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Through the eyes of the editor
THE JOURNAL OF
PROSTHETIC DENTISTRY MAY 1980 VOLUME
43
NUMBER 5
Through the eyes of the editor
There is a current wave of interest in the retention of submerged vital roots to enhance residual alveolar ridge maintenance. This method expands the scope of complete denture therapy but lacks good controlled longitudinal studies to support its efficacy. P. Delivanis, 0. Day, C. Esposito, and R. Bickley (p. 487) review clinical considerations for root-submergence procedures and identify important points for the dentist’s selection of roots to be saved. A report of a patient treatment clarifies further the authors’ objectives and the clinical protocol used. G. A. 2’. Herbert J. Mueller and Evan H. Greener (p. 491) describe the aqueous chemistry of four commercial denture cleansers. They report that the mechanism of hydrogen peroxide decomposition varies with each cleanser solution. For the oxygen forming cleansers, the oxygen concentration increased to maximum solubility in water even though the effervescing had ceased. The chloride ion varied the most in each of the four cleansers. Mueller and Greener do not indicate how their findings affect the efficacy of the cleansers, but they refer to previous work which has shown that whitening of resin and corrosion of base metal alloy components can occur. One manufacturer even instructs patients to soak the dentures overnight in the cleansing solution. This has a strong and rapid bleaching effect on denture base resins and resin teeth which can spoil the appearance of the dentures. Patients should be instructed as to the proper selection and use of materials for denture care.
S. H. P. As a dominant hereditary oral disease, dentinogenesis imperfecta may be anticipated. The abnormal color and translucent appearance of the teeth may be recognized shortly after eruption. Early diagnosis suggests complete crown therapy which prevents the rapid attrition of the teeth. If unattended, patients with dentinogenesis imperfecta wear their teeth to the level of the gingiva. William S. Licht and Edward E. Leveton (p. 497) discuss the merits of
THE JOURNAL OF PROSTHETIC~DENTISTRY
overdenture therapy for patients with advanced attrition and describe the treatment. The teeth are virtually prepared for overdentures by attrition, and endodontic therapy is generally unnecessary. Overdenture therapy for advanced pathologic attrition serves many purposes and is particularly indicated for young adults.
w. L. F. Mavroskoufis and G. M. Ritchie (p. 501) made a study of face-forms and tooth forms. The outline forms of maxillary central incisors were compared with the “actual” and “apparent” face-forms in 70 individuals. The results refuted the typal theory of Leon Williams.
S. H. P. The possible effect of diuretic drug intake on complete denture retention was investigated by Allen J. Green and Larry Harman (p. 506). A testing device that measured the force needed to displace the maxillary denture was used to obtain data during and after medication. Their results showed a significant decrease in denture retention during diuretic intake. The study emphasizes the necessity of obtaining a meaningful medical history before starting prosthodontic treatment so that this phenomenon can be detected and the patient forewarned.
L. B. Stephen Glazier, David N. Firtell, and Larry L. Harman (p. 508) made a study of dimensional change in the posterior palatal seal region when the prominence of the maxillary ridge was varied. They used a basic cast and increased the ridge prominence with wax until seven sets of casts were replicated, each set with ridges 1.5 mm greater in prominence than its predecessors. Acrylic resin teeth were arranged on half of the adapted baseplates, and porcelain teeth were arranged on the remainder. The bases were processed, separated from the casts, and washed in cold water. The authors do not state whether the bases were allowed to cool to room temperature before separating, since chilling too quickly might increase distortion.
