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The natural course of anterior disc displacement without reduction in the temporomandibular joint: Follow-up at 6, 12, and 18 months
J Oral Maxillofac Surg 55234-238, 1997
The Natural Course of Anterior Disc Displacement Without Reduction in the Temporomandibular Joint: Folio w-up at 6, 12, and 18 Months SHUICHI SATO, DDS, PHD,” HIROSHI KAWAMURA, DDS, PHD,t HIROSHI NAGASAKA, DDS, PHD,$ AND KATSUTOSHI MOTEGI, MD, DDS, PHD§ Put-pose: The purpose of this study was to examine the natural course of anterior disc displacement without reduction in the temporomandibular joint
CTMJ). Patients and Methods: The subjects were patients who had been diagnosed as having anterior disc displacement without reduction in the TMJ, but who had not undergone any treatment. Forty-four patients were followed for 6 months, 38 for 12 months, and 22 for 18 months. Clinical signs and symptoms were evaluated at each follow-up, and the incidence of successful resolution was determined using the criteria established in 1984 by the American Association of Oral and Maxillofacial Surgeons. Results: The range of motion increased at each time during the follow-up period. Tenderness in the TMJ and the masticatory muscles was alleviated, but the noise in the TMJ remained unchanged at each follow-up time. The incidence of successful resolution was 34.1% at 6 months, 50.0% at 12 months, and 68.2% at 18 months. Conclusions: The clinical signs and symptoms of anterior disc displacement without reduction tend to be alleviated during the natural course of the condition. This should be taken into consideration when anterior disc displacement without reduction is treated.
Anterior disc displacement without reduction in the temporomandibular joint (TMJ) has been treated with medication, occlusal appliances with or without manual repositioning,r3’ physical therapy,3 and surgery.4-‘1 Although most patients benefit from these treatments, we often find some patients whose symptoms improve
spontaneously without any treatment. Lundh et al” found natural alleviation of the signs and symptoms in patients with painful anterior disc displacement without reduction, and no significant benefit of a stabilization splint over no treatment, after 12 months. Therefore, an understanding of the natural history of this disease seems to be necessary if one wishes to evaluate the actual effect of a particular treatment. The purpose of this study was to clarify the natural course of anterior disc displacement without reduction in the TMJ.
Received from the Department of Oral and Maxillofacial Surgery I, Tohoku University School of Dentistry, Sendai, Japan. * Lecturer. 1‘ Associate Professor. $ Assistant. 5 Professor. Address correspondence and reprint requests to Dr Sato: Department of Oral and Maxillofacial Surgery I, Tohoku University School of Dentistry, 4-l Seiryo-machi, Aoba-ku, Sendai 980-77, Japan. 0 1997 American
Association
of Oral and Maxillofacial
Patients
and Methods
The subjects were 44 patients who had been diagnosed as having anterior disc displacement without reduction in the TMJ by a history of clicking followed
Surgeons
0278-2391/97/5503-0005$3.00/o
234
235
SAT0 ET AL Table 3. Resolution After Months, and 1% Months
Table 1. Changes in Maximum Mouth Opening and Lateral Excursion in the 44 Patients With Anterior Disc Displacement Without Reduction at 6 Months Initial Maximum mouth opening (mm) Lateral excursion to the affected side (md Lateral excursion to the unaffected side (mm)
Visit
Paired
Follow-up
35.4 i
NOTE. 6.8 i 2.25
7.3 2 2.01
NS
6.6 !I 2.28
6.6 i
NS
Changes of Clinical at 6 Months
2.84
Findings
Noise in the TMJ Tenderness in the TMJ Tenderness in the masticatory NOTE.
Values
are given
Yes
10 (22.7) 37 (84.1) 16 (36.4)
muscles as number
(%).
12 Months (n = 38)
18 Months (n = 22)
15 (34.1) 29 (65.9)
19 (50.0) 19 (50.0)
15 (68.2) 7 (31.8)
Values
are given
as number
(%).
