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Jaw Dysfunction in Viola and Violin Players
A R T IC L E S
Jaw dysfunction in viola and violin players Judith Ann Hirsch, PhD W. D. McCall, Jr., PhD B. Bishop, PhD
Violin and viola players often experience pain and stiffness in the right temporomandibular joint area. This study attempts to document jaw dysfunction in a group of professional musicians and to correlate it with practice time and instrument weight and size.
T
JS he classic symptoms in temporo mandibular joint (TMJ) pain dysfunc tion syndrome are pain and tenderness in the TMJ area; noises emanating from the TMJ during jaw movement (click ing, crepitus); and limited or irregular m andibular m ovem ents.1’3 One or more of these symptoms have been re ported in more than half of the samples from the general population, and 30% of the population report two or more symptoms.4'5 The etiology of this syndrome is c o n tro v e rs ia l and p o o rly u n d e r stood.1'2 If patients with obvious de generative disease of the TM J are excluded, a number of patients remain w h o do n o t h a v e d i s c e r n i b l e pathologic conditions that would ex p la in th e ir sym ptom s. Su gg ested causes for TMJ pain dysfunction have in c lu d e d : m a c ro tra u m a ,6 m icro t r a u m a ,7 o c c lu s a l d e f e c t s ,1 in tracapsular defects,1 jaw muscle ten sion,5 bruxing,8 and emotional dys
838 ■ JADA, Vol. 104, June 1982
functions that result in jaw muscle tension.2,9 In spite of considerable in terest in correlating emotional charac teristics and the presence of the signs and symptoms of TMJ pain dysfunc tion syndrome, a causal relationship has not been established.1-2-8 However, a reflex phenomenon, the masseteric silent period, is prolonged in patients
F ig 1 ■ H o ld in g v io la. Viola is balanced between collarbone and left thumb, held low in left hand, with little raising of left shoul der. V iolin (not pictured) is held at h igher angle, less in left hand, and left shoulder is m ore elevated.
with TMJ pain dysfunction syndrome, com pared w ith asym ptom atic sub jects.10,11 Further, increased severity of symptoms is associated with increased silent period duration.1012 Professional and serious amateur violin and viola players often experi ence pain and stiffness in the right TMJ area after continuous playing for three hours or more.13-14 Although these in strumentalists may not have consis tent occlusal disorders or emotional dysfunctions,13 they do have a poten tial mechanical trauma in common. The instrument is placed on the left side of the collar bone, and its weight is supported between the left side of the mandible on the chinrest and the left thumb on the instrument neck (Fig I ) .15-16 Some players also raise the left
A R T IC L E S
shoulder or use a shoulder pad to pro vide additional support,17 especially necessary during active shifting of the left-hand position up and down the fingerboard . 16,18 The degree of instru ment support required varies with the individual, 15-19 the technical demands of the m usic ,16,18,19 and the size and weight of the instrument. A typical violin weighs 1 . 8 lb and has a body length of 14 inches; a typical viola weighs 3 lb and has a body length of I 6 V2 inches. If symptoms of TMJ pain dysfunc tion syndrome can be induced by me ch an ical irritation of the T M J ,6,7,14 then the frequency of these signs and symptoms might be greater in a group of violinists and violists than in the general population, and they would be greater for those who play the larger, heavier viola. The purposes of this study were to document in a group of professional violinists and violists the occurrence of pain, joint sounds, and irregularities of mandibular movement; deviation from midline of the mandible on max imal opening; the relationships be tween mandibular deviation and other factors, such as practice time, instru ment weight, and instrument size; and the silent periods of the masseteric and anterior tem poralis m uscles as re corded in surface electromyograms.
out what kinds of problems exist, and if the use of certain chinrests (Fig 2) and shoulder pads was correlated with the presence or absence of such prob lems. The concept of TMJ pain dys function was not m entioned. How ever, the subjects were asked if they had sought treatment for jaw prob lems. Only one violist had sought re lief and had been treated with a bite splint. The rest simply endured the pain, and on occasion would apply heat or manipulate the affected area. If pain was severe, the subject took aspi rin or an equivalent. All these musicians were aware of the problem, either in themselves or in th e ir c o lle a g u e s and p u p ils, and readily volunteered to participate in the survey and have their maximal jaw opening (incisal edge to edge)5 mea sured. Each subject sat in front of the exam iner and was asked to slowly open the mouth as widely as possible and then let it close. The examiner noted the presence and direction of any deviation from the midline and audible clicking and palpable crepi tus. Then, two rules attached at 90° to each other were used to measure the deviation of the jaw from the midline at maximal opening. The vertical rule was aligned with the upper incisor midline, and the subject was asked to open m axim ally five to ten tim es,
Materials and methods
while the jaw deviation was recorded on the horizontal rule and the distance between incisal edges was recorded on the vertical rule. The greatest accuracy with which the examiner could read the measuring device (error of mea surement) was 0.5 mm. The left side of the neck was exam ined for the “practice mark,” a cal loused discoloration of the skin below the mandibular angle. The mark was rated absent, present, or noticeably evident. The same area was palpated for a lump under the practice mark and an asym m etry in acu ten ess of the mandibular angle on the left side as compared with the right side. The lump and the asymmetry were rated as present or absent in each subject.
D ental students Eighty-seven men and 28 women of two co n se cu tiv e fresh m an d ental classes, who had no history of TMJ pain dysfunction syndrome, agreed to provide data on mandibular excur sions and signs and symptoms of TMJ pain dysfunction syndrome. These students had been exposed to informa tion about TMJ pain dysfunction syn drome in lectures in both clinical and basic science courses. None played or had played either violin or viola.
Types of chinrests
Subjects Professional violists and violinists (30 men, 36 women) were asked to volun teer for a survey about any problems with their jaws. Fifty-one violists and 15 violin ists were questioned in a nonclinical environment. The mean number of years of playing was 28 for the violinists and 34 for the violists; how ever, the mean age for these players was only 38 ± 11 years for the violinists and 42 ± 13 years for the vio lists. The majority of these instrumen talists began study of their instruments between 6 and 12 years of age. In fact, some players began study as young as 3 years of age.
F ig
2 ■ T y p es of
chinrests. Type A, or D resd en
m o d e l,
clamps on left side of in s tru m e n t. T y p e B clam ps in center, over tailpiece, with cup ex tending over left side of instrument. Type C clamps in center and
A
B
cup is d irec tly over
Dresden
Over the tailpiece model
tailpiece.
S u r v e y o f th e TM J signs a n d sym ptom s The field investigator explained that she was collecting these data to find Hirsch—McCall—Bishop : JAW DYSFUNCTION IN VIOLA AND VIOLIN PLAYERS ■ 839
A R T IC L E S
People who play the violin or viola have signs and symptoms that are sim ilar to those of the TMJ pain dysfunction syndrome.
