Use of protrusive splint therapy in anterior disk displacement of the temporomandibular joint: A 1- to 3-year follow-up

MOHL

Contributing

ET AL

authors

Heidi C. Crow, D.M.D., Postdoctoral Fellow, Department of Oral Medicine, State University of New York at Buffalo, School of Dental Medicine, Buffalo, N.Y. Richard K. Ohrbach, D.D.S., M.S., Clinical Assistant Professor, Department of Oral Medicine, State University of New York at Buffalo, School of Dental Medicine, Buffalo, N.Y.

Octavia Plesh, D.M.D., M.S., Assistant Professor, Department of Restorative Dentistry, University of California at San Francisco, School of Dentistry, San Francisco, Calif. Alan J. Gross, D.D.S., M.S., Clinical Associate Professor, Department of Oral Medicine and Fixed Prosthodontics, State University of New York at Buffalo, School of Dental Medicine, Buffalo, N.Y.

Use of protrusive splint therapy in anterior disk displacement of the temporomandibular joint: A l- to 3-year follow-up Ross H. Tallents, D.D.S.,* Richard W. Katzberg, Donald J. Macher, D.M.D.,*** and Christopher

M.D.,** A. Roberts,

D.D.S.****

Eastman Dental Center, Rochester, N.Y. Sixty-eight patients, who were determined clinically (by the presence of audible and palpable joint sounds) and arthrographically to have meniscus displacement with reduction, had protrusive splits constructed, and the results were evaluated for a minimum of 1 year to a maximum of 3 years. Eighteen additional patients, arthrographically determined to have meniscus displacement with reduction, served as a nontreatment group for comparison. Odds ratios were calculated to compare the proportions of subjects who experienced follow-up symptoms on the two regimens. Results indicated that with splint therapy there was a statistically significant reduction of the intensity of jaw joint pain, temporal headache, ear pain, and pain in front of the ear, and there was a decrease in the probability of a closed lock condition developing. Splint therapy is less likely to reduce frontal headache, neck pain,and clenching ofteeth. (J PROSTAET DENT 1990;63:336-41.)

c*

licking sounds in the temporomandibular joint (TMJ) have been demonstrated following the passageof the posterior band of the meniscusover the condyle in jaw opening-l?2 Such clicking hasbeen observedin 7% to 44% of the population. 3-6However, long-term studiesthat evaluate treatment need or outcome in these presumedproblemsare limited.7-11 A method hasbeendescribedfor attempting to evaluate the effectivenessof protrusive splint therapy (PST) by using the arthrogram to determine optimal protrusion and exclude patients with “clicking” when a reducing meniscus was not present.12-l4 This investigation describesthe clinical outcome in pa-

*Senior Clinical Associate, Department of Prosthodontics; Clinical and Research Associate, Department of Orthodontics. **Associate Professor, Diagnostic Radiology, University of Rochester; Clinical and Research Associate, Department of Orthodontics. ***Attending St&, St. Mary’s Hospiti, private practice, Rochester, N.Y. ****Orthodontics Resident. 10/l/17914

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tients who were treated with protrusive splints compared with a similar group who did not receive splint treatment.

METHODS

AND

MATERIAL

Sixty-eight patients, who were determined clinically by the presenceof audible and palpable joint soundsand arthrographically to have meniscusdisplacement with reduction, had protrusive splints constructed as described previously.14 Eighteen additional patients, also arthrographically determined to have meniscus displacement with reduction, served as a nontreatment group for comparison. These patients had elected not to have splint treatment after the risks, benefits, and alternatives had been discussed.Subjective (location of pain, clicking, and headache)and objective (rangeof movement, deviations on opening) signsand symptomswere tabulated at the initial examination and at subsequentfollow-up examinations after treatment. The treatment group wore protrusive splints for 6 months. All of the treatment patients, with the exception of two, required orthodontics or a metal overlay removable partial denture to close the posterior open occlusion.The follow-up examinations were performed at 1 year (15 patients), 2 years (39 patients), and 3 years (14

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I. Distribution of clicking patients Women Group

NO.

Treatmentpatients Unilateral 49 Bilateral 11 Nontreatmentpatients Unilateral 16

Table

II. Timing of opening click and mean protrusion Protrusion

Men %

No.