tance at attempted full mouth opening and lateral excursions were measuredwith a millimeter ruler. Noise in the TMJ and tendernessin the TMJ and masticatory muscles were evaluated by palpation. Changes in the range of motion at maximal mouth opening were analyzed by conventional statistical methods, and the difference from that at the beginning of the study and that at each follow-up time was evaluated using a paired ttest. Chi-squared tests were used to assesschanges in the noise and tenderness in the TMJ and changes in tendernessin the masticatory muscles if the observed frequencies in the 2 X 2 contingency tables differed from those expected. The clinical evaluation was conducted according to the criteria presented by the American Association of Oral and Maxillofacial Surgeons Ad Hoc Study Group on TMJ Meniscus Surgery.i3 The criteria for clinical resolution of signs and symptoms were as follows: tendernessthat is absent or so mild, brief, and infrequent as to be of no concern for the patient; range of motion greater than 35 mm at maximal mouth opening and greater than 6 mm in protrusive and lateral excursions; regular diet that, at worst, avoided tough or hard foods; and minimal inconvenience to the patient by their diet. Results
SIX-MONTH FOLLOW-UP In the 44 patients followed for 6 months, maximal mouth opening increasedfrom 30.1 k 7.09 mm to 35.4
in the 44 Patients
Initial Findings
6 Months (n = 44)
P < ,001
6.59
by limitation of opening without clicking, and confirmed by both arthrography and magnetic resonance imaging (MRI). The criteria for including a patient in this study were as follows: 1) constant or frequent pain in the TMJ, 2) a range of motion less than 35 mm at the initial visit, 3) no previous TMJ treatment, and 4) acceptance of observation without any treatment as the initial choice. Forty-four patients were followed for 6 months, 38 of them for 12 months, and 22 for 18 months. The number of patients who did not respond to repeated recall letters or who had undergone secondary treatment was three at the 6-month follow-up, two at the 12-month follow-up, and eight at the 1%month follow-up. The patients who were followed for 6 months consisted of 2 men or boys and 42 women or girls, with a mean age 30.5 years (range, 13 to 58 years). The patients who were followed for 12 months consisted of 2 men or boys and 36 women or girls, with a mean age 30.5 years (range, 13 to 58 years). The patients who were followed for 18 months consisted of 2 men or boys and 20 women or girls, with a mean age 35.9 years (range, 18 to 58 years). A complete record of maximal mouth opening, lateral excursions, noise in the TMJ, and tenderness in the TMJ and masticatory muscles was obtained at the initial visit and at each follow-up. The interincisal dis-
Table 2. Reduction
12
t-Test Successful Unsuccessful
30.1 i 7.09
6 Months,
Visit
With
Anterior
h-Month No 34 (77.3) 7 (15.9) 28 (63.6)
Yes
9 (20.5) 17 (38.6) 5 (11.4)
Disc
Displacement
Without
Follow-up NO
35 (89.5) 27 (61.4) 39 (88.6)
Chi-Squared
Test
NS
P < ,001 P < ,005
236
THE
Table 4. Changes in Maximum Mouth Opening and Lateral Excursion in the 38 Patients With Anterior Disc Displacement Without Reduction at 12 Months
Table 8. Changes in Maximum Mouth Opening and Lateral Excursion in the 22 Patients With Anterior Disc Displacement Without Reduction at 18 Months
Initial Maximum mouth opening (mm) Lateral excursion to the affected side m4 Lateral excursion the unaffected side (mm)
Visit
Paired
Follow-up
30.8 i- 7.09
36.9 IL 7.15
P < ,001
7.0 t 2.02
7.1 t 2.01
NS
6.6 k 2.41
6.6 ?I 1.78
NS
Maximum mouth opening (mm) Lateral excursion to the affected side (mm) Lateral excursion to the unaffected side (mm)
Findings Noise in the TMJ Tenderness in the TMJ Tenderness in the masticatory NOTE.
Values
are given
muscles
as number
(%).
10 (26.3) 32 (84.2) 14 (36.8)
29.7 k 6.30
REDUCTION
Follow-up
Paired
38.0 I 7.52
t-Test
P < ,001
6.7 t 2.20
7.5 i
2.32
NS
6.3 i
6.6 f 2.06
NS
2.17
FOLLOW-UP
In the 22 patients followed for 18 months, maximal mouth opening increasedfrom 29.7 -t 6.30 mm to 38.0 5 7.52 mm (paired t-test, significant at P < .OOl) (Table 6). Lateral excursion to the affected side and that to the unaffected side remained unchanged at 18 months (Table 6). Joint noise (crepitation) was present in six patients (27.3%) at the initial visit, and decreased by 9.1% (x2 test, not significant at P > .05). Tenderness in the TMJ decreased by 77.3% (x” test, significant at P < .OOS),and tenderness in the masticatory muscles decreased by 22.8% (x2 test, not significant at P > .05) (Table 7). According to the criteria for clinical resolution, The incidence of successfulresolution was 68.2% (Table 3). Discussion The results of this study suggest that the clinical signs and symptoms of anterior disc displacement without reduction in the TMJ tend to be alleviated during the subsequentnatural course. However, in our inclusion criteria we selected patients who accepted
in the 38 Patients
Yes
WITHOUT
Visit
EIGHTEEN-MONTH
In the 38 patients followed for 12 months, maximal mouth opening increased from 30.8 t 7.09 mm to 36.9 t 7.15 mm (paired t-test, significant at P < .OOl) (Table 4). Lateral excursion to the affected side and that to the unaffected side remained unchanged at 12 months (Table 4). Joint noise (crepitation) was present in 10 patients (26.3%) at the initial visit, and increased by 2.6% (x2 test, not significant at P > .05) at 12 months. Tenderness in the TMJ decreasedby 52.6% (x” test, significant at P < .OOS), and tenderness in the masticatory muscles decreased by 28.9% (x2 test, significant at P < .OOl) (Table 5). According to the
Initial
ADD
criteria for clinical resolution, the incidence of successful resolution was 50.0% (Table 3).
TWELVE-MONTH FOLLOW-UP
Findings
OF
Initial
to
Changes of Clinical at 12 Months
COURSE
t-Test
5 6.59 mm (paired t-test, significant at P < .OOl) (Table 1). Lateral excursion to the affected side and that to the unaffected side remained unchanged at 6 months (Table 1). Joint noise (crepitation) was present in 10 patients (22.7%) at the initial visit. It decreased by 2.2% (x2 test, not significant at P > .05) at 6 months. Tenderness in the TMJ decreased by 45.5% (x2 test, significant at P < .OOl), and tenderness in the masticatory muscles decreased by 25.0% (x2 test, significant at P < .005) (Table 2). According to the criteria for clinical resolution, The incidence of successful resolution was 34.1% (Table 3).
