Arthroscopic Lysis and Lavage Versus Operative Arthroscopy in the Outcome of Temporomandibular Joint Internal Derangement: A Comparative Study Based on Wilkes Stages

ANESTHESIA/FACIAL PAIN J Oral Maxillofac Surg 69:2513-2524, 2011

Arthroscopic Lysis and Lavage Versus Operative Arthroscopy in the Outcome of Temporomandibular Joint Internal Derangement: A Comparative Study Based on Wilkes Stages Raúl González-García, MD, PhD,* and Francisco J. Rodríguez-Campo, MD† Purpose: To assess whether arthroscopic lysis and lavage (ALL) or operative arthroscopy (OA) is more effective

for the treatment of temporomandibular joint (TMJ) internal derangement at any stage of involvement. In 458 patients (611 joints) with internal derangement of the TMJ classified as Wilkes stages II through V, arthroscopy was performed. Pain (visual analog scale score, 0-100) and maximal interincisal opening were assessed at 1, 3, 6, 9, 12, and 24 months after surgery. Results: ALL was performed in 308 of 611 arthroscopies (50.4%), and OA was performed in 303 arthroscopies (49.59%). A significant decrease in pain (P ⬍ .001) was observed for all patients at any time during the follow-up period from the first month postoperatively to the end of the 2-year follow-up period. A highly significant increase in mouth opening greater than 13 mm was observed in the group of patients classified as Wilkes stage IV from the first month postoperatively. When we compared ALL versus OA among Wilkes stages, no significant differences in terms of pain were observed during the entire follow-up period. Conclusions: Both ALL and OA are equally effective at decreasing pain in patients with TMJ internal derangement of any Wilkes stage. Patients classified as Wilkes stage IV presenting with chronic closed lock of the TMJ had the highest decrease in pain and the highest increase in mouth opening among the stages, thus confirming these patients as the best candidates for arthroscopy. © 2011 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 69:2513-2524, 2011 Patients and Methods:

Internal derangement of the temporomandibular joint (TMJ) was defined by Dolwick and Riggs1 as an abnormal relation between the temporomandibular disc with respect to the mandibular condyle, the temporal fossa, and the temporal eminence of the TMJ. Clinically, it may be accompanied by pain,

*Attending Surgeon, Department of Oral and Maxillofacial-Head and Neck Surgery, University Hospital Infanta Cristina, Badajoz, Spain. †Attending Surgeon, Department of Oral and Maxillofacial-Head and Neck Surgery, University Hospital La Princesa, Madrid, Spain. Address correspondence and reprint requests to Dr GonzálezGarcía: Calle Los Yébenes 35, 8C, 28047 Madrid, Spain; e-mail: [email protected] © 2011 American Association of Oral and Maxillofacial Surgeons

0278-2391/11/6910-0012$36.00/0 doi:10.1016/j.joms.2011.05.027

limitation of mouth opening, clicking, and locking. In 1978 Wilkes2 first established a classification to correlate clinical and radiologic signs with surgical findings. Later, with the advent of minimally invasive surgical approaches, Bronstein and Merrill3 correlated Wilkes stages with arthroscopic findings. Since then, several arthroscopic approaches have also been used, with most of them being classified as isolated arthroscopic lysis and lavage (ALL) or a more complex operative arthroscopy (OA). The term “lysis” was first used by Sanders,4 meaning “sweeping with a blunt probe to eliminate the suction cup effect of the disc to the fossa and to lyse adhesions.” The technique consists of performing a lysis, or breaking of adherences, between the articular surfaces, as well as lavage with abundant serum and intraoperative mandibular movements, or “sweeping.” In our series ALL was performed by a

