free 
 movement of the mandible is hindered. 
 
 To relieve such contacts, trim the bite rim or impres- 
 sions as thin as may be necessary but without cutting 
 through the impressions or altering their margins. It is 
 often necessary to cut away portions of the tray. 
 
 If the impression cannot be trimmed thin enough to 
 avoid interference, adjust the Condyle Path Register as 
 described for Figure 124. Lock the bites together by the 
 method described for Figure 126, remove them from the 
 mouth and dismiss the patient. Pour casts and mount 
 them in the articulator, using the technic given. 
 
 Remove the upper impression from the cast, leaving 
 the lower in place. Make a baseplate of Dentsply Base 
 Plate Composition for the upper. Make a compound bite 
 rim on this baseplate and fit it to the flat surface of the 
 Horseshoe Plate, with the incisor guide pin in place. In 
 the same manner remove the lower impression and adapt 
 a baseplate to the lower ridge, make a compound bite rim 
 and fit it to the upper bite rim. 
 
 Attach the Horseshoe Plate to the block on the Condyle 
 Path Register, open the articulator and allow the Horse- 
 shoe Plate to move on the top of the lower bite rim and 
 bring the points of the horizontal pencils to be opposite 
 the heads of the condyle pins. Then press down on the 
 Horseshoe Plate so as to make an imprint of its pins on 
 
 126 
 
the occlusal surface of the lower bite rim. Remove the 
 Face Bow and attach the Horseshoe Plate to the lower bite 
 rim using the technic described for Figure L09. 
 
 IIcni the occlusal surface of the upper bite rim to a 
 very shallow depth and close ii upon t lie Horseshoe Plate to 
 equalize biting pressure. Trim the occlusal surface of the 
 tipper bite rim so thai it is smooth. When the patienl 
 returns, take records described in following pages, 
 
 Fig. 103. 
 
 A Horseshoe Plate. 
 
 B-B Wings of Condyle Path Register. 
 
 D Gooseneck and stand for supporting Register when mounting casts, 
 
 E Incisor Path Marker. 
 
 F-F Uprights from w Lngs supporting pencil.-. 
 
 G-G Screws, which, when turned move the wings horizontally. 
 
 H Setscrew 01 Rectangular Blocks of Register. 
 
 1-1 Milled tracks on which wings are moved. 
 
 .7 One of the two horizontal pencils. 
 
 K One of the two vertical pencils. 
 
 Condyle Path Registeb and A.ccess6hess. 
 
 In this illustration the Condyle Path Register is shown 
 attached to the Horseshoe Plate supported by the black 
 gooseneck and its stand. The gooseneck and supporting 
 frame are used only when mounting the casts in the artic- 
 ulator. The set-screw locks the Register to the gooseneck. 
 
 127 
 
The Condyle Path Register is used to make tracings of 
 two inclinations of the condyle path and also as a Face 
 Bow. It has a central rectangular block in which are two 
 holes to receive the pins of the Horseshoe Plate "A" and 
 through which passes a cylindrical transverse rod that 
 has at each end the geared tracks "I" on which the wings 
 "B" of the register may be moved inward and outward 
 at will, by turning the milled nuts u Gr" to bring the ver- 
 tical pencil "K" or the ' horizontal pencil " J" to the 
 desired relation to the sides of the face over the head of 
 the condyles. The vertical cylindrical rods "FF" may be 
 raised or lowered to help in adjusting the pencils "J" 
 and "K" and locked by turning the set-screw shown just 
 below the arrow leading from the letter "F." 
 
 When the lower jaw is moved from right to left and 
 the horizontal pencil points are correctly set they can 
 make a tracing of the descending inclination of the con- 
 dyle path on a card held in a vertical position against 
 the side of the face. 
 
 The vertical pencil points "K" make tracings on the 
 glass tabs of the lateral path register shown in illustra- 
 tion which indicate the lateral inclination of the condyle 
 path. 
 
 The Incisor path recording instrument "E" when at- 
 tached to the upper bite rim, in the median line is used 
 to trace a record of the incisor path on a blackened area 
 on the front of the Horseshoe Plate "A" which is attached 
 to the occlusal surface of the lower bite rim. This record 
 assists in correctly adjusting the articulator as well as in 
 determining when the bite is correct. 
 
 128 
 
Fig. 10(5. 
 
 Locating the Heads of the Condyles. 
 
 It is essential to that technic which follows that the 
 location of the centers of the heads of the condyles should 
 he indicated upon the face in such way that the Condyle 
 Path Register or the Snow Face Bow can lie properly 
 adjusted. 
 
 These locations can be most easily made by the use of 
 a flexible ruler which should be placed againsl the side 
 of the face so that its lower border extends from the 
 upper margin of the external auditory meatus to the outer 
 corner of the eye, as shown above. With an Eastman 
 negative retouching pencil or a soft lead pencil, draw a 
 line forward along the lower border of the ruler for about 
 % of an inch from the anterior margin of the meatus. 
 Draw a line vertically across this one aboul \b inch from 
 the anterior margin of the meatus. The intersection of 
 these lines will usually locate the center of the head OJ 
 the condyle. Mark the location of the center of the head 
 
 of the other condyle in the same way, 
 
 V29 
 
Fig. 106A. 
 
 Locating the Hoeseshoe Plate, Part II. 
 
 Release the hold upon the Condyle Path Register. Stand 
 in front of the patient and part the lips, see that about y 2 
 inch of the Horseshoe Plate is visible and note whether the 
 points of the recording pencils can be adjusted to reach the 
 crosses made over the centers of the heads of the condyles. 
 
 If the relations are fonnd to be satisfactory, instruct 
 the patient to bite forcibly on the Horseshoe Plate and force 
 the pins on its under surface into the bite rim. The im- 
 pressions the pins make will be used later to correctly lo- 
 cate the Horseshoe Plate for attaching the bite rim. 
 
 130 
 
Fie:. 107. 
 
 Withdrawing the Condyle Path Register. 
 
 Support the distal end of the right wing of the Condyle 
 Path Register with the left hand. Place the thumb and 
 two lingers of the right hand on opposite sides of the an- 
 terior part of the Horseshoe Plate and pinch the thumb and 
 fingers together so that they will slide forward on the con- 
 verging margins of the plate. If this pressure is contin- 
 ued after the thumb and fingers come into contact with 
 the center block of the Condyle Path Register, this block 
 will be forced off the Horseshoe Plate without discomfort 
 to the patient. 
 
 Lay the Condyle Path Register aside and remove the 
 upper impression, and the lower impression with the 
 Horseshoe Plate attached. 
 
 131 
 
Fig. 10S. 
 
 Attaching the Horseshoe Plate to the Bite 
 
 Rim. 
 
 Dry the occlusal surface of the lower hite rim and all 
 of the Horseshoe Plate. Seat the pins of both sides of the 
 Horseshoe Plate in the imprints in the occlusal surface of 
 the bite rim, as here shown. Direct a mouth blow pipe 
 name from an alcohol lamp on the occlusal surface of the 
 Horseshoe Plate at the point "B," and heat carefully until 
 the pins can be pressed all the way down. Do not overheat 
 or the plate may sink into the bite rim and destroy the 
 plane of occlusion. 
 
 Partly chill the side on which the pins are down and 
 heat the opposite side and press the pins down in like 
 manner. Thoroughly chill the entire rim. 
 
 132 
 
Fig 109. 
 
 Equalizing Biting Strain on the Bite Rims. 
 
 The seating of the Horseshoe Plate may have destroyed 
 the equal biting stress on the opposite sides of the bite rims. 
 Heat the occlusal surface of the upper Lite rim with a 
 mouth blow pipe flame from an alcohol lamp to a depth 
 of about 1/32 of an inch. Equalize the temperature in 
 hot water, place in the mouth, (lie lower impression and 
 Horseshoe Hate being in position, and cause the patient 
 to touch the tip of the tongue to the centre of the hack of 
 tlit- hard palate, close and swallow. When the upper bite 
 rim is hard, remove it and trim the margins of the oc- 
 clusal surface until it shows no imprints of the edges of 
 the Horseshoe Plate. 
 
 If the biting pressure is equal all around, it will be 
 possible for the patient to snap the rims together with a 
 sharp, definite sound. Unequal pressure will cause a 
 mullled, prolonged sound. 
 
 i:::; 
 
Fig. 110. 
 
 Adjusting the Horizontal Pencils. 
 
 Smear the occlusal surface of the Horseshoe Plate with 
 cocoa butter. Replace the central block of the Face Bow 
 on the projecting pins of the Horseshoe Plate, so that the 
 block touches the point of the plate. Move the right wing 
 of the Condyle Path Register until the point of the hori- 
 zontal pencil touches the face. Loosen the lock nut and 
 move the horizontal pencil of one side until its point is at 
 the intersection of the lines over the head of the condyle. 
 Lock the pencil in this position. Adjust the other pencil. 
 
 Special care must be used to lock the pencil holders 
 firmly or they may move slightly and confuse the records. 
 
 Move the wings outward until the points of the pencils 
 are about Va inch from the face. 
 
 134 
 
Fig. HI. 
 
 Registering the Descending Inclination of 
 the Condyle Path. 
 
 A device suggested by Dr. Zurbrigg is very convenient 
 for holding the card in recording the descending inclina- 
 tion of the condyle paths. It consists of two card holders 
 and a connecting wire. Each card holder is made by fold- 
 ing a shoe! of brass and soldering a sleeve on one side of the 
 fold. Platinoid wire of sufficient length to go over tho 
 head as shown is bent near the ends to lit into the sleeves. 
 
 Insert a card into the right holder and support it as 
 shown so that its lower margin parallels the wing of the 
 Condyle Path Uegister. Move the wing of the Condyle 
 Path Register toward the face until the pencil presses 
 against the card with light spring pressure. Place the 
 finger againsl the card, just in front of the upper part 
 of the ear, and hold it firmly against the fare. 
 
 Cause the patient to move the jaw from right to left 
 with the bite rims lightly in contact. The pencil records 
 the descending inclination of the condyle path habitual to 
 the patient. Make records for both sides. 
 
> 
 
 A B 
 
 Correct and Incorrect Descending Inclina- 
 tion Record. 
 
 If the record of the descending inclination exhibits 
 several parallel lines, as shown at "A" it is probable that 
 the card has been gradually raised by the operator while 
 the record was being made. If the record is of the char- 
 acter shown at U B" the patient is probably dropping the 
 jaw slightly as it moves from side to side, or there may be 
 interference between material of the upper and lower im- 
 pression or between the upper impression and the ramus. 
 This causes the lower impression to tip a little and the 
 Condyle Path Register and the recording pencil tip with 
 it resulting in the characteristic marks here shown. 
 => When the pencil starts from the point of "rest and makes 
 a forward and return movement in the same path as at 
 "C", the record is accurate. 
 
 If any doubt exists as to the accuracy of the records, 
 raise the card half an inch, keeping its lower margin par- 
 allel to the wing of the register, and make a duplicate 
 record. This may be done a third time if desired. Remove 
 the register as described for Figure 107. 
 
 136 
 
Fig. 113. 
 
 Attaching the Incisor Path Marker to the 
 Impression. 
 
 Invert llie upper impression and hold ns shown. Hold 
 the incisor path marker with the pin released between the 
 thumb and finger and heat the points of the pins in the 
 flame, but not until the marker becomes uncomfortable to 
 hold. Press the points of the pins against the labial sur- 
 face of the upper impression so that the recording point 
 and its holder will be in the median line. Reheat the pins 
 and attach the marker firmly in position. 
 
 The vertical position of the marker should be such that 
 when the spring governing the marking point is released, 
 only the cone of the marker projects below the level of 
 the incisal edge when the bite rim is in the proper po- 
 sition. 
 
 i.'.r 
 

 
 Fig. 114. 
 
 Blackening the Hoeseshoe Plate. 
 
 Roll cotton on the end of a toothpick or match, dip in 
 oil of cloves, light it, and with the smoke blacken the an- 
 terior part of the occlusal surface of the Horseshoe Plate. 
 
 Lay a ball of Dentsply Base Plate Wax about 1/16 
 inch in diameter at the point of the Horseshoe Plate and 
 with a very hot and clean spatula, or a mouth blow pipe 
 flame, flow it over the black surface as far back as the 
 first notch on each side. This wax film is merely a pro- 
 tection for the lampblack and should *be as thin as pos- 
 sible. 
 
 Wipe away the uncovered lampblack. 
 
 138 
 
Pig. 115. 
 
 Taking the Incisor Path Record. 
 
 Lock the pin of the Incisor Path Marker in the raised 
 position. Place the upper and lower impressions in the 
 mouth. Release the pin and have the patient move the 
 jaw from side to side with the bite rims lightly in contact 
 aboul a dozen limes, and then move from front to hack. 
 These movements should cut the wax from a well defined 
 V shaped area, with a pointed front. 
 
 [f the record does not present a sharp point, an abnor- 
 mal habit of holding the jaw may be suspected. Patients 
 long without posterior teeth may hold the jaw forward of 
 the normal resl position. A correct record may usually 
 be had from such patients by causing them to open the 
 mouth, touch the tip of the tongue to the rear of the center 
 of the vault and close with the tongue in that position, and 
 then move the jaw to one side and hold. Repeat the open- 
 ing, the tongue placing, and the closing, and have the pa- 
 lieni move to the other side. Repeal several times. 
 
 139 
 
Correct and Incorrect Incisor Path Records. 
 
 (Illustrations on page following.) 
 
 If the lower jaw is protruded during record taking so 
 that the condyles are forward of their normal position 
 for mastication, the marker will trace an indefinite path, 
 with a rounded point, like that shown at "A" in Figure 
 116. Such a record is incorrect and of no value. 
 
 Normal masticating movements give the sharp pointed 
 form of record shown in "B" and "G." We believe that 
 if there is no movement of the impressions during record 
 taking, there is no exception to this statement. When the 
 lower jaw is very flat, hold the lower impression in place 
 during record taking. 
 
 The record in "B" shows the usual extent of movement. 
 That in "C" is from a patient with unusually extensive 
 lateral and protrusive movements. 
 
 If the record on one side of the median line is much 
 shorter than on the other, examine the upper impression 
 over the tuberosities on the side opposite the short record. 
 It may be that the impression in this region is so thick 
 that it interferes with the free movement of the jaw. See 
 the reference to this subject on page 126. 
 
 Incisor path records are important not only for making 
 possible the reproduction of the individual jaw movements 
 in the articulator, but they constitute the only exact method 
 of determining when the lower jaw is in correct relation 
 to the upper for locking the bite rims together. When 
 the lower jaw is at rest with the point of the marker at 
 the apex of a record as at "D," Figure 116, the upper 
 and lower bites are in correct antero-posterior and lateral 
 relations. 
 
 If, when the jaw is at rest, the point of the marker 
 touches the record at "E" the bites are in correct lateral 
 relations, but the jaw is protruded. 
 
 If, with the jaw at rest, the point of the marker is at 
 "F," the bites are in correct antero-posterior relations but 
 incorrect lateral relations. 
 
 140 
 
Correct and Incorrect Lncisob Path Records. 
 
 Dentists will do well to learn to look on this record as a 
 picture which shows whether the bite plates are in correct 
 relation. Lock the marking pin in the raised position. 
 
 For ;i description of these records and their significance, 
 see the preceding page. 
 
 in 
 

 [11111 
 
 Fig. 117. 
 
 Drawing Base Lines for the Lateral 
 Inclination Records. 
 
 Lay the Lateral Path Register on the bench with the 
 ground glass side upward. Place a rule across both glasses 
 as shown. Hold it in one position and draw the line 
 shown at "A" about ^ inch from the narrow end of the 
 glasses. The line on one glass is a continuation of that on 
 the other and both lines are approximately parallel to the 
 square- bar at the back of the register. 
 
 About 14 inch from the line "A" toward the wide ends 
 of the glasses, draw the line "B," parallel to the line "A." 
 
 These lines are to serve as starting points from which 
 to make records for determining the lateral inclination of 
 the condyle path and are called base lines. 
 
 143 
 
Fig. 118. 
 
 Adjusting the Vertical Pencils. 
 
 Place the Condyle Path Ilegister in position on the 
 Horseshoe Plato. Loosen the lock nut holding the recording 
 pencil tin one side. Turn the vertical pencil toward the 
 lace Move the wing of the Condyle Path Register inward 
 u ni 1 1 i he ] mi iii (il the vertical pencil is level with and oppo- 
 site the intersection of the lines over the head of the con- 
 dyle Loch the pencil so firmly in position thai it cannot 
 be moved during record taking. Adjust the pencil on 
 the opposite side in the same way. Move the wings of the 
 Condyle Path Register outward until the vertical pencils 
 are aboul 1 •'« inch from the face, as here shown. 
 
 143 
 
Fig. 110. 
 
 Holding the Lateral Path Register, Part I. 
 
 Have the patient sit on a low stool or depress the chair 
 and drop the headrest. Stand directly behind the patient 
 with the arms free from the body. Grasp the Register with 
 both hands as here shown and carry it from above down- 
 ward and backward about the head until the glasses are 
 above the points of the pencils but not in contact with them. 
 Place the ends of the second fingers in the external audi- 
 tory canals. The arms of the Register should rest across 
 the bases of the thumbs and the outer joints of the middle 
 fingers. The index fingers rest on top of the arms of the 
 Register with just enough pressure to prevent the Register 
 slipping forward. The third fingers rest on the base of the 
 skull and the thumbs are placed as shown. 
 
 144 
 
Pig. 120. 
 
 Holding the Lateral Path Register, Part II. 
 
 Hold the Register as described and bring the two pos- 
 terior base lines in contact with the points of the pencils. 
 Slope the glasses downward and forward at about the 
 same inclination as the tracings of (lie descending inclina- 
 tion of the condyle paths. The glasses should "float" upon 
 the pencil points so that they may follow any change in 
 elevation of the pencils as they move. If the glasses rest 
 heavily on the pencils during the movement, the leverage 
 may be sufficient to dislodge the lower impression from the 
 ridge and give incorrect records. 
 
 Patients show a strong tendency fo move the head dur- 
 ing the talcing of ibis record. Do not try to bold the bend 
 still; instruct the patient to resist ibis tendency and poise 
 the bunds and Register so that they may move with tin- 
 head as nearly as possible. It is sometimes advantageous 
 to have ;in assistanl bold the lower impression firmly in 
 place wbi le ibis record is made. 
 
 145 
 
Fig. 121. 
 
 Recording the Lateral Inclination. 
 