Table 5. Reduction
NATURAL
Visit
With
Anterior
12-Month NO
28 (73.7) 6 (15.6) 24 (63.2)
Yes
11 (28.9) 12 (31.6) 3 (7.9)
Disc
Displacement
Without
Follow-up NO
27 (72.1) 26 (68.4) 3.5 (92.1)
Chi-Squared NS P < ,001 P < ,005
Test
SAT0
237
ET AL
Table 7. Reduction
Changes of Clinical at 18 Months
Findings
in the 22 Patients
Initial Findings
YCS
Noise in the TMJ Tenderness in the TMJ Tenderness in the masticatory NOTE.
Values
are given
Visit
muscles
as number
6 (27.3) 19 (86.4) 8 (36.4)
With
Anterior
1 &Month No
Yes
16 (72.7) 3 (13.6) 14 (63.6)
4 (18.2) 2 (9.1) 3 (13.6)
Disc
Displacement
Without
Follow-up NO
18 (81.8) 20 (90.9) 19 (86.4)
Chi-Squared
Test
NS P < ,005 NS
(%).
observation as the first choice of treatment, and thus, their symptoms may have been mild, and this needs to be considered in interpretation of the results. Also to be considered is that some patients were dropped from this trial becausethey did not respond to repeated recall letters or wished secondary treatment. Two patients underwent secondary treatment within 6 months of the initial visit (infusion of sodium hyaluronate), two patients did so between 6 and 12 months (infusion of sodium hyaluronate in one patient and TMJ disc repositioning surgery in one patient), and six patients did so between 12 and 18 months (TMJ disc repositioning surgery). Those patients who had undergone secondary treatment had more severe signs and symptoms than those that did not drop out of this study. There have been some reports in which the natural course of anterior disc displacement without reduction has been examined. Lundh et al” evaluated pain in the TMJ and masticatory muscles in the 26 patients with painful anterior disc displacement without reduction who had not had any treatment for 12 months. The results showed that the pain disappearedin about one third of the patients, another third improved, and 16% of the patients were worse at the 12-month follow-up. Kurita et alI4 also examined the signs and symptoms of 19 patients with anterior disc displacement without reduction who had not had any treatment for 12 months. The results showed that maximal mouth opening increased from 29.6 2 5.90 mm to 41.5 5 7.00 mm, and pain in the TMJ decreasedfrom 89% to 37% at 12 months. Approximately one third of patients had no dysfunction, another third improved, and in about one third of the patients the symptoms remained unchanged at 12 months according to their criteria for clinical resolution. Our results are in accord with those of Lundh et all2 and Kurita et a1.14However, because in our study arthrographic examination of the inferior joint space was performed for detecting disc perforation or disc adhesion to the surface of condyle, and the condition of the inferor joint space, this could not be excluded completely as a possible factor in the improvement in patients’ symptoms. Kircos et all5 and Katzberg et all6 examined the TMJ
disc in asymptomatic subjects by MRI and observed that disc displacement was seenin approximately 30% of asymptomatic subjects. These results suggest that disc displacement does not always cause clinical signs and symptoms, and that clinical signs and symptoms are more relevant in establishing a diagnosis of a TMJ disorder. Our results show that the clinical signs and symptoms of anterior disc displacement without reduction in the TMJ tend to be alleviated during the subsequent course, and that one should take this into consideration when anterior disc displacement without reduction of the TMJ is treated. References 1. Okeson JP: Long-term treatment of disk-interference disorders of the temporomandibular joint with anterior repositioning occlusal splints. J Prosthet Dent 60:611, 1988 2. Chung SC, Kim HS: The effect stabilizaion splint on the TMJ closed lock. J Craniomandib 11:95, 1993 3. Kirk W, Calabrese DK: Clinical evaluation of physical therapy in the management of internal derangement of the temporomandibular joint. J Oral Maxillofac Surg 47:113, 1989 4. McCarty W, Farrar W: Surgery for internal derangement of the temporomandibular joint. J Prosthet Dent 42:191, 1979 5. Dolwick MF, Sanders WB: Temporomandibular joint internal derangement and arthrosis: A surgical atlas. St Louis, MO, Mosby, 1985, p 197 6. Benson BJ, Keith DA: Patient response to surgical and nonsurgical treatment for internal derangement of the temporomandibular joint. J Oral Maxillofac Surg 43:770, 1985 7. Kerstens HCJ, Tuinzing DB, Van der Kwast WAM: Eminectomy and discoplasty for correction of the displaced temporomandibular joint disc. J Oral Maxillofac Surg 47: 150, 1989 8. Montgomery MT, Gordon SM, Sickels JEV, et al: Changes in signs and symptoms following temporomandibular joint disc repositioning surgery. J Oral Maxillofac Surg 50:320, 1992 9. McCain JP, Sanders B, Koslin MG, et al: Temporomandibular joint arthroscopy: A 6-year multicenter retrospective study of 4,831 joints. J Oral Maxillofac Surg 50:926, 1992 10. Holmlund AB, Gynther G, Axelsson S: Diskectomy in treatment of internal derangement of the temporomandibular joint. Oral Surg Oral Med Oral Path01 76:266, 1993 11. Zingg M, Iizuka T, Geering AH, et al: Degenerative temporomandibular joint disease: Surgical treatment and long-term results. J Oral Maxillofac Surg 52: 1149, 1994 12. Lundh H, Westesson P-L, Eriksson L, et al: Temporomandibular joint disc displacement without reduction: Treatment with flat occlusal splint versus no treatment. Oral Surg Oral Med Oral Path01 73:655, 1992
238
DISCUSSION
13. Dolwick MF: 1984 Criteria for TMJ Meniscus Surgery. Chicage, IL, American Association of Oral and Maxillofacial Surgeons, 1984, p 31 14. Kurita K, Westesson P-L, Yuasa H, et al: Clinical findings of closed lock. (2) Natural history over a 6 or 12 month period. J Jpn Sot TMJ 5:415, 1993
15. Kircos LT, Ortendahl DA, Mark AS, et al: Magnetic resonance imaging of the TMJ disc in asymptomatic volunteers. J Oral Maxillofac Surg 45:852, 1987 16. Katzberg RW, Westesson P, Tallents RH, et al: Anatomic disorders of the temporomandibular joint disc in asymptomatic subjects. J Oral Maxillofac Surg 54:147, 1996
J Oral Maxillofac Surg 55238-239, 1997
Discussion The Natural Course of Anterior Disc Displacement Without Reduction in the Temporomandibular Joint: Follow-up at 6, 12, and 18 Months