Jaw motion Seven subjects, five violinists and two violists, whose playing histories were representative of the group, had pho tographs taken of their mandibular movements during maximal voluntary opening and closing. A small light bulb was taped to the chin just below the space between the lower incisors. While the teeth were in centric occlu sion, the bulb was lined up with the maxillary incisors. The subject was asked to quickly perform a maximal jaw opening and closing. After a short period of practice, the subject rested and then performed the maneuver while the shutter of an oscilloscope camera was held open. Several pic tures were made for each subject. Mea surements of mandibular deviation were not different from those obtained by direct visual measurements.
Electromyography These same five violinists and two vio lists also volunteered to have the silent period of both masseter muscles and the right anterior temporalis muscle measured by electromyography. Bipo lar surface electrom yograph ele c trodes were placed on the skin over the right anterior temporalis and both masseter muscles,10 and a ground elec trode was clipped to the left ear. The subject was asked first to relax and then to clench his or her jaw. The elec trical activity of the three muscles was recorded on magnetic tape and poly graph paper. The silent period was obtained by tapping the mandibular symphysis with a tendon hammer while the sub ject clenched maximally.1012 The time that the stimulus occurred was re corded electronically on the fourth channel by means of a simple “makebreak” circuit, which was placed be tween the tendon hammer and the sub ject’s chin. The subject was again instructed to clench the jaw maximally, and im mediately the chin was tapped five 840 ■ JADA, Vol. 104, June 1982
times at irregularly spaced time inter vals of about one second by one inves tigator. The subject was again asked to relax the jaw, and after a minute or two, was instructed to clench maxi mally again, while a second inves tigator performed five chin taps. After the procedure, tape speed was reduced by a factor of 8; and the signals were, played back on the polygraph paper at a paper speed of 100 mm / sec for sub sequent measurement.
The records were analyzed by hand independently by one of the inves tigators and by a technician who was unaware of the specific purpose of the study. The variables measured were the latency and duration of the silent period for all three muscles. Latency was defined as the time from the stimulus to the last peak of the ongoing muscle activity preceding the silent period.12 Duration of the silent period was defined as the time from the last peak of ongoing muscle activity to the first peak in the ongoing electromyograph. Statistical significant (P < .05) was determined by an unpaired t-test.
Results Playing history and symptoms The playing history for all the subjects is shown in Table 1. The mean number of years of playing and the mean number of hours per week spent on the
Table 1
■ Playing history of
51 violists and 15 violinists.___________________
Years of playing* Violists Group 1: 10 to 25 hr/wk 13 women, 2 men Group 2: 26 to 45 hr/wk 12 women, 7 men Group 3: 46 to 65 hr/wk 3 women, 4 men Total 28 women, 23 men Violinists 20 to 50 hr/wk 8 women, 7 men ‘ Mean ± standard deviation. tS e e Figure 2.
instrument for the middle group (that is, 25 to 45 hours, n = 19) were not dif ferent from the means of these vari ables for the entire group of 51 violists. The mean values of the playing history for the violinists were not significantly different from the mean values for either the entire group of 51 violists or the middle group of 19 violists. With only one exception, none of the vio lists or violinists younger than 30 years (26) had any dentures, crowns, or missing teeth (except for third molars). One female violinist (the exception) had a partial denture that replaced three teeth in the right side of the man dible. Of the entire group of violists, 24% had partial dentures; of the 15 vio linists, 27% had partial dentures. None had complete dentures. All who had partial dentures were older than 45 years old, except for the one violinist just mentioned. These musicians had unusually good dental health. None of the dental students played or had played the violin or viola. None of these dental students had any den tures, crowns, or missing teeth other than third molars. All the students were younger than 30 years of age. The type of chinrest used seemed to affect the presence or absence of the practice mark and lump (Fig 2). Both A and B chinrests contact the left man dibular angle during playing. The type C chinrest, which fits directly over the tailpiece of the viola, enables the player to hold the instrument nearly directly beneath the chin. Because the instrument usually does not touch the angle of the jaw under these circum stances, a practice mark and lump may not develop. The frequencies of occurrence of joint sounds, pain, and blunting of the left mandibular angle are shown in Table 2. The maximal jaw openings
Type o f Hours a ch in restt week playing A B C
No. with practice mark
No. with lump
27 ± 16
18 ± 4
4
7
4
14 (93%)
27 ± 14
39 ± 4
7 12
0
19 (100%)
18 (95%)
46 ± 16
58 ± 7
8
8
1
16 (94%)
12 (71%)
34 ± 17
39 ± 17
5 49 (96%)
38 (75%)
28 ± 12
35 ± 10
0
12 (80%)
19 27 8
7
15 (100%)
8 (53%)
A R T IC L E S
Table 2 ■ Mandibular deviations, maximal jaw openings, and frequency of occurrence of TMJ joint sounds, pain, and palpably worn left mandibular angles in violists, violinists, and dental students. No. of subjects
Hours a week playing*
Violists Group 1 (15) Group 2 (19) Group 3 (17) Total (51) Violinists 15 Dental students 115
18 39 58 39
± ± ± ±
4 4 7 17
35 ± 10
Mandibular deviation* (mm)
Direction Right None Left
Maximal opening* (mm)
TMJ sounds (clicking) 12 18 17 47
2.1 1.7 2.1 2.5
12 18 17 47
3 0 0 3
0 1 0 1
4.5 4.8 5.0 4.8
4.4 ± 1.5
15
0
0
4.3 ± 0.8
0.1 ± O .lt
32
59
24
5.2 ± 1.0
3.1 6.0 7.1 5.5
± ± ± ±
± ± ± ±
0.9 0.7 1.0 0.9
TMJ pain
Blunt left mandibular angle
9 (60%) 17 (89%) 14 (82%) 40 (78%)
13 19 17 49
14 (93%)
11 (73%)
15 (100%)
32 (28%)
4 (3%)
(80%) (95%) (100%) (92%)
(87%) (100%) (100%) (96%)
0
*Mean ± standard deviation. tTwenty-two (19%) of the dental students had mandibular deviations from the midline of greater than 3 mm.
and mandibular deviations for the musicians are shown in Table 2 and Figure 3. A typical example of the irregular mandibular movement seen in a violist is shown in Figure 4. Note that the mandible deviates from the midline on opening in a smooth curve. However, on closing, there is a horizontal jump back to the midline, which was as sociated with an audible click in both the right and left TMJ. All the perform ers had jaw motions that deviated from the midline on opening and clicked back into place on closing. All these violinists and violists returned the jaw to the midline. Five of the 15 violinists and two of the 51 violists also volunteered for electromyographic studies of jawclosing muscles. These players were representative of their respective groups in that the mean maximal jaw opening for these violinists was 4.6 ±
0.9 cm, and for the two violists was 4.5 cm and 3.3 cm. The mean mandibular deviation for the five violinists was 4.3 ±1.4 mm, and the values for the two violists were 4.6 mm and 8.3 mm. Latencies and durations of the silent periods for the five violinists and two violists are shown in Table 3. There were no significant differences be tween the latencies and durations of the silent period among the three mus cles (right anterior temporalis, right masseter, and left masseter), nor were there any significant differences be tween the means obtained by the two people who analyzed the data.