 Instruct the patient to keep the bite rims in contact 
 with very light pressure and move the jaw slowly, first 
 to the right and then to the left. This movement to the 
 right should make a long tracing on the left glass in front 
 of the base line which slopes downward and inward as here 
 shown, and a shorter tracing on the right glass continued 
 back of the base line, either as a continuation of the for- 
 ward inclination on that side or with a different slant, and 
 vice versa. 
 
 Both lateral records are taken at the same time, while 
 one descending inclination is recorded at a time. 
 
 The pencils must start on the base line and finish on 
 the base line with the jaw in the rest position. Any other 
 position of the pencils with the jaw at rest indicates that 
 the Lateral Path Kegister has moved and that the record is 
 valueless. Other records may be taken starting at the base 
 lines in front of the two just used. 
 
 14C 
 
Fig. 122. 
 
 Correct and Incorrect Lateral Paths. 
 
 A lateral path record which is incorrect in two impor- 
 tant particulars is shown at "A" in Number 2. The reg- 
 ister moved enough during the taking of the record so that 
 when the jaw was returned to a. position of rest the pencil 
 was :ii "D" instead of on the hase line. The loop in the 
 record shows rhat the patient made the record with jaw 
 protruded, or that the lower impression moved on the 
 ridge, perhaps because the glasses pressed too heavily on 
 the pencils or the lower impression was not stable on the 
 ridge, or because of an interference described on page 1-7. 
 Discard such a record and make a new one. 
 
 The loop at "A," Number 1, shows that the patient pro- 
 truded the jaw during al leasl one cycle of jaw movement. 
 
 At "B" in Number 1 is shown a good record from a pa- 
 tient who has worn artificial dentures for a long time. Con- 
 trol of the jaw movements has been losl to such an extent 
 that the pencil did not move continuously in the same line, 
 but moved in parallel lines. 
 
 Ai "B" in Number 2 is shown a correct record from a 
 patienl who has recently lost the natural teeth and who-, 
 jaw movements have not become indefinite as a result oi 
 wearing improperly made dentures. 
 
 it: 
 
Fig. 123. 
 
 Adjusting the Condyle Path Register and 
 Removal. 
 
 Make sure that the point of the incisor path marker pin 
 is at the point of the incisor path tracing. 
 
 Return the points of the horizontal pencils to the po- 
 sition in Figure 106A, in contact with the tissues over the 
 condyles, and lock them firmly in position so that they 
 cannot be disturbed during subsequent manipulation. 
 
 With an Eastman negative retouching pencil make a 
 mark on each wing of the face bow directly at the end of 
 the milled tract, while the pencils are in position as shown. 
 
 Move both wings away from the face so that the pencils 
 will "clear'' and remove the face bow from the Horseshoe 
 Plate in the manner described for Figure 107. 
 
 148 
 
Pig. 124. 
 
 Correcting Lack of Fit in the Impression. 
 
 Hoar the end of a tracing 1 stick in the bnnsen flame until 
 it becomes almost fluid. Trace the softened compound 
 mi the area of the impression which is defective as shown 
 at "A." Dip this section of the impression quickly into 
 hot water, remove, seal the impression on the ridge and 
 chill the compound in position until it is set. 
 
 While a little moisture remains on the palatal surface 
 of the impression, direct a mouth blowpipe flame from an 
 alcohol lamp against the margin of the added compound 
 and the adjacent area of the impression as shown at "B." 
 1 1 cat this area to a flowing stage as quickly as possible 
 without burning the compound. Dip the impression in hot 
 water, quickly remove and place in position in the mouth. 
 When the compound is set, remove. With a sharp knife 
 trim away the compound which projects beyond the margin 
 as originally determined, as shown at "C." 
 
 A second method of correcting errors due to lack of im- 
 pression material in the base impression is as follows: 
 Have the lower impression in place in the mouth. Heat 
 the end of a tracing stick till fluid and add a suf- 
 ficient amount of compound to the defective portion of tin 1 
 impression to till up the defect. Chill the impression and 
 
 149 
 
Correcting Lack or Fit in the Impression. 
 Continued. 
 
 addition in cold water. Heat the added material and the 
 surface of the impression adjacent to it with the mouth 
 blowpipe flame and reduce the temperature of the hot ma- 
 terial by immersing in the hot water and instantly remov- 
 ing it. Place the impression in the mouth, have the patient 
 close and suck. Chill the impression thoroughly in place 
 and remove. 
 
 This method will usually yield satisfactory results at the 
 first insertion. 
 
 The marginal flanges of the upper impression are some- 
 times deficient in adaptation, due to difficulty encountered 
 in carrying the material above the tuberosity to a proper 
 height while taking the base impression. Other portions 
 of the margins of the flanges are also subject to faulty 
 adaptation if the impression material was too cold when the 
 base impression was taken. Defects such as this may be 
 corrected by making additions of compound to the imper- 
 fect portion of the impression with a tracing stick. 
 
 In using the tracing stick for the first technic given, care 
 must be exercised to use all the speed possible 1 in the opera- 
 tion after the hot material is added to the impression. If 
 much time elapses between the tracing of the hot material 
 on the flange and the final placing and seating of the im- 
 pression on the ridge, the flange will absorb heat from the 
 tracing and become sufficiently softened to bend in the 
 process of seating the impression creating another type of 
 error difficult both to detect and correct and frequently 
 serious enough to make necessary the repetition of steps of 
 impression taking up to the point where the tracing com- 
 menced. 
 
 The first technic that follows is usually employed when 
 retention is defective before the bite rim is added to the 
 lower ; the second is used after the bite rims are built on 
 the impression. 
 
 150 
 
Pig. 125. 
 
 Peepabing the Bite Rims for Locking. 
 
 Smooth the buccal surfaces of the upper and lower hite 
 rims for an inch back of the cuspids, on both sides, so that 
 there are no undercuts or indentations. If any traces of 
 the notches cut on the occlusal surfaces of the upper bite 
 rims remain, fill them. 
 
 Deepen the vertical lines made across the buccal sur- 
 faces of both bite rims, l/o inch back of the cuspids, into 
 irregular V-shaped notches as shown above. Cut two rect- 
 angular pieces of 30-gauge brass or aluminum about l/o x 
 % inch, and bend a little of one of the long edges of each 
 at right angles to the rest of the surface, to serve as handles. 
 The side of each piece opposite to the handle is to be cov- 
 ered with soft compound from the heater to a depth of 
 from y$ to 14 inch. 
 
 The rectangles are called "Bite Lock Trays." 
 
 1.-.1 
 
Fig. 12G. 
 
 Locking the Bites. 
 
 Drop the pin of the Incisor Path Marker and cause the 
 patient to close the jaw so that the point of the marker 
 will be in the point of the incisor path tracing. Instruct 
 the patient to hold the jaw firmly in this position. Grasp 
 the handle of one bite lock tray with the pliers, as shown, 
 apply soft compound to it. Carry it into the mouth so that 
 the long diameter of the tray is parallel to the occlusal 
 plane, and take an impression that includes the notches 
 in the buccal surfaces of the bite rims. Take an impres- 
 sion of the other side in the same manner. When the 
 bite lock impressions are chilled remove and place them 
 in cold water until the impressions are poured and the 
 casts ready for mounting on the articulator. 
 
 This method is equally applicable whether compound 
 impressions and bite rims are used, or baseplate compo- 
 sition bases and wax bite rims. 
 
 152 
 
Determining the Depth of Relief. 
 
 The depth of relict of any individual mouth will de- 
 pend upon the relation of the hard areas in the center of 
 the mouth to the sofl area of the ridges, on the form and 
 extent of the bony areas in the center of the mouth, on 
 the necessity of preventing interference with the circula- 
 tion in the palatine vessels and on the history of previous 
 dentures. 
 
 The depth of relief is estimated on the amounl of settling 
 anticipated in the plate. In Class I and Class II months. 
 not of recent extraction, and with no history of rapid 
 settling, only shallow relief sufficient to offsel the warping 
 in vulcanizing will be necessary. When the ridges exhibit 
 much soft tissues, and the mouth is flat, only slight relief 
 should he made. In recent extraction cases, much deeper 
 relief must he made over the hard areas. 
 
 In cases where there is a marked bony prominence in the 
 center of the mouth and where the tissues have been irri- 
 tated by the pressure of previous plates, the relief must be 
 uniform and deep over the hard area. 
 
 Any interference with the circulation in the palatine 
 blood vessels will hasten the resorption of the ridge tissues 
 and will cause loss of fit of the denture. It is probable 
 that the loss of fit frequently seen in dentures constructed 
 from tight fitting impressions is due to this cause. Free- 
 dom of circulation in the palatine blood vessels may be as- 
 sured by scraping the impression at the location of the 
 palatine foramina as described for Figure 126. If any 
 bony prominences are located near the foramina, the relief 
 should provide for them. 
 
 A depth of relief slightly in excess of immediate needs 
 will do no harm. 
 
 If the relief is made in the impression as described on 
 the following page it will result in a denture of uniform 
 thickness over the palatal surface. Such dentures are less 
 likely to split than those in which tin 1 relief is made on the 
 cast after opening the flask. 
 
 153 
 
KJKL^ 
 
 Fig. 127. 
 
 Relieving the Impression. 
 
 With a small Kingsley scraper, relieve an area about 
 14 inch in diameter to a depth of about 1/16 inch over 
 each of the three palatine foramina "B" "B" "B." Draw 
 a median line "J" through the area "A" and lines parallel 
 to it "K-K" on each side, about y$ inch apart until the 
 whole area is lined. Scratch each line into the impression. 
 
 With a large hoe excavator channel the median line 
 to the depth required for relief as far as the line "H." 
 Diminish the depth outside the line "H" so that at the 
 boundary of the area "A" the channel passes imperceptibly 
 into the palatal surface of the impression. Channel the 
 lines "K-K" not quite so deep as the median line. 
 Channel successive lines to a shallower depth. Channeling 
 establishes the depth of relief required in different parts 
 of the area "A." Have the relieved area blend imper- 
 ceptibly into the palatal surface of the impression. 
 
 With a scraper cut down the ridges of compound be- 
 tween the channels to the depth of the channels. Smooth 
 the scraped area with sand paper and finish by rubbing 
 with cotton slightly moistened with wood alcohol. 
 
 If cutting the relief has reduced the "suction," examine 
 the impression at the posterior • margin and the frenum 
 notch and add black wax where bubbles are seen to escape 
 when the impression is seated. 
 
 154 
 
Fig. 128. 
 
 Preparing the Impressions for Making Casts, 
 
 Part I. 
 
 Any tine grooves or imperfections in the ridge surfaces 
 of the impressions may be filled by softening Trubyte 
 carding wax between the fingers and working it into the 
 depressions with a lukewarm wax spatnla. 
 
 Fold a sheet of soft wax and with the doubled sheet form 
 a floor to fill the tongue space of the lower impression by 
 attaching it to the lingual side of the lingual flanges about 
 1/1 C) inch away from the rounded edge of the flange all 
 around. 
 
 Fold a sheet of the sumo wax lengthwise and cut a strip 
 1 /j inch wide, the long way. Attach one end of the strip 
 t<i the wax floor at the lingual side of one heel. Bend it 
 around the heel, around the buccal and lingual surface and 
 around the other heel to the other side of the wax floor. 
 With a hot spatula, attach it to the impression, keeping it 
 1/16 inch away from the rest of the flange and taking care 
 nnt to soften or distort the flange. 
 
 Attach a 1 \ inch strip around the upper impression in 
 the same way, with the exception that across the posterior 
 margin, the level of the wax should he 1/16 inch below the 
 level of the palatal surface of the impression. 
 
 155 
 
Fig. 129 
 
 Preparing the Impressions for Making Casts, 
 
 Part II. 
 
 From a sheet of soft wax, folded lengthwise, cut a strip 
 about one inch wide and bend around each model outside 
 the narrow wax rim first placed. Attach this strip to the 
 top of narrow wax rim with a hot spatula. When the 
 strip has encircled the model, it will form a cup which will 
 retain the cast material. The edge of this strip should 
 extend far enough above the highest point of the impres- 
 sion, when in position for pouring, to insure a model at 
 least 3/16 inch thick at its thinnest part. (A sheet of 
 tin or lead may be substituted for this wax strip.) 
 
 When the casts are made they will be found very con- 
 venient for the shaping of baseplates and flasking and 
 will permit accurate reproduction of the muscle trimmed 
 margins in the dentures. Coat the impression and wax 
 addition with thin Sandarac Varnish. 
 
 156 
 
Fig. 130. 
 
 Protecting the Bite Rims and Records During 
 Casting. 
 
 Small pieces of black carding wax are shown above at- 
 tached to the occlusal surface of the upper bite rim and 
 the occlusal surface of the Horseshoe Plate. This wax 
 protects both rims and especially the incisor path record 
 during the jarring of the cast material. Extend the pieces 
 of wax along the Horseshoe Plate as far as the front of the 
 incisor path record, without touching it. Lay the third 
 piece of wax across the others above the record but not in 
 contact with it. Do not place wax so that during manipu- 
 lation or the removal of the wax this record will be de- 
 -t roved. 
 
 Additional wax may be added to make the impressions 
 set level. 
 
 157 
 
Pig. 131. 
 
 Mixing the Material for Casts. 
 
 Weinstein's Artificial Stone and Spence's Plaster are 
 preferable to plaster of Paris for casts. The manufac- 
 turer's directions for the use of each are given on .the 
 packages. We employ the same technic to free both from 
 objectionable bubbles. To avoid confusion only the technic 
 for Spence's Plaster is given. . 
 
 Take about 3y 2 parts of Spence's plaster to one of 
 water, by bulk. Sift the plaster slowly into the water 
 and spatulate thoroughly against the sides of the plaster- 
 bowl for 5 minutes, using a bone paper cutter as a spatula. 
 When mixing is finished the consistency is right if material 
 dropped from the end of spatula will not flatten out. 
 
 Procure an enameled tray of fibre or paper mache, like 
 that above shown, about 8 x 10 inches, and with shallow 
 sides. Place in the tray about 3 ounces of the mixed Spence 
 Plaster and jar the tray sharply against the top of the 
 bench until bubbles cease to appear on the surface of the 
 plaster. If bubbles come to the surface but do not break, 
 break them by tapping with the finger. 
 
 With an ordinary flexible plaster spatula, raise some of 
 the mixed plaster from the tray and place in the incisor 
 depression of either impression. 
 
 158 
 
Fig. 132. 
 
 Making the Casts, Part I. 
 
 Hold the impression firmly in one hand and jar it 
 sharply against the bottom of the other hand. Flow the 
 first materia] placed, as far over the palatal surface as it 
 will lid, then add more on top of it and jar. Repeat until 
 the entire surface of the impression is covered to a depth 
 of about % inch. If the plaster tends to collect in the 
 ridge depressions, work it to the other surface with the 
 spatula and maintain an even thickness. 
 
 Add to the Spence Plaster in the howl enough dry 
 Spence Plaster to bring the mix just to that consistency 
 which will show a clean fracture when broken hetwecn the 
 fingers hut is not crumbly. Mould this thickened mass 
 into a roll about half an inch in diameter and pack into the 
 ridge depressions by tapping' with the fingers. 
 
 159 
 
Fis. 133. 
 
 Making the Casts, Part II. 
 
 Continue to add the thickened material in the manner 
 just described, tapping each portion to a union with that 
 already in the impression, until the cup formed by the 
 wax rim is level full, as shown above. In handling this 
 material, it will be found that repeated tapping will cause 
 it to spread better than it can be made to do by greater 
 pressure applied once or twice. 
 
 The object of mixing this material to two consistencies 
 is to eliminate bubbles and yet make a stronger cast than 
 would be possible if the thin mixture were used throughout. 
 
 The supporting wax may be removed from Spence 
 Plaster in about 2 hours and the impressions removed in 
 about 4 hours. The wax may be removed from Wein- 
 stein's Stone models in about 6 hours and the impressions 
 removed in 12 hours. 
 
 160 
 
R 43° 38° L 
 
 Fig. 134. 
 
 Reproducing the Descending Inclination of 
 the Condyle Path, Pakt I. 
 
 If the Gysi Adaptable articulator is to lie used, it should 
 he adjusted to reproduce the descending' and lateral in- 
 clinations of the condyle path, as recorded by the patient. 
 
 Lav the card with the record of the descending' inclina- 
 tion of the condyle path on the bench and draw a line long 
 enough to reach across both edges of the card, through the 
 Straight center portion of the record as shown under "L" 
 a hove, disregarding any short curves at either end. The 
 purpose of this line is to magnify the record. It is much 
 easier to accurately measure the inclination of the long line 
 than that of the shorter actual record. A transparent rule 
 such as that beside the path under "R" above will be found 
 advantageous for drawing this line. 
 
 Place the point of the aluminum Degree Plate which 
 forms pari of the articulator, at the end of the prolonged 
 
 record where it crosses the Lower edge of the card, and SO 
 that its zero side coincides with the lower margin of the 
 
 card. Xote where the line continued upward through the 
 record, crosses the upper edge of the Degree Piute and 
 record the number of degrees on the card above the record. 
 
 The descending inclination of the righl condyle path is 
 here 43° j of the left path 38°. 
 
 161 
 
Fig. 135. 
 
 Reproducing the Descending Inclination or 
 the Condyle Path, Part II. 
 
 The descending inclination of the right condyle path is 
 to be reproduced by moving the pointer "A" on the right 
 side of the articulator, on the vertical Degree Plate "JB" 
 until it registers the same number of degrees of downward 
 inclination as the right path in Figure 133, 43°. The 
 upper line on this Degree Plate registers 20°, the second 
 line 30° and the third line 40°. To set a downward in- 
 clination of, say 25°, fix the pointer half way between 
 the marks for 20° and 30°. For an inclination of 10° set 
 the pointer as far above the 20° line as the 30° line is 
 below it. 
 
 To move the pointer "A" loosen the setscrew "C" by 
 means of the pin "D" which is attached to the straight 
 Incisor Guide Pin. Place the pointer as desired and before 
 tightening the setscrew, make sure that the vertical flange 
 of the artificial fossa is in contact with the inner side of 
 the condyle pin. This adjustment may be effected by plac- 
 ing a knife blade between the pointer "A" and the Degree 
 Plate and forcing the pointer slightly outward. 
 
 Lock the setscrew, taking care not to strip the threads. 
 Adjust the inclination on the left side in the same way. 
 
 162 
 
Pig. 13G 
 
 Reproducing the Latebal Inclination or the 
 Condyle Path. Part I. 
 