Allen W. Tarro, DA4D Lowell, Massachusetts The authors of this article state that their results show that the clinical signs and symptoms of anterior disc displacement without reduction (ADD w/o R) tend to be alleviated over time without treatment. However, there are some serious flaws in arriving at that general conclusion from the material presented. First, there is a major problem with the baseline information. Forty-four patients started this study. These patients, who had ADD w/o R accepted observation as the first choice of treatment. The authors did state that their symptoms may have been mild, but, unfortunately, we have no specific information on the other characteristics of these symptoms. With the small number of subjects in this study, it is important to provide information on each individual patient. Although there certainly may be trends observed in following groups of patients, temporomandibular disorders are often complex, with multifactorial causes.‘,* Specific information about individual cases can identify causes and lead to correct diagnosis and treatment. In this study, groups of patients were reported as having limited mouth opening, temporomandibular joint (TMJ) tenderness, and some also had tenderness in the masticatory muscles. How much pain was experienced by each of these patients? How long did each patient have pain? Were there other symptoms? What was the character (severity, onset, duration, etc) of these symptoms? What caused these symptoms? Was any trauma involved? If so, was it acute trauma or chronic trauma? Because more than 35% of the patients had muscle symptoms, were parafunctional jaw habits involved in these cases? These are just some questions that are important to answer in evaluating TMJ disorders. However, none of these matters were addressed in this article. It is difficult for me to imagine 44 of my patients with limited mouth opening, as well as significant pain in the joint or in the muscles around the joint, agreeing to have nothing done but observation for 18 months. There appears to be a number of patients included in this study with pain both in the joint and in the muscles around
the joint. The authors report that more than 35% of the patients had tenderness in the masticatory muscles initially, and at 6, 12, and 18 months. This also flaws the study, because some or all of the symptoms of these patients could be related to a primary muscle problem just as well as to an internal derangement.3 There are also statistical questions that arise on reading the article and evaluating the data provided. There were 44 patients at the start of this study. However, the authors state that the number of patients who did not respond to repeated recall letters or had undergone secondary treatment was three at the 6-month follow-up, two more at the 12-month follow-up, and eight more at the lEGmonth follow-up. That totals 13 patients. But, the l&month follow-up had 22 rather than 31 patients. What happened to the nine missing patients? Furthermore, the percentage of successful resolution of symptoms reported by the authors must be questioned. In the Discussion, the authors stated that 10 patients had undergone secondary treatment, and that these patients had more severe signs and symptoms than those that did not drop out of the study. Again, the question arises as to how severe the symptoms were in the patients who remained in the study. However, beside that point, these 10 patients must be considered nonresolved patients in the statistics. This alters the resolution results reported by the authors. There are also 12 other patients, of the initial 44, that were not considered in the statistics: the three who did not respond to repeated recall letters and the missing nine patients. This is a significant number of patients, which must be taken into consideration when evaluating the results reported. The treatment of closed lock TMJ cases must be predicated on a number of factors. Significant pain and jaw dysfunction are two main reasons for treatment. Treatment is focused on modalities that will bring the patient to the range within which he or she can function adequately without pain. It is not aimed necessarily at correcting every condition that is considered abnormal. There is a treatment ladder, starting with the simplest and least expensive treatment, that is ascended until resolution of the patient’s symptoms occurs4 However, there are exceptions to this treatment philosophy. Current research has shown that in cases of closed lock, especially of sudden onset and with minimal past TMJ history, arthrocentesis is an indicated and very beneficial treatment.‘a6 My experience supports this finding, but I have had much less success in treating closed lock cases by arthrocentesis when this condition has persisted for over 6 months. Therefore, in my opinion, very early treatment with arthro-
The Natural Course of Anterior Disc Displacement Without Reduction in the Temporomandibular Joint: Folio w-up at 6, 12, and 18 Months SHUICHI SATO, DDS, PHD,” HIROSHI KAWAMURA, DDS, PHD,t HIROSHI NAGASAKA, DDS, PHD,$ AND KATSUTOSHI MOTEGI, MD, DDS, PHD§ Put-pose: The purpose of this study was to examine the natural course of anterior disc displacement without reduction in the temporomandibular joint
CTMJ). Patients and Methods: The subjects were patients who had been diagnosed as having anterior disc displacement without reduction in the TMJ, but who had not undergone any treatment. Forty-four patients were followed for 6 months, 38 for 12 months, and 22 for 18 months. Clinical signs and symptoms were evaluated at each follow-up, and the incidence of successful resolution was determined using the criteria established in 1984 by the American Association of Oral and Maxillofacial Surgeons. Results: The range of motion increased at each time during the follow-up period. Tenderness in the TMJ and the masticatory muscles was alleviated, but the noise in the TMJ remained unchanged at each follow-up time. The incidence of successful resolution was 34.1% at 6 months, 50.0% at 12 months, and 68.2% at 18 months. Conclusions: The clinical signs and symptoms of anterior disc displacement without reduction tend to be alleviated during the natural course of the condition. This should be taken into consideration when anterior disc displacement without reduction is treated.