2513

2514 single-puncture technique where lysis was directly performed with the arthroscope, and an outflow needle was used for lavage. In our series OA consisted of a double-puncture technique for the introduction of the arthroscope and a working cannula to perform electrocoagulation of the posterior ligament, injection of substances, and/or myotomy of the lateral pterygoid muscle. Comparison of ALL versus OA for the treatment of chronic closed lock (CCL) of the TMJ was previously performed by our group.5 In this study no differences in relation to pain relief or increase in maximal interincisal opening (MIO) between ALL and OA for the treatment of CCL of the TMJ were observed. We also observed that arthroscopy of the TMJ was a useful technique for the treatment of patients with CCL of the TMJ regardless of the status of the upper joint surface or the synovial lining,6 with a significant decrease in pain and a parallel increase in MIO from the first month postoperatively in patients with any grade of synovitis and/or chondromalacia. Despite these previous findings in patients with CCL classified as Wilkes stage IV,7 controversy exists in relation to which technique—ALL or OA—is more effective for the treatment of TMJ internal derangement. This may be generalized to the rest of the Wilkes stages,2 because a systematic review of arthroscopic results among stages is still absent. In a review of the literature, Laskin8 showed that the results of OA were no better than isolated ALL. It was believed that restoring joint mobility rather than disc position was the most important factor, because it produced a better distribution of forces within the joint, providing the perfusion of nutrients and the elimination of inflammatory tissue breakdown products.9 However, Indresano10 recognized that lavage only treated inflammation and questioned the ability of simple ALL to correct mechanical aspects of internal derangement, and thus he advocated for advanced double-puncture techniques for OA to treat both mechanical and inflammatory aspects of TMJ internal derangement. Moses and Poker11 and Segami et al12 reported that improvement in MIO was significantly better when extensive techniques involving anterior release of the disc and lateral capsular release were used, than when only conventional ALL was used. The purpose of this study was to compare ALL versus OA in relation to the clinically established Wilkes classification.2,3 The efficacy of both arthroscopic methods was also evaluated in relation to precise follow-up intervals among stages. We hypothesize that there is no difference between OA and ALL in the treatment of TMJ disorders.

TEMPOROMANDIBULAR JOINT INTERNAL DERANGEMENT

Patients and Methods PATIENTS

Our series consisted of 670 joints (341 right and 329 left joints) in 500 consecutive patients (49 male and 451 female patients) undergoing arthroscopic procedures in our department between 1995 and 2004. Data were analyzed retrospectively. All the patients had undergone previous unsuccessful nonsurgical treatment and had a variety of grades of internal derangement according to Wilkes staging. Preoperative conservative treatment consisted of nonsteroidal anti-inflammatory drugs, together with muscle relaxants, for 2 weeks. Medical treatment was followed by splint therapy up to 12 weeks if no improvement was observed. Surgery was considered if an adequate trial of nonoperative treatments failed in patients. To eliminate possible selection bias, included patients had unilateral involvement or had bilateral involvement with similar Wilkes stages in both TMJs. Some of the patients were excluded from this study because of lack of similar Wilkes stages bilaterally. Some other patients had unilateral involvement and were classified as Wilkes stage I, so they were also excluded. Therefore 458 patients (611 joints) classified as Wilkes stages II through V and also presenting unilateral involvement or presenting bilateral involvement with similar Wilkes stages were finally selected. This research was approved by the local institutional review board. All patients received 1 g of amoxicillin–clavulanic acid intraoperatively. One gram of amoxicillin–clavulanic acid was also administered every 8 hours during the early postoperative period for 5 days. We also administered 4 mg of dexamethasone 4 times a day during the first 24 hours postoperatively. Patients began physiotherapy, consisting of active exercises for mouth opening, laterality, and protrusion, on day 2 postoperatively. A 100-mm visual analog scale (VAS) (range, 0-100) was used for the evaluation of TMJ pain before and after the procedure. The absence of pain was scored as 0. If pain was present, the patient was asked to select a score from 1 to 100. MIO, mandibular protrusion, and lateral excursion movements were also measured. Surgical procedures and evaluation of the patients were done by the 2 main surgeons (F.J.R.-C. and R.G.-G.). Patients in Wilkes stages II through IV were assessed at 1, 3, 6, 9, 12, and 24 months after surgery. Success for ALL and OA was evaluated according to criteria of the American Association of Oral and Maxillofacial Surgeons,13 later modified by Eriksson and Westesson,14 who considered the technique successful when a VAS score of less than 20 and MIO of 35 mm or more were obtained.