number of these individuals have pain in the TMJ area on the right side, joint sounds in the left TMJ, and large devia tions of the mandible to the right of the midline on maximal opening. Further, these musicians have a common factor t h a t a p p e a r s r e l a t e d to t h e s e symptoms: the playing of an instru ment that requires long hours of con tact with the left side of the mandible. Considerable evidence suggests that these musicians exert pressure on the
Discussion This study has demonstrated that people who play the violin or viola have signs and symptoms that are similar to those of the TMJ pain dys function syndrome. A significant
10
A
Open
t
8-
y
Jaw deviation on
6-
maximal
i
opening
A
(mm)
4■
Left
10 to 25
26 to 45
46 +
Violists
26 to 45 Violinists
Hr/wk
Fig 4 ■ M andibular m ovement in violist during m axim al voluntary jaw opening and closing,
Fig 3 ■ M ean jaw deviations on m axim al opening (five to ten trials) for 51 violists, separated into
drawn from photograph. M otion is representa
three groups by hours per w eek o f playing, and for 15 violinists who played 2 6 to 45 hours per
tive of all players with jaw deviations greater
week. Open circles (O) denote those violists who used center chinrest (type C) (n = 5).
than 2 mm from m idline.
H irsch-M cCall-Bishop : JAW DYSFUNCTION IN VIOLA AND VIOLIN PLAYERS ■ 841
A R T IC L E S
Table 3 ■ Silent period latencies and durations in the right anterior tem poralis, right masseter, and left masseter muscles in five violinists and two violists. Subject
Violinists 1 2 3 4 5 Violists 6 7 Mean Standard deviation
Latency (msec)
Duration (msec)
Right anterior temporalis
Right anterior temporalis
Right masseter
Left masseter
Right masseter
Left masseter
11.6 1.1 10.1 1.1
13.4 1.1 10.8 1.3
12.3 1.3 9.2 0.7
24.3 3.7 23.1 3.5 25.6 6.6 29.1 3.7 18.5 1.6
27.8 8.6 24.3 4.5
11.4 0.5 10.9 0.9
24.1 3.1 23.8 3.7 27.2 4.3 28.2 3.6 18.7 1.9
-
-
-
-
-
-
11.4 0.7 10.6 1.4
11.8 0.6 10.4 1.3
26.2 4.3 19.2 2.6
11.4 0.8 10.4 1.3 10.9
13.3 0.8 13.9 1.0 12.3
9.0 0.9 9.3 1.2 10.4
21.8 2.3 31.8 5.0 25.1
21.3 1.7 31.3 2.5 24.7
23.2 2.6 30.0 3.8 25.2
0.7
1.5
1.3
4.4
4.4
3.8
left side of the mandible with the vio lin or viola. First, there is the presence of a callous (the practice mark) in these musicians. Second, the angle of the left side of the mandible is palpably smoother than that of the right side. Third, the violists who supported their instruments directly under the chin using a center chinrest, rather than at the side, did not have significant man dibular deviations or other symptoms of TMJ pain dysfunction syndrome. Further, the size of the mandibular de viation was related to the amount of viola playing (the number of hours a week spent playing the instrument). The weight and size of the instrument were also factors. The frequency of oc currence of pain and the size of the mandibular deviation were signifi cantly greater in the violists than in the violinists. Herman13 measured in 30 violinists the force exerted by the mandible to support the instrument between the left shoulder and jaw without assis tance from the left hand. Using a sling attached to a scale, he was able to show that the support of a 1.5 lb to 2 lb (0.8 kg) violin required from 8 oz to 5 lb of force (0.4 to 4.5 newtons). Presumably, the larger, heavier viola (2.5 to 3.5 lb or 1.5 kg) might require even greater forces to be supported at the shoulder and jaw. However, in actual perfor mance, the instrument is also partly supported by the thumb of the left hand. In addition, Herman found a normal distribution of normal occlu sions and malocclusions among these 842 ■ JADA, Vol. 104, June 1982
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30 subjects with some tendency to ward anterior overbite. There is one report in which early ar thritic changes were demonstrated in a 22-year-old female violinist.14 We are not aware of any other literature with similar evidence for degenerative changes in the TMJ in violinists; how ever, we find no incompatibility with the suggestions of Reider14 that play ing the violin could produce changes in the TMJ. Therefore, it is likely that the major mechanical factor in the jaw dysfunction that we observed in these violists and violinists was the force exerted on the mandible in maintain ing the position of the instrument. The mean maximal jaw openings (incisal edge to edge) observed by Travell5 in normal (asymptomatic) people were 5.9 cm for men and 5.3 cm for women. Eight-nine percent of the subjects had maximal jaw openings greater than 5.0 cm. In our study, the mean maximal jaw opening in the 95 of 115 dental students, who were asymptomatic for TMJ pain dysfunc tion syndrome or who had only occa sional clicking, was 5.5 ± 0.8 cm. The mean maximal jaw openings for the violinists (4.3 ± 0.8 cm) and the violists (4.8 ± 0.9 cm) were signifi cantly less than those reported in the dental students. This reduction in jaw opening could not be attributed to age or sex. The mean mandibular deviations in both the violinists and violists were significantly greater than those ob served in the 115 dental students. In
addition, with only one exception among the violists, when there was a deviation of the mandible on opening, the deviation was toward the right. Three of the violists reported no symptoms and had no observable mandibular deviations. Another two players had deviations of 2.0 mm or less. All these musicians used a center chinrest and held the viola directly under the midpoint of the mandible. Four of these subjects played ten to 25 hours a week (group 1) and one played 46 to 65 hours a week (group 3). Three of the four violists in group one had used only a center chinrest, had no wearing of the left mandibular angle, nor any mandibular deviation. The fourth violist in group one, who used a center chinrest, had previously used a type A chinrest. This player had a mandibular deviation of 1.8 mm and wearing of the left mandibular angle. The last violist in group 3 had previ ously used a type B chinrest for 35 years, but on purchasing a larger in strument, he found it necessary to switch to a center chinrest, which he has used for the past 15 years. A man dibular deviation of 2/0 mm was pre sent and the left mandibular angle was worn, as it was in the players who used a type A or B chinrest. All of the vio linists and the other violists used either type A or B chinrests, had man dibular deviations greater than 2 mm, and had wearing of the left mandibular angle. Of the players who played more than 30 hours per week, all had man dibular deviations greater than 3 mm. Two violinists (one man, one woman) not included in this study, who play left-handed (that is, the in strument is held on the right side), had mandibular deviations toward the left side, reported pain in the left TMJ area, and had joint noises and stiffness in the right TMJ area. In one of the vio linists, the right mandibular angle was worn. This is the mirror image of the signs observed in the right-handed players. There was no difference in silent period latency or duration in the jawclosing muscles in the musicians from that measured in asymptomatic sub jects. In other studies performed in the same laboratory, values for latency and duration of silent periods in jaw clos ing muscles (masseter and anterior temporalis) have been reported in “normal” patients,10-12 patients with
A R T IC L E S