Anterior disc displacement without reduction in the temporomandibular joint (TMJ) has been treated with medication, occlusal appliances with or without manual repositioning,r3’ physical therapy,3 and surgery.4-‘1 Although most patients benefit from these treatments, we often find some patients whose symptoms improve
spontaneously without any treatment. Lundh et al” found natural alleviation of the signs and symptoms in patients with painful anterior disc displacement without reduction, and no significant benefit of a stabilization splint over no treatment, after 12 months. Therefore, an understanding of the natural history of this disease seems to be necessary if one wishes to evaluate the actual effect of a particular treatment. The purpose of this study was to clarify the natural course of anterior disc displacement without reduction in the TMJ.
Received from the Department of Oral and Maxillofacial Surgery I, Tohoku University School of Dentistry, Sendai, Japan. * Lecturer. 1‘ Associate Professor. $ Assistant. 5 Professor. Address correspondence and reprint requests to Dr Sato: Department of Oral and Maxillofacial Surgery I, Tohoku University School of Dentistry, 4-l Seiryo-machi, Aoba-ku, Sendai 980-77, Japan. 0 1997 American
Association
of Oral and Maxillofacial
Patients
and Methods
The subjects were 44 patients who had been diagnosed as having anterior disc displacement without reduction in the TMJ by a history of clicking followed
Surgeons
0278-2391/97/5503-0005$3.00/o
234
235
SAT0 ET AL Table 3. Resolution After Months, and 1% Months
Table 1. Changes in Maximum Mouth Opening and Lateral Excursion in the 44 Patients With Anterior Disc Displacement Without Reduction at 6 Months Initial Maximum mouth opening (mm) Lateral excursion to the affected side (md Lateral excursion to the unaffected side (mm)
Visit
Paired
Follow-up
35.4 i
NOTE. 6.8 i 2.25
7.3 2 2.01
NS
6.6 !I 2.28
6.6 i
NS
Changes of Clinical at 6 Months
2.84
Findings
Noise in the TMJ Tenderness in the TMJ Tenderness in the masticatory NOTE.
Values
are given
Yes
10 (22.7) 37 (84.1) 16 (36.4)
muscles as number
(%).
12 Months (n = 38)
18 Months (n = 22)
15 (34.1) 29 (65.9)
19 (50.0) 19 (50.0)
15 (68.2) 7 (31.8)
Values
are given
as number
(%).