2515 20.54 ⫾ 22.0 38.04 ⫾ 6.20 6.38 ⫾ 4.36 7.42 ⫾ 2.53 7.86 ⫾ 6.09 23.79 ⫾ 23.97 36.18 ⫾ 6.62 5.72 ⫾ 2.54 6.99 ⫾ 2.80 7.23 ⫾ 2.60 González-García and Rodríguez-Campo. Temporomandibular Joint Internal Derangement. J Oral Maxillofac Surg 2011.

25.10 ⫾ 23.27 35.86 ⫾ 7.13 5.82 ⫾ 2.31 7.10 ⫾ 2.59 7.53 ⫾ 2.52 25.02 ⫾ 22.88 35.52 ⫾ 6.35 5.48 ⫾ 2.30 6.88 ⫾ 2.66 7.07 ⫾ 2.44 32.99 ⫾ 23.49 29.59 ⫾ 6.38 4.35 ⫾ 2.26 5.49 ⫾ 2.63 5.87 ⫾ 2.81

28.90 ⫾ 23.80 32.59 ⫾ 7.22 5.06 ⫾ 2.59 6.45 ⫾ 2.82 6.39 ⫾ 2.72

12 mo (mean ⫾ SD) 9 mo (mean ⫾ SD) 6 mo (mean ⫾ SD)

54.47 ⫾ 22.98 29.43 ⫾ 7.76 4.39 ⫾ 2.36 6.24 ⫾ 3.04 6.15 ⫾ 3.21

The mean age was 29.76 years (range, 14-69 years) for the whole series, although the most prevalent group comprised patients aged between 20 and 29 years. Of 458 evaluated patients, 419 (91.5%) were female patients and 39 (8.5%) were male patients. Unilateral TMJ involvement was present in 305 patients (66.6%), whereas bilateral TMJ involvement was present in 153 (33.4%), with a total number of 611 joints evaluated. The mean preoperative VAS score was 54.47 ⫾ 22.98 (Table 1). The mean preoperative MIO for the whole series was 29.43 ⫾ 7.76 mm (95% confidence interval, 1-35 mm), as shown in Table 1. Mean preoperative mandibular protrusion and mandibular lateral excursion are also shown in Table 1.

Pain score on VAS MIO (mm) Protrusion (mm) Right lateral excursion (mm) Left lateral excursion (mm)

Results

3 mo (mean ⫾ SD)

We used SPSS statistical software (version 13.0; SPSS, Chicago, IL) to analyze the data. Descriptive statistics for continuous and categorical variables were obtained. For the whole group of patients without considering Wilkes staging, the Student t test for paired data was used to compare mean values for pain (VAS) and MIO preoperatively and postoperatively. In an attempt to compare isolated ALL of the TMJ versus OA with respect to pain (VAS) and MIO values after arthroscopy, 2 independent groups were established, and subsequently, the Student t test for unpaired data was applied. One-way analysis of variance (ANOVA) was used to compare pain and MIO among Wilkes stages II through V at each time point in each group (ALL and OA), with VAS and MIO as dependent factors and Wilkes stage as an independent factor. P ⬍ .05 was considered statistically significant.

1 mo (mean ⫾ SD)

STATISTICS

Preoperative (mean ⫾ SD)

Nasoendotracheal intubation with the patient under general anesthesia was initially performed. After the entrance of a 23-gauge needle into the superior joint space, distension of the capsule was performed with lactated Ringer solution. This maneuver favored the introduction of a cannula within the superior joint space by means of punctures with sharp- and blunttipped trocars. Continuous lavage with lactated Ringer solution was maintained with an irrigation line. A Dyonics 2.2-mm 30° arthroscope (Smith & Nephew, Andover, MA) was used in all patients. Arthroscopic procedures were classified into 2 main groups: ALL and OA. Within the latter group, several techniques were performed, such as electrocautery of the posterior ligament, myotomy of the lateral pterygoid muscle attachments, myotomy together with electrocautery, motor debridement, and disc suturing.