483
THROUGH
The authors carefully ground and finely sanded the posterior palatal seal regions and then measured the dimensional changes. They found that the dimensional change increased with ridge prominence, although no significant changes were related to the kind of teeth used. Since shrinkage across the posterior palatal seal manifests itself in a linear direction by pulling in the flanges buccal to the tuberosities and lifting the acrylic resin away from the cast across the palate, it can be assumed that on a given cast there would be greater posterior seal distortion by altering the ridge height, thereby increasing the linear distance. S. H. P. Endodontically treated posterior teeth have many shortcomings which complicate their restoration. Despite a propensity for weakness, nonvital molars hold a key position toward desirable and conservative oral rehabilitation. Several methods for restoring these severely disadvantaged teeth have forestalled misfortune. Arun Nayyar, Richard E. Walton, and Leon A. Leonard (p. 511) propose a new, and by far the simplest,, method for restoring nonvital molars to an uncomplicated future. The technique has the advantage of reducing time and costs. It has been clinically tested over an adequate period and serves to permit a wide variety of uses for the restored teeth. The technique should become an important adjunct to conservative dentistry. w. L. Arthur C. Post, Bernard Balaban, Harvey A. Ackerson, and Richard D. Vaught (p. 516) review several methods for treating cross-bites. They then present a treatment using both surgical and restorative procedures which produces a predictable, acceptable result. The development of treatment modalities such as this gives insight to expand our treatment possibilities. S. E. G. Robert E. Garfield (p. 521) presents the rationale and technique for a convertible periodontal prosthesis which uses Ceka attachments in pulpless teeth for retention and stabilization. This versatile system seems well suited for patients having severe psychologic blocks against loosing all of their teeth, in situations where remaining teeth are essentially hopeless. S. E. G. Dentistry is not immune to the possibility that a paltry problem may require a major remedy. Migration of teeth, which reduces distances vital to conservative treatment, often requires a major correction. Reginald C. Day (p. 527) offers a convenient solution to one such situation caused by drifting teeth. It is a relatively simple method which
484
THE EYES OF THE EDITOR
provides somewhat less than perfect esthetics but possesses the virtues of conservation and economy. This is truly a technique to .be tucked away in one’s mind and drawn upon when needed. w. L. Most of the recent articles on dowel and core restorations relate to retention and stress analysis. While these physical properties may determine success or failure, another facet of rational technique concerns the effect of the dowel upon the dentin. This may have little meaning with cemented smooth-surface dowels. Threaded dowels fall into a different category but need not violate the integrity of the dentin. Osvaldo Zmener (p. 530) investigated the effects of three kinds of threaded dowels upon the walls of reamed canals. He reports the effects of conical and cylindrical threaded dawels which, during insertion, prepare corresponding threads in the dentin. The third dowel system used a tap to thread the wall of the canal. The dowel was then screwed into the threaded canal in soft cement. The results confirm some of the findings of a similar investigation of noncemented pins (J PROSTHET DENT 26:631, 1971) and contain directives on how to practice a noniatrogenic technique. This investigation, coupled with the information derived from previously published reports, should serve as a guide to the selection of a threaded dowel. w. L. Fotofil, a recently introduced composite resin, is unique; it is activated by visible light. This in itself would be of little interest except that the material has other virtues. M. A. Bassiouny and A. A. Grant (p. 536) report on a comparison between the physical properties of Fotofil and Adaptic in both short- and long-term studies. While the differences were not dramatic, there are some advantages and slight disadvantages to the light-cured resin. Perhaps the most important contribution of the light-activated composite resin is that, as a single-paste system, it eliminates possible air entrapment since it does not need mixing. w. L. While laboratory research should simulate clinical experience, exaggerated dosage is often employed to reduce the time factor. Kai Chiu Chan, James L. Fuller, and Abbas A. Hormati (p. 542) used this principle to determine whether certain foods were capable of staining composite resin restorations. They also evaluated the efficacy of toothbrushing to reduce the stain. Their findings contrast with those of a previous study (J PROSTHET DENT 28:164, 1972) which reported superficial discoloration of a composite resin after 2 years in the mouth. One must assume that the participants brushed their teeth regularly and that exposure to stain-causing foods was intermittent. Dr. Chan
MAY1980
VOLUME
43
NUMBER
5
THROUGH THE EYES OF THE EDITOR
and associates have demonstrated that certain foods can stain composite resins. Patients should know this and know how to minimize the discoloration.
w. L.
Mitsuo Kishimoto, Herbert T. Shillingburg, Jr., and Manville G. Duncanson, Jr. (p. 546) have compared syringes for the force required to express a given load and for the ease of handling as demonstrated by a drawing test. Some disposable syringes required 100 pounds of force to operate, compared to 13 to 21 pounds for -the metal reusable syringes. There was no difference among the syringes in the tendency to trap air bubbles. The airactivated syringe was most easily controlled.