 Lay the Condyle Path Register on a piece of white paper 
 with the ground sides of the glasses upward. Place the 
 edge of a transparent ruler along the record and starring 
 al the point "C" in "A" where the record crosses the base 
 line, draw a line which follows the general inclination of 
 that section of the record between "C" and "LV Prolong 
 the line to "E" al the edge of the glass. 
 
 Place a card so thai its corner is at "C" and its lower 
 margin coincides with the base line, and draw the line 
 "F" perpendicular to the base line. Prepare the record 
 of the other condyle in like manner. 
 
 Turn the Condyle Path Register so that the ground side 
 of the glasses is downward as in "B." Place the Degree 
 Plate which comes with the articulator so thai its point 
 is at "C" and its zero side coincides with the line "F." 
 Read the number of degrees recorded by the line "*('-K." 
 .Vote the inclination in degrees on the card which records 
 the downward inclination. Oo the same with the record 
 of the other condyle. The right lateral inclination is 13 
 for this case and the left is 5°. 
 
Fig. 137. 
 
 Reproducing the Lateral Inclination oe the 
 Condyle Path, Part II. 
 
 The lateral inclination of the condyle path is to be re- 
 produced in the articulator by rotating the plate "A" which 
 carries on its nnder side, the artificial glenoid fossa, abont 
 its pivot "B." The upper surface of the plate "A" is 
 marked to show the lingual inclination of the vertical 
 flange of the fossa on its other side. 
 
 The farthest backward of the lines is marked "0," and 
 when this line is at the edge of the slot through which the 
 plate works, the condyle cannot move laterally but must 
 move- straight forward. When the second line is at the 
 edge of the slot, the fossa is inclined 10°. An inclination 
 of 15° is shown by the short line half way between the 10° 
 and 20° marks. The third long line shows an inclination 
 of 20° and the fourth such line an inclination of 30°. 
 
 To rotate the plate "A," loosen the set screw which 
 works in the hole "C" and which has here been removed to 
 allow the plate and its markings to be better seen. 
 
 When the proper lateral inclination of the plate "A" is 
 effected, tighten the setscrew. Adjust the plate on the 
 other side of the articulator in the same way. 
 
 164 
 
MHHI^^HH 
 
 Pig. 138. 
 
 Locking the Bite Rims for Mounting. 
 
 As soon as the wax vims about the cost can bo removed, 
 thoroughly dry the Bite Locks. Remove all traces of wax 
 from the occlusal and buccal surfaces of the bite rim. 
 Place the upper and lower bite rims in contact and sot the 
 Bite Locks into the notches of which they took impressions. 
 Drop the Incisor Path Marker and see that the point is in 
 the point of the record. With a hot spatula seal the mar- 
 gins of the Bite Locks to the buccal surfaces of the bite 
 rims. The impressions thus locked, are ready to be placed 
 in the art iculator. 
 
 Raise the pin of the Incisor Path Marker and luck it in 
 this position. 
 
 165 
 
Fig. 139. 
 166 
 
Mounting Casts on the Adaptable 
 Articulator. 
 
 Make sure that all the set screws of the articulator arc 
 (Irmly sel to prevenl movemenl of the parts. 
 
 Substitute the Curved Incisor Guide Pin for the straight 
 pin. The upper end of this pin should be flush with the 
 sleeve which holds it. Place the Gooseneck in the black 
 supporting frame and hick ii by means of the setscrew. 
 1 nserl the horizontal end of the ( looseneck into the hole in 
 the forward end of the center block of the Condyle Path 
 Register. Push the rods of the Horseshoe Plate, with bites 
 and models attached, their full length into the back of the 
 same block. Do not change the positions of the pencils. 
 
 Rotate the milled screws of the Condyle Path Register 
 so as to bring the marks made in Figure 123 to the ends 
 of the milled tracks. 
 
 Carefully introduce the articulating frame from the rear 
 and move it mil il the curve of the Incisor Guide Pin partly 
 encircles the front of the Horseshoe Plate and the ends of 
 the horizontal pencils are directly opposite the tops of the 
 condyle pins when viewed from front and top and equi- 
 distant from them. 
 
 If, when the wings of the Condyle Path Register are ad- 
 justed so that the marks made in Figure 123 are at the 
 ends of the milled tracks, the distance between the points 
 of the horizontal pencils is so ureal as to make difficull the 
 adjustment of the pencils to the condyle pins in the manner 
 described above, the wings of the Register may be moved 
 in the following manner. When the points of the horizon- 
 tal pencils are nearly equidistant from the condyle pins, 
 measure the distance between the pencil and the condyle 
 pin which appear to be closer together. Beginning at the 
 black marks shown in Figure L23, lay oil' this distance on 
 each wing of the Register, away from the median line, 
 and make marks similar to those first made. Move both 
 wings of the register until the marks just made are at the 
 
 in; 
 
Mounting the Casts on the Adaptable 
 Articulator- -Continued. 
 
 ends of the milled i racks. This method insures moving 
 each pencil an equal distance toward the median Line. 
 Bringing the pencil close to the condyle pins in this man- 
 ner makes easy the establishment of correel relations. 
 
 Raise or lower the Gooseneck until the points of the 
 pencils are on a level with the heads of the condyle pins. 
 
 Some patients present such long rami that it is impos- 
 sible to bring the points of the horizontal pencils level with 
 the heads of the condyle pins because the lower cast, even 
 if very thin, strikes the lower how of the articulator. In 
 such cases adjust the Gooseneck until the lower cast jusl 
 clears the lower how. Move the Condyle Path Register 
 until the pencils on the two sides are equal distances above 
 the condyle pins when viewed from the front, and in the 
 same relation to them as the normal case viewed from 
 the side and from above. 
 
 The casts are now in position to be sealed to the articu- 
 lator. 
 
 If the casrs arc made of Spence plaster, it will he unnec- 
 essary to scire or wet them for the attachment of plaster of 
 Paris. With Silex, paint an area about an inch in diameter 
 in the center of the upper surface of the upper cast. This 
 reduces the area of attachment of the plaster and makes 
 it easier to free the cast for flasking. 
 
 Make a medium thick mix of plaster of Paris and How 
 over the upper how and cast, so that it will he at leasl ' [ 
 inch thick where if covers the how. 
 
 When the plaster attaching the upper cast to the upper 
 how is hard, carefully remove the Condyle Path Register 
 from the Horseshoe Plate. Invert the articulator as in 
 Figure 1 U and raise the lower how out of contact with 
 the Incisor Guide Pin. Paint an area an inch in diame- 
 ter in the center of the cast with Silex and heap plaster, 
 mixed medium thick, on the bottom of the lower cast. 
 
 1G9 
 
Fig. 141. 
 
 Mounting the Casts on the Adaptable 
 Articulator — Continued. 
 
 Bring the lower bow downward into contact with the 
 Incisor Guide Pin. 
 
 . Make sure that the rotation pins are in contact with the 
 vertical wall of the groove in which they work and that 
 the condyles are in contact with the glenoid fossae. If the 
 rotation points and condyle pins are not in the relation 
 described, hold what is normally the upper part of the 
 articulator, and pull downward and backward on what is 
 normally the lower part, while the plaster is soft, until the 
 pins are in the proper positions. 
 
 Form plaster over the lower bow so as to completely en- 
 close it and attach it firmly to the cast. Press a sheet of 
 glass upon the soft plaster until it touches the articulating 
 frame in front and back, to form a flat surface on which 
 the articulator may rest. 
 
 170 
 
'ig. 1 12. 
 
 Locating the Rotation Points, Part I. 
 
 Remove the Bite Locks from both sides. Loosen the set- 
 screw holding the rotation pin on the right side, and move 
 the pin as far from the center as possible. Remove the In- 
 cisor Guide Pin. Hold the casts as shown and by straight- 
 ening the fingers raise the upper bite rim slightly out of 
 contact with the Horseshoe Plate. This prevents the [n- 
 cisor Path Marker destroying the pattern on the Horse- 
 shoe Plate. Move the upper cast to the left unl il the poinl 
 of the Incisor Path .Marker is near the left and usually in 
 front of the incisor path record. Make sure that the left 
 condyle pin is in contact with its fossa. 
 
 By pressure outward on the lock nut, move the rotation 
 pin away from the median line. Watch the poinl of the 
 Incisor Path Marker, and when il is seen to enter the in- 
 cisor path record, tighten the lock nni jusl enough to fix 
 the rotal ion pin. 
 
 Bear in mind thai the righl rotation poinl governs the 
 movement of the [ncisor Path Marker on the lefl side of 
 the median line and vice versa. 
 
 171 
 
Locating the Rotation Points, Part II. 
 
 Allow the upper cast to move back toward the median 
 line and note whether the point of the Incisor Path Marker 
 follows the anterior margin of the incisor path record. If 
 it does, tighten the lock nut just a little by means of the 
 L shaped pin, but take care not to strip the threads. 
 
 If the point of the Marker travels in front of the margin 
 of the record, move the rotation point away from the 
 median line. If it diverges inward from the margin of the 
 record, move the rotation point toward the median line. 
 
 Adjust the rotation point on the other side in the same 
 manner. 
 
 172 
 
Fig. 144. 
 
 Marking Lines on the Upper Cast. 
 
 Remove the Incisor Path Marker. With n knife, pro- 
 long the median line and the cuspid location lines upward 
 on the cast. With a pair of dividers, prick off points on 
 the upper cast in a line parallel to the occlusal plane and 
 make a permanent line, "A-B" through them. With the 
 dividers space off the distance "C-E" on the line "('-IT' 
 equal to the distance from the point "C" to the plane of 
 occlusion. If the plane of occlusion is lost during the 
 arrangement of the teeth, it may he re-established parallel 
 to the line "A-B" and as far below it as from "C" to "E." 
 This line "A-B" is especially valuable while one is learn- 
 ing to arrange teeth but may not he so important when one 
 is proficient. Tt was therefore omitted from the casts in 
 the illustrations that follow. 
 
 Insert a knife under the Horseshoe Plate and pry it 
 from the bite rim. Invert the art iculator and hold the bite 
 rims together. Place a knifeblade againsl tin- buccal sur- 
 face of tlie lower at the right cuspid and inscribe the lo- 
 cation of the anterior margin of the lower bite rim on the 
 occlusal surface of the upper, from cuspid to cuspid. This 
 will permit a correct re-formal ion of the lower bite rim. 
 
 173 
 

 1 i 
 
 il 
 
 -'■-"■ ^" 
 
 
 
 
 Fig. 145. 
 
 Removing the Lower Impression erom the 
 Cast. 
 
 Separate the lower section of the articulator from the 
 upper by the method described in Fig. 156. Immerse the 
 lower impression in water of 120° F. by suspending the 
 lower part of the articulator over the edge of the hot water 
 vessel in the manner shown, and adding water until it cov- 
 ers the compound but does not reach the plaster. When 
 the compound is sufficiently soft, remove it from the im- 
 pression. Do not remove the upper impression from the 
 upper cast at this time. 
 
 Powdered soapstone or talcum rubbed on the impres- 
 sion surface of the cast will give it a fine finish and facili- 
 tate the adaptation of the baseplate. 
 
 174 
 
Adapting Baseplate. 
 
 The following fcechnic is for adapting the upper base- 
 plate. Adapt the lower in like manner. 
 
 Adjust the gas so that it produces a Bunsen flame 4 
 inches high. Hold ;i blank of Dentsply Baseplate Com- 
 pound as shown and pass the outer 2/3 sideways in con- 
 tact with the top of the flame, so that the blank crosses 
 the flame in one second. Pass it 5 times in this way. 
 If the blank be then held horizontally the healed portion 
 should maintain its shape for about a second and then 
 wilt. Ef the baseplate be held in the flame until it wilts, 
 it will he overheated and will burn the Angers during 
 adaptat ion. 
 
 Place the blank on the upper cast as shown in Figure 
 117 and adapt the palatal portion of the softened area 
 closely to the cast by pressing for aboul hall' a second in 
 one place, then raising the finger and moving it forward 
 and repeating the pressure. The heat may he uncomfort- 
 able to the finger if the pressure is continuous. Continue 
 the adaptation over the alveolar border and the buccal 
 ami labial surfaces. 
 
 When the adapted section is thoroughly chilled, use it 
 as a handle while heating the other side which is then 
 
 adapted. Any small portion of the flange not satisfactorily 
 adapted may he separately heated and adapted. 
 
 175 
 
Fig. 148. 
 
 Fig. 149. 
 
 Adapting Baseplate — Continued. 
 
 Figure 148 shows a view of the palatal side of the 
 partly adapted baseplate from the rear. Several creases 
 are seen at the median line, in front, where the baseplate 
 was folded when it was adapted to the labial surface. Turn 
 the baseplate so that the left margin points directly down- 
 ward and hold the folded portion against the side of the 
 base of the flame for one second. Remove and wait two 
 seconds to allow the heat to penetrate the material; then 
 hold against the flame for a second. Repeat this form of 
 heating until the surface of the baseplate in front of the 
 ridge is very soft ; then wait two or three seconds. Place 
 the baseplate upon the cast and with intermittent finger 
 pressure adapt the baseplate to the ridge so that the creases 
 are eliminated as shown in the median line in Figure 1 50. 
 
 The line "C-C-C" marks the outer margin of the exten- 
 sion on the cast made by the narrow wax rim added in 
 Figure 133. : Trim away the surplus which extends out- 
 ward from this line. It can be best trimmed by passing 
 the surface once through the flame and cutting with 
 shears. 
 
 Heat the baseplate, which rests on tlie extension of the 
 cast material, by passing' it once through the flame and 
 folding the heated portion upon the buccal and labial sur- 
 faces by pressure as shown in Figure 150 and to the fin- 
 ished form shown on the right side of Figure 151. The 
 
 176 
 
Fig. 150. 
 
 Fig. 151. 
 
 Adapting Baseplate — Continued. 
 
 folded portion is not heated enough to fuse with the base- 
 plate againsl which it is folded. Fold the extension across 
 the heel in the same manner. The margins thus shaped 
 must conform to the muscle trimmed margins of the im- 
 pression and constitute a valuable reinforcement of the 
 baseplate. 
 
 When the cast presents an undercut which makes it dif- 
 ficult to withdraw the baseplate without marring the im- 
 pression, adapt the baseplate only so far beyond the be- 
 ginning of the undercut as will permit withdrawal without 
 binding. 
 
 [f the baseplate is broken during manipulation, place 
 the broken pieces on the cast with the edges together. With 
 a very hot spatula fuse the edges. Melt some of the sur- 
 plus baseplate in the flame as sealing wax is melted and 
 drop it on the break. Smooth the surface with the hot 
 spat nia. 
 
 In making partial dentures, especially lowers, any 
 baseplate extending about the teeth should be reinforced by 
 embedding hot wires in the baseplate, melting baseplate 
 over the wires and smoothing the surface with a hot 
 spatula. 
 
 'Idie lower baseplate should be formed so thai the lingual 
 and bucco-labial margins are turned up in ihe manner 
 described for the margins of the upper, 
 
 177 
 
Fig. 152. 
 
 Re-forming the Lower Bite Rim. 
 
 The lower baseplate is in position on the lower cast. 
 Soften the compound which formed the lower impression 
 and bite rim in hot water and mould it into a roll half an 
 inch in diameter and about as long as the bite rim. Place 
 this on the lower baseplate so that the center of the mass is 
 approximately over the center of the lower ridge. With 
 the incisor guide pin in place, close the upper bite rim 
 upon the roll. 
 
 When the roll is cool, trim the excess fullness from the 
 labial surface until the line scratched upon the occlusal 
 surface of the upper bite rim in Figure 152 shows when 
 the upper and lower are in contact. Trim the buccal sur- 
 faces from the cuspids to the heel flush with the buccal 
 surfaces of the upper rim. 
 
 With a flame from the mouth blow pipe and the alcohol 
 lamp, heat the occlusal surface of the lower bite rim to a 
 very shallow depth and press it upon a moist glass to smooth 
 the surface, but do not change the height of the plane of 
 occlusion. Attach the bite rim to the lower baseplate as 
 follows. With a very hot flame from the mouth blow pipe 
 and an alcohol lamp, heat the compound in the deepest 
 part of the impression made by the ridge of baseplate, until 
 it sputters, but do not heat the sides or margin of this de- 
 pression. Place the bite rim upon the lower baseplate and 
 close the upper upon it. 
 
 178 
 
u 
 
 Fi S . 150. 
 
 Trimming and Marking the Lower Bite Rim. 
 
 With a sharp knife trim the lingual surface of the lower 
 bite rim to the form shown here. This surface slopes from 
 the lingual margin of the baseplate upward and a little 
 outward. This places the compound in the relation to the 
 ridge which it is desired that the finished denture shall 
 occupy. This form of lingual surface must sometimes he 
 modified in the region of the lower second molars, bul when 
 it can be effected ii allows free action of the tongue withoul 
 danger of displacing the lower denl ure. 
 
 Trim the buccal surface so thai the width of the occlusal 
 surface ol the rim in the bicuspid region is aboul equal to 
 the bucco-lingual diameter of the bicuspids and the width 
 of the surface in the molar region is about equal to the 
 buCCO-lingual diameter of the molars. Locate the center 
 of the occlusal surf ace al the cuspids and al the heels. Con- 
 ned the two points with lilies having a slight outward 
 
 curvature similar to thai of the rim. as shown above. 
 
 179 
 
Fig. 154. 
 
 Building the Lower Bite Rim Forward. 
 
 Soften a small quantity of Dentsply Baseplate Wax over 
 the flame and with it build the labial surface of the lower 
 bite rim forward to be flush with the labial surface of the 
 upper bite rim. The upper bite rim is to be rebuilt in 
 wax, and this method of adding to the lower affords a guide 
 to assist in establishing proper fullness in the upper bite 
 rim. 
 
 Remove the upper impression from the cast, using the 
 same technic as was described for the lower in Figure 150. 
 
 Make the upper base plate, using the technic described 
 for Figures 146 to 151 inclusive. 
 
 180 
 
Fig, 155. 
 
 Re-forming the Upper Bite Rim. 
 
 TIi is lute rim is to l>o re-formed in wax. Pass the lone; 
 diameter of a sheet of Dentsply base plate wax above a 
 bunsen flame until one side of it is fluid. Hold it with the 
 lluid side upward. Double the melted side upou itself. Be- 
 ginning at one end of the fold, pinch the softened surfaces 
 together, gradually working toward the other end. Repeat 
 this heating, folding and pinching process three times in 
 all. Xow heat the strip and double it lengthways upon 
 itself. When the folding is complete, grasp two surfaces 
 of the strip so formed between the thumb and index fingei 
 of one hand, and the two remaining surfaces between the 
 thumb and index finger of the other hand and gradually 
 work the roll between the fingers, pinching it into the form 
 of a square bar. 
 