tance at attempted full mouth opening and lateral excursions were measuredwith a millimeter ruler. Noise in the TMJ and tendernessin the TMJ and masticatory muscles were evaluated by palpation. Changes in the range of motion at maximal mouth opening were analyzed by conventional statistical methods, and the difference from that at the beginning of the study and that at each follow-up time was evaluated using a paired ttest. Chi-squared tests were used to assesschanges in the noise and tenderness in the TMJ and changes in tendernessin the masticatory muscles if the observed frequencies in the 2 X 2 contingency tables differed from those expected. The clinical evaluation was conducted according to the criteria presented by the American Association of Oral and Maxillofacial Surgeons Ad Hoc Study Group on TMJ Meniscus Surgery.i3 The criteria for clinical resolution of signs and symptoms were as follows: tendernessthat is absent or so mild, brief, and infrequent as to be of no concern for the patient; range of motion greater than 35 mm at maximal mouth opening and greater than 6 mm in protrusive and lateral excursions; regular diet that, at worst, avoided tough or hard foods; and minimal inconvenience to the patient by their diet. Results
SIX-MONTH FOLLOW-UP In the 44 patients followed for 6 months, maximal mouth opening increasedfrom 30.1 k 7.09 mm to 35.4
in the 44 Patients
Initial Findings
6 Months (n = 44)
P < ,001
6.59
by limitation of opening without clicking, and confirmed by both arthrography and magnetic resonance imaging (MRI). The criteria for including a patient in this study were as follows: 1) constant or frequent pain in the TMJ, 2) a range of motion less than 35 mm at the initial visit, 3) no previous TMJ treatment, and 4) acceptance of observation without any treatment as the initial choice. Forty-four patients were followed for 6 months, 38 of them for 12 months, and 22 for 18 months. The number of patients who did not respond to repeated recall letters or who had undergone secondary treatment was three at the 6-month follow-up, two at the 12-month follow-up, and eight at the 1%month follow-up. The patients who were followed for 6 months consisted of 2 men or boys and 42 women or girls, with a mean age 30.5 years (range, 13 to 58 years). The patients who were followed for 12 months consisted of 2 men or boys and 36 women or girls, with a mean age 30.5 years (range, 13 to 58 years). The patients who were followed for 18 months consisted of 2 men or boys and 20 women or girls, with a mean age 35.9 years (range, 18 to 58 years). A complete record of maximal mouth opening, lateral excursions, noise in the TMJ, and tenderness in the TMJ and masticatory muscles was obtained at the initial visit and at each follow-up. The interincisal dis-
Table 2. Reduction
12
t-Test Successful Unsuccessful
30.1 i 7.09
6 Months,
Visit
With
Anterior
h-Month No 34 (77.3) 7 (15.9) 28 (63.6)
Yes
9 (20.5) 17 (38.6) 5 (11.4)
Disc
Displacement
Without
Follow-up NO
35 (89.5) 27 (61.4) 39 (88.6)
Chi-Squared
Test
NS
P < ,001 P < ,005
236
THE
Table 4. Changes in Maximum Mouth Opening and Lateral Excursion in the 38 Patients With Anterior Disc Displacement Without Reduction at 12 Months
Table 8. Changes in Maximum Mouth Opening and Lateral Excursion in the 22 Patients With Anterior Disc Displacement Without Reduction at 18 Months
Initial Maximum mouth opening (mm) Lateral excursion to the affected side m4 Lateral excursion the unaffected side (mm)
Visit
Paired
Follow-up
30.8 i- 7.09
36.9 IL 7.15
P < ,001
7.0 t 2.02
7.1 t 2.01
NS
6.6 k 2.41
6.6 ?I 1.78
NS
Maximum mouth opening (mm) Lateral excursion to the affected side (mm) Lateral excursion to the unaffected side (mm)
Findings Noise in the TMJ Tenderness in the TMJ Tenderness in the masticatory NOTE.
Values
are given
muscles
as number
(%).
10 (26.3) 32 (84.2) 14 (36.8)
29.7 k 6.30
REDUCTION
Follow-up
Paired
38.0 I 7.52
t-Test
P < ,001
6.7 t 2.20
7.5 i
2.32
NS
6.3 i
6.6 f 2.06
NS
2.17
FOLLOW-UP
In the 22 patients followed for 18 months, maximal mouth opening increasedfrom 29.7 -t 6.30 mm to 38.0 5 7.52 mm (paired t-test, significant at P < .OOl) (Table 6). Lateral excursion to the affected side and that to the unaffected side remained unchanged at 18 months (Table 6). Joint noise (crepitation) was present in six patients (27.3%) at the initial visit, and decreased by 9.1% (x2 test, not significant at P > .05). Tenderness in the TMJ decreased by 77.3% (x” test, significant at P < .OOS),and tenderness in the masticatory muscles decreased by 22.8% (x2 test, not significant at P > .05) (Table 7). According to the criteria for clinical resolution, The incidence of successfulresolution was 68.2% (Table 3). Discussion The results of this study suggest that the clinical signs and symptoms of anterior disc displacement without reduction in the TMJ tend to be alleviated during the subsequentnatural course. However, in our inclusion criteria we selected patients who accepted
in the 38 Patients
Yes
WITHOUT
Visit
EIGHTEEN-MONTH
In the 38 patients followed for 12 months, maximal mouth opening increased from 30.8 t 7.09 mm to 36.9 t 7.15 mm (paired t-test, significant at P < .OOl) (Table 4). Lateral excursion to the affected side and that to the unaffected side remained unchanged at 12 months (Table 4). Joint noise (crepitation) was present in 10 patients (26.3%) at the initial visit, and increased by 2.6% (x2 test, not significant at P > .05) at 12 months. Tenderness in the TMJ decreasedby 52.6% (x” test, significant at P < .OOS), and tenderness in the masticatory muscles decreased by 28.9% (x2 test, significant at P < .OOl) (Table 5). According to the
Initial
ADD
criteria for clinical resolution, the incidence of successful resolution was 50.0% (Table 3).
TWELVE-MONTH FOLLOW-UP
Findings
OF
Initial
to
Changes of Clinical at 12 Months
COURSE
t-Test
5 6.59 mm (paired t-test, significant at P < .OOl) (Table 1). Lateral excursion to the affected side and that to the unaffected side remained unchanged at 6 months (Table 1). Joint noise (crepitation) was present in 10 patients (22.7%) at the initial visit. It decreased by 2.2% (x2 test, not significant at P > .05) at 6 months. Tenderness in the TMJ decreased by 45.5% (x2 test, significant at P < .OOl), and tenderness in the masticatory muscles decreased by 25.0% (x2 test, significant at P < .005) (Table 2). According to the criteria for clinical resolution, The incidence of successful resolution was 34.1% (Table 3).