D. E. B.
Stephen Pare1 (p. 552) presented several methods for retaining facial prostheses without the use of adhesives. Continued use of adhesives for retention reduces their effectiveness. Some patients have difficulty applying the adhesives. A certain percentage of patients develop allergic responses to adhesives. Poor hygiene reduces the effectiveness of adhesives. Whenever possible the prosthodontist should circumvent the use of adhesives for retaining facial prostheses. The methods for avoiding adhesives incorporate the use of anatomic projections or mechanical interlocks. Examples include nasal, auricular, and orbital prostheses.
L. J. B.
Joseph B. Barron and John W. Johnson (p. 561) describe a technique which provides a resilient transparent custom facial surgical dressing for maxillofacial patients experiencing facial resection. By employing a readily available vacuum machine and resilient transparent mouthguard material, a custom dressing can be fabricated simply and inexpensively. This is a valuable aid to the surgeon and a boon to the maxillofacial patient. The many advantages gained with the use of this custom facial dressing make it a valuable contribution to the treatment of maxillofacial patients.
I. K. A.
Oscar Beder and Philip Weinstein (p. 565) studied 102 adolescents to explore the difficulties they have had in coping with orofacial anomalies. The patients who were seen for congenital and acquired disorders were administered the Cornell Medical Index (CMI). Certain sections of the CM1 appeared to be useful for identifying psychologic problems. To the adolescent, personal appearance and the body image concept mean a great deal to effective psychosocial functioning. There is evidence that girls with facial deformities have more problems than boys. Teenagers with
THE JOURNAL
Of PROSTHETIC
DENTISTRY
congenital problems have more psychologic problems than those with acquired problems. No differences were found between children with severe and less severe facial deformities. Results indicate that facial deformities are the most tragic handicap a person can have from a psychologic and social aspect. The CM1 may prove useful in predicting coping strategies especially for patients with acquired deformities.
L. J, B. Franc0 Mongini (p. 568) reports on a study of 22 patients with temporomandibular joint (TMJ) paindysfunction syndrome to determine the influence of occlusal therapy on remodeling and reshaping of the mandibular condyle. Polytomography of the TM,J in four to six different planes in centric occlusion at 3 mm intervals were made for each patient with a device for centering the patient’s head, as well as an analysis of the patient’s occlusion, before and after treatment. Conclusions of the study were that reshaping of the condyle due to bone remodeling may occur after occlusal therapy. The new shape of the condyle tends to be rounded from its previous flattened shape. Degenerative changes in the condyle as a result of occlusal disarrangement can be treated by proper occlusal therapy. This study provides additional corroboration to the clinical concept of the interrelationship between occlusion and the TMJ and its influence on the morphology of the condyle.
I. K. A. Yasuyuki Kawazoe, Hiroo Kotani, Taizo Hamada, and Sanae Yamada (p. 578) studied 14 subjects. Seven subjects with myofascial pain-dysfunction (MPD) syndrome had predeflective occlusal contacts in the intercuspal position (centric occlusion). Seven healthy subjects had normal occlusions without clinical evidence of dysfunction of the stomatognathic system. Subjects were selected in order to observe the integrated electromyographic (EMG) activities of the masseter muscle during maximum voluntary isometric contraction with and without an occlusal splint in the mouth. The quantitative study was made to determine whether or not the elimination of occlusal interference by means of the occlusal splint would contribute to muscular relaxation. Recordings were made with the teeth of the subjects maximally clenched with the stabilization splint and maximum intercuspal clenching without a splint. EMG recordings were made three times for each clenching. The mean height of the integrated EMG potential of masseter muscles were evaluated. In patients with MPD syndrome, the integrated EMG potentials were significantly lower with the splint than without the splint. In healthy subjects there was no significant difference in the integrated EMG potentials with or without the splint. These results suggest that the elimination of occlusal interference by treatment with an occlusal splint could reduce the degree of sensory information from the periodontal recep-
485
THROUGH
tor. This could result in a decrease in masseter muscle activity. L. J. B. P. M. Sinclair, P. R. C. Turner, and R. B. Johns (p. 581) studied mercury levels in the hair and in fingernails and toenails in 61 dental students and faculty members. The sample was broken down into seven groups, and the level of mercury varied among the groups depending upon how much contact they had with amalgam. The particular analysis technique proved to be easily manageable and apphcable for large numbers. J. J. S. Serving the oral health needs of the public is the primary mission of the dental profession. In his presidential address to the American Prosthodontic Society, Dr. Harold R. Ortman (p. 586) discusses the topics of inflation, consumerism, the Federal Trade Commission, and den-
Journal
adopts new policy
THE EYES OF THE EDITOR
turism and tells how they affect prosthodontic services to patients. Dr. Ortman issues the challenge to the individual dentist to fulfill his role in proper patient treatment and to communicate with his various constituents concerning the most likely solution to the problems we face. J. C. H. Attention to detail in laboratory procedures greatly improves the final fit of gold restorations. Donald B. Beck (p. 590) describes a technique using a binoccular dissecting microscope for the accurate trimming of dies. D. H. G. Paul L. Saxton (p. 592) describes a technique for the soldering of nonprecious alloys. The energy dispersive x-ray of the fusion zone shows a high nickel and gold concentration which should verify that intermetallic fusion has taken place. D. H. G.