%

Affected

Total Opening click

89

6

11

55

85

2

15

13

89

2

11

18

No. of patients

Early Mid Late P > 0.05 (early

patients). The patients did not have posttreatment arthrograms. Pain in the jaws wasrated by the patient on a scaleof 0 to 10, with 0 representing no pain and 10 representing intensepain. The frequency of pain wasscoredas“occasionally, ” “sometimes,” or “constantly” in the ears,in front of the ears, or associatedwith headaches.The duration of prior symptoms in the treatment group ranged from 2 weeksto 5 years and in the nontreatment group 1 week to 7 years. Symptoms in the treatment group were of higher intensity than in the nontreatment group. The patients rated their subjective awarenessof clenching of the teeth during sleepor during tension before and after treatment as “better,” “the same,” or “worse.” The timing of the openingclicking soundswasgraded as “early, ” “mid,” or “late” in the opening jaw movement. This event wasobservedfluoroscopically. Clicks were classified as “early” when they occurred in the first few millimetersof condyle translation, “mid” when the condyle was midway on the posterior slope of the articular eminence, and “late” when occurring at or beyond the articular eminence. The linear measurementof the timing of the closing event was performed on a Hanau articulator (Hanau Engineering Co. Inc., Buffalo, N.Y.) as described previously.12 For each symptom, two crosstabulations of subjectsaccording to study regimen and poststudy symptom score (present or not present) were prepared-one for subjects who had experienced the symptom before the study and onefor subjectswho had not experiencedthe symptom before the study. Consideration of these symptoms enabled us to study two phenomena, (1) the effect that the active treatment may have had on the elimination of the symptom, and (2) the relative frequencies of poststudy occurrence of the symptom amongsubjectson the two regimenswho had not experienced the symptom before. These tables were summarized by using the calculation of odds ratios, which are numeric quantities enablingusto estimatethe proportions of subjects who experienced poststudy symptoms on the two regimens. In addition to providing a useful means of testing whether differences in outcome exist between the two

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Table

III.

side

E

SD

39

2.55

27

2.93

2

3.17

Bilateral Vertical greatest

side

TI

SD

0.68

1.62

0.80

0.88

1.99

0.83

0.71

2.63

0.42

to mid).

Mean vertical opening

Before treatment

Early Mid Late

mm)

Unaffected

Opening

Opening click

(in

No. of patients

(mm)

After treatment

Change

fl

SD

%

SD

%

SD

25

42.33

0.95

40.05

0.70

-2.28

0.88

33

41.95

1.85

40.07

0.87

-1.78

1.86

2

44.00

4.50

39.50

3.50

-6.00

1.00

patients are categorized overlap has been added. decreases in opening).

by joint with latest opening reduction. P < O.ooO2 (greatest initial values showed

treatment regimens,the calculationsallow usto expressthe magnitude of such differences. In the present context, an oddsratio lessthan 1 would indicate that subjectsreceiving PST are lesslikely to experience a symptom than are subjects in the control group; conversely, an odds ratio greater than 1 would indicate that subjectsreceiving PST are more likely to experience a symptom than are those in the control group. A repeated-measuresanalysis15using the Grizzle et a1.16 weighted least squaresmethod was performed by using thesetables. This analysisenabled us to comparethe distribution of baselinesymptom experience for subjects in the two groups. When no significant difference between regimenswith respectto baselinesymptom experiencewas indicated, this analysis also provided a comparison between regimenswith respect to the distribution of poststudy symptom experience and wasalso used to compare the effects of the two treatment regimeson symptom status experienced during the study. The pain intensity data were analyzed by calculating for each subject the difference between pain intensity scores before and after the study, and the Wilcoxon test wasused to comparethe relief scoresacrossthe two treatment regimens. Analysis of variance was used for analysis of the vertical opening data. All of the calculations were performed by using SAS software (SAS Institute, Cary, N.C.); the cross-tabulations and oddsratios were prepared by using PROC FREQ; the

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TALLENTS

Table IV. Frequency of experience of posttreatment treatment, with associated odds ratios*

symptoms, by type of symptom, pretreatment Pretreatment

Type

of symptom

Treatment

of teeth

Clenching

PST Control PST Control PST Control PST Control PST Control PST Control PST Control PST Control