 Place the incisor imide pin in position. Pay this square 
 bar of wax on the occlusal surface of the lower bite rim 
 and close the upper upon it. Trim the buccal margins 
 flush with the buccal margins of the lower bite rim. trim 
 the Labial margin flush with the labial margin of the wax 
 addition to the lower. Shape the upper part of the labial 
 surface t « > about the fullness and the form of the compound 
 bite rim which was removed. The illustration above shows 
 the completed upper wax with the wax addii ion to the front 
 el' the lower bite l'iin removed. 
 
 1S1 
 
Fig. 15G. 
 
 Removing and Replacing the Upper Part of 
 the Adaptable and Simplex Articulators. 
 
 Grasp the front portion of the articulator between the 
 thumb and first finger of the right hand as shown. Grasp 
 the rear vertical portion of the articulating frame with 
 the first three fingers of the left hand and place the end 
 of the left thumb under the front end of the vertical 
 flange of the fossa. Push directly upward on this flange 
 until the rotation pin rises above the level of the front 
 wall of the groove in which it works. Carry the end of 
 the left thumb forward and the upper part of the frame 
 with it until that part of the articulator — in contact, with 
 the spring — slides out from under the spring and the 
 upper section of the articulator is separated from the 
 lower. 
 
 To assemble the articulator reverse the procedure de- 
 scribed above. Locate the left condyle and the left rota- 
 tion pin correctly and engage the web of the articulator 
 under the spring, place the left thumb under' the for- 
 ward end of the right fossa. Now grasp the front part 
 of the articulator as illustrated so that the Guide Pin 
 is in contact with the Incisor Guide Incline, then press 
 upward and backward with the thumb until the rotation 
 pin clears the anterior wall of its groove. Release the 
 upward pressure, when the rotation pin and the condyle 
 will settle into their proper locations. 
 
 182 
 
Part IV 
 Arranging The Teeth 
 
Arranging the Teeth. 
 
 The upper bite rim was formed to give a desired ex- 
 pression to the upper lip and in arranging teeth it is 
 essential that they maintain the fullness and curvature 
 established by this rim. Begin at the central on each side 
 and work backward to the cuspid. Detailed instructions 
 for setting these teeth will bo given. 
 
 The upper bicuspids and molars are to be so placed 
 that the center of their longitudinal grooves will be 
 as nearly over the lines traced on the occlusal surface of 
 the lower bite rim in Figure 141) as the curvature of the 
 upper bite rim and esthetics will permit. 
 
 It is usually better to allow the upper teeth to set 
 outside of the upper ridge a little rather than move the 
 lower teeth into the tongue space. 
 
 When the upper teeth are all in position, the lower 
 teeth on each side will be set in the following order, 
 first molar, second bicuspid, first bicuspid;, cuspid, in- 
 cisors, and second molars. 
 
 In setting the teeth use only enough wax about each 
 tooth to attach it to the baseplate, leaving the addition 
 of wax for the restoring of expression until the teeth have 
 been tried in the mouth and satisfactorily adjusted. It 
 is advantageous to use as little wax as possible in placing 
 the teeth because the shrinkage of a large quantity of 
 fluid wax may distort the baseplate and pull the teeth 
 out of the desired position. 
 
 To begin setting the teeth, cut a place clear through 
 the upper bite rim, on one side of the median line, as 
 shown, large enough to receive the upper central incisor. 
 
 184 
 
Arranging The CJppeb Anteriors. 
 
 Remove the upper bow from the articulator. Procure 
 ;i Trubyte Occlusal Plane or a flat piece oi wood or alumi- 
 iiiim 2 j 2 inches square, and use it as shown in the follow- 
 ing illustrations to take the place of the occlusal surface 
 of the lower bite rim. 
 
 Before waxing the upper central in place, try lor me- 
 chanical suitability. II uecessary carve away the base- 
 plate under the tooth or grind the ridgelap, or do hoih 
 so that the tooth will uol rest directly against the cast. 
 The long ;i\is of the upper central should be vertical when 
 seen from the front and inclined downward and forward 
 
 when seen from the side ;is shown in " I '." and "C". The 
 
 incisal edge is in contact with the occlusal plane. The 
 upper centrals are not sel ;it right angles to the median 
 lino, luii the distal angles are inclined slightly backward 
 and begin the curvature of the tooth row to follow the 
 contour of the bite rim. 
 
 is;, 
 
Fig. 158. 
 
 Arranging the Upper Antebiors — Continued 
 
 Cut a space through the upper bite rim for the upper 
 lateral and try it in place as the central was tried. Set 
 it so that the incisal edge is about % of a millimeter above 
 the level of the occlusal plane and so that the long axis 
 is inclined as shown in "B" and "0." This downward 
 and forward inclination of the vertical axis of the upper 
 laterals results in making the neck of this tooth less promi- 
 nent than that of the upper central. This depression will 
 be found very valuable when giving expression to the 
 teeth. 
 
 The incisal edges of the laterals are set to maintain the 
 curvature established by the incisal edge of the upper 
 bite rim, as shown at "B." 
 
 186 
 
Kiu. i.v.i. 
 
 Arranging the Upper Anteriors — Continued 
 
 ('lit a space clear through the upper bite rim to re- 
 ceive the upper cuspid. Try the tooth for length as the 
 central and lateral were tried. Sel the tooth so thai its 
 tip just touches the occlusal plane and its long axis is 
 inclined as shown in "I!" "C" and at the edge of the 
 toot 1 1 coin i urn' the curve of the l>iie rim as shown at " 1 >". 
 
 The labial ridge o1 the cuspid is properly the dividing 
 line between the labial and buccal sections of the ridge. 
 I he labial surface mesial to the ridge faces the lip and 
 maintains the general curvature established bv the cen- 
 tral and lateral. The surface distal to this ridge laces 
 the cheek and begins the curvature characteristic of the 
 bicuspids and molars. The effecl of setting Trubvte cus- 
 pids in this position is to carry the distal angles farther 
 
 1ST 
 
Fig. 1G0. 
 
 Arranging the Upper Anteriors — Continued. 
 
 inward toward the median line than has been possible 
 with the conventional forms of cuspids. When Trubyte 
 cnspids are set in this way, only the mesial aspect can be 
 seen from the front. This permits the use of teeth large 
 enough for the month, without their appearing too large. 
 The esthetic effect of this arrangement is greatly enhanced 
 by the natural shading of the teeth in the set- 
 When the central, lateral and cnspid of one side have 
 been set, set the central, lateral and cnspid on the other 
 side in the same manner. 
 
 Replace the upper part of the articulator in the manner 
 described for Figure 156 and use the occlusal surface of 
 the lower bite rim as the occlusal plane while setting the 
 upper bicuspids and molars. 
 
 188 
 
Fig. 161. 
 
 Arranging the Upper Posteriors. 
 
 When the bite is so close as to make it impossible to 
 use the length of bicuspids and molars desired without 
 destructive grinding, the base plate against which the 
 teeth are to rest should be scraped as thin as possible 
 without perforating it. Trubyte bicuspids and molars 
 are made in four mcsio-distal widths 28, 30, 32, and o4 
 millimeters. Each width is made in three vertical Lengths 
 known as short, medium and long, distinguished by the 
 letters "S," "M," "L" on the neck end. The manufac- 
 turer's card with the anteriors, the bicuspids and molars 
 of the mcsio-distal width and vertical length most suit- 
 able for the' average case. The range of length makes ir 
 possible for the dentist to select shorter or longer teeth 
 to accompany any given anteriors, if his judgmenl so 
 indicates. Tie may also select wider or narrower bicuspids 
 and molars than those regularly carded, but when bicuspids 
 and molars wider than those regularly carded are se- 
 lected to go with any given anteriors. the mesial sides of 
 the lower lirst bicuspids and perhaps the distal sides of 
 
 the lower cuspid will require some grinding, to provide 
 
 room for the placing of the lower anterior. 
 
 1S9 
 
Arranging the Upper Posteriors, Continued. 
 
 Fit each posterior tooth to its position before waxing 
 it in place, as the anteriors were fitted. Make sure that 
 each tooth is short enough so that there is a free space of 
 at least a millimeter between it and the baseplate. Cut 
 a strip one-half inch wide along the side of a sheet of 
 Dentsply Baseplate Wax and soften one end of it in the 
 flame. Detach a small portion and form it into a cone. 
 Soften the end of the cone in the flame and force it about 
 the pins or into the recess in the diatoric tooth. Using the 
 tooth as a handle, soften the other end of the cone and 
 press it upon the ridge with the tooth in approximately the 
 correct position. Close the articulator so that the incisor 
 guide pin comes into contact with the incisor guide in- 
 cline. Adjust the teeth so that the center of the longitu- 
 dinal groove is over the front-to-back line on the occlusal 
 surface of the lower bite rim. The buccal cusp of the 
 
 190 
 
Fi«. 163 
 
 Arranging the Uppee Posteriors, Continued. 
 
 upper first bicuspid should touch the occlusal surface of 
 the lower bite; the lingual cusp should be raised about one- 
 half millimeter above that rim. When the tooth is first 
 placed, the long axis of the tooth, as seen from the buccal, 
 should be vertical, as shown at "A" in Figure 163. This 
 may be slightly modified in establishing articulation. 
 
 The second bicuspid should be set like the first except 
 that both cusps touch the opposing bite rim, as shown at 
 "B" in Figure 163. Rotate both bicuspids upon their 
 long axes so that the occlusal surfaces are inclined as shown 
 by the lines in "C," Figure L63. 
 
 With the straight edge of the Trubyte Occlusal Plane 
 test the position of the buccal surface of the bicuspids in 
 relation to the cuspids. When these teeth are in proper 
 relation for the average case, the straight edge should 
 touch the buccal surfaces of all three teeth. 
 
 101 
 
Fig. 164 
 
 Arranging the Upper Posteriors, Continued. 
 
 Attach the upper first molar to the ridge as the bicuspids 
 were attached. The long axis of this tooth, when seen 
 from the buccal is inclined downward and backward as 
 shown at "A" Figure 164. Only the mesio-buccal cusp 
 of this tooth should touch the occlusal surface of the 
 opposing bite, the disto-lingual cusp being slightly raised 
 and the buccal cusp being raised about three-quarters of a 
 millimeter out of contact, as shown in "B," Figure 164. 
 This arrangement produces the average compensating 
 curve. When a greater curvature is required, the distal 
 cusps should be elevated more. The tooth should be ro- 
 tated upon its long axis as shown at "C" in Figure 164. 
 
 The upper second molar is now placed in position, with 
 its lingual cusp lightly touching the occlusal plane and 
 the buccal cusp raised about one and one-half millimeters 
 out of contact. If a greater curvature is desired, the 
 lingual cusp should be elevated out of contact and the 
 buccal cusp elevated in a corresponding degree. The long 
 axis seen from the buccal, is inclined downward and back- 
 ward more than was the first molar. 
 
 192 
 
ft 
 
 WORKING YjJ BALANCING 
 
 BITE ^/VK' BITE 
 
 v\a. [<;.-, 
 
 LINES SHOWING TOOTH MOVEMENT 
 
 IN 
 WORKING 
 CONTACT 
 
 9 V, 
 
 .48 Q 
 
 IN 
 
 BALANCING 
 
 CONTACT 
 
 Fig. 1G6 
 
 
 
 
 
 WW 
 
 Kr "> A. 
 
 J ¥ 
 
 
 
 ^'D-l:2 
 
 
 
 \ 
 
 
 
 
 
 WORKING BITE 
 
 LEFT 
 
 SIDE 
 
 
 Fig. 1G7 
 
 TrtffS 
 
 1 
 
 BALANCING BITE LEFT SIDE 
 Fig. 168 
 
 Description on page following. 
 
 193 
 
Working and Balancing Molar Contacts. 
 
 The dotted triangle in Figure 165 shows the rest posi- 
 tion of the mandible. The triangle in solid outline and 
 the diagrams of the teeth show the position of the 
 mandible during mastication on the patient's right side. 
 The side on which the patient is masticating is commonly 
 referred to as the "working side." The opposite side is 
 the "balancing side." When the upper and lower teeth 
 come into working contact, the upper and lower buccal 
 margins are interdigitated. The movement of the teeth 
 on the working back to a position of rest is nearly at right 
 angles to the median line. The movement of the teeth on 
 the balancing side is much more nearly parallel to the 
 median line. The arrows on this diagram are those of 
 the movement of the teeth on the articulator. 
 
 The white lines on the occlusal surface of the molars "In 
 Working Contact/' in Figure 166, show the line of move- 
 ment of the lower teeth across the uppers during mastica- 
 tion. The white lines across the occlusal surfaces of the 
 molars bracketted in Figure 166 with the title "In Bal- 
 ancing Contact" show the line of movement of the lower 
 molars across the uppers on the balancing side. The 
 arrangement of teeth to harmonize with these lines of 
 movement will be easy if they were carved with these move- 
 ments in view; otherwise it will be difficult. Trubyte 
 teeth were carved to produce these movements in the 
 average case, and when used on the Simplex articulator 
 require practically no grinding. When the Adaptable is 
 used the teeth will require grinding in proportion as the 
 adjustments vary from the average. 
 
 Relations of the upper and lower teeth on the left side 
 in working contact, are shown in Figure 167. The rela- 
 tions of the teeth on the same side, in balancing contact, 
 are shown in Figure 168. 
 
 194 
 
Fig. 170 
 
 How to Move the Articulator Properly. 
 
 There are correct and incorrect ways of moving the 
 hows of the Adaptable and Simplex articulators from sidG 
 to side, in arranging teeth. If the incorrect way is fol- 
 lowed, the articulator will be of little use. 
 
 Hold the articulator above and below, as it is here shown 
 in the right hand. This holds the Incisor Guide Pin in con- 
 tact with the Incisor Guide Incline and any opposing teeth 
 lightly in contact. Place the fore part of the ball of the 
 thumb of the other hand on the inner side of the artificial 
 fossa as shown at "A" (not against the front as shown at 
 U B"), and make pressure outward, downward and back- 
 ward. This forces the vertical flange of the fossa against 
 the condyle pin and compels the condyles to follow the 
 correct downward and lateral inclinations. The arrange- 
 ment of the teeth will be greatly facilitated it* the condyle 
 is compelled to follow the correct path every time the ar- 
 ticulator is moved. 
 
 Do nnt place the thumbs against the front ot' the two 
 fossae ;ii one time to make side to side movements, lesl 
 (me sid( be pivoted againsl ;i thumb instead of following 
 its proper path. Use both thumbs at once only to throw 
 the teeth into incising relation. 
 
 195 
 

 ™"*™i"*ji? 
 
 [(^■e* 
 
 iLj 
 
 J .^^^ 
 
 J? i 
 
 Zl 
 
 
 Fig. 171 
 
 PiS. 173 
 
 kgj 
 
 %y 
 
 \ 
 
 
 
 
 Fig. 172 
 
 Fig. 174 
 
 Fig. 175 
 
 For description see the page following. 
 
 196 
 
Arranging the Teeth. The Loweb First 
 Molar. 
 
 Apply ;i cone of wax to ;i lower firs! molar. Open the 
 articulator and attach the molar to the ridge in approxi- 
 mately the correct position, but too high. ( 'lost' the 
 articulator, forcing the molar inward the ridge. Guide i 1 
 
 to correct occlusal relations with the uppers as in Figure 
 171. Wax the molar firmly in posit inn. Make pressure 
 on the right fossa of the articulator as described for Figure 
 170 and throw this molar into working bite with the 
 uppers, as in Figure 17± 
 
 A black line has been drawn along the buccal ridge of 
 the middle cusp of the lower molar. It should be con- 
 tinuous with the black line in the buccal groove of the 
 upper molar. The break in the line in Figure 172 shows 
 that the lower molar is too far forward for articulation. 
 Figures 171 and 172 show that teeth may be in good posi- 
 tion for occlusion without being in position to articulate. 
 
 In figure 17-"I the lower molar has been moved back- 
 ward so that the black line is continuous with the line on 
 the upper, in working bite, but the buccal cusps do not 
 interdigitate with the upper cusps. Errors of this kind 
 can usually be corrected by depressing the buccal cusps of 
 the upper molar, but in this case the steep descending in- 
 clination of the condyle path, with the slight lateral incli- 
 nation, necessitated grinding the teeth to a deeper l>ite. 
 
 With a fine grit inverted cone stone the mesial marginal 
 ridge of the upper molar and the distal marginal ridge of 
 the lower molar were ground until they could be properly 
 interdigitated. This grinding is shown in Figure 171. 
 
 In Figure 175 the mojars are shown in working bite 
 after deepening of the sulci by grinding has been completed 
 and the lower molar reset to proper contact with the upper. 
 The -pace between the upper second bicuspid and the low< r 
 molar in Figure 17-"> has been decreased by deepening the 
 bite of the molars and raisins the lower molar. 
 
 197 
 
Fig. 176 
 
 Fig. 178 
 
 Fig. 1 77 
 
 Fig. 179 
 
 Fig. ISO 
 
 For description see page following. 
 
 198 
 
Arranging the Teeth.- The Loweb First 
 Molar. Continued. 
 
 The lower first molar in Figure L76 is in the same 
 position on the ridge thai ii occupied in Figure 17.">, but 
 the articulator has been moved so as to throw this side into 
 balancing relation. The triangular ridge of the mesio- 
 lingual cusp of the upper molar should slide in the 
 disto-buccal groove of the lower molar, along the white 
 lines of contact "In Balancing Bite" in Figure 160, but 
 cusp and groove are separated by a slight space. A defect 
 dt' this kind can usually be corrected by depressing the 
 lingual cusp of the upper molar until contact is established 
 and waxing the upper firmly in that position. It may be 
 necessary to rotate either the upper or the lower on its 
 vertical axis until the cusp works smoothly in the groove. 
 
 Examine the working bite articulation from the lin- 
 gual, as shown in Figure 177. The slight prominence of 
 the mesio-lingual cusp of the lower molar, indicated by the 
 arrow, prevents correct relations in the working bite. 
 Grind this away with the inverted cone stone, being care- 
 ful to maintain the original inclination of the cusp planes. 
 Do not grind a flat surface on the tip of the cusp. After 
 grinding, raise the lingual cusp of the lower molar until it 
 takes the relation of the upper shown in Figure 178, when 
 in working bite. 
 