for illustrations
in color
The Editorial Council and publisher of THE JOURNAL OF PROSTHETIC DENTISTRY have agreed to publish articles that contain color illustrations at a reduced cost to authors. Authors will pay only $225 per color page, or part thereof, and can present from one to eight illustrations on each page. Two high-quality 35 mm color transparencies (an original and duplicate) must be submitted for each illustration, and manuscript length cannot exceed 10 to 12 double-spaced typewritten pages. The Editor and his reviewers have final authority to determine if color illustrations afford the most effective presentation. Articles containing color will appear in selected issues beginning in 1980. Authors are requested to include a statement when they submit their manuscript agreeing to pay $225 for each page of color. Billing will come from the publisher after the author has approved color proofs and the article is scheduled for publication. Manuscripts and illustrations will be accepted immediately for evaluation.
486
MAY
1980
VOLUME
43
NUMBER
5
PROSTHETIC DENTISTRY MAY 1980 VOLUME
43
NUMBER 5
Through the eyes of the editor
There is a current wave of interest in the retention of submerged vital roots to enhance residual alveolar ridge maintenance. This method expands the scope of complete denture therapy but lacks good controlled longitudinal studies to support its efficacy. P. Delivanis, 0. Day, C. Esposito, and R. Bickley (p. 487) review clinical considerations for root-submergence procedures and identify important points for the dentist’s selection of roots to be saved. A report of a patient treatment clarifies further the authors’ objectives and the clinical protocol used. G. A. 2’. Herbert J. Mueller and Evan H. Greener (p. 491) describe the aqueous chemistry of four commercial denture cleansers. They report that the mechanism of hydrogen peroxide decomposition varies with each cleanser solution. For the oxygen forming cleansers, the oxygen concentration increased to maximum solubility in water even though the effervescing had ceased. The chloride ion varied the most in each of the four cleansers. Mueller and Greener do not indicate how their findings affect the efficacy of the cleansers, but they refer to previous work which has shown that whitening of resin and corrosion of base metal alloy components can occur. One manufacturer even instructs patients to soak the dentures overnight in the cleansing solution. This has a strong and rapid bleaching effect on denture base resins and resin teeth which can spoil the appearance of the dentures. Patients should be instructed as to the proper selection and use of materials for denture care.
S. H. P. As a dominant hereditary oral disease, dentinogenesis imperfecta may be anticipated. The abnormal color and translucent appearance of the teeth may be recognized shortly after eruption. Early diagnosis suggests complete crown therapy which prevents the rapid attrition of the teeth. If unattended, patients with dentinogenesis imperfecta wear their teeth to the level of the gingiva. William S. Licht and Edward E. Leveton (p. 497) discuss the merits of
THE JOURNAL OF PROSTHETIC~DENTISTRY
overdenture therapy for patients with advanced attrition and describe the treatment. The teeth are virtually prepared for overdentures by attrition, and endodontic therapy is generally unnecessary. Overdenture therapy for advanced pathologic attrition serves many purposes and is particularly indicated for young adults.
w. L. F. Mavroskoufis and G. M. Ritchie (p. 501) made a study of face-forms and tooth forms. The outline forms of maxillary central incisors were compared with the “actual” and “apparent” face-forms in 70 individuals. The results refuted the typal theory of Leon Williams.