TMJ pain dysfunction syndrome,10-12 and children before orthodontic treatment20 The durations of the silent periods are significantly longer in all the patient populations than in the normal patients, whereas the dura tions in the asymptomatic subjects are no different from those seen in either the violinists and violists. This finding of normal silent period durations of the jaw closing muscles was unexpected in the light of Her man’s report that musicians use a vise-like grip on the instrument be tween the left side of the mandible and the shoulder.13 The most prevalent theme of schools of violin technique written by the great teachers and per formers is to avoid unnecessary mus cular tension.15-19 The teeth are sepa rated during performance. The man dible is shifted toward the left and down onto the chinrest. This occurs when the performer needs to stabilize the instrument when shifting the left hand from a high position closer to the face to a lower position farther from the face. Surface electromyograms from the right anterior temporalis, right masseter, and left masseter muscles were recorded in one violist while she sup ported the viola solely at the shoulder with the left arm at her side, and dur ing performance of moderately de manding works. Subjective impres sion of the muscular tension involved in instrument support was that it was located primarily in the digastric and left sternocleidomastoid muscles, and occasionally in the left trapezius mus cle if the shoulder was raised. At no time was any significant activity ob served in the electromyograph rec ords. During this performance, the teeth were generally slightly apart; and occasionally during active shift ing downward, the mandible opened and pushed leftward and down onto the viola chinrest. Thus, the force applied to the man dible is not caused by a vise-like grip ping of the instrument associated with clenching of the teeth, but is caused by passive balancing of forces by hooking the jaw over the chinrest. Furthermore, the player does not grip the instrument solely at the shoulder, but also sup ports it on the left thumb and collar bone.1516 Even during active shifting of the left hand up and down the
fingerboard, the thumb remains in constant contact with the neck of the instrument. In other words, a violin or viola is held “like a bridge, not a di ving board.”15
Conclusion We have described in a population of violin and viola players signs and symptoms that are identical to those of TMJ pain dysfunction syndrome. The frequency of occurrence of TMJ noises and pain in the TMJ area was greater in these musicians than in a group of den tal students, and was higher in violists than in violinists who played the same number of years and hours a week. The limitation of mandibular movement and rightward deviation of the mandi ble on opening were significantly greater in these musicians than in the general population. The extent of mandibular deviation increased as the number of playing hours increased and was greater for the violists than for the violinists. This condition is dif ferent from that of classic TMJ paindysfunction syndrome, in that there is no prolongation of the electromyo graph silent period in the jaw closing m uscles. The presence of the symptoms in viola and violin players is related to chronic irritation and me chanical displacement of the mandible by the position of the viola or violin, rather than to any active contraction of the jaw-closing muscles. Because force exerted on the mandible during play ing may contribute to the development of signs and symptoms of jaw dysfunc tion, violinists and violists should use a technique that reduces the force on the mandible by the instrument, which may help to prevent or minimize the pain and dysfunction. fTi&l
The informed consent of all human subjects who participated in the experimental investiga tion reported was obtained after the nature of the procedures and possible discomforts had been explained fully. This study was supported by NIH grants P O lHL-14414 and ROl-D E-04889. The authors thank Victor Stern, professor of viola, University of Miami, Fla; Gerard Reinagel, professor emeritus of m usic and violin, and Joan Smutko, instructor o f violin, Niagara County Community College, NY, for their critical review of this manuscript.
Dr. Hirsch is research assistant professor, de partment of physiology; Dr. M cCall is associate" p rofessor, departm ent of oral m ed icin e; Dr. Bishop is professor, department of physiology, School of Medicine and Dentistry, State Univer sity of New York at Buffalo, Buffalo, 14214. Ad dress requests for reprints to Dr. Hirsch. 1. DeBoever, J.A. Functional disturbances of th e tem porom andibular jo in ts. Oral S c i Rev 2:100-117, 1973. 2. Rugh, J.D., and W. K. Solberg. Psychological im plications in tem porom andibular pain and dysfunction. Oral Sci Rev 7:3 -3 0 ,1 9 7 6 . 3. Greene, C.S., and others. The TMJ paindysfunction syndrome: heterogeneity of the pa tient population. JADA 79 (5 ):1 1 6 8 -1 1 7 2 ,1969. 4. Agerberg, G., and Carlsson, G.E. Functional disorders of the masticatory system. Distribution of symptoms according to age and sex as judged from investigation by questionnaire. Acta Odontol Scand 30:597-613, 1972. 5. Travell, J. Temporomandibular joint dys function. Temporomandibular joint pain referred from the muscles of the head and neck. J Prosthet Dent 10(4):745-763, 1960. 6. Moffett, B. The m orphogenesis of the tem poromandibular joint. Am J Orthod 52:401-415, 1966. 7. Ricketts, R. C linical im plications of the tem poromandibular joint. Am J Orthod 52:416-439, 1966. 8. Reding, G.R.; Zepelin, H.; and Monroe, L.J. Personality study of nocturnal teeth-grinders. Percept Mot Skills 26:523-531, 1968. 9. Guralnick, W.; Kaban, L.B.; and Merrill, R.G. Temporomandibular join t afflictions. N Engl J Med 299(3):123-129, 1978. 10. Bessette, R.; B ish op ,B .; andM ohl, N. Dura tion of the masseteric silent period in patients with TM J syndrome. J Appl Physiol 30(6):8648 6 9 ,1 9 7 1 . 11. Bailey, J.O.; M cCall, W.D.; and Ash, M.M. Electromyographic silent periods and jaw motion parameters: quantitative measures of temporo m an d ib u lar jo in t d y sfu n c tio n s. J D ent R es 56(3):249-254, 1977. 12. McCall, W.D.; Uthman, A.A.; and Mohl, N.D. TM J sym ptom severity and EMG silent periods. J Dent Res 57(5-6]:709-714, 1978. 13. Herman, E. Orthodontic aspects of musical instrument selection. Am J Orthod 65:519-530, 1974. 14. Reider, C.E. Possible premature degenera tive tem porom andibular join t disease in vio linists. J Prosthet Dent 35(6):662-664, 1976. 15. Rolland, P. Basic principles of violin play ing. M u sic E d u cator’s N ation al C on feren ce, W ashington, DC, 1959, pp 10-11. 16. Menuhin, Y., and Primrose, W. Violin and viola. New York, Schirm er Books, 1976, pp 23, 2 9 -3 1 ,4 2 ,4 6 , 179-181. 17. Flesch, C. The art of violin playing. Book one: technique in general, applied technique. New York, Carl Fisher, Inc, 1924, pp 14-49. 18. Neumann, F. V iolin left hand technique: a survey of related literature. Urbana, 111, American String Teachers Assoc. 1969, pp 19-38, 43-44, 49-53, 65. 19. A uer, L. V io lin p layin g as I te ach it. Philadelphia, J. B. Lippincott Co, 1960, pp 10-11, 35. 20. Felli, A.J., and McCall, W.D., Jr. Jaw muscle silent periods before and after rapid palatal ex pansion. Am J Orthod 76:676-681, 1979.