 The upper and lower molars, in occlusion, should mesh 
 as in Figure 179. The buccal cusp of the lower should till 
 the V-shaped longitudinal groove between the lingual and 
 buccal cusps of the upper. The lingually inclined plane 
 on the lower buccal cusp should be in contact with the 
 buccally inclined plane of the lingual cusp. 
 
 Figure ISO shows the relation of the upper and lower 
 molars in working bite. 
 
 199 
 
Fig. 181 
 
 Pig. 182 
 
 Arranging the Teeth. — The Bicuspids. 
 
 After completing the articulation of the upper and lower 
 molars for the case here illustrated, the distal marginal 
 ridge of the upper second bicuspid was ground in the man- 
 ner described for the first molars until the buccal cusp of 
 the bicuspid could be brought down in contact with the 
 buccal cusp of the lower molar when in working bite rela- 
 tion. The tooth was then examined from the lingual and 
 adjusted to mesh properly with the lower molar in working- 
 bite. 
 
 Attach a cone of wax to the neck of the lower second 
 bicuspid and place it on the ridge in the manner described 
 for the molar and with a spatula press it into approximate 
 occlusion with the upper second bicuspid. Move the artic- 
 ulator so as to test the articulation in working bite, which 
 is shown in Figure 182, and in balancing bite. When the 
 lower second bicuspid has been properly articulated with 
 the upper second bicuspid, move the upper first bicuspid 
 into proper articulating relations with the lower, as shown 
 in Figure 182. 
 
 The space between the lower second bicuspid and the 
 molar in Figure 182 will exist whenever the conditions of 
 the case necessitate a compensating curve of more than 
 
 soo 
 
average Bteepness. The existence of such spaces compen- 
 sates, in part, for the shrinkage of rubber in vulcanizing 
 and reduces the liability of error from the teeth hcing 
 forced into improper contact through thai shrinkage. 
 
 Set the lower first bicuspid for occlusion and then for 
 articulation by the methods described. Arrange the lower 
 first molar and the bicuspids of the opposite sjde, using 
 the same technic. Do not set the lower second molars unl il 
 the arrangemenl of the teeth has been tested in the month 
 and proven satisfactory. 
 
 Set the lower six anteriors to approximate positions to 
 determine whether they meet the requirements of the case 
 as to width and length. If insufficient space exists between 
 the lower bicuspids to permit setting the lower anteriors 
 because of irregularities in the alignment of the upper 
 anteriors, additional space may be made by grinding the 
 distal sides of the lower cuspids or the mesial sides of the 
 lower first bicuspids. If sufficient space cannot be pro- 
 vided by such grinding, or if, because of the necessity of 
 setting the lower incisors directly above the lower ridge, an- 
 teriors considerably narrower than those regularly carded 
 with the uppers are required, select anteriors of the next 
 smallest size in the same form, using the Mould Guide il- 
 lustrated on page 116. If no Mould Guide is available turn 
 to the table of dimensions of anteriors on page 115. In 
 the left hand column locate the number of the mould being 
 used. In the column headed "Width of six anteriors, set 
 up," learn the combined width of these lower anteriors. 
 By means of the dimensions in the second and third col- 
 umns, determine upon anteriors of the length and as much 
 narrower as seem necessary. Order the desired teeth by 
 means of the mould number which will be found on the 
 same line in the column at the left. 
 
 In cases requiring anteriors much shorter than those 
 regularly carded with the uppers, they may be found 
 among .Moulds 3B, 3C, 3D, Hi, or 1C 
 
 201 
 
Pig. 183 
 
 Fig. 184 
 
 Fig. 185 
 
 Fig. 186 
 
 / I. 
 
 Fig. 188 
 
 Fig. 187 
 
 202 
 
Arranging the Teeth.— The Cuspids. 
 
 Adjust the upper cuspid to the Lower firs! bicuspid. It 
 is generally accessary to grind the mesial slope of the 
 
 buccal cusp of the lower bicuspid and the distal slope of 
 the cutting edge of the cuspid to permit establishing cor- 
 rect relations. 
 
 The upper latera] adjoining the cuspid should be re- 
 moved from its place without beating the wax, so thai it 
 can be easily replaced. This will facilitate articulating 
 the lower cuspid, as iu Figure L83. 
 
 Grind the mesial slope of the cutting edge of the upper 
 cuspid to locate the tip of that tooth just anterior to the 
 mesial contact point of the lower bicuspid. The facet thus 
 established must not be inclined lingually, hut must he a' 
 righl angles to the long axis of the tooth. The tendency in 
 grinding this facet is to incline it too steeply from the 
 mesial to distal, making the cuspid too pointed and in- 
 creasing the difficulty of articulating it with the lower 
 teeth. The mesio-distal inclination of the facet on the 
 mesial half of the tooth should he practically parallel to 
 the mesio-distal inclination of the buccal cusps of the upper 
 bicuspids, as shown in Figure 184. 
 
 Set the lower cuspid in position and grind the mesio- 
 distal inclination of the distal half of the cutting edge, 
 to be parallel to the inclination of the cutting edge of the 
 mesial half of the upper cuspid as in Figure 185. 
 
 The facet on the mesial slope on the upper cuspid is to 
 he ground to the lingual inclination shown by the outline 
 in Figure L86, so that a straight edge placed in contact 
 with the facet will touch the wax at the mesio-lingual cusp 
 of the lirst molar. Grind the facet on the distal slope of 
 the cutting edge of the lower cuspid to a labial inclination 
 which is the complement of the lingual slope o\' the upper 
 cuspid with which it occludes, as shown in Figure 187. 
 The inclinat ion of the long axis of each lower cuspid is also 
 shown in Figure 1ST. 
 
 203 
 
In the upper part of Figure 187 the complementary in- 
 clination of the facets on the cutting edges of the cuspids is 
 shown with the cuspids in occlusion. In the lower part of 
 the Figure the cuspids are shown in articulation with the 
 lower about to begin the return from an extreme lateral 
 excursion. The complementary inclinations of the facets 
 make it possible for the cuspids to remain in contact 
 throughout these movements. This form of articulation by 
 the cuspids is very important in maintaining the stability 
 of the dentures and in protecting the upper laterals from 
 breakage. If the lower cuspids are set to too deep an 
 underbite, the dentures are almost sure to be tipped out of 
 position by improper cuspid contacts ; the force of the 
 closure will be brought upon the thin edged laterals which 
 are not fitted to stand it, and they will be broken from the 
 plate. This form of improper contact is very apt to occur 
 in finished dentures unless guarded against and is dis- 
 astrous. 
 
 Replace the upper lateral but do not attach it. Move 
 the articulator to produce the working and balancing rela- 
 tions and grind the mesial edge of the lower cuspid so that 
 it clears the slope on the distal angle of the upper lateral 
 as in Figure 185. The upper laterals and the lower cuspids 
 should not come into contact in any movement of the jaw. 
 
 The facet on the cutting edge of the upper lateral should 
 incline upward and backward more than that on the edge 
 of the cuspid, as is shown in Figure 188. When this facet 
 has been ground, articulate the lower lateral with it. Do 
 not grind facets on the cutting edges of the lower incisors. 
 Grind facets on the edges of the upper centrals to the incli- 
 nations shown in Figure 188 and articulate the lower cen- 
 trals with them. 
 
 The lower incisors should be set with the necks directly 
 over the ridge and the long axis of the teeth should be in- 
 clined as is shown in Figure 188. 
 
 Figure 185 shows the lower cuspid in occlusal contact 
 with the upper cuspid but not with the lateral. 
 
 204 
 
Fig. 180 
 
 Arranging the Teeth. — The Incising Bite. 
 
 Before trying the teeth in the month hold the articulator 
 in the incising position shown above and slightly alter 
 the arrangement of the incisors and cuspids if necessary 
 so that they will come into proper contact. 
 
 The upper centrals should touch the lower centrals as 
 shown. The upper laterals may, in certain arrangements, 
 i ouch the lower laterals, but they should not touch the 
 lower cuspids. All instances of broken laterals, not dne 
 to careless handling, which have come to the attention of 
 the writers have been found to be due to a cuspid striking 
 the lateral in the incising or the working bite. 
 
 The lower cuspids should touch the upper cuspids but 
 nut the upper laterals in masticating movements. 
 
 When the lower is in central occlusion the lower incisors 
 and possibly the lower cuspids should not be in contact. 
 The lower incisors should not be allowed to supporl the 
 dentures in lateral protrusive movements bul should 
 share this strain with the bicuspids and the cuspids. The 
 pressure on the cuspids should be heavier than on the 
 upper laterals or the lower incisors. 
 
 20:> 
 
Fig. 190 
 
 The Incising Bite — Continued. 
 
 The danger of breaking the incisors in use of the den- 
 ture will be eliminated if the foregoing instructions are 
 observed and the errors seen in the finished denture are 
 corrected by grinding with a stone while the dentures are 
 examined for these contacts in the mouth. 
 
 The lower first bicuspid should be in contact with the 
 upper cuspid which acts as a protector for the upper 
 lateral and prevents the incisors from receiving any ex- 
 cessive strain. The tip of the cusp of the lower second 
 bicuspid may touch the tip of the upper first bicuspid cusp 
 but this is not essential. The tip of the upper 
 second bicuspid should come into contact with the mesio- 
 buccal cusp of the lower first molar. The lingual cusps 
 of the bicuspids and molars also 'come into contact in the 
 incising bite relation. Occasionally the lingual cusps will 
 touch so heavily that the buccal cusps cannot come into 
 contact. If any cusp rides so heavily on an opposing cusp 
 as to prevent the teeth from coming into the proper rela- 
 tion with their antagonists, a little careful grinding will 
 correct the trouble. 
 
 206 
 
[nspecting the Trial Dentures i\ the Mouth. 
 
 II the plane of occlusion bas been correctly established 
 and the bite correctly taken there remains only the neces- 
 sity for determining whether the arrangemenl of the teeth 
 especially the ten anteriors can be altered so as to improve 
 the patient's expression and increase the natural appear- 
 ance of the dentures. The mosl satisfactory results in 
 this respect can only be obtained by placing the dentures 
 in the mouth and engaging the patient in conversation or 
 by having the patienl read aloud while watching the 
 appearance of the teeth and the patient's expression as tho 
 lips and mandible move. 
 
 Flic esthetics of tooth arrangemenl is largely a matter 
 of art and hence no hard and fast rules can lie laid down 
 governing this work. The following suggestions may be 
 found of assistance. 
 
 Most people expose all or nearly all of the length of 
 the central incisor when the lips are retracted in a broad 
 smile or in hearty laughter. The edges of the incisors 
 in the feminine type usually parallel the curvature of the 
 lower lip while in the masculine type they tend to parallel 
 the straighter line of the upper lip. 
 
 The upper incisors normally show more than the bicus- 
 pids so that their tips appear to be set at a lower level 
 than the tips of the bicuspids. Tn most artificial dentures 
 the reverse condition exists. 
 
 The upper lip rarely comes in contact with the bicus- 
 pids when the lip is retracted in smiling; a space exists 
 between the bicuspids and the lip during this action which 
 casts a shadow over these teeth tending to decrease their 
 conspicuousness. 
 
 The upper bicuspids are set so that they do not touch 
 the lip when the patienl smiles, the arch is narrowed, 
 usually resulting in a marked improvement in speech. 
 This arrangemenl of the upper bicuspids assists in giving 
 stability to the lower denture by bringing the lower bi- 
 cuspids more directly over the crest of the lower ridge. 
 
 207 
 
Inspecting the Trial Dentures in the 
 Mouth — Continued. 
 
 When looking at the bicuspids of a patient whose lip 
 is raised as in smiling, from a point directly in front of 
 the patient, it will often be fonnd that the amount of 
 bicuspid showing depends largely on the type of the pa- 
 tient's face. The bicuspids are usually most visible in 
 faces of the ovoid type and less visible in the mouths of 
 patients who have square and oval faces and least promi- 
 nent in faces that are markedly tapering in type. 
 
 The curve of the upper alveolar ridge in the bicuspid 
 region may be used as an aid to getting the proper esthetic 
 effect for the bicuspids by setting them to a curve that par- 
 allels the curve of the ridge. 
 
 In the instructions given for setting the anterior teeth 
 the inclinations given were for the average case. At this 
 time it may be possible to improve the patient's appear- 
 ance by altering the inclinations of the various teeth to suit 
 the requirements of the case presenting or to increase or 
 decrease the prominence of the laterals or of the cuspids. 
 
 The lower anteriors should be kept .over the crest of the 
 lower ridge to let the lower lip fall to an almost vertical 
 position. The upper centrals may be brought forward to 
 carry the upper lip to a position where the upper lip is 
 more prominent than the lower, which is normal. 
 
 Where conditions permit, the roll effect often seen on 
 the lower lip can he had if the upper incisors just touch 
 the inner edge of the lower lip when the mandible is at 
 rest with the occlusal surfaces of the dentures slightly 
 separated. 
 
 When the arrangement of the teeth has been accom- 
 plished in a satisfactory way soft wax may be added to 
 the labial flanges of the upper and the lower dentures 
 till the desired fullness of the upper lips and cheeks is 
 obtained. 
 
 208 
 
Arranging the Teeth Lo\i i i; Second Molars 
 
 Th( - _ "lu i lower second molars is left till the 
 - they are the teeth principally affected when a 
 • compel - _ curve is developed, and requi] - 
 grinding, [f s a curve without proper grinding they 
 
 influence the motion of the articulator and 
 re with th< manipulation of it. 
 
 When the "try-in" is complete and all relations are satis- 
 . s he 1-nvor second molars and articulate them in 
 the manner described for the other teeth. Occasionally the 
 lingnal cusps of the upper second molars will ride heavily 
 in the disto-bnccal grooves of the lower second molar in the 
 balancing relation so that they interfere with the correct 
 relati - the other teeth in articulation. This is espe- 
 cially apl ccur when a steep compensating- curve is 
 lished. To correct this, use the inverted cone carbo- 
 rundum stone and deepen the disto-bnccal groove of the 
 lower molar and flatten the slope of the buccal incline of 
 the lingual cusp of the upper second molar till the bicus- 
 - and first molars of both sides assume correct relations. 
 When the Simplex articulator is used it is better to grind 
 the lingual cusps of the upper second molar and the groove 
 e lower second molar so that these teeth cannot touch 
 in the balancing bite relation rather than to permit them 
 heavily. 
 The curve made by the* occlusal surface of the lower 
 mol; - - id bicuspids should be governed at least 
 in part by the curvature of the posterior portion oi the 
 lower ridge 1: the occlusal surfaces of the lower molars 
 are set parallel to this section of the ridge, the force ap- 
 plied through the teeth in the act of masticating will be al 
 right ans - the surface of the ridge, and the pressure 
 will thereby seat the lower denture rigidly in {dace and 
 will a tendency of the lower to move. A lower 
 ridge that has _ curve will call for a correspondingly 
 great curvature in the arrangement of the molars and 
 bicus] 
 
 COO 
 
_, 
 
 Fig. 191 
 
 Arranging the Teeth. — The Lower Second 
 Molars — Continued. 
 
 In practice the curvature of the lower molars must be 
 modified to meet the requirements of the upper set for 
 stability. In many cases a curvature great enough to 
 stabilize with the lower will tend to create a forward 
 pressure on the upper which would dislodge it. If the 
 upper ridge is flat, set the bicuspids and molars to develop 
 a curve (b) which will be half way between the flat- 
 ness of the upper (a) and the steepness of the lower (c). 
 
 Bear in mind that as the curve that is indicated in the 
 Figures 163 and 164 is departed from the necessity for 
 orindine' increases. 
 
 210 
 
Part Y 
 
 The Simplex Articulator 
 
 and 
 
 The Snow Face Bow 
 
The Simplex Articulator and Accessories. 
 
 Dentists who do not wish to use the Adaptable articu- 
 lator will find the Gysi Simplex articulator satisfactory. 
 It requires no measurements of patient's jaw movements 
 and no adjustments. The rotation points are fixed in the 
 positions necessary to reproduce the average downward 
 and lateral inclinations of the condyle paths as carefully 
 recorded by Prof. G-ysi in 400 cases. The upper bow is 
 supported by an Incisor Guide Pin as in the Adaptable. 
 
 The Simplex articulator is used by many dentists with- 
 out the accessories, shown in Figure 192, but the use of 
 the Face Bow and the accessories will enable them to avoid 
 errors which might otherwise pass unrecognized and will 
 result in a higher average of satisfaction to both patients 
 and dentists than could be achieved without their use. The 
 average time required by the technic to be described, about 
 30 minutes when the technic has been mastered, is negli- 
 gible as compared with the time which would be lost if 
 unrecognized errors necessitated remaking the case. 
 
 The use of the Snow Face Bow enables the dentist to 
 mount the impressions and bites in the same relation to 
 the centers of motion in the articulator that they occupy 
 to the centers of motion of the j aw. 
 
 The supreme importance of taking correct bites justifies 
 the use of the Incisor Path Marker and the Horseshoe 
 Plate and the Slip Joint Stem. 
 
 Building Separate Bite Plates. 
 
 If the impressions are not to be used for taking the 
 bites, it will be necessary to pour casts as described for 
 Figure 132, to shape over them base plates as described 
 for Figure 151, to build a bite rim upon the upper base 
 
 212 
 
ujL J -4) k 
 
 
 Fig. 102 
 
 THE GYSI SIMPLEX ARTICULATOR OUTFIT COMPRISES 
 
 A Gysi simplex Articulator "A" composed of 1 Articulating Frame, in 
 two parts, 1 upper and 1 lower -Model Support, 1 Straight Incisor Guide 
 I 'in "B", two Face Bow adapters of the articulator "N". An Incisor 
 Guide incline "I". 
 
 Aii Incisor Guide "C" for mounting casts on the articulator when t ho 
 Face Bow is not used. 
 
 A Snow Face How. "D" with condyle roils "P P" and lock nuts "K R" 
 and a Cylindrical Block "\Y". 
 
 A Horseshoe Plate "E" and Slip Joint Stem "F". The Horseshoe Plate 
 is used with the Incisor Path Marker to obtain, correct bites. The Slip 
 Joint stem connects the Horses! Plate with the Face Bow. 
 
 A Mouth Piece for the Face Bow "II" used only when mash bites are 
 taken. 
 