S. H. P. The possible effect of diuretic drug intake on complete denture retention was investigated by Allen J. Green and Larry Harman (p. 506). A testing device that measured the force needed to displace the maxillary denture was used to obtain data during and after medication. Their results showed a significant decrease in denture retention during diuretic intake. The study emphasizes the necessity of obtaining a meaningful medical history before starting prosthodontic treatment so that this phenomenon can be detected and the patient forewarned.
L. B. Stephen Glazier, David N. Firtell, and Larry L. Harman (p. 508) made a study of dimensional change in the posterior palatal seal region when the prominence of the maxillary ridge was varied. They used a basic cast and increased the ridge prominence with wax until seven sets of casts were replicated, each set with ridges 1.5 mm greater in prominence than its predecessors. Acrylic resin teeth were arranged on half of the adapted baseplates, and porcelain teeth were arranged on the remainder. The bases were processed, separated from the casts, and washed in cold water. The authors do not state whether the bases were allowed to cool to room temperature before separating, since chilling too quickly might increase distortion.
483
THROUGH
The authors carefully ground and finely sanded the posterior palatal seal regions and then measured the dimensional changes. They found that the dimensional change increased with ridge prominence, although no significant changes were related to the kind of teeth used. Since shrinkage across the posterior palatal seal manifests itself in a linear direction by pulling in the flanges buccal to the tuberosities and lifting the acrylic resin away from the cast across the palate, it can be assumed that on a given cast there would be greater posterior seal distortion by altering the ridge height, thereby increasing the linear distance. S. H. P. Endodontically treated posterior teeth have many shortcomings which complicate their restoration. Despite a propensity for weakness, nonvital molars hold a key position toward desirable and conservative oral rehabilitation. Several methods for restoring these severely disadvantaged teeth have forestalled misfortune. Arun Nayyar, Richard E. Walton, and Leon A. Leonard (p. 511) propose a new, and by far the simplest,, method for restoring nonvital molars to an uncomplicated future. The technique has the advantage of reducing time and costs. It has been clinically tested over an adequate period and serves to permit a wide variety of uses for the restored teeth. The technique should become an important adjunct to conservative dentistry. w. L. Arthur C. Post, Bernard Balaban, Harvey A. Ackerson, and Richard D. Vaught (p. 516) review several methods for treating cross-bites. They then present a treatment using both surgical and restorative procedures which produces a predictable, acceptable result. The development of treatment modalities such as this gives insight to expand our treatment possibilities. S. E. G. Robert E. Garfield (p. 521) presents the rationale and technique for a convertible periodontal prosthesis which uses Ceka attachments in pulpless teeth for retention and stabilization. This versatile system seems well suited for patients having severe psychologic blocks against loosing all of their teeth, in situations where remaining teeth are essentially hopeless. S. E. G. Dentistry is not immune to the possibility that a paltry problem may require a major remedy. Migration of teeth, which reduces distances vital to conservative treatment, often requires a major correction. Reginald C. Day (p. 527) offers a convenient solution to one such situation caused by drifting teeth. It is a relatively simple method which
484
THE EYES OF THE EDITOR
provides somewhat less than perfect esthetics but possesses the virtues of conservation and economy. This is truly a technique to .be tucked away in one’s mind and drawn upon when needed. w. L. Most of the recent articles on dowel and core restorations relate to retention and stress analysis. While these physical properties may determine success or failure, another facet of rational technique concerns the effect of the dowel upon the dentin. This may have little meaning with cemented smooth-surface dowels. Threaded dowels fall into a different category but need not violate the integrity of the dentin. Osvaldo Zmener (p. 530) investigated the effects of three kinds of threaded dowels upon the walls of reamed canals. He reports the effects of conical and cylindrical threaded dawels which, during insertion, prepare corresponding threads in the dentin. The third dowel system used a tap to