H irsch-M cC all-Bishop: JAW DYSFUNCTION IN VIOLA AND VIOLIN PLAYERS ■ 843
Jaw dysfunction in viola and violin players Judith Ann Hirsch, PhD W. D. McCall, Jr., PhD B. Bishop, PhD
Violin and viola players often experience pain and stiffness in the right temporomandibular joint area. This study attempts to document jaw dysfunction in a group of professional musicians and to correlate it with practice time and instrument weight and size.
T
JS he classic symptoms in temporo mandibular joint (TMJ) pain dysfunc tion syndrome are pain and tenderness in the TMJ area; noises emanating from the TMJ during jaw movement (click ing, crepitus); and limited or irregular m andibular m ovem ents.1’3 One or more of these symptoms have been re ported in more than half of the samples from the general population, and 30% of the population report two or more symptoms.4'5 The etiology of this syndrome is c o n tro v e rs ia l and p o o rly u n d e r stood.1'2 If patients with obvious de generative disease of the TM J are excluded, a number of patients remain w h o do n o t h a v e d i s c e r n i b l e pathologic conditions that would ex p la in th e ir sym ptom s. Su gg ested causes for TMJ pain dysfunction have in c lu d e d : m a c ro tra u m a ,6 m icro t r a u m a ,7 o c c lu s a l d e f e c t s ,1 in tracapsular defects,1 jaw muscle ten sion,5 bruxing,8 and emotional dys
838 ■ JADA, Vol. 104, June 1982
functions that result in jaw muscle tension.2,9 In spite of considerable in terest in correlating emotional charac teristics and the presence of the signs and symptoms of TMJ pain dysfunc tion syndrome, a causal relationship has not been established.1-2-8 However, a reflex phenomenon, the masseteric silent period, is prolonged in patients
F ig 1 ■ H o ld in g v io la. Viola is balanced between collarbone and left thumb, held low in left hand, with little raising of left shoul der. V iolin (not pictured) is held at h igher angle, less in left hand, and left shoulder is m ore elevated.
with TMJ pain dysfunction syndrome, com pared w ith asym ptom atic sub jects.10,11 Further, increased severity of symptoms is associated with increased silent period duration.1012 Professional and serious amateur violin and viola players often experi ence pain and stiffness in the right TMJ area after continuous playing for three hours or more.13-14 Although these in strumentalists may not have consis tent occlusal disorders or emotional dysfunctions,13 they do have a poten tial mechanical trauma in common. The instrument is placed on the left side of the collar bone, and its weight is supported between the left side of the mandible on the chinrest and the left thumb on the instrument neck (Fig I ) .15-16 Some players also raise the left
A R T IC L E S
shoulder or use a shoulder pad to pro vide additional support,17 especially necessary during active shifting of the left-hand position up and down the fingerboard . 16,18 The degree of instru ment support required varies with the individual, 15-19 the technical demands of the m usic ,16,18,19 and the size and weight of the instrument. A typical violin weighs 1 . 8 lb and has a body length of 14 inches; a typical viola weighs 3 lb and has a body length of I 6 V2 inches. If symptoms of TMJ pain dysfunc tion syndrome can be induced by me ch an ical irritation of the T M J ,6,7,14 then the frequency of these signs and symptoms might be greater in a group of violinists and violists than in the general population, and they would be greater for those who play the larger, heavier viola. The purposes of this study were to document in a group of professional violinists and violists the occurrence of pain, joint sounds, and irregularities of mandibular movement; deviation from midline of the mandible on max imal opening; the relationships be tween mandibular deviation and other factors, such as practice time, instru ment weight, and instrument size; and the silent periods of the masseteric and anterior tem poralis m uscles as re corded in surface electromyograms.
out what kinds of problems exist, and if the use of certain chinrests (Fig 2) and shoulder pads was correlated with the presence or absence of such prob lems. The concept of TMJ pain dys function was not m entioned. How ever, the subjects were asked if they had sought treatment for jaw prob lems. Only one violist had sought re lief and had been treated with a bite splint. The rest simply endured the pain, and on occasion would apply heat or manipulate the affected area. If pain was severe, the subject took aspi rin or an equivalent. All these musicians were aware of the problem, either in themselves or in th e ir c o lle a g u e s and p u p ils, and readily volunteered to participate in the survey and have their maximal jaw opening (incisal edge to edge)5 mea sured. Each subject sat in front of the exam iner and was asked to slowly open the mouth as widely as possible and then let it close. The examiner noted the presence and direction of any deviation from the midline and audible clicking and palpable crepi tus. Then, two rules attached at 90° to each other were used to measure the deviation of the jaw from the midline at maximal opening. The vertical rule was aligned with the upper incisor midline, and the subject was asked to open m axim ally five to ten tim es,
Materials and methods
while the jaw deviation was recorded on the horizontal rule and the distance between incisal edges was recorded on the vertical rule. The greatest accuracy with which the examiner could read the measuring device (error of mea surement) was 0.5 mm. The left side of the neck was exam ined for the “practice mark,” a cal loused discoloration of the skin below the mandibular angle. The mark was rated absent, present, or noticeably evident. The same area was palpated for a lump under the practice mark and an asym m etry in acu ten ess of the mandibular angle on the left side as compared with the right side. The lump and the asymmetry were rated as present or absent in each subject.
D ental students Eighty-seven men and 28 women of two co n se cu tiv e fresh m an d ental classes, who had no history of TMJ pain dysfunction syndrome, agreed to provide data on mandibular excur sions and signs and symptoms of TMJ pain dysfunction syndrome. These students had been exposed to informa tion about TMJ pain dysfunction syn drome in lectures in both clinical and basic science courses. None played or had played either violin or viola.
Types of chinrests
Subjects Professional violists and violinists (30 men, 36 women) were asked to volun teer for a survey about any problems with their jaws. Fifty-one violists and 15 violin ists were questioned in a nonclinical environment. The mean number of years of playing was 28 for the violinists and 34 for the violists; how ever, the mean age for these players was only 38 ± 11 years for the violinists and 42 ± 13 years for the vio lists. The majority of these instrumen talists began study of their instruments between 6 and 12 years of age. In fact, some players began study as young as 3 years of age.
F ig
2 ■ T y p es of
chinrests. Type A, or D resd en
m o d e l,
clamps on left side of in s tru m e n t. T y p e B clam ps in center, over tailpiece, with cup ex tending over left side of instrument. Type C clamps in center and
A
B
cup is d irec tly over
Dresden
Over the tailpiece model
tailpiece.
S u r v e y o f th e TM J signs a n d sym ptom s The field investigator explained that she was collecting these data to find Hirsch—McCall—Bishop : JAW DYSFUNCTION IN VIOLA AND VIOLIN PLAYERS ■ 839
A R T IC L E S
People who play the violin or viola have signs and symptoms that are sim ilar to those of the TMJ pain dysfunction syndrome.