Frontal headache Jaw sounds Neck pain and headache Pain in ear Pain in front of ear Temporal

headache

Jaw locking

Symptoms

% With

% With post-trt symptoms

11

23 9 35 10 1 3 45 9 26 12 5 I 22 11 33 0

52.2 0.0 22.9 20.0 0.0 66.7 11.1 0.0 23.1 16.7 40.0 28.6 9.1 27.3 3.0 0.0

Odds

ratio

10.42 1.14 0.40 2.39 1.39 1.40 0.33 --t

status, and

status

Asymptomatic

post-trt symptoms

ET AL

n

45 9 33 8 67 15 23 7 42 6 63 11 46 I 35 18

present

Odds ratio

64.4 77.8 42.4 62.5 40.3 93.3 43.5 71.4 30.1 66.1 55.6 81.8 52.2 85.7 20.0 100.0

0.83 0.68 0.43-f 0.61 0.467 0.687 0.61t O.Olf

*For tables containing a saro, 0.5 was added to everycell for odds ratio calculations. tOdda ratio significantly less than 1 (p < 0.05). tNo odds ratio could be calculated because there were no control subjects.

categorical modeling and testing wasperformed by using PROCCATMOD.PROCNPARlWAYwasusedfortheWilcoxon tests, and PROC GLM wasused for the analysisof variance.A level of significanceof p 0.05 was usedin all tests.

RESULTS Sixty-eight treatment patients and 18nontreatment patients were followed up for a minimum of 1 year to a maximum of 3 years. A total of 13 bilateral and 55 unilateral arthrograms were included in the treatment group (Table I). All nontreatment patients had unilateral studies(Table I). The sex distribution in the treatment group was 7.5:1 (women to men) and in the nontreatment group was 8~1. The mean age in the treatment group was 30.4 years (SD 10.4) and in the nontreatment group was 33.9 years (SD 13.6). In Table II the timing of the opening clicking soundwas classifiedas early in 39, mid in 27, and late in two. The timing

of the reciprocal

phase of the closing click is also

shownin Table II. For the early opening clicks the average amount

of protrusion

required

to produce

optimal

menis-

cal position on the affected side was2.55 mm; for the mid opening clicks it was 2.93 mm; and for the late opening clicks it was 3.17 mm. The average amount of protrusion required on the affected side was not statistically significant in the comparisonof the early and mid opening clicks. The amount of protrusion on the unaffected side for the early opening clicks was 1.62 mm, for the mid opening

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clicks 1.99mm, and for the late opening clicks 2.63mm. In the nontreatment group there were six early, eight mid, and four late opening clicking sounds.The closing phase wasnot measured. Table III presentsdata on the meanvertical openingbefore and after treatment. Analysis of variance revealsthat the patients with the largest initial amounts of opening demonstrated the greatest decreasesin opening after treatment (p < 0.0002).There were no changesin the nontreatment group. Twenty-seven of 68 treatment patients perceived joint noise after treatment and 16 of 18 in the nontreatment group perceived joint noise at follow-up. Clinical evaluation of treatment patients failed to reveal clicking (meniscus displacementwith reduction) sounds,but crepitation was detected in four patients. In the nontreatment group, 14 still had soundssuggestiveof meniscusdisplacement with reduction, but four had no clicking sounds,suggesting progressionto a nonreducing meniscus,although there was normal range of motion. Table IV presents a summary of the crosstabulations and analysesof symptom data. For subjects who were symptomatic before the study, we noted odds ratios less than 1 for all parameters. Four parameters (jaw sounds, pain in the ear, pain in front of the ear, and temporal headache)

had odds ratios significantly

less than 1, indi-

cating that the chances that a symptomatic (prestudy) subject will still present with symptoms at follow-up are

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Table V. Summary statistics for initial pain scoresand pain relief scores Initial Treatment

regimen

PST Controi

Sample 69

14

size

Mean

3.30 2.71

lessfor those receiving PST than for nontreatment subjects. Although a higher number of PST subjectshad prestudy symptomsof ear pain, pain in front of ear, and temporal headache,the proportion of subjectswho had these symtoms at follow-up did not differ between the two regimens,suggestingthat a greater degreeof improvement was attained by subjects who received the PST therapy. Patients with a history of jaw locking were lesslikely to have jaw locking at follow-up than nontreatment subjects,and patient with no history of jaw locking did not have an increasedincidence at follow-up. Table V summarizesthe prestudy pain scoresand the pain relief scoresfor subjectsin the two treatment regimen groups.The meanpain scorefor subjectsin the PST group washigher than that for the nontreatment group. However, the difference between the two regimenswith respect to pain relief scoreswasmuch more dramatic and wasfound to be statistically significant by the Wilcoxon test. Twelve (17.7%) of the 68 patients with splint therapy subsequently required surgery to correct meniscalabnormality. Six had progressedto meniscusdisplacementwithout reduction (closedlock), four began to have recurrent clicking, and two had inadequate reduction of pain. The surgery wasperformed within the first 6 months of splint treatment.