thread the wall of the canal. The dowel was then screwed into the threaded canal in soft cement. The results confirm some of the findings of a similar investigation of noncemented pins (J PROSTHET DENT 26:631, 1971) and contain directives on how to practice a noniatrogenic technique. This investigation, coupled with the information derived from previously published reports, should serve as a guide to the selection of a threaded dowel. w. L. Fotofil, a recently introduced composite resin, is unique; it is activated by visible light. This in itself would be of little interest except that the material has other virtues. M. A. Bassiouny and A. A. Grant (p. 536) report on a comparison between the physical properties of Fotofil and Adaptic in both short- and long-term studies. While the differences were not dramatic, there are some advantages and slight disadvantages to the light-cured resin. Perhaps the most important contribution of the light-activated composite resin is that, as a single-paste system, it eliminates possible air entrapment since it does not need mixing. w. L. While laboratory research should simulate clinical experience, exaggerated dosage is often employed to reduce the time factor. Kai Chiu Chan, James L. Fuller, and Abbas A. Hormati (p. 542) used this principle to determine whether certain foods were capable of staining composite resin restorations. They also evaluated the efficacy of toothbrushing to reduce the stain. Their findings contrast with those of a previous study (J PROSTHET DENT 28:164, 1972) which reported superficial discoloration of a composite resin after 2 years in the mouth. One must assume that the participants brushed their teeth regularly and that exposure to stain-causing foods was intermittent. Dr. Chan
MAY1980
VOLUME
43
NUMBER
5
THROUGH THE EYES OF THE EDITOR
and associates have demonstrated that certain foods can stain composite resins. Patients should know this and know how to minimize the discoloration.
w. L.
Mitsuo Kishimoto, Herbert T. Shillingburg, Jr., and Manville G. Duncanson, Jr. (p. 546) have compared syringes for the force required to express a given load and for the ease of handling as demonstrated by a drawing test. Some disposable syringes required 100 pounds of force to operate, compared to 13 to 21 pounds for -the metal reusable syringes. There was no difference among the syringes in the tendency to trap air bubbles. The airactivated syringe was most easily controlled.
D. E. B.
Stephen Pare1 (p. 552) presented several methods for retaining facial prostheses without the use of adhesives. Continued use of adhesives for retention reduces their effectiveness. Some patients have difficulty applying the adhesives. A certain percentage of patients develop allergic responses to adhesives. Poor hygiene reduces the effectiveness of adhesives. Whenever possible the prosthodontist should circumvent the use of adhesives for retaining facial prostheses. The methods for avoiding adhesives incorporate the use of anatomic projections or mechanical interlocks. Examples include nasal, auricular, and orbital prostheses.
L. J. B.
Joseph B. Barron and John W. Johnson (p. 561) describe a technique which provides a resilient transparent custom facial surgical dressing for maxillofacial patients experiencing facial resection. By employing a readily available vacuum machine and resilient transparent mouthguard material, a custom dressing can be fabricated simply and inexpensively. This is a valuable aid to the surgeon and a boon to the maxillofacial patient. The many advantages gained with the use of this custom facial dressing make it a valuable contribution to the treatment of maxillofacial patients.
I. K. A.
Oscar Beder and Philip Weinstein (p. 565) studied 102 adolescents to explore the difficulties they have had in coping with orofacial anomalies. The patients who were seen for congenital and acquired disorders were administered the Cornell Medical Index (CMI). Certain sections of the CM1 appeared to be useful for identifying psychologic problems. To the adolescent, personal appearance and the body image concept mean a great deal to effective psychosocial functioning. There is evidence that girls with facial deformities have more problems than boys. Teenagers with
THE JOURNAL
Of PROSTHETIC
DENTISTRY
congenital problems have more psychologic problems than those with acquired problems. No differences were found between children with severe and less severe facial deformities. Results indicate that facial deformities are the most tragic handicap a person can have from a psychologic and social aspect. The CM1 may prove useful in predicting coping strategies especially for patients with acquired deformities.