Jaw motion Seven subjects, five violinists and two violists, whose playing histories were representative of the group, had pho tographs taken of their mandibular movements during maximal voluntary opening and closing. A small light bulb was taped to the chin just below the space between the lower incisors. While the teeth were in centric occlu sion, the bulb was lined up with the maxillary incisors. The subject was asked to quickly perform a maximal jaw opening and closing. After a short period of practice, the subject rested and then performed the maneuver while the shutter of an oscilloscope camera was held open. Several pic tures were made for each subject. Mea surements of mandibular deviation were not different from those obtained by direct visual measurements.
Electromyography These same five violinists and two vio lists also volunteered to have the silent period of both masseter muscles and the right anterior temporalis muscle measured by electromyography. Bipo lar surface electrom yograph ele c trodes were placed on the skin over the right anterior temporalis and both masseter muscles,10 and a ground elec trode was clipped to the left ear. The subject was asked first to relax and then to clench his or her jaw. The elec trical activity of the three muscles was recorded on magnetic tape and poly graph paper. The silent period was obtained by tapping the mandibular symphysis with a tendon hammer while the sub ject clenched maximally.1012 The time that the stimulus occurred was re corded electronically on the fourth channel by means of a simple “makebreak” circuit, which was placed be tween the tendon hammer and the sub ject’s chin. The subject was again instructed to clench the jaw maximally, and im mediately the chin was tapped five 840 ■ JADA, Vol. 104, June 1982
times at irregularly spaced time inter vals of about one second by one inves tigator. The subject was again asked to relax the jaw, and after a minute or two, was instructed to clench maxi mally again, while a second inves tigator performed five chin taps. After the procedure, tape speed was reduced by a factor of 8; and the signals were, played back on the polygraph paper at a paper speed of 100 mm / sec for sub sequent measurement.
The records were analyzed by hand independently by one of the inves tigators and by a technician who was unaware of the specific purpose of the study. The variables measured were the latency and duration of the silent period for all three muscles. Latency was defined as the time from the stimulus to the last peak of the ongoing muscle activity preceding the silent period.12 Duration of the silent period was defined as the time from the last peak of ongoing muscle activity to the first peak in the ongoing electromyograph. Statistical significant (P < .05) was determined by an unpaired t-test.
Results Playing history and symptoms The playing history for all the subjects is shown in Table 1. The mean number of years of playing and the mean number of hours per week spent on the
Table 1
■ Playing history of
51 violists and 15 violinists.___________________
Years of playing* Violists Group 1: 10 to 25 hr/wk 13 women, 2 men Group 2: 26 to 45 hr/wk 12 women, 7 men Group 3: 46 to 65 hr/wk 3 women, 4 men Total 28 women, 23 men Violinists 20 to 50 hr/wk 8 women, 7 men ‘ Mean ± standard deviation. tS e e Figure 2.
instrument for the middle group (that is, 25 to 45 hours, n = 19) were not dif ferent from the means of these vari ables for the entire group of 51 violists. The mean values of the playing history for the violinists were not significantly different from the mean values for either the entire group of 51 violists or the middle group of 19 violists. With only one exception, none of the vio lists or violinists younger than 30 years (26) had any dentures, crowns, or missing teeth (except for third molars). One female violinist (the exception) had a partial denture that replaced three teeth in the right side of the man dible. Of the entire group of violists, 24% had partial dentures; of the 15 vio linists, 27% had partial dentures. None had complete dentures. All who had partial dentures were older than 45 years old, except for the one violinist just mentioned. These musicians had unusually good dental health. None of the dental students played or had played the violin or viola. None of these dental students had any den tures, crowns, or missing teeth other than third molars. All the students were younger than 30 years of age. The type of chinrest used seemed to affect the presence or absence of the practice mark and lump (Fig 2). Both A and B chinrests contact the left man dibular angle during playing. The type C chinrest, which fits directly over the tailpiece of the viola, enables the player to hold the instrument nearly directly beneath the chin. Because the instrument usually does not touch the angle of the jaw under these circum stances, a practice mark and lump may not develop. The frequencies of occurrence of joint sounds, pain, and blunting of the left mandibular angle are shown in Table 2. The maximal jaw openings
Type o f Hours a ch in restt week playing A B C
No. with practice mark
No. with lump
27 ± 16
18 ± 4
4
7
4
14 (93%)
27 ± 14
39 ± 4
7 12
0
19 (100%)
18 (95%)
46 ± 16
58 ± 7
8
8
1
16 (94%)
12 (71%)
34 ± 17
39 ± 17
5 49 (96%)
38 (75%)
28 ± 12
35 ± 10
0
12 (80%)
19 27 8
7
15 (100%)
8 (53%)
A R T IC L E S
Table 2 ■ Mandibular deviations, maximal jaw openings, and frequency of occurrence of TMJ joint sounds, pain, and palpably worn left mandibular angles in violists, violinists, and dental students. No. of subjects
Hours a week playing*
Violists Group 1 (15) Group 2 (19) Group 3 (17) Total (51) Violinists 15 Dental students 115
18 39 58 39
± ± ± ±
4 4 7 17
35 ± 10
Mandibular deviation* (mm)
Direction Right None Left
Maximal opening* (mm)
TMJ sounds (clicking) 12 18 17 47
2.1 1.7 2.1 2.5
12 18 17 47
3 0 0 3
0 1 0 1
4.5 4.8 5.0 4.8
4.4 ± 1.5
15
0
0
4.3 ± 0.8
0.1 ± O .lt
32
59
24
5.2 ± 1.0
3.1 6.0 7.1 5.5
± ± ± ±
± ± ± ±
0.9 0.7 1.0 0.9
TMJ pain
Blunt left mandibular angle
9 (60%) 17 (89%) 14 (82%) 40 (78%)
13 19 17 49
14 (93%)
11 (73%)
15 (100%)
32 (28%)
4 (3%)
(80%) (95%) (100%) (92%)
(87%) (100%) (100%) (96%)
0
*Mean ± standard deviation. tTwenty-two (19%) of the dental students had mandibular deviations from the midline of greater than 3 mm.
and mandibular deviations for the musicians are shown in Table 2 and Figure 3. A typical example of the irregular mandibular movement seen in a violist is shown in Figure 4. Note that the mandible deviates from the midline on opening in a smooth curve. However, on closing, there is a horizontal jump back to the midline, which was as sociated with an audible click in both the right and left TMJ. All the perform ers had jaw motions that deviated from the midline on opening and clicked back into place on closing. All these violinists and violists returned the jaw to the midline. Five of the 15 violinists and two of the 51 violists also volunteered for electromyographic studies of jawclosing muscles. These players were representative of their respective groups in that the mean maximal jaw opening for these violinists was 4.6 ±
0.9 cm, and for the two violists was 4.5 cm and 3.3 cm. The mean mandibular deviation for the five violinists was 4.3 ±1.4 mm, and the values for the two violists were 4.6 mm and 8.3 mm. Latencies and durations of the silent periods for the five violinists and two violists are shown in Table 3. There were no significant differences be tween the latencies and durations of the silent period among the three mus cles (right anterior temporalis, right masseter, and left masseter), nor were there any significant differences be tween the means obtained by the two people who analyzed the data.