 \ Curved Incisor Guide Pin, "I" used only while mounting casts with 
 t he Face Bow. 
 
 An Incisor Path Marker. "K" used with the Horseshoe Plate for de- 
 termining correct bites. 
 
 An Anterior Supporting Block, "L" to support the front of the Face 
 Bow when mount Ing i ast s. 
 
 Two Bite Lock Trays "M" for locking bites together. 
 
 plates, adapting the technic described for Figure 1."-". to 
 take the bite with base plate bite rims, using the technic 
 described for the impression bite rims beginning <>n page 
 137. 
 
 213 
 
Fig. 193 
 
 Attaching the Horseshoe Plate. 
 
 Both bites are in the mouth. Attach the horseshoe plate 
 to the slip-joint stem and hold it so that the pins rest 
 upon the occlusal surface of the lower bite rim and about 
 Y2 inch of the Horseshoe Plate projects in front of the 
 upper bite rim when it is closed upon the lower. See that 
 the Slip Joint Stem projects forward, about in the median 
 line. Have the patient close and impress the points of the 
 pins on the occlusal surface of the lower. Remove 
 the Horseshoe Plate and lower bite rim. Detach the Slip- 
 Joint Stem and set the Horseshoe Plate on the lower bite 
 rim as described for Figure 108. Equalize the biting 
 strain as described for Figure 109. Attach the Incisor 
 Path Marker to the upper bite rim as described for Figure 
 113. Make the crosses on the face as described for 
 Figure 106. 
 
 214 
 
^K 
 
 ^* 
 
 % 
 
 f 
 
 'J 
 
 Fig. 104 
 
 Adjusting the Face Bow to the Face. Part 1. 
 
 Push the right condyle rod as far inward as it will go 
 and lock it there. Place the inner end of this condyle red 
 over the intersection of the lines over the right condyle. 
 Push the other condyle rod gently hut firmly against the 
 face, with its inner end over the left condyle, and lock it 
 there. 
 
 Count the notches external to the sleeve of the lock mil 
 on the condyle rod on the patient's left. Remove the 
 Face Bow from the i:\cv. Divide the number of notches 
 which were external to the sleeve of the lock nut on the 
 left by 2. Adjust each condyle rod so that half of 
 the total notches exposed on the left rod are external to the 
 sleeve of each lock nut, when the nut is tightened. This 
 insure- centering the Face Bow when it i< replaced upon 
 the face. 
 
 215 
 
r / 
 
 Fig. 195 
 
 Adjusting the Face Bow to the Face. Part 2. 
 
 Carry the Face Bow to position on the face, beginning 
 with the condyle rods at the level with the angles of the 
 jaw as shown in Figure 195. Move them upward and 
 slightly backward to their positions over the crosses. The 
 pressure exercised upon the face by the condyle rods should 
 be sufficient to aid in holding them in position, but 
 should not be painful to the patient. If only a slight 
 adjustment of the condyle rods is necessary to achieve this 
 effect, it can be made on one side. If much adjustment 
 must be made, it should be divided between the two sides. 
 Lay the Face Bow aside until the incisor path record has 
 been taken. Take this record as described beginning with 
 Figure 115. 
 
 216 
 
Taking the [ncisob Path Record. 
 
 Attach the [ncisor Path Marker to the labial surface of 
 the upper bite rim in the median line, in such position 
 that when the spring controlling the pin is released onlv 
 the cone of the Marker projects below the incisal edge, as 
 illusl rated in Figure 1 13. 
 
 I Slacken the anterior portion of the upper surface oi 
 the Eorseshoe Plate as described for Figure 114, and 
 lightly coat it with wax. Place the lower impression and 
 Horseshoe Plate in the mouth and make the incisor path 
 record as described for Figure 115. When the jaw is at 
 rest and the point of the Incisor Path Marker is in the 
 point of the incisor path record, the bite is correct. 
 
 While the point of the Incisor Path Marker rests in 
 the anterior point of the incisor path record, make ver- 
 tical marks across the buccal surfaces of both bite rims 
 as illustrated on the left in Figure 125. Lock the pin of 
 the Incisor Path Marker in a raised position. Deepen the 
 vertical line across the buccal surface of the bite rim into 
 notches as illustrated on the right in Figure 125. 
 
 While the use of this incisor path record in connection 
 with the Simplex articulator does not permit of any 
 adjustment of the articulator to reproduce habitual jaw 
 movements, it is invaluable because it is the onlv known 
 means of determining accurately when bites are correct 
 in all horizontal relations. This is one of the steps where 
 what appears at a casual glance to lie a waste of time will 
 generally prove, in the end. to be an economy of time, 
 because of the avoidance of errors otherwise undetectable. 
 It will be well to review what has been offered in connec- 
 tion with the taking of the bite by this method on page 140. 
 
 21' 
 
Fig. 196 
 
 Adjusting the Face Bow to the Face. Part 3. 
 
 With both bite rims and the Horseshoe Plate in the 
 mouth, and with the point of the Marker in the point of 
 the incisor path record, place the Slip Joint Stem upon 
 the rods of the Horseshoe Plate. Insert the outer end 
 of the Slip Joint Stem into the hole of the cylindrical 
 block on the arch of the Face Bow. Pass the Face Bow 
 about the face in the position shown in Figure 196 and 
 move the condyle rods upward and backward to their posi- 
 tions over the crosses. Hold the Face Bow in this position 
 and lightly set the lock screw of the cylindrical block. 
 Examine on both sides of the face and make sure that the 
 condyle rods of both sides are over the crosses. Then lock 
 the set-screw of the cylindrical block so firmly that no 
 change in the relation of the Face Bow to the bite rim can 
 occur during the following manipulation. 
 
 218 
 

 Fig. 197 
 
 Removing the Face Bow . 
 
 Loosen the lock nuts of the condyle rods and move 
 them outward, away from the face as shown here. Place 
 the thumh and lirsi finger on the opposite sides of the 
 anterior margin of the Horseshoe Plate with the hand 
 below the Face Bow as shown. Place the inner side of the 
 tip of the third finger againsl the face side of ihe cylin- 
 drical block and press ii upward while pinching the 
 sides of the Horseshoe Plate. This action will force the 
 Slip Joint from the Horseshoe Plate. Lay the Face Bow 
 aside until it is needed for mounting the cast upon the 
 articulator. Take the bite lock impressions as described 
 for Figure 126. Prepare impressions for making casts 
 and make the casts as described, beginning on page L55. 
 Fasten the bites together with the Bite Locks as described 
 for Fisrure 138. 
 
 219 
 
V~'*msik~ \ <|W 
 
 Pig. 198 
 
 Mounting Casts on the Simplex Articulator 
 With a Face Bow, Part 1. 
 
 The articulator is here shown with the hite rims fas- 
 tened together by the Bite Locks "M" and mounted on 
 the Horseshoe plate "E" and the Slip Joint Stem "F" 
 which passes through the cylindrical block of the Face 
 Bow "W". The Condyle Bods of the Face Bow "P" are 
 over the Face Bow adapters of the articulator "1ST". The 
 Curved Incisor Guide Pin "I" is in place. The Anterior 
 Supporting Block receives both the Slip Joint Stem "F" 
 and the Straight Incisor Guide Pin a B" and its set screw 
 is locked to support the Horseshoe Plate and Slip Joint 
 Stem parallel with the table. The notch "S" on the frame 
 of the articulator locates the proper level of the occlusal 
 plane when the Face Bow is not used. 
 
 The technic for mounting bites and casts on the Simplex 
 Articulator by means of the Snow Face Bow is given on 
 the next page. 
 
 220 
 
Mounting Casts <>\ the Simplex Aeticulatob 
 With a Face How. Part 2. 
 
 The Simplex articulator is a little wider than the ar- 
 ticulator for which the Face Bow was designed. It is 
 therefore necessary to arrange the condyle rods to accom- 
 modate this additional width. This may be done by set- 
 ting both condyle rods in the Face Bow in such way thai 
 one notch and balf the distance to the next one is external 
 to the sleeve of the lock nnt, or by adapting it to the 
 articulator in the same way that it was adapted to the 
 face in Figure 196. Tighten the lock nuts. 
 
 Replace the straight Incisor Guide Pin with a curved 
 Incisor Guide Pin and see that the top of the pin is flush 
 with the top of the sleeve in which it is held. Lock it 
 in this position. If base plates and bite rims were \\^'(\ 
 for taking biles instead of the impression bite rims, tie 
 t lie casts into the base plate bites which are already 
 mounted on the Horseshoe Plate and set the pins of the 
 Horseshoe Plate firmly into the Slip Joint Stem of 
 the Face How. Spring the inner ends of the condyle rods 
 over the Face Bow Adapters (cylindrical projections on 
 the articulator external to the beads of the condyle pins). 
 
 The anterior part of the Face Bow must be supported 
 so that the occlusal plane of the bite rims is parallel to 
 the flat surface on which the articulator rests. This may 
 be done by means of an improvised stop for the cylin- 
 drical bloc'-: of the Face Bow or by means of the Anterior 
 Supporting Block shown in Figure 198. The projecting 
 end of the Slip Joint Stem is placed through the large hole 
 in the Anterior Supporting Block and the straight Incisor 
 Guide Pin of the articulator is placed in the other hole. 
 "When the Slip Joint Stem is parallel with the top of the 
 table tighten the set-screw of the Anterior Supporting 
 Block, which locks all the parts in thai relation. 
 
 Attach the casts to the model bows using the technic 
 described for Figures L39, 1 tO and 141. 
 
 221 
 
Fig. 199 
 
 Mounting Casts on the Simplex Articulator 
 Without the Face Bow. 
 
 Dentists who do not wish to employ the Face Bow may 
 mount casts upon the Simplex articulator without it, but 
 probably not with the same freedom from error as when 
 the Face Bow is used. 
 
 If a line from the center of the vault be prolonged up 
 the back of the upper cast and one from the frenum be 
 prolonged up the front of it and these be joined by a line 
 along the top of the cast, as shown in Figure 198, it will 
 be easy to center the cast laterally under the upper model 
 bow. The antero-posterior position of the bite rims 
 should be such that the incisal edge of the upper bite at 
 the median line will be about l/o inch back of the posterior 
 side of the Incisor Guide Pin. 
 
 Lock the straight Incisor Guide Pin in the articulator 
 so that its top is flush with the top of the sleeve by which 
 it is held. Place the Incisor Guide on the Incisor Guide 
 
Fig 200 
 
 Mounting Casts ox the Simplex Articulator 
 
 Without the Face Bow — Continued. 
 
 Pin with its point facing directly backward in the median 
 line and lock the set-screw into the depression in the 
 straight pin. Place an clastic band around the set-screw of 
 the Incisor Guide and in the notches on the outside of the 
 vertical pari of the articulator frame "S", Figure 192. 
 The occlusal plane of the bite rim should he on a level with 
 this hand. 
 
 Place a -on mass of carding wax on the top of the lower 
 model bow and press the lower cast down upon it until the 
 occlusal plane of the bite rim is level with the elastic hand, 
 and the incisal edge of the upper bite rim at the median 
 line touches the point of the Incisor Guide or is about 
 1 o inch back of the posterior surface of the Incisor Guide 
 Pin, and adjust the casts till the line across the top of the 
 upper is beneath the centre i\\' the upper how. Attach the 
 cast to the articulator by the technic described for Figures 
 130, 140, 141. 
 
Face Bow Technic for Large Cases. 
 
 The Simplex articulator is built on the average of a 
 great many cases and is therefore smaller than the larger 
 cases that present. This difference will be apparent on 
 large cases only when the Face Bow is used, and may be 
 overcome by the following technic. 
 
 Adjust the Face Bow as if the case were of the average 
 size. When the Face Bow is locked in the proper relation 
 to the face remove it without 
 loosening the adjustment and 
 apply it to the articulator, in 
 which the curved pin has 
 been placed. If the posterior 
 end of the Slip Joint Stem 
 (or the rim of the bite por- 
 tion of the mouthpiece, when 
 that is used) is not slightly 
 distal to the rear of the 
 straight sections of the 
 curved pin, the casts will be 
 mounted too far forward in 
 
 the articulator to permit of correct manipulation. To 
 make the proper adjustment note the distance between the 
 rear edge of the block of the Slip Joint Stem and the 
 distal surface of the straight sections of the curved pin. 
 Make a short line on the side of the face extending for- 
 ward from the intersection of the lines marking the con- 
 dyle location and parallel to the plane of occlusion. Space 
 off on this line a distance equal to that noted when examin- 
 ing the relation of the Slip Joint Stem to the articulator 
 pin. Make a similar line and space off an equal distance 
 on the opposite side of the face. Readjust the Face Bow 
 to the new marks and proceed as ■usual from this point. 
 
 Fig. 201 
 
 224 
 
Part VI 
 
 Flasking, Vulcanizing, 
 
 Finishing 
 
 and Perfecting 
 
 the Fit 
 
Fig. 202 
 
 Preparation oe Trial Dentures eor Flashing. 
 
 Part I. 
 
 Place the trial dentures correctly on the casts and attach 
 by heating the edges. Remove loose teeth one at a time, 
 thoroughly dry the teeth and wax and firmly reset the teeth. 
 
 Wax the labial and buccal surfaces adjacent to the teeth 
 to a greater fullness than desired in the finished denture 
 to permit of finishing and polishing. No wax should be 
 added to the Dentsply Baseplate Composition that covers 
 the palate of the upper as this material is of the proper 
 thickness to produce a thin, strong palate of uniform thick- 
 ness in the denture. 
 
 It is best to have the buccal surfaces of the lower convex 
 where possible, especially in the molar region. Concave 
 surfaces tend to make it difficult for the tongue to sweep 
 food forward to a position where it can be carried onto 
 the occlusal surfaces of the teeth for mastication. 
 
 Fill the interproximal spaces with wax but not enough 
 to permit the teeth to be dislodged in packing. Wax 
 should be added, where necessary, in a plastic condition 
 and worked to the proper contour with a moderately warm 
 spatula. Fluid wax may warp the trial denture or draw 
 teeth out of position on cooling. 
 
 Do not carve finished gum festoons or flow the surface 
 of the wax smooth. This may cause the wax to change 
 form and derange the articulation. Final contouring and 
 festooning is easily done with a vulcanite finishing bur 
 as described later. 
 
 226 
 
Fig. 203. 
 
 Preparation of Trial Dentures fok Flasking, 
 
 Part II. 
 
 This illustration shows the tin piece to reproduce the 
 rugae in place, and the wax in which the incisors and cus- 
 pids are held, carved so that the rubber will imitate the 
 full natural contour of the lingual surfaces of these teeth, 
 both of which greatly assist in articulation of words. 
 
 When the wax is left thick at the point where it is being- 
 cm by the knife, polishing the vulcanite is made easier. 
 
 The extra thickness of Dentsply Baseplate Composition 
 across the heel should now be cut away. 
 
 This illustration shows thai the extensive grinding neces- 
 sitated by the rather unusual inclinations of the condyle 
 paths in this case has not altered the forms of the teeth, 
 and their masticating power has not been reduced. The 
 secondary cusps have not been destroyed and they are in 
 position to permit the establishment o[' the numerous 
 small, sharp-edged facets essential to etlicient mastication 
 with the limited power it is possible to exercise through 
 artificial dentures. 
 
 The final grinding in the mouth will he illustrated later. 
 
Pig. 204. 
 
 Flasking the Dentures. 
 
 Fill the cup portion of a B.D.M. Co. flask, No. 22C, 
 with equal parts of Spence plaster and plaster of Paris, 
 mixed thick. Imbed the cast in it until the outer edge of 
 the extension left on the cast is about level with the flask 
 rim. Shape the investing plaster as shown in the illus- 
 tration. When the plaster is hard draw on it a pencil 
 line extending entirely around the cast so that it will 
 everywhere be % inch distant from the wax or baseplate. 
 Coat the surface of the plaster with thin Sandarac to act 
 as a separating medium. 
 
 Make a second mix of equal parts of Spence plaster and 
 plaster of Paris but not so thick as the first. With a small 
 spatula work some of it carefully into the crevices between 
 the teeth, as illustrated on page 229. Then cover the 
 entire wax trial plate and the teeth. Clean the rim of 
 the cup portion of the flask, place the ring in position 
 
 228 
 

 
 Flanking the Dentures, Continued. 
 
 upon it, and till the ring with the remainder of the second 
 mix. Scat the lid. Do not let any plaster escape between 
 the cup of the flask and the ring. Place the thisk in ;i 
 Donham clamp or under a weigh.1 until the plaster sets, 
 [mmerse the flask for L5 minutes in a dish containing 
 about 2 quarts of water at L18-120 F, when the wax will 
 ho soft enough to permil opening the flask withoul danger 
 of breaking the cast. If the baseplate slicks to the cast, 
 soften ii by directing a bunsen flame upon it. 
 
 A small colander with line perforations in the bottom 
 will he found convenient tor bolding the flask while wash- 
 ing tin 1 wax away from the cast and the tooth. To pre- 
 pare for washing away the wax, add carbonate of soda, 
 usually known as washing soda, to actively boiling water 
 in proportion of one tablespoonful to two quarts of water. 
 This mixture cms wax much more readily than plain 
 water and leaves the teeth very clean. Hold the colander 
 above the vessel in which the mixture is boiling. With .1 
 small dipper pour some of the boiling solution over the 
 surface to be cleaned. 
 
 229 
 
Fig-. 200. 
 
 Preparation of Channel for Waste Rubber. 
 
 This illustration shows a section of a flask with a chan- 
 nel cut for receiving the surplus rubber. 
 
 The narrow band of plaster left between the space filled 
 by the rubber and the channel facilitates the escape of 
 surplus rubber and the closing of the flask in testing for 
 quantity; and keeps the rubber under pressure, retaining 
 in the denture expanding rubber that would escape 
 through waste gates during the initial period of vulcanizing. 
 
 In the last period of vulcanizing, the rubber loses vol- 
 ume and draws away from the teeth, leaving spaces where 
 fluid food may lodge. The Snow waste channel will mini- 
 mize error caused by this change. 
 
 The waste channel is cut with a Kingsley scraper up to 
 the pencil line shown on page 228, leaving a strip of 
 plaster from 1/16" to %" wide between the rubber space 
 and the channel. The channel may extend outward to 
 the metal flask rim and should be about 1/g" deep at its 
 centre, sloping up toward the narrow plaster rim and the 
 edge of the flask from this point. 
 
 230 
 
\v 
 
 c 
 
 ) 
 
 Pig. 207. 
 
 Packing and Testing., Part I. 
 