L. J, B. Franc0 Mongini (p. 568) reports on a study of 22 patients with temporomandibular joint (TMJ) paindysfunction syndrome to determine the influence of occlusal therapy on remodeling and reshaping of the mandibular condyle. Polytomography of the TM,J in four to six different planes in centric occlusion at 3 mm intervals were made for each patient with a device for centering the patient’s head, as well as an analysis of the patient’s occlusion, before and after treatment. Conclusions of the study were that reshaping of the condyle due to bone remodeling may occur after occlusal therapy. The new shape of the condyle tends to be rounded from its previous flattened shape. Degenerative changes in the condyle as a result of occlusal disarrangement can be treated by proper occlusal therapy. This study provides additional corroboration to the clinical concept of the interrelationship between occlusion and the TMJ and its influence on the morphology of the condyle.
I. K. A. Yasuyuki Kawazoe, Hiroo Kotani, Taizo Hamada, and Sanae Yamada (p. 578) studied 14 subjects. Seven subjects with myofascial pain-dysfunction (MPD) syndrome had predeflective occlusal contacts in the intercuspal position (centric occlusion). Seven healthy subjects had normal occlusions without clinical evidence of dysfunction of the stomatognathic system. Subjects were selected in order to observe the integrated electromyographic (EMG) activities of the masseter muscle during maximum voluntary isometric contraction with and without an occlusal splint in the mouth. The quantitative study was made to determine whether or not the elimination of occlusal interference by means of the occlusal splint would contribute to muscular relaxation. Recordings were made with the teeth of the subjects maximally clenched with the stabilization splint and maximum intercuspal clenching without a splint. EMG recordings were made three times for each clenching. The mean height of the integrated EMG potential of masseter muscles were evaluated. In patients with MPD syndrome, the integrated EMG potentials were significantly lower with the splint than without the splint. In healthy subjects there was no significant difference in the integrated EMG potentials with or without the splint. These results suggest that the elimination of occlusal interference by treatment with an occlusal splint could reduce the degree of sensory information from the periodontal recep-
485
THROUGH
tor. This could result in a decrease in masseter muscle activity. L. J. B. P. M. Sinclair, P. R. C. Turner, and R. B. Johns (p. 581) studied mercury levels in the hair and in fingernails and toenails in 61 dental students and faculty members. The sample was broken down into seven groups, and the level of mercury varied among the groups depending upon how much contact they had with amalgam. The particular analysis technique proved to be easily manageable and apphcable for large numbers. J. J. S. Serving the oral health needs of the public is the primary mission of the dental profession. In his presidential address to the American Prosthodontic Society, Dr. Harold R. Ortman (p. 586) discusses the topics of inflation, consumerism, the Federal Trade Commission, and den-
Journal
adopts new policy
THE EYES OF THE EDITOR
turism and tells how they affect prosthodontic services to patients. Dr. Ortman issues the challenge to the individual dentist to fulfill his role in proper patient treatment and to communicate with his various constituents concerning the most likely solution to the problems we face. J. C. H. Attention to detail in laboratory procedures greatly improves the final fit of gold restorations. Donald B. Beck (p. 590) describes a technique using a binoccular dissecting microscope for the accurate trimming of dies. D. H. G. Paul L. Saxton (p. 592) describes a technique for the soldering of nonprecious alloys. The energy dispersive x-ray of the fusion zone shows a high nickel and gold concentration which should verify that intermetallic fusion has taken place. D. H. G.
for illustrations
in color
The Editorial Council and publisher of THE JOURNAL OF PROSTHETIC DENTISTRY have agreed to publish articles that contain color illustrations at a reduced cost to authors. Authors will pay only $225 per color page, or part thereof, and can present from one to eight illustrations on each page. Two high-quality 35 mm color transparencies (an original and duplicate) must be submitted for each illustration, and manuscript length cannot exceed 10 to 12 double-spaced typewritten pages. The Editor and his reviewers have final authority to determine if color illustrations afford the most effective presentation. Articles containing color will appear in selected issues beginning in 1980. Authors are requested to include a statement when they submit their manuscript agreeing to pay $225 for each page of color. Billing will come from the publisher after the author has approved color proofs and the article is scheduled for publication. Manuscripts and illustrations will be accepted immediately for evaluation.
486
MAY
1980
VOLUME
43
NUMBER
5