number of these individuals have pain in the TMJ area on the right side, joint sounds in the left TMJ, and large devia tions of the mandible to the right of the midline on maximal opening. Further, these musicians have a common factor t h a t a p p e a r s r e l a t e d to t h e s e symptoms: the playing of an instru ment that requires long hours of con tact with the left side of the mandible. Considerable evidence suggests that these musicians exert pressure on the
Discussion This study has demonstrated that people who play the violin or viola have signs and symptoms that are similar to those of the TMJ pain dys function syndrome. A significant
10
A
Open
t
8-
y
Jaw deviation on
6-
maximal
i
opening
A
(mm)
4■
Left
10 to 25
26 to 45
46 +
Violists
26 to 45 Violinists
Hr/wk
Fig 4 ■ M andibular m ovement in violist during m axim al voluntary jaw opening and closing,
Fig 3 ■ M ean jaw deviations on m axim al opening (five to ten trials) for 51 violists, separated into
drawn from photograph. M otion is representa
three groups by hours per w eek o f playing, and for 15 violinists who played 2 6 to 45 hours per
tive of all players with jaw deviations greater
week. Open circles (O) denote those violists who used center chinrest (type C) (n = 5).
than 2 mm from m idline.
H irsch-M cCall-Bishop : JAW DYSFUNCTION IN VIOLA AND VIOLIN PLAYERS ■ 841
A R T IC L E S
Table 3 ■ Silent period latencies and durations in the right anterior tem poralis, right masseter, and left masseter muscles in five violinists and two violists. Subject
Violinists 1 2 3 4 5 Violists 6 7 Mean Standard deviation
Latency (msec)
Duration (msec)
Right anterior temporalis
Right anterior temporalis
Right masseter
Left masseter
Right masseter
Left masseter
11.6 1.1 10.1 1.1
13.4 1.1 10.8 1.3
12.3 1.3 9.2 0.7
24.3 3.7 23.1 3.5 25.6 6.6 29.1 3.7 18.5 1.6
27.8 8.6 24.3 4.5
11.4 0.5 10.9 0.9
24.1 3.1 23.8 3.7 27.2 4.3 28.2 3.6 18.7 1.9
-
-
-
-
-
-
11.4 0.7 10.6 1.4
11.8 0.6 10.4 1.3
26.2 4.3 19.2 2.6
11.4 0.8 10.4 1.3 10.9
13.3 0.8 13.9 1.0 12.3
9.0 0.9 9.3 1.2 10.4
21.8 2.3 31.8 5.0 25.1
21.3 1.7 31.3 2.5 24.7
23.2 2.6 30.0 3.8 25.2
0.7
1.5
1.3
4.4
4.4
3.8
left side of the mandible with the vio lin or viola. First, there is the presence of a callous (the practice mark) in these musicians. Second, the angle of the left side of the mandible is palpably smoother than that of the right side. Third, the violists who supported their instruments directly under the chin using a center chinrest, rather than at the side, did not have significant man dibular deviations or other symptoms of TMJ pain dysfunction syndrome. Further, the size of the mandibular de viation was related to the amount of viola playing (the number of hours a week spent playing the instrument). The weight and size of the instrument were also factors. The frequency of oc currence of pain and the size of the mandibular deviation were signifi cantly greater in the violists than in the violinists. Herman13 measured in 30 violinists the force exerted by the mandible to support the instrument between the left shoulder and jaw without assis tance from the left hand. Using a sling attached to a scale, he was able to show that the support of a 1.5 lb to 2 lb (0.8 kg) violin required from 8 oz to 5 lb of force (0.4 to 4.5 newtons). Presumably, the larger, heavier viola (2.5 to 3.5 lb or 1.5 kg) might require even greater forces to be supported at the shoulder and jaw. However, in actual perfor mance, the instrument is also partly supported by the thumb of the left hand. In addition, Herman found a normal distribution of normal occlu sions and malocclusions among these 842 ■ JADA, Vol. 104, June 1982
-
30 subjects with some tendency to ward anterior overbite. There is one report in which early ar thritic changes were demonstrated in a 22-year-old female violinist.14 We are not aware of any other literature with similar evidence for degenerative changes in the TMJ in violinists; how ever, we find no incompatibility with the suggestions of Reider14 that play ing the violin could produce changes in the TMJ. Therefore, it is likely that the major mechanical factor in the jaw dysfunction that we observed in these violists and violinists was the force exerted on the mandible in maintain ing the position of the instrument. The mean maximal jaw openings (incisal edge to edge) observed by Travell5 in normal (asymptomatic) people were 5.9 cm for men and 5.3 cm for women. Eight-nine percent of the subjects had maximal jaw openings greater than 5.0 cm. In our study, the mean maximal jaw opening in the 95 of 115 dental students, who were asymptomatic for TMJ pain dysfunc tion syndrome or who had only occa sional clicking, was 5.5 ± 0.8 cm. The mean maximal jaw openings for the violinists (4.3 ± 0.8 cm) and the violists (4.8 ± 0.9 cm) were signifi cantly less than those reported in the dental students. This reduction in jaw opening could not be attributed to age or sex. The mean mandibular deviations in both the violinists and violists were significantly greater than those ob served in the 115 dental students. In
addition, with only one exception among the violists, when there was a deviation of the mandible on opening, the deviation was toward the right. Three of the violists reported no symptoms and had no observable mandibular deviations. Another two players had deviations of 2.0 mm or less. All these musicians used a center chinrest and held the viola directly under the midpoint of the mandible. Four of these subjects played ten to 25 hours a week (group 1) and one played 46 to 65 hours a week (group 3). Three of the four violists in group one had used only a center chinrest, had no wearing of the left mandibular angle, nor any mandibular deviation. The fourth violist in group one, who used a center chinrest, had previously used a type A chinrest. This player had a mandibular deviation of 1.8 mm and wearing of the left mandibular angle. The last violist in group 3 had previ ously used a type B chinrest for 35 years, but on purchasing a larger in strument, he found it necessary to switch to a center chinrest, which he has used for the past 15 years. A man dibular deviation of 2/0 mm was pre sent and the left mandibular angle was worn, as it was in the players who used a type A or B chinrest. All of the vio linists and the other violists used either type A or B chinrests, had man dibular deviations greater than 2 mm, and had wearing of the left mandibular angle. Of the players who played more than 30 hours per week, all had man dibular deviations greater than 3 mm. Two violinists (one man, one woman) not included in this study, who play left-handed (that is, the in strument is held on the right side), had mandibular deviations toward the left side, reported pain in the left TMJ area, and had joint noises and stiffness in the right TMJ area. In one of the vio linists, the right mandibular angle was worn. This is the mirror image of the signs observed in the right-handed players. There was no difference in silent period latency or duration in the jawclosing muscles in the musicians from that measured in asymptomatic sub jects. In other studies performed in the same laboratory, values for latency and duration of silent periods in jaw clos ing muscles (masseter and anterior temporalis) have been reported in “normal” patients,10-12 patients with
A R T IC L E S