DISCUSSION This study wasnot designedto comparetreatment. We cannot considerthe treatment samplesto be representative of al1individuals who may be assignedto PST or control. The results of this study may be biased by the manner in which the subjectswere assignedto the treatment group. The variety of patients’ pain and complaint make it difhcult to separaterelated and unrelated clinical findings. For example, patients with pain in the ears, pain in front of the ear, and headachesmay not have all of these symptoms relieved by splint treatment and up to 50% of the relief may be attributed to placeboeffectsl’ This investigation, however, describes some interesting trends after treatment that cannot necessarilybeexclusiveiy attributed to the treatment per se. Splint therapy for the clicking joint in this investigation resulted in statistically significant reduction in the intensity of jaw-joint sounds,temporal headache,ear pain, and pain in front of the ear, and it decreasedthe probability of a closedIO& condition developing. It waslesslikely to redue frontal headache,neck pain, and clenching of teeth,

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pain SD

scores

Pain relief Median

1.06 1.27

3 3

Mean

2.55 0.43

SD

1.19 1.70

scores Median

3 0

Protrusive splint therapy may require denta restorative care and even surgical management(17.7%). It may not be possible,therefore, to treat clicking by providing an optimal anatomic position of the meniscus through protrusive splint therapy. It has also been suggestedthat even when the optimal anatomic position of the meniscusis established,treatment may still fail to maintain this relationship.18 A major goal in protrusive splint treatment is the elimination of joint sounds by recapturing the meniscus. Twenty-seven of the 68 patients (39.7% ) in the treatment group said they were still aware of joint sounds,yet there was no longer an indication of a displaced and reducing meniscuson clinical examination. This suggeststhe possibility of associateddegenerative changesin bone or soft tissueeven though these patients appeared to be making progressas determined by our other clinical criteria. Successfultherapy should result in a smallerproportion of symptomatic subjects at follow-up, both among those who weresymptomatic and amongthose who were asymptomatic. For asymptomatic prestudy subjectsthe oddsratios of regimenversuspoststudy pain status wereall greater than 1, with the exception of temporal headache,indicating that this value could not be ruled out as a true value. This indicates that symptoms in asymptomatic subjects would be equally likely to develop with or without protrusivesplint therapy. Thus protrusive splint therapy doesnot present an added risk of symptomsdevelop~g in patients who are presently asymptomatic. For subjectswho were symptomatic before the study, we noted that the oddsratios for all of the parameterswere less than 1. For jaw sounds,ear pain, pain in front of the ear, and temporal headachesthe associated95% confidence interval doesnot contain a 1, indicating that the odds that a symptomatic patient will still have symptoms at followup are lessfor those receiving protrusive splint treatment. Overall pain intensity decreasedsignificantly. Nmetythree percent of patients had significant pain reduction. Therefore, this short-term investigation supports the contention that protrusive splints are effective treatment for the painful clicking jaw. Lundh et al.” found that removal of the protrusive splint resulted in the return of clicking and pain on chewing. The idea that clicking may lead to in~~ittent locking and finally to complete locking asa progressiveof the disease process has been suggested.8Closed locking was present in 35 patients before treatment. Sevenpatients still

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ET AL

Fig. 1. (A) Teeth at centric occlusal position (note midline), (B) Mandible has been protruded to reduce clicking sounds (note midline). (C and D) Right and left lateral views demonstrate posterior open bite created as result of pro~ueion of mandible.