 Heat slowly the portion of the flask containing- the teeth 
 until the teeth become so hot that the fingers cannot lie held 
 upon them. Fold one end of a sheet of pink rubber to 
 make a strip V. inch wide and of double thickness. Cut 
 this strip crosswise into pieces Y2 inch long and a little Less 
 I ban Yg inch in width. Place one end of one of these 
 strips in each interproximal space beginning at the distal 
 side of jhc first molar. Allow the balance of the strip 
 to extend vertically upward. When strips have been placed 
 between all of the teeth up to the mesial of the opposite 
 liist molar, return to the first one placed and bend it 
 around the gingival margin of the tooth into the next 
 approxinial space ahead "1' it. Repeat this until the 
 pieces lake the position shown on the right side of thi- 
 figure. Pack these pieces of pink rubber around the neck- 
 of the teeth as shown mi the Lefl above. 
 
 Cut strips of baseplate rubber aboul ' s inch wide- and 
 pack" the diatoric holes of the posterior teeth and around 
 the pins of the anterior teeth until they an' covered. 
 
Fig. 208. 
 
 Packing and Testing, Paet II. 
 
 The balance of the sheet of pink rubber is now folded 
 longitudinally and cut lengthwise into three strips of 
 equal width. Then lav a strip of pink rubber of double 
 thickness against the buccal and labial sides of the flask on 
 top of the pink rubber already in place, as shown above. 
 Short pieces cut from the end of the strips of pink rubber 
 may be placed over the lateral and cuspid region or wher- 
 ever very bold contouring is to be done, to give additional 
 thickness. 
 
 Strips of base rubber of about y 2 to % inches in width 
 are now laid over the palatine area. Do not place any 
 pieces of base rubber to overlie the pink until the packing 
 has been tested. 
 
 To test, place a thin piece of moistened percaline or 
 cambric over the hot soft rubber ; place the cast section on 
 the flask, put in a small flask press and very slowly and 
 cautiously bring pressure to bear on the flask contents, 
 following the yielding rubber slowly with pressure so that 
 the evils of rapid closing may be avoided. 
 
 232 
 
w 
 
 Fie. 209. 
 
 Packing and Testing, Part III. 
 
 When much pressure is needed to completely close the 
 flask or when the sections of the flask come into contact. 
 open the flask and examine the contents and either add 
 more material or remove the surplus as indicated. Replace 
 the percaline and place in the press and boil for fifteen 
 or twenty minutes. 
 
 Carefully close the press until resistance is great enough 
 to require strength to close the sections, then open and 
 repeat the cutting away process until the seel ions of the 
 flask come almosl into perfeel contact all around, being 
 separated at most hv only erlough space to accommodate 
 the thickness of the percaline. Then finally close and 
 place in the Donham clamps shown in the illustration on 
 the next page, preparatory to vulcanizing. 
 
 If the test percaline slicks to the rubber a syringe full 
 .if ho! water squirted Over it till wet. will make it easy i«> 
 remove. 
 
Fig. 210. 
 
 Vulcanizing and Opening the Flasks. 
 
 The following plan of vulcanizing yields good results. 
 Put about four ounces of water into the pot of a A^/o 
 three case vulcanizer. Invert the flasks and the clamp 
 and place in the vulcanizer and close it. Adjust the tem- 
 perature regulator to hold the temperature at 270° or 
 280° F. Heat the vulcanizer with the blow-off open till 
 steam escapes, then shut the blow-off and let the vulcanizer 
 run for three-quarters of an hour. jSTow move the tem- 
 perature regulator to hold a temperature of 305° F. and 
 continue the vulcanizing for one hour and fifty minutes. 
 
 If possible let the vulcanizer cool slowly. Do not open 
 the blow-off valve to hasten the cooling. If this is neces- 
 sary to hasten cooling immerse the pot of the vulcanizer 
 in cold water. 
 
 The dentures must be carefully removed from the 
 flasks to prevent breaking teeth or so cracking them that 
 they will break later in the mouth. Do not hammer the 
 flasks. This bends the flasks out of shape and the shock 
 of the blows transmitted to the teeth may crack them. 
 Cut away the plaster on the bucco-labial surface of the 
 denture until the bottom of the flask is reached, when 
 the denture may be safely released. 
 
 234 
 
Fig 211. 
 
 Preparing Dentures eor Polishing, Part I. 
 
 A series of casts of mouths exhibil Lng bold festooning and 
 including the incisors and bicuspids, will be found to l>e of 
 greal assistance in imitating natural festooning. 
 
 The festooning of the vulcanite should be much holder 
 than the finished result expected as the contour will be 
 much softened in polishing. 
 
 With the tile remove the surplus vulcanite al the mar- 
 gins of the denture after brushing away the plaster which 
 adheres to the denture with a three row stiff bristle brush. 
 The beveled chisels are/nexl used tocarve away the vulcanite 
 to the desired gingival outline, on both the bucco-labial 
 and lingual surfaces, cutting at right angles to the tooth. 
 Vulcanite burs are then used in a hand piece to carve 
 the rubber to the required contour. By using tin 4 bur 
 with light pressure and a drawing motion as it cuts, the 
 carved surface will be lefl smooth enough to polish. A 
 
 new sharp bur is hest adapted to rapid Cutting and one 
 that is worn is hest suited to finishing. Small depres- 
 sions, that the large bur will not reach, may be carved with 
 a large rose bur. The interproximal spaces are freed, from 
 the tins of rubber which project between the teeth with 
 the needle-pointed bur revolving rapidly in the hand piece. 
 
 335 
 
Fig. 212. 
 
 Preparing Dentures for Polishing, 
 Part II. 
 
 With the square and beveled chisels, round the edges of 
 the gingival festoons which were left square. If the lingual 
 contour of the natural teeth is to be reproduced in the vul- 
 canite these surfaces should be carved to the proper shape 
 with the chisels which should be very sharp. Finally, go 
 over the curved surfaces with chisels and make these sur- 
 faces so smooth that they will require only brushing with 
 pumice to be ready for the final polish. 
 
 The flanges of the dentures should be carved to a round 
 or cylindrical contour and not left sharp or very thin. 
 
 All small nodules or projections on the inside of the 
 dentures should be removed with a small Kingsley scraper 
 but this surface should be only cleaned with a brush and 
 not polished. 
 
 236 
 
Polishing 
 
 Mix one pari of einer) powder with from six to ten 
 parts of pumice and place the whole id a shallow pan 
 with sufHcienl water to render the mixture quite fluid. 
 Place a single-row stiff bristle brush on the lathe spindle, 
 and, starting with the gingival festoons, finish these to a 
 surface smooth enough to polish; follow this by finishing 
 the lingual surfaces oi the anterior teeth. 
 
 In reaching into the fine depressions al the gingiva] of 
 the buccal surfaces and on the lingual of the upper 
 teeth, the denture may he held so that the bristles of the 
 revolving brush will strike the tooth and glance from it to 
 the surface to be polished travelling in the direction of the 
 depression to he finished. Do not allow the bristles to run 
 long enough in one place to cut a channel. Xcxt finish 
 the lingual interproximal spaces hetween the bicuspids and 
 molars, and then the main portions of the buccal and 
 lingual surfaces, using the rag wheel and a small fell cone 
 to reach places that the rag wheel will not touch. 
 
 A rotary motion should he imparted to the denture 
 when it is being dressed on the rag wheel and plenty of the 
 pumice mixture should be used to keep the denture wet. 
 Tf roughness is detected, in the interdental spaces a sharp 
 chisel should he used to plane these rough places smooth 
 preparatory to a second dressing with the bristle wheel. 
 
 For the glossing, place the flannel wheel on the lathe 
 and hold a cake of Sure Shine against it for a second or 
 two, then hold the denture in light contact with the wheel 
 while it revokes vapidly, alternately pressing the denture 
 into the surface of the wheel and withdrawing it while 
 at the same time working hands in a rotary direction. 
 
 The dentures should he coated with vaseline or kepi in 
 water till ready for inserting in the mouth. This mini- 
 mizes danger of warping. 
 
Testing Occlusion for Rocking. 
 
 Hold the upper and lower dentures in occlusion and test 
 them to see whether the change in vulcanizing has been 
 sufficient to cause the lower to rock on the upper. The 
 dentures are held in occlusion with pressure applied alter- 
 nately in the cuspid and molar regions. Locate and cor- 
 rect the points of improper contact. Cautiously grind 
 these points with a small inverted cone carborundum stone. 
 
 The inclined planes of the buccal cusps of the lower 
 bicuspids will usually be found to hit the inclined planes 
 of the lingual cusps of the upper bicuspids too heavily. 
 When this occurs grind both of the offending cusps slightly 
 in such way that the bite will be deepened and not made 
 more shallow. 
 
 Examine the lower denture and cut away all projecting 
 portions of rubber which fit into undercuts in the contour 
 of the lower ridge. If these projections are not removed 
 from the denture they will prevent the lower jaw from 
 taking the correct bite relation. When the lower denture 
 has been well prepared to receive a wafer of compound it 
 will flare like a V with no projecting portions to interfere 
 with the smooth, even slope of the sides. 
 
 238 
 
Refitting the Lowek Denture, Part I. 
 
 Take a cast of an average size lower jaw that has a 
 fairly high medium thin ridge and mould over it a wafer 
 of Perfection compound which has been softened in water 
 at 115° to 118° F. Do not thin the wafer in moulding. 
 Trim away the surplus material till only a little more 
 than is needed to cover the under surface of the denture 
 remains. 
 
 Warm the Wank and with bibulous paper or absorbent 
 cotton moistened in the hot water, press the blank against 
 the flanges of the denture and adapt the compound well 
 to the contour of the denture as at "A". Trim away the 
 surplus material at the margins with a sharp knife as at 
 ••|!". Chill the blank in cold water and remove it from 
 the denture. Dry the denture and the blank thoroughly. 
 Place the dried blank in the dried denture and seal the 
 margins of the compound to the denture with a hot wax 
 spatula, pulling the soft compound toward the margins 
 of the flanges in the operation as at "C". The entire 
 margin of the compound must be thoroughly sealed to the 
 denture so that moisture cannot penetrate between the 
 denture and the compound and interfere with the com- 
 pound adhering to the rubber. 
 
 This part of the technic may be finished in the labora- 
 tory. 
 
 239 
 
Fig. 21 "j. 
 
 240 
 
Refitting the Loweb Denture, Part II. 
 
 h Is Importanl to the success of the work thai the po- 
 sitions ol the fingers shown in the illustrations on the 
 opposite page be closely imitated. Ii is importanl also to 
 practice the following steps with the lined denture cold. 
 
 Place the upper denture in the mouth. With :i si ick 
 of cocoa butter grease the palm side of the join! of the 
 lirst finger of the right hand. The water in the heater 
 should be maintained nt a temperature of 150° b\ With 
 n water syringe thai has a. l/l(i inch opening, or a hoi 
 pouring cup, direct a stream of the hoi water upon the 
 compound of the lower denture so thai the deeper por- 
 tions of the impression will receive the most hear. The 
 margins of the flanges should he healed only slightly. ( !on- 
 tinue the pouring or heating for about six seconds or for 
 a sufficient length of time to soften the compound slightly. 
 Grasp the denture between the thumb and first finger 
 with the ridge surface facing' the palm of the hand. 
 
 Place the lower teeth in the correct occlusal relation 
 to the upper and hold in this position while the thumb 
 and forefinger of the left hand are placed in contact 
 with the buccal flange of the lower in the bicuspid region 
 in such a manner that the lower will he held firmly in 
 contact with the upper denture. 
 
 When the left hand is placed so that the lower denture 
 is securely held against the upper, release the thumb 
 of the right hand from contact with the lower and turn 
 the right hand palm down. The index finger of the 
 right hand is now used to pull the Ii]) outside of the 
 thumb and firsl finger of the left hand, so that the lip 
 will not Interfere with the smooth closing of the lower 
 jaw that is necessary if the bite is to ho taken correctly. 
 (If the margins of the compound have been healed too 
 much there is danger of tearing them loose from the den- 
 ture af ihis l ime.) 
 
 Xow direct the patient to place the tip ol' the tongue 
 
 241 
 
Refitting the Lower Denture 
 (Part II, Continued). 
 
 against the rear portion of the upper vault and slowly 
 close the lower jaw till the ridge makes an imprint in the 
 soft compound on the bottom of the lower denture. As 
 the ridge of the jaw approaches the point where it touches 
 the compound it will press against the thumb and finger 
 which hold the lower denture against the upper at the 
 point where they extend slightly under it. Allow the up- 
 ward pressure of the ridge to force the fingers and thumb 
 upward while they still maintain a firm pressure on the 
 denture to keep it seated against the upper. 
 
 When the mouth has been closed the fingers should be 
 removed and the patient instructed to suck while con- 
 tinuing the biting process. Chill the compound with cold 
 water and remove the denture from the mouth. Chill it 
 thoroughly by immersing in cold water, then place in the 
 mouth and examine to see whether the cuspids strike in 
 occlusion as they did when the preliminary examination 
 for occlusion was made. If more space is found between 
 the upper and lower cuspids than should be this indicates 
 an error, to correct which, heat the compound on the 
 under side of the denture and repeat the technic to this 
 point. It is sometimes necessary to add a new' blank of 
 compound to the under side of the lower and repeat the 
 entire technic. 
 
 When the lower is properly seated on the ridge so 
 that the patient can open the mouth and snap the lower 
 teeth quickly against the upper, producing a sharp, clear 
 noise, and when a close examination reveals no defect in 
 the occlusion or articulation such as would be due to seat- 
 ing the lower incorrectly against the upper, the fit may 
 be still further improved by heating the compound with 
 a hot water stream, which should lie allowed to touch only 
 the deep portions of the compound made by the ridge, 
 for about eight seconds, then placing the lower in the 
 
 24a 
 
Refitting the Loweh Denture 
 ( Pari I [, Continued). 
 
 mouth tin the ridge, requesting the patient to close with 
 the tongue touching the roof of the mouth, exert biting 
 pressure, and suck. 
 
 Chill the compound to a stage in which if will nol 
 change its form and remove from the mouth and complete 
 the chilling in cold water. 
 
 With a tracing stick make additions to the flanges of 
 the compound in the areas over the location of the pro- 
 jections of vulcanite that were cut away at the beginning 
 of the operation. At these points the single thickness of 
 the compound wafer requires reinforcing to provide 
 enough material to take a correct impression of the tissues. 
 Chill the added compound and proceed as directed in the 
 technic described for the use of the tracing stick on page 
 3 49, instructing the patient to suck. 
 
 The lower denture should he perfectly stable on the 
 ridge and exhibit marked suction. If it has stability and 
 no suction, press one side against the ridge with the 
 fingers of one hand which are supported by pressure of 
 the thumb on the lower border of the mandible, and grad- 
 ually lower the other side till seated on the ridge, watch- 
 ing for appearance of bubbles. Repeat this several times 
 and watch closely for the appearance of bubbles which 
 will be formed in the region where air escapes at the 
 point of imperfect adaptation. Corred the adaptation by 
 adding compound from a tracing stick, as described in a 
 previous paragraph. Imperfect adaptation which inter- 
 feres with suction is most likely to occur at the heels of 
 the denture and at the I'reiium linguae. 
 
 843 
 
Refitting the Lowek Denture, Part III. 
 
 It frequently happens that the. lower denture is not 
 made long enough to secure stability and suction. To 
 correct this condition trace a bulk of soft compound on 
 the upper side of the heel of the denture as shown at the 
 top of the page. Place the denture in the mouth, the upper 
 being in place, and have the patient close and suck. If 
 the surface of this addition is not smooth enough, correct 
 the defects by the use of the tracing stick. 
 
 The edges of the compound addition should be trimmed 
 so that the margins of the flanges will be well rounded. 
 The flanges should not be allowed to extend below the ex- 
 ternal oblique line on the buccal side nor below the mylo- 
 hyoid line on the lingual side. Place the lower denture 
 against the upper in occlusion and make sure that the 
 compound additions do not strike the upper so as to inter- 
 fere with lateral motions of the jaw. 
 
 244 
 
Refitting the Lower Dextuke, Part IV. 
 
 Scrape away the compound which has been forced 
 upward on the buccal and lingual flanges of the lower. 
 Make a very stiff mixture of equal parts of Spence plaster 
 and plaster of Paris and till the cup portion of a flask. 
 Work some of this stiff mixture into the interproximal 
 spaces and the occlusal surfaces of the teeth. With gentle 
 rotating pressure force the denture into the plaster in the 
 flask, i ill the edge of the bucco-labial flange is at the level 
 of the edge of the flask. The denture should be placed 
 well forward in the flask to provide ample room to prepare 
 a Hat sloping surface back of the heel to facilitate parting 
 for packing. Smooth the plaster as shown in the illustra- 
 tion and trim it to the point where the compound joins the 
 rubber excepl ni the heel where ibis is impossible. When 
 the plaster bus hardened, coat it with ibin sandarac var- 
 nish and lay on the plaster a strip of wax as shown, aboul 
 Wo inch away from the compound. 
 
Fig. 21 S. 
 
 Refitting the Lower Denture, Part V. 
 
 Seal the ring of the flask firmly and evenly upon the 
 poured cup section. Make a mixture of pure Spence 
 plaster or of half Spence and half plaster of Paris, free 
 it from bubbles as described on page 158 and distribute it 
 over the impression in the manner used in making the 
 casts. Fill the ring to the top and place the lid on it 
 and set a weight on the lid or clamp the flask lightly in 
 a clamp or press. Allow the plaster to set thoroughly and 
 heat the flask before opening for about fifteen minutes in 
 water at about 118° F. If the flask is overheated, the 
 compound will adhere very tenaciously to the rubber. 
 
 Refitting the Lower Denture, Part VI. 
 
 The rubber which replaces the compound should be 
 thick enough to vulcanize properly but only as much 
 thicker than this as conditions make absolutely necessary. 
 At the places where the compound was very thin cut away 
 enough vulcanite with an oval vulcanite bur to provide 
 
 246 
 
Refitting the Lower Denture, Continued. 
 
 space for a bulk of rubber one-half nun. thick. With the 
 same bur freshen the cut ire surface of exposed vulcanite. 
 The cduvs of the flanges may be squared with a carborun- 
 dum stone. Cut grooves with a wheel bur as shown in 
 the illustration, one o\' which extends entirely around the 
 periphery of the denture about 1/16 of an inch away from 
 the edge, the others diagonally across the surface of it. 
 