Table 1. VAS AND FUNCTION (MIO, LATERAL EXCURSION MOVEMENTS, AND PROTRUSION) OF WHOLE SERIES INCLUDING ALL WILKES STAGES FROM II THROUGH V AND ARTHROSCOPIC PROCEDURES

SURGICAL TECHNIQUE

24 mo (mean ⫾ SD)

GONZÁLEZ-GARCÍA AND RODRÍGUEZ-CAMPO

28.29 ⫾ 25.45§ 34.56 ⫾ 30.15‡ Abbreviations: F, female; M, male. *Results obtained in 10 of 17 patients. †Results obtained in 4 of 17 patients. ‡Results obtained in 9 of 17 patients. §Results obtained in 7 of 17 patients.

González-García and Rodríguez-Campo. Temporomandibular Joint Internal Derangement. J Oral Maxillofac Surg 2011.

36.75 ⫾ 28.20† 15.20 ⫾ 14.35* 46.15 ⫾ 19.75 41.82 4:1

53.18 ⫾ 30.45

29.10 ⫾ 21.24*

16.06 ⫾ 18.48 20.78 ⫾ 22.47 21.74 ⫾ 21.81 25.62 ⫾ 23.91 34.46 ⫾ 24.08 30.25 11:1

53.33 ⫾ 23.17

29.47 ⫾ 23.94

25.89 ⫾ 25.05 23.78 ⫾ 21.99 28.39 ⫾ 23.60 26.45 ⫾ 22.92 30.32 ⫾ 22.62 27.61 10:1

56.62 ⫾ 21.53

29.85 ⫾ 25.15

24.31 ⫾ 24.24 35.32 ⫾ 29.91 33.39 ⫾ 27.31 21.38 ⫾ 18.67 24.26 ⫾ 21.16 29.48 ⫾ 22.68 54.96 ⫾ 23.10 28.95 18:1

II (57 patients [12.44%], 72 joints [11.78%]) III (132 patients [28.82%], 183 joints [29.95%]) IV (252 patients [51.95%], 333 joints [54.50%]) V (17 patients [3.50%], 23 joints [3.76%])

24 mo 12 mo 9 mo 6 mo

VAS (Mean ⫾ SD)