Fig. 2. Degree of posterior open bite is determined by overlap of anterior teeth. A, Less vertical overlap than B prior to protrusion. B has greater posterior open bite. had occasional episodes of closed lock, usually in the form of stiffness or tightness in the morning. This finding may suggest that the patients are still susceptible to progression to a closed lock if they have intermittent locking as a pre340

treatment condition.18 Lundh et al.“i stated that two of 24 patients (9%) had recurrent clicking even with full-time splint wear, and one (4 % ) progressed to meniscus displacement without reduction (closed lock). Headache can often lead to emotional stress and vice versa. A comparison of treatment versus nontreatment patients for the presence of frontal headache and neck ache demonstrated that not all headaches were elirn~~~d by treatment (Table IV), ~though relief of temporal headache improved. These findings create a dilemma from the standpoint of patient management. Lous and Olesen13 suggested that some patients with mandibular dysfunction probably suffer from migraine or from combinations of headaches. Patient expectations as to the pains that will be resolved with splint treatment should be discussed at the time therapy is considered. This investigation suggests that specifically frontal headache and neck pains are less likely to disappear or diminish with splint therapy directed at recapturing a displaced meniscus. Treatment with protrusive splints usually creates a posterior open bite (Fig. 1). Table II shows the later the opening clicking sound occurs, the greater is the trend for mandibular protrusion to obtain acceptable meniscal position. The greater the vertical overlap of the anterior teeth, the more accentuated will be the posterior open bite (Fig. 2). Our past clinical impressions have shown that s~ptoms return when there is an attempt to return the mandible to its original centric occlusal position. This demonstrates the necessity for dental restorative care, such as orthodontics and prosthodontics, if patients are to remain free of pain. Lundh et all’ reported that when an anterior repositioning splint was inserted, reciprocal clicking was eliminated in all patients. After 17 weeks (11 weeks after removal of the splint), 16 of 24 patients experienced reciprocal clicking. Pain had also increased during chewing after splint reMARCH

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and Howard20 have shown poor clinical

success at 3 years (36%) with repositioning treatment

where the splint wasremoved after 3 to 4 months of splint therapy. Roberts et al.21 found that patients with meniscus displacementwith reduction had greater vertical opening than patients with normal meniscaf position or patients with meniscusdisplacement without reduction. Patients with early, mid, or late opening clicks tended to have decreasedclicking during protrusive splint therapy. This observation may be suggestiveof a healing process,that is, tightening of stretched capsular ligaments. Clenching of the teeth was not improved in eornp~~so~ with the nontreatment group. Kydd and Colin22demonstrated in EMG studiesthat clenching or bruxing were not reduced with the use of occlusal splints. Christensenz3 demonstrated that voluntary clenching can cause jawmuscle pain and fatigue. These factors may lead to the long-term failure of treatment in patients with parafunctional habits. Twelve patients elected surgical intervention to correct meniscalabnormality. Surgery wasrecommendedfor the folIowing reasons:in six patients the condition progressed to a closedlock; in four patients clicking recurred and abnormal protrusion of the mandible would have been required to obtain normal meniscalrelationships;and two patients did not have sufficient improvement in their pain profiles. Four of the six whosecondition progressedto a closed lock had intermittent locking as a pretreatment finding; the four in whom clicking recurred had intermittent locking asa pretreatment finding; and oneof two in the group where pain wasnot sufficiently reduced had locking asa pretreatment finding. This suggeststhat intermittent locking may predisposethe outcome to failure despite appropriate splint treatment.

3.

4.

5.

6.

7. 8. 9.

10.

11.

12.

13.

14. 15.

16. 17.

18.

56~224-5. 19. Lous I, Olesen J. Ev~uation

CONCLUSION Sixty-eight treatment and 18 nontreatment patients were included in this study and the results were compared by evaluating subjective and objective findings. The overall evaluation of treatment as opposed to nontreatment demonstrated that protrusive splint therapy followed by orthodontic or restorative treatment is a viable option for treatment of meniscaldisplacement with reduction. This study differs from those of Clark’O and Maloney and Howard20in that splints were not removed at the end of the reagent period. Clinicians and patients should be made awareof the option for surgicalmanagement,becausesome symptomsmay remain and the disorder may not be completely arrested.