TMJ pain dysfunction syndrome,10-12 and children before orthodontic treatment20 The durations of the silent periods are significantly longer in all the patient populations than in the normal patients, whereas the dura tions in the asymptomatic subjects are no different from those seen in either the violinists and violists. This finding of normal silent period durations of the jaw closing muscles was unexpected in the light of Her man’s report that musicians use a vise-like grip on the instrument be tween the left side of the mandible and the shoulder.13 The most prevalent theme of schools of violin technique written by the great teachers and per formers is to avoid unnecessary mus cular tension.15-19 The teeth are sepa rated during performance. The man dible is shifted toward the left and down onto the chinrest. This occurs when the performer needs to stabilize the instrument when shifting the left hand from a high position closer to the face to a lower position farther from the face. Surface electromyograms from the right anterior temporalis, right masseter, and left masseter muscles were recorded in one violist while she sup ported the viola solely at the shoulder with the left arm at her side, and dur ing performance of moderately de manding works. Subjective impres sion of the muscular tension involved in instrument support was that it was located primarily in the digastric and left sternocleidomastoid muscles, and occasionally in the left trapezius mus cle if the shoulder was raised. At no time was any significant activity ob served in the electromyograph rec ords. During this performance, the teeth were generally slightly apart; and occasionally during active shift ing downward, the mandible opened and pushed leftward and down onto the viola chinrest. Thus, the force applied to the man dible is not caused by a vise-like grip ping of the instrument associated with clenching of the teeth, but is caused by passive balancing of forces by hooking the jaw over the chinrest. Furthermore, the player does not grip the instrument solely at the shoulder, but also sup ports it on the left thumb and collar bone.1516 Even during active shifting of the left hand up and down the
fingerboard, the thumb remains in constant contact with the neck of the instrument. In other words, a violin or viola is held “like a bridge, not a di ving board.”15
Conclusion We have described in a population of violin and viola players signs and symptoms that are identical to those of TMJ pain dysfunction syndrome. The frequency of occurrence of TMJ noises and pain in the TMJ area was greater in these musicians than in a group of den tal students, and was higher in violists than in violinists who played the same number of years and hours a week. The limitation of mandibular movement and rightward deviation of the mandi ble on opening were significantly greater in these musicians than in the general population. The extent of mandibular deviation increased as the number of playing hours increased and was greater for the violists than for the violinists. This condition is dif ferent from that of classic TMJ paindysfunction syndrome, in that there is no prolongation of the electromyo graph silent period in the jaw closing m uscles. The presence of the symptoms in viola and violin players is related to chronic irritation and me chanical displacement of the mandible by the position of the viola or violin, rather than to any active contraction of the jaw-closing muscles. Because force exerted on the mandible during play ing may contribute to the development of signs and symptoms of jaw dysfunc tion, violinists and violists should use a technique that reduces the force on the mandible by the instrument, which may help to prevent or minimize the pain and dysfunction. fTi&l
The informed consent of all human subjects who participated in the experimental investiga tion reported was obtained after the nature of the procedures and possible discomforts had been explained fully. This study was supported by NIH grants P O lHL-14414 and ROl-D E-04889. The authors thank Victor Stern, professor of viola, University of Miami, Fla; Gerard Reinagel, professor emeritus of m usic and violin, and Joan Smutko, instructor o f violin, Niagara County Community College, NY, for their critical review of this manuscript.
Dr. Hirsch is research assistant professor, de partment of physiology; Dr. M cCall is associate" p rofessor, departm ent of oral m ed icin e; Dr. Bishop is professor, department of physiology, School of Medicine and Dentistry, State Univer sity of New York at Buffalo, Buffalo, 14214. Ad dress requests for reprints to Dr. Hirsch. 1. DeBoever, J.A. Functional disturbances of th e tem porom andibular jo in ts. Oral S c i Rev 2:100-117, 1973. 2. Rugh, J.D., and W. K. Solberg. Psychological im plications in tem porom andibular pain and dysfunction. Oral Sci Rev 7:3 -3 0 ,1 9 7 6 . 3. Greene, C.S., and others. The TMJ paindysfunction syndrome: heterogeneity of the pa tient population. JADA 79 (5 ):1 1 6 8 -1 1 7 2 ,1969. 4. Agerberg, G., and Carlsson, G.E. Functional disorders of the masticatory system. Distribution of symptoms according to age and sex as judged from investigation by questionnaire. Acta Odontol Scand 30:597-613, 1972. 5. Travell, J. Temporomandibular joint dys function. Temporomandibular joint pain referred from the muscles of the head and neck. J Prosthet Dent 10(4):745-763, 1960. 6. Moffett, B. The m orphogenesis of the tem poromandibular joint. Am J Orthod 52:401-415, 1966. 7. Ricketts, R. C linical im plications of the tem poromandibular joint. Am J Orthod 52:416-439, 1966. 8. Reding, G.R.; Zepelin, H.; and Monroe, L.J. Personality study of nocturnal teeth-grinders. Percept Mot Skills 26:523-531, 1968. 9. Guralnick, W.; Kaban, L.B.; and Merrill, R.G. Temporomandibular join t afflictions. N Engl J Med 299(3):123-129, 1978. 10. Bessette, R.; B ish op ,B .; andM ohl, N. Dura tion of the masseteric silent period in patients with TM J syndrome. J Appl Physiol 30(6):8648 6 9 ,1 9 7 1 . 11. Bailey, J.O.; M cCall, W.D.; and Ash, M.M. Electromyographic silent periods and jaw motion parameters: quantitative measures of temporo m an d ib u lar jo in t d y sfu n c tio n s. J D ent R es 56(3):249-254, 1977. 12. McCall, W.D.; Uthman, A.A.; and Mohl, N.D. TM J sym ptom severity and EMG silent periods. J Dent Res 57(5-6]:709-714, 1978. 13. Herman, E. Orthodontic aspects of musical instrument selection. Am J Orthod 65:519-530, 1974. 14. Reider, C.E. Possible premature degenera tive tem porom andibular join t disease in vio linists. J Prosthet Dent 35(6):662-664, 1976. 15. Rolland, P. Basic principles of violin play ing. M u sic E d u cator’s N ation al C on feren ce, W ashington, DC, 1959, pp 10-11. 16. Menuhin, Y., and Primrose, W. Violin and viola. New York, Schirm er Books, 1976, pp 23, 2 9 -3 1 ,4 2 ,4 6 , 179-181. 17. Flesch, C. The art of violin playing. Book one: technique in general, applied technique. New York, Carl Fisher, Inc, 1924, pp 14-49. 18. Neumann, F. V iolin left hand technique: a survey of related literature. Urbana, 111, American String Teachers Assoc. 1969, pp 19-38, 43-44, 49-53, 65. 19. A uer, L. V io lin p layin g as I te ach it. Philadelphia, J. B. Lippincott Co, 1960, pp 10-11, 35. 20. Felli, A.J., and McCall, W.D., Jr. Jaw muscle silent periods before and after rapid palatal ex pansion. Am J Orthod 76:676-681, 1979.
H irsch-M cC all-Bishop: JAW DYSFUNCTION IN VIOLA AND VIOLIN PLAYERS ■ 843