Table 5. Reduction
NATURAL
Visit
With
Anterior
12-Month NO
28 (73.7) 6 (15.6) 24 (63.2)
Yes
11 (28.9) 12 (31.6) 3 (7.9)
Disc
Displacement
Without
Follow-up NO
27 (72.1) 26 (68.4) 3.5 (92.1)
Chi-Squared NS P < ,001 P < ,005
Test
SAT0
237
ET AL
Table 7. Reduction
Changes of Clinical at 18 Months
Findings
in the 22 Patients
Initial Findings
YCS
Noise in the TMJ Tenderness in the TMJ Tenderness in the masticatory NOTE.
Values
are given
Visit
muscles
as number
6 (27.3) 19 (86.4) 8 (36.4)
With
Anterior
1 &Month No
Yes
16 (72.7) 3 (13.6) 14 (63.6)
4 (18.2) 2 (9.1) 3 (13.6)
Disc
Displacement
Without
Follow-up NO
18 (81.8) 20 (90.9) 19 (86.4)
Chi-Squared
Test
NS P < ,005 NS
(%).
observation as the first choice of treatment, and thus, their symptoms may have been mild, and this needs to be considered in interpretation of the results. Also to be considered is that some patients were dropped from this trial becausethey did not respond to repeated recall letters or wished secondary treatment. Two patients underwent secondary treatment within 6 months of the initial visit (infusion of sodium hyaluronate), two patients did so between 6 and 12 months (infusion of sodium hyaluronate in one patient and TMJ disc repositioning surgery in one patient), and six patients did so between 12 and 18 months (TMJ disc repositioning surgery). Those patients who had undergone secondary treatment had more severe signs and symptoms than those that did not drop out of this study. There have been some reports in which the natural course of anterior disc displacement without reduction has been examined. Lundh et al” evaluated pain in the TMJ and masticatory muscles in the 26 patients with painful anterior disc displacement without reduction who had not had any treatment for 12 months. The results showed that the pain disappearedin about one third of the patients, another third improved, and 16% of the patients were worse at the 12-month follow-up. Kurita et alI4 also examined the signs and symptoms of 19 patients with anterior disc displacement without reduction who had not had any treatment for 12 months. The results showed that maximal mouth opening increased from 29.6 2 5.90 mm to 41.5 5 7.00 mm, and pain in the TMJ decreasedfrom 89% to 37% at 12 months. Approximately one third of patients had no dysfunction, another third improved, and in about one third of the patients the symptoms remained unchanged at 12 months according to their criteria for clinical resolution. Our results are in accord with those of Lundh et all2 and Kurita et a1.14However, because in our study arthrographic examination of the inferior joint space was performed for detecting disc perforation or disc adhesion to the surface of condyle, and the condition of the inferor joint space, this could not be excluded completely as a possible factor in the improvement in patients’ symptoms. Kircos et all5 and Katzberg et all6 examined the TMJ
disc in asymptomatic subjects by MRI and observed that disc displacement was seenin approximately 30% of asymptomatic subjects. These results suggest that disc displacement does not always cause clinical signs and symptoms, and that clinical signs and symptoms are more relevant in establishing a diagnosis of a TMJ disorder. Our results show that the clinical signs and symptoms of anterior disc displacement without reduction in the TMJ tend to be alleviated during the subsequent course, and that one should take this into consideration when anterior disc displacement without reduction of the TMJ is treated. References 1. Okeson JP: Long-term treatment of disk-interference disorders of the temporomandibular joint with anterior repositioning occlusal splints. J Prosthet Dent 60:611, 1988 2. Chung SC, Kim HS: The effect stabilizaion splint on the TMJ closed lock. J Craniomandib 11:95, 1993 3. Kirk W, Calabrese DK: Clinical evaluation of physical therapy in the management of internal derangement of the temporomandibular joint. J Oral Maxillofac Surg 47:113, 1989 4. McCarty W, Farrar W: Surgery for internal derangement of the temporomandibular joint. J Prosthet Dent 42:191, 1979 5. Dolwick MF, Sanders WB: Temporomandibular joint internal derangement and arthrosis: A surgical atlas. St Louis, MO, Mosby, 1985, p 197 6. Benson BJ, Keith DA: Patient response to surgical and nonsurgical treatment for internal derangement of the temporomandibular joint. J Oral Maxillofac Surg 43:770, 1985 7. Kerstens HCJ, Tuinzing DB, Van der Kwast WAM: Eminectomy and discoplasty for correction of the displaced temporomandibular joint disc. J Oral Maxillofac Surg 47: 150, 1989 8. Montgomery MT, Gordon SM, Sickels JEV, et al: Changes in signs and symptoms following temporomandibular joint disc repositioning surgery. J Oral Maxillofac Surg 50:320, 1992 9. McCain JP, Sanders B, Koslin MG, et al: Temporomandibular joint arthroscopy: A 6-year multicenter retrospective study of 4,831 joints. J Oral Maxillofac Surg 50:926, 1992 10. Holmlund AB, Gynther G, Axelsson S: Diskectomy in treatment of internal derangement of the temporomandibular joint. Oral Surg Oral Med Oral Path01 76:266, 1993 11. Zingg M, Iizuka T, Geering AH, et al: Degenerative temporomandibular joint disease: Surgical treatment and long-term results. J Oral Maxillofac Surg 52: 1149, 1994 12. Lundh H, Westesson P-L, Eriksson L, et al: Temporomandibular joint disc displacement without reduction: Treatment with flat occlusal splint versus no treatment. Oral Surg Oral Med Oral Path01 73:655, 1992
238
DISCUSSION