3 mo 1 mo Preoperative

Mean Age (yr) Gender (F/M) Wilkes Stage

ALL was performed in 156 patients (34.06%), whereas OA was performed in 302 patients (65.93%). Within the latter group, electrocautery of the posterior ligament was performed in 245 OA procedures (81.12%). Isolated myotomy of the lateral pterygoid muscle attachments was performed in 13 of 302 OA procedures (4.3%), whereas myotomy together with electrocoagulation of the posterior ligament was performed in 24 (7.94%). Motor debridement was performed in 36 OA procedures (11.92%), whereas disc suturing was performed in 37 OA procedures (12.25%). Several arthroscopic findings were observed, although TMJ was completely normal in 38 (6.21%) of the procedures. Grade I and grade II synovitis15 was observed in 270 (44.18%) of the TMJs, whereas grade III and grade IV synovitis was observed in 212 (34.69%). Grade I and grade II chondromalacia16 was present in 238 (38.95%) of the TMJs, whereas grade III and grade IV chondromalacia was observed in 147 (24.05%). Fibrous adherences within the upper joint space were present in 18.03% of the TMJs, whereas obliteration of the superior joint space was only observed in 4.75%. Osteophytes and loose bodies were only observed in 2.29% and 0.65% of the arthroscopies, respectively. In relation to TMJ pain, the mean VAS score decreased to 32.99, 28.90, 25.02, 25.10, 23.79, and 20.54 at 1, 3, 6, 9, 12, and 24 months after surgery, respectively. After the application of the Student t test for paired data, we could observe a significant decrease in TMJ pain after arthroscopy (P ⬍ .001) from the first month postoperatively to the end of the follow-up period (Table 1). With respect to MIO, the mean values changed to 29.59 mm, 32.59 mm, 35.52 mm, 35.86 mm, 36.18 mm, and 38.04 mm at 1, 3, 6, 9, 12, and 24 months postoperatively, respectively. Values for mandibular protrusion and mandibular lateral excursion are shown in Table 1. We could observe a significant increase in MIO after arthroscopy (P ⬍ .001) from the third month after surgery to the end of the follow-up period. A significant increase in lateral excursion movements after arthroscopy (P ⬍ .05) was achieved from the sixth month after surgery to the end of the follow-up period. Similarly, a significant increase in mandibular protrusion after arthroscopy (P ⬍ .001) was also observed from the third month after surgery to the end of the follow-up period. Of 458 patients, 57 (12.44%), 132 (28.82%), 252 (51.95%), and 17 (3.50%) were classified as Wilkes stages II, III, IV, and V, respectively. In relation to the number of involved joints, 72 (11.78%), 183 (29.95%), 333 (54.50%), and 23 (3.76%) were classified as Wilkes stages II, III, IV, and V, respectively (Tables 2, 3). The mean preoperative VAS score was 54.96,

TEMPOROMANDIBULAR JOINT INTERNAL DERANGEMENT

Table 2. PAIN SCORE ON VAS PREOPERATIVELY AND AT FOLLOW-UP ACCORDING TO WILKES STAGES

2516

2517

30.14 ⫾ 4.67§ 27.89 ⫾ 5.55‡ Abbreviations: F, female; M, male. *Results obtained in 10 of 17 patients. †Results obtained in 4 of 17 patients. ‡Results obtained in 9 of 17 patients. §Results obtained in 7 of 17 patients.

González-García and Rodríguez-Campo. Temporomandibular Joint Internal Derangement. J Oral Maxillofac Surg 2011.

26.00 ⫾ 7.61† 29.30 ⫾ 4.39* 27.62 ⫾ 5.63 41.82 4:1

26.47 ⫾ 7.68

27.60 ⫾ 6.78*

37.79 ⫾ 6.25 35.51 ⫾ 6.67 34.82 ⫾ 7.25 34.85 ⫾ 6.36 28.60 ⫾ 6.02 30.25 11:1

24.68 ⫾ 4.87

31.18 ⫾ 7.06

38.49 ⫾ 5.76 37.31 ⫾ 5.67 37.95 ⫾ 6.23 36.50 ⫾ 5.88 30.04 ⫾ 6.57 27.61 10:1

34.86 ⫾ 6.09

34.08 ⫾ 6.93

40.19 ⫾ 5.59 39.50 ⫾ 6.13 39.06 ⫾ 5.09 39.57 ⫾ 5.64 37.26 ⫾ 5.81 33.23 ⫾ 6.28 38.72 ⫾ 4.48 28.95 18:1

II (57 patients [12.44%], 72 joints [11.78%]) III (132 patients [28.82%], 183 joints [29.95%]) IV (252 patients [51.95%], 333 joints [54.50%]) V (17 patients [3.50%], 23 joints [3.76%])

6 mo 1 mo Preoperative

Mean Age (yr) Gender (F/M) Wilkes Stage

Table 3. MIO PREOPERATIVELY AND AT FOLLOW-UP ACCORDING TO WILKES STAGES§

3 mo

MIO (Mean ⫾ SD)