 Warm the flask slowly over an electric heater or a slow 
 gas flame till the vulcanite is hot enough to be uncom- 
 fortable to touch, then lay on it a series of strips of rubber 
 about one-qnarter inch wide, till the surface is covered. 
 Tt is better to have a surplus of rubber than not enough to 
 insure the forcing of the softened rubber into the grooves 
 when the test closure is made. Coat the cast and the 
 adjacent plaster of the reverse half of the flask with Silex, 
 allow to stand for a minute, then wash away the sur- 
 plus Silex under the water faucet. Place percaline be- 
 tween the sections of the flask and put them together in a 
 flask-press, exerting very slight sustained pressure so as 
 to follow the rubber as it flov^s. When further closing 
 with very light pressure is impossible, open the flask and 
 cut away the surplus rubber which has flowed over the 
 retaining wall, replace the percaline and close the flask 
 till resistance to pressure is felt. Boil the flask for fifteen 
 minutes or more and apply closing pressure to the press. 
 Much better results are obtained by using sufficient heat 
 and, opening the flasks three or four times, if necessary, 
 to remove surplus rubber than by attempting to force in- 
 sufficiently heated rubber to How. When the metal edges 
 of the flask sections come together, remove the percaline 
 and surplus rubber, place in a Donham clamp and vul- 
 canize, holding the temperature at 270° F. three-quarters 
 
 of an hour, then raise it to -'Jl'O F. and hold here for 
 tiftv-tivo minutes. 
 
 •: i ;■ 
 
Fitting the Dentures to the Mouth and 
 Perfecting the Articulation. 
 
 When the upper and lower dentures are in place in the 
 mouth, the occlusal surfaces of the teeth should permit of 
 easy, free lateral and protrusive movements of the man- 
 dible. A slight unavoidable shifting of the teeth occurs 
 in vulcanizing and this interferes with the occlusal sur- 
 faces of the two sets gliding as freely on one another in 
 the mouth as they did in the articulator. It has com- 
 monly been supposed that grinding in the articulator 
 would accomplish the change necessary to establish accu- 
 rate smooth working of the teeth in mastication. While 
 this is true to a degree it must be remembered that there 
 is always present in natural dentures a certain freedom or 
 latitude of movement which permits the teeth to slide 
 freely without engaging accurately in a definite restricted 
 way. 
 
 This latitude of movement is due to a very slight yield- 
 ing of the inter-articular tissues of the temporo mandib- 
 ular articulation and also to some extent to a yielding of 
 individual teeth in their sockets and to a variation in 
 muscular tension which cannot be duplicated in a metal 
 articulator. 
 
 It seems natural to suppose that the most rational place 
 to secure the final adjustment of the dentures to each 
 other would be in the mouth. Following this plan the lati- 
 tude of movement peculiar to the patient may be used to 
 produce a free movement in the articulation of the den- 
 tures, which will permit the patient to use the habit- 
 ual movements in masticating with comfort and efficiency. 
 
 While grinding the teeth in the mouth the dentures 
 are supported on their respective ridges and the patient 
 directed to work the jaw in lateral and protrusive move- 
 ments with a suitable abrasive between the occlusal sur- 
 faces of the teeth. 
 
 248 
 
Fig. mo. 
 
 Fitting the Dentures to the Mouth and 
 Perfecting the Articulation — Cont. 
 
 Before commencing to grind the teeth in the mouth, 
 correct visible errors in articulation by grinding, where 
 necessary, with a carborundum stone, observing the fol- 
 lowing points : 
 
 When the lower is protruded, so that the median line 
 above is directlv over the median line below and the in- 
 cisors hit end on, the dentures should be balanced on the 
 centrals in front; the upper cuspid should touch the lower 
 first bicuspid; the second upper bicuspids should resl on 
 the lower first molars or the mesial cusps of the upper 
 first molar should rest on the lower firsl molars to balance 
 and support the dentures in the rear. Other supports may 
 exist bul no heavy pressure should be permitted to come 
 on the lower second molar. The mesial cusp of the lower 
 cuspid should not touch the upper lateral in this or any 
 other relation of the dentures. 
 
 When it is necessary to shorten the lower incisors to 
 let the upper cuspids touch the lower firsl bicuspids, -rind 
 away the lingual surfaces and nol the labial. The tips of 
 
 249 
 

 Fitting the Dentures to the Mouth and 
 Perfecting the Articulation — Cont. 
 
 the cusps of other interfering teeth may also be ground 
 where necessary to establish proper supporting contacts 
 without decreasing danger of the efficiency of the dentures. 
 
 Try the dentures in right, and left lateral articulation 
 and correct the contacts of any teeth that prevent proper 
 relations of adjoining teeth in both the working and bal- 
 ancing bite for both sides of the denture. 
 
 When this has been accomplished mix one part of a 
 cocoa butter such as is sold for coating synthetic fillings, 
 with about four parts by volume of Copper Carbo powder. 
 The mixing can be best done on a glass slab with a hot 
 cement spatula. Dry the teeth of both dentures and smear 
 the lingual surfaces of the upper incisors and the occlusal 
 surfaces of the lower posteriors with the abrasive mix- 
 ture. Place the dentures on the ridges and hold them 
 there, while the patient moves the lower from right to 
 left, keeping it in the retrnded position. 
 
 At first it will be noted that the lateral movement tends 
 
 250 
 
Fig. 221. 
 
 Fitting the Dentures to the Mouth and 
 
 Perfecting the Articulation — Cont. 
 
 to cause the dentures to rotate: however, this tendency 
 decreases as the grinding progresses. 
 
 It is not sufficient to let the patient chew the abrasive. 
 The dentures must be firmly supported on their ridges 
 till all tendency to rotate disappears. 
 
 Follow the grinding from side to side with grinding 
 for the fronl to back movements of the jaw. 
 
 Allowing for occasional short rests for the patient if 
 aged, this operation should consume from twenty minutes 
 to one-half hour. It is of course impossible to use this 
 method effectively on plain line dentures or teeth that are 
 no1 anatomically correct in design — as the amount of 
 grinding necessary under these conditions will render im- 
 possible anything like fair results. 
 
 The grinding should be continued only until the den- 
 tures work smoothly. 
 
 Smooth off sharp edges on the incisal of the anteriors 
 with sandpaper disks, treal the cusp edges in the same 
 manner and the operation is complete. 
 
 .•••i 
 
Fig. 222. 
 
 Finis 
 
 The teclmic described in the foregoing pages produces 
 artificial dentures which are natural in appearance, com- 
 fortable in use, stable in all positions of the jaw and effi- 
 cient in mastication. 
 
 Such denture service, and only such denture service 
 when it can be rendered, discharges the obligations which 
 are placed upon us by our professional position, by the 
 dependence of edentulous patients upon our knowledge 
 and skill, by the economic worth of many edentulous per- 
 sons and by their right to life, health and the pursuit of 
 happiness. 
 
 For this reason we have called service of this quality 
 
 PROFESSIONAL DENTURE SERVICE. 
 
 250 
 
Index 
 
 PART 
 
 Impressions and Bn es 
 
 page 
 
 Attaching the Impression Compound ■"'! 
 
 Attaching the Lower Bite Rim 62 
 
 Attn. •hin- the Upper Bite Rim— Part I 44 
 
 Attaching the Upper Bite Kim Part II 45 
 
 Attaching the Upper Bite Rim- -Part III . 4C 
 
 Carrying the Bite Rimmed Lower Tray Into the Mouth 63 
 
 Carrying the Compound Flanges High 39, i" 
 
 Chilling the Compound Next to Tray 33 
 
 Chilling the Right-hand Marginal Flange 35 
 
 Classification of Tissue Conditions in Edentulous Mouths .... 16-19 
 
 Completing the Upper Bite Rim 54 
 
 Compound-Plaster Impressions 95 
 
 Correcting Errors in Rite Rim Depth — Part I '<- 
 
 Correcting Errors in Bite Rim Depth — Part II 53 
 
 Determining Length of Trav -I 
 
 Establishing the Plane of Occlusion — Part I 4s 
 
 Establishing the Piano of Occlusion — Part II 4!> 
 
 Equalizing Surface Temperature of Compound 36 
 
 Forming the Lower Bite Kim 61 
 
 Guide Rimming the Lower Tray .iT 
 
 Heater for Impression Compound 23 
 
 Heating the Upper Buccal Flange for Muscle Trimming T'.i 
 
 Heights of the Bite Rims 89-9] 
 
 Impression Marked for Relief 86 
 
 Inserting the Lower Tray 58 
 
 Inserting the Tray for the Lower Impression ii7 
 
 Introducing Compound for Upper Impression — Part I 31 
 
 Introducing Compound for Upper Impression — Pari II 38 
 
 Locating Compressible Palatal Tissues 20 
 
 Lower Trays 55 
 
 Merits of Compound Impressions 14 
 
 Muscle Trimming the Lower Lingual Flange — Part I 7 1 
 
 Muscle Trimming the Lower Lingual Flange— Pari II ~'< 
 
 Muscle Trimming i he Labial Flange of the Upper Impression 
 
 Part I 81 
 
 Muscle Trimming the Labial Flange of the Upper Impression 
 
 Part II *L> 
 
 Muscle Trimming die Upper Buccal Flanges 80 
 
 Outlining Areas for Compression and Relief 83 
 
 Perfecting Adaptation of the Upper Flange to the Ridge vv 
 
 Perfecting Hie l "i i of the Trav Part I 'J I 
 
 Perfecting the Lit of the Trav — Part II 25 
 
 Perfecting the Lit of the Tray — Tart III 26, 27 
 
 Placing tin' P.ite Rimmed Lower Tray....*. til 
 
 Plaster Upper Compound Lower 96 
 
 Preparing the Upper Tray for the Attachment of '!"■ Compound 28 
 Preparing the Upper Tray for the Attachmenl of the Lite Rim. 29 
 
 Relief Over the Course of the Palatine Artery 84 
 
 Restoring facial Expression— Part I 92 
 
 Restoring facial Expression— Pari II 93 
 
 Restoring Facial Expression— Part III :'i 
 
 Seating the Lower Tray 59, Co 
 
 Shaping the Compound for the Lower Impression 66 
 
 Shaping t he Compound in I he Tray 32 
 
 Shaping the Lower Tray 56 
 
INDEX— Continued. 
 Impressions and Bites — Continued 
 
 TAGE 
 
 Softening Palatal Surface of Compound 34 
 
 Stabilizing the Lower Impression 78 
 
 Teclmic for Heating Flange for Muscle Trimming 71 
 
 Test for Quantity 30 
 
 The Plane of Occlusion — Front View 50 
 
 The Plane of Occlusion — Side View 51 
 
 The Incomplete Lower Impression 69 
 
 The Relation of the Lower to the Ridge 77 
 
 Transferring Markings to Impression 85 . 
 
 Trimming the Buccal Flange 70 
 
 Trimming the Impression for Length 42, 43 
 
 Trimming the Lower Rite Itim. . ; 65 
 
 Trimming the Lower Buccal Flange 73 
 
 Trimming Lower Labial Flange — Cuspid to Cuspid 72 
 
 Trimming the Surplus from the Lower Impression 70 
 
 Trimming the Surplus from Upper Impression 41 
 
 Trimming the Upper Impression at the Frenum 87 
 
 Trimming Upper Impression Trays 22 
 
 Turning Up the Surplus Compound on Buccal and Labial Sur- 
 faces 68 
 
 What the Occlusal Plane Is 47 
 
 PART II 
 
 Selecting the Size, Form and Shade in Artuucial Teeth 
 
 Determining the Type of Face 113 
 
 Dimensions Trubyte Moulds — Uppers 114 
 
 Dimensions Trubyte Moulds — Lowers 115 
 
 Harmony of Form in Faces and Teeth 102-105 
 
 Locating the Distal Sides of the Cuspids 99. 
 
 Marking the Median Line 98 
 
 Measuring for Width of Upper Anteriors 101 
 
 Shading in Artificial Teeth 119 
 
 Suggestions for the Selection of Shades 121 
 
 Surface Texture and Tooth Shades 123 
 
 Table of Colors in the Twentieth Century Shade Guide 122 
 
 Trubyte Selection Rim 118 
 
 Trubyte Teeth— Mould Guide 110 
 
 Typal Forms in Natural Teeth • 112 
 
 Typal Ovoid Face 110 
 
 Tvpal Square Faces 100 
 
 Tvpal Tapering Faces 108 
 
 Use of a Mould Guide . , , , 117 
 
 PART III 
 
 Measuring Habitual Masticating Movements 
 
 Adapting Baseplate 175-177 
 
 Adjusting the Condyle Path Register and Removal 148 
 
 Adjusting the Horizontal Pencils 134 
 
 Adjusting the Vertical Pencils 143 
 
 Attaching the Horseshoe Plate to the Bite Rim 132 
 
 Attaching the Incisor Path Marker to the Impression 137 
 
 Blackening the Horseshoe Plate 138 
 
 Building the Lower Bite Rim Forward 180 
 
 Condyle Path Register and Accessories 127 
 
 254 
 
INDIA Continued. 
 Measuring M \ r. i i i \ i. Masticating Movements Continued 
 
 iw.i: 
 
 Correct and Incorrect Descending Inclination Record 130 
 
 Correct and Incorrect Incisor Path Records 140 
 
 Correcl and Incorrect Lateral Baths i it 
 
 Correcting Lack of Fit in the Impressions 149, 150 
 
 Determining the Depth of Relief 15:! 
 
 Drawing Base Lines Cor the Lateral Inclination Records Ill" 
 
 Equalizing Biting Strain on the Bite Kims i:::: 
 
 Holding- the Lateral Path Register- Bart l in 
 
 Holding the Lateral Bath Register Bart II 14." 
 
 Interferences thai Brevenl Correct Records 120 
 
 Locating the Heads of the Condyles 12!) 
 
 Locating the Horseshoe Blate 130 
 
 Locating the Rotation Poinis— pari i 171 
 
 Locating the. Rotation J'oinis Bail If 1 tu 
 
 Locking Hi'' Bites 152 
 
 Locking the Bite Kims fur Mounting 165 
 
 Making ('.-ists Bart I 159 
 
 Making Casts — Bart II ICO 
 
 Marking Lines on the Upper Cast IT.'! 
 
 Mixing (In' Material for Casts 158 
 
 Mounting Casts on the Adaptable Articulator 1G7-170 
 
 Preparing the Bite for Locking 153 
 
 Preparing the Impressions for Making Casts — Part I 155 
 
 Preparing the Impressions for Making Casts — Part II 1~><; 
 
 Protecting the Bite Kims ami Records During Casting 157 
 
 Recording the Lateral Inclination in; 
 
 Re-Forming the Lower Bite Rim 178 
 
 Re-Forming the Upper Bite Kim . , i s i 
 
 Registering the Descending Inclination of the Condyle Path.... 135 
 
 Relieving the Impression 1'54 
 
 Removing the Cower Impression from the Cast 174 
 
 Removing and Replacing the Upper Bart of tin' Adaptable and 
 
 Simplex Articulators 182 
 
 Reproducing the Descending Inclination of the Condyle Path — 
 
 Part I .' 161 
 
 Reproducing the Descending Inclination of the Condyle Bath — 
 
 Part II .' 162 
 
 Reproducing the Lateral Inclination of the Condvle Path — 
 
 Part I ' 163 
 
 Reproducing the Lateral Inclination of the Condyle Path — 
 
 Part II 164 
 
 Taking the Incisor Path Record 139 
 
 Trimming and Marking the Lower Bite Rim 1T0 
 
 Why It Is Worth While to Reproduce .law .Movements T_>.". 
 
 Withdrawing the Condyle Path Register 131 
 
 I" \UT IV 
 
 Arranging the Teeth 
 
 Arranging the Teeth 1S4 
 
 Arranging the Upper Anteriors 185-188 
 
 Arranging the Upper Posteriors 189-192 
 
 Arranging the Teeth- The Lower First Molar 196 199 
 
 Arranging the Teeth — The Bicuspids 200 202 
 
 Arranging the Teeth— The Cuspids 203-204 
 
 Arranging the Teeth — The Incising Bite 205-206 
 
 Arranging the Teeth — The Lower Second Molars 209, 210 
 
 llow to Move the Articulator Properly 195 
 
 Inspecting the Trial Dentures in the Mouth 207, 208 
 
 Working and Balancing Molai Contacts 194 
 
 355 
 
INDEX— Continued. 
 
 PART V 
 Simplex Akticulatok and Snow Face Bow 
 
 PAGE 
 
 Adjusting the Face Bow to the Face — Part I 215 
 
 Adjusting the Face Bow to the Face — Part II 21(5 
 
 Adjusting the Face Bow to the Face— Part III 21S 
 
 Attaching the Horseshoe Plate 214 
 
 Building Separate Bite Plates 212 
 
 Face Bow Technic for Large Cases 224 
 
 Mounting Casts on the Simplex Articulator with a Face Bow — 
 
 Part I 220 
 
 Mounting Casts on the Simplex Articulator with a Face Bow — 
 
 Part II 221 
 
 Mounting Casts on the Simplex Articulator without the Face 
 
 Bow 222, 223 
 
 Removing the Face Bow 210 
 
 Simplex Articulator and Accessories 212 
 
 Taking the Incisor Path Record , 217 
 
 PART VI 
 
 Flasking, Vulcanizing, Finishing and Perfecting the Fit 
 
 Fitting the Dentures to the Mouth and Perfecting the Articu- 
 lation 248-251 
 
 Flasking the Dentures — Part I 228 
 
 Flasking the Dentures — Part II 229 
 
 Finis 252 
 
 Packing and Testing — Part I 231 
 
 Packing and Testing — Part II 232 
 
 Packing and Testing — Part III 233 
 
 Polishing 237 
 
 Preparation of Channel for Waste Rubber '. 230 
 
 Preparing Dentures for Polishing — Part I 235 
 
 Preparing Dentures for Polishing — Part IT 236 
 
 Preparation of Trial Dentures for Flasking — Part I 220 
 
 Preparation of Trial Dentures for Flasking — Part II 227 
 
 Refitting the Lower Denture — Part I 239 
 
 Refitting the Lower Denture — Part II 241-243 
 
 Refitting the Lower Denture — Part III 244 
 
 Refitting the Lower Denture — Part IV 245 
 
 Refitting the Lower Denture — Part V 240 
 
 Refitting the Lower Denture — Part VI 247 
 
 Testing Occlusion for Rocking 238 
 
 Vulcanizing and Opening the Flasks , , 234 
 
 256 
 
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