13. Dolwick MF: 1984 Criteria for TMJ Meniscus Surgery. Chicage, IL, American Association of Oral and Maxillofacial Surgeons, 1984, p 31 14. Kurita K, Westesson P-L, Yuasa H, et al: Clinical findings of closed lock. (2) Natural history over a 6 or 12 month period. J Jpn Sot TMJ 5:415, 1993
15. Kircos LT, Ortendahl DA, Mark AS, et al: Magnetic resonance imaging of the TMJ disc in asymptomatic volunteers. J Oral Maxillofac Surg 45:852, 1987 16. Katzberg RW, Westesson P, Tallents RH, et al: Anatomic disorders of the temporomandibular joint disc in asymptomatic subjects. J Oral Maxillofac Surg 54:147, 1996
J Oral Maxillofac Surg 55238-239, 1997
Discussion The Natural Course of Anterior Disc Displacement Without Reduction in the Temporomandibular Joint: Follow-up at 6, 12, and 18 Months
Allen W. Tarro, DA4D Lowell, Massachusetts The authors of this article state that their results show that the clinical signs and symptoms of anterior disc displacement without reduction (ADD w/o R) tend to be alleviated over time without treatment. However, there are some serious flaws in arriving at that general conclusion from the material presented. First, there is a major problem with the baseline information. Forty-four patients started this study. These patients, who had ADD w/o R accepted observation as the first choice of treatment. The authors did state that their symptoms may have been mild, but, unfortunately, we have no specific information on the other characteristics of these symptoms. With the small number of subjects in this study, it is important to provide information on each individual patient. Although there certainly may be trends observed in following groups of patients, temporomandibular disorders are often complex, with multifactorial causes.‘,* Specific information about individual cases can identify causes and lead to correct diagnosis and treatment. In this study, groups of patients were reported as having limited mouth opening, temporomandibular joint (TMJ) tenderness, and some also had tenderness in the masticatory muscles. How much pain was experienced by each of these patients? How long did each patient have pain? Were there other symptoms? What was the character (severity, onset, duration, etc) of these symptoms? What caused these symptoms? Was any trauma involved? If so, was it acute trauma or chronic trauma? Because more than 35% of the patients had muscle symptoms, were parafunctional jaw habits involved in these cases? These are just some questions that are important to answer in evaluating TMJ disorders. However, none of these matters were addressed in this article. It is difficult for me to imagine 44 of my patients with limited mouth opening, as well as significant pain in the joint or in the muscles around the joint, agreeing to have nothing done but observation for 18 months. There appears to be a number of patients included in this study with pain both in the joint and in the muscles around
the joint. The authors report that more than 35% of the patients had tenderness in the masticatory muscles initially, and at 6, 12, and 18 months. This also flaws the study, because some or all of the symptoms of these patients could be related to a primary muscle problem just as well as to an internal derangement.3 There are also statistical questions that arise on reading the article and evaluating the data provided. There were 44 patients at the start of this study. However, the authors state that the number of patients who did not respond to repeated recall letters or had undergone secondary treatment was three at the 6-month follow-up, two more at the 12-month follow-up, and eight more at the lEGmonth follow-up. That totals 13 patients. But, the l&month follow-up had 22 rather than 31 patients. What happened to the nine missing patients? Furthermore, the percentage of successful resolution of symptoms reported by the authors must be questioned. In the Discussion, the authors stated that 10 patients had undergone secondary treatment, and that these patients had more severe signs and symptoms than those that did not drop out of the study. Again, the question arises as to how severe the symptoms were in the patients who remained in the study. However, beside that point, these 10 patients must be considered nonresolved patients in the statistics. This alters the resolution results reported by the authors. There are also 12 other patients, of the initial 44, that were not considered in the statistics: the three who did not respond to repeated recall letters and the missing nine patients. This is a significant number of patients, which must be taken into consideration when evaluating the results reported. The treatment of closed lock TMJ cases must be predicated on a number of factors. Significant pain and jaw dysfunction are two main reasons for treatment. Treatment is focused on modalities that will bring the patient to the range within which he or she can function adequately without pain. It is not aimed necessarily at correcting every condition that is considered abnormal. There is a treatment ladder, starting with the simplest and least expensive treatment, that is ascended until resolution of the patient’s symptoms occurs4 However, there are exceptions to this treatment philosophy. Current research has shown that in cases of closed lock, especially of sudden onset and with minimal past TMJ history, arthrocentesis is an indicated and very beneficial treatment.‘a6 My experience supports this finding, but I have had much less success in treating closed lock cases by arthrocentesis when this condition has persisted for over 6 months. Therefore, in my opinion, very early treatment with arthro-