characteristics of condylar paths in internal derangements of the TMJ, J l’msm DI&+T 19?~4~~8-~. Molin C, Carlsson GE, Friling B, Hedegard B. Frequency of symptoms of mandibular dysfunction in young Swedish men. J Oral Rehabil 1976:3:9-18. Nilner M, Lassing SA. Prevalence of functional disturbances and diseases of the stomotognathic system in 7-14 year olds. Swed Dent J 1981;5:173-87. Hansson T, Niiner M. A study of the occurrences of symptoms of diseases of the temporom~dibular joint masticatory musculature and related structures. J Oraal Rehahii 1975;2:313-24. Egermark-Eriksson I, Carlsson GE, Ingerval B. Prevalence of mandibular dysfunction and oral parafunction in 7, 11, and 15 year old Swedish children. Eur J Orthol 1981;3:163-72. Greene CS, Turner C, Laskin DM. Long term outcomes of TMJ clicking in 100 MPD patients [Abstract]. J Dent Res 1982;6t:218. Farrar WD. Diagnosis and treatment of anterior dislocation of the artic&u disc. NY J Dent 1971;41:548. Anderson GC, Schulte JK, Goodkind RJ. Comparative study of two treatment methods for internal derangements of the temporomandibular joint. J PROSTHET DENT 1985;53:392-7. Clark GT. Treatment of iaw clicking with temnoromandibular renositioning: analysis of 25 caies. d Cranjomand &act 1984;2:264-70. _ Lundh H, Westesson PL, Kopp 6, Tillstrom BA. Anterior positioning splint in the treatment of tem~romandibul~ joints with reciprocal clicking: comparison with a flat splint and untreated group. Oral Surg Oral Med Oral Pathol 1985;60:131-6. Tallents RH, Katzberg RW, Miller TL, Manzione JV, Oster C. Evaluation of arthrographically assisted splint therapy in treatment of TMJ disk displacement. 3 F%OSTHET DENT 1985$3:836-S. Miller TL, Katzberg RW, Tallen& RH, Beasetts RW, Hayakawa K. Temporomandibul~ joint clicking with nonreducing anterior dispiacemerit of the meniscus. Radiology 1985;151:121-4. Tallents RH, Katzberg RW, Miller TL, Ma&one JV, Oster C. Arthrographically assisted splint therapy. J PROSTHW DENT 1985;53:235-8. Koch GG, Landis JR, Freeman JL, Freemand DH Jr, Lehnen RG. A general methodology for the analysis of experiments with repeated measurement of categorical data. Biometrics 1977;33:133-58. Grizzle JE, Starmer CE, Koch GG. Analysis of categorical data by linear models. Biometrics 1~~2~489-~. Goodman P, Green CS, Laskin DM. Response of patients with myofascial pain-dysfunction syndrome to mock equilibration. J Am Dent Assot 1976;92:755-8. Tallents RH, Katzberg RW, Macher DJ, et al. Arthrographically assisted splint therapy. A 6-month followup. J PROSTHET DENT 1986;

20.

21.

22. 23.

of pericranial tenderness and oral function in patients with common migraine, muscle contraction headache, and combination headache. Pain 1982;12:385-93. Maloney F, Howard J. Internal derangements of the temporomandibular joint. III. Anterior repositioning splint therapy. Aust Dent J 1986;31:30-9. Roberta CA, Tailenta RA, Espeiand MA, Handelman SL, Katzberg RW. Mandibui~ range of motion versus a~~~raphic diagnosis of the temporomandibular joint. Oral Surg Oral Med Oral Path01 19~60:2~-51. Kydd WL, Colin D. Duration of nocturnal tooth contacts during bruxing. J PROSTHET DENT 1985;53:717-21. Christensen LV. Facial pain and internal pressure of the masster muscle in experimental bruxism in man. Arch Oral Biol 1971;16:1021-31.

Reprint requests to: DR. Ross H. TALLENT~ 1333 LAKE AYE. ROCHESTER, NY 14613

Contributing 1. Isberg-Helm A, Westesson PL. Movement of disc and ccndyle in temporomandibular joints with clicking. An arthrographic and cineradiographic study on autopsy specimens. Acta Odontol Stand 1982;40:15164. 2. Farrar WR, McCarty WL Jr. Inferior joint space arthrography and THE

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authors

Roberto S. Woodworth, D.D.S., Tem~rom~dibu~~ Joint Resident, Department of Orthodontics, Eastman Dental Center, Rochester, N.Y. Howard M. Proskin, Ph.D., Coordinator of Biostatistics, Eastman Dental Center, Rochester, N.Y. 341