9 mo

12 mo

24 mo

GONZÁLEZ-GARCÍA AND RODRÍGUEZ-CAMPO

56.62, 53.33, and 53.18 for Wilkes stages II, III, IV, and V, respectively. A significant decrease in pain (P ⬍ .001) was observed for every group of patients at any time during the follow-up period from the first month after surgery to the end of the 2-year follow-up period (Table 4). For Wilkes stages II, III, IV, and V, VAS values decreased to 24.26, 29.85, 29.47, and 29.10, respectively, at the third month, and they further changed to 24.31, 25.89, 16.06, and 28.29, respectively, at the second year (Table 2, Fig 1). In relation to mandibular function, mean preoperative MIO was 38.72 mm, 34.86 mm, 24.68 mm, and 26.47 mm for Wilkes stages II, III, IV, and V, respectively. For Wilkes stages II and III, only a slight increase in mouth opening was observed (39.57 mm and 36.50 mm, respectively) from the sixth month after surgery, with an endpoint increase of less than 4 mm for both groups. A similar increase in MIO was observed for Wilkes stage V patients, although the values at 6 months and 24 months (29.30 mm and 30.14 mm, respectively) were lower than those for stages II and III, in a similar fashion to preoperative differences in MIO values between Wilkes stages II and III and Wilkes stage V (Table 3). In the group of patients with Wilkes stage II, no significant increase in mouth opening was observed at any time during the follow-up period. In fact, a significant decrease in MIO (P ⬍ .001) was observed at the first month, which disappeared starting with the third month. This phenomenon was also observed in Wilkes stage III patients. However, patients within this group showed a significant increase in mouth opening from 9 months to 24 months, at which time no significant differences were again observed. In the group of patients with Wilkes stage IV, significant differences (P ⬍ .001) in terms of mouth opening were observed from the first month postoperatively to the end of the follow-up period (Table 4). Interestingly, a final increase by more than 13 mm was observed in this group from the first month after surgery (34.85 mm and 37.79 mm at 6 months and 24 months, respectively), despite the fact that preoperative MIO values were lower than those for Wilkes stages II and III (Table 3, Fig 2). In the group of patients with Wilkes stage V, no significant differences in terms of mouth opening were observed at any time during the follow-up period. Table 5 summarizes mean VAS and MIO values for ALL versus OA for Wilkes stages II through V. When comparing ALL versus OA, we observed no significant differences in terms of pain among Wilkes stages during the whole follow-up period, except for a significant difference (P ⫽ .03) at 9 months in the group of patients classified as Wilkes stage III (Table 6). However, this difference did not persist during the rest of the follow-up and was not considered clinically relevant. In relation to mouth opening, significant

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TEMPOROMANDIBULAR JOINT INTERNAL DERANGEMENT

Table 4. STATISTICAL ASSOCIATION BETWEEN PREOPERATIVE AND POSTOPERATIVE PAIN SCORE ON VAS AND BETWEEN PREOPERATIVE AND POSTOPERATIVE MIO ACCORDING TO WILKES STAGE DETERMINED WITH STUDENT t TEST FOR PAIRED DATA (P VALUES)

P Value Preoperative vs 1 mo

Preoperative vs 3 mo

Preoperative vs 6 mo

Preoperative vs 9 mo

Preoperative vs 12 mo

Preoperative vs 24 mo

VAS MIO

⬍.001*† ⬍.001*‡

⬍.001*† .30

⬍.001*† .47

⬍.001*† .46

⬍.001*† .56

⬍.001*† .14

VAS MIO

⬍.001*† ⬍.001*‡

⬍.001*† .42

⬍.001*† .32

⬍.001*† ⬍.01*†

⬍.001*† ⬍.01*†

⬍.001*† .06

VAS MIO

⬍.001*† ⬍.001*†

⬍.001*† ⬍.001*†

⬍.001*† ⬍.001*†

⬍.001*† ⬍.001*†

⬍.001*† ⬍.001*†

⬍.001*† ⬍.001*†

VAS MIO

⬍.001*† .92

⬍.001*† .31

⬍.001*† .74

⬍.001*† .33

⬍.001*† .62

⬍.001*† .17

Wilkes Stage II III IV V

*Statistically significant (P ⬍ .05). †Significant decrease in pain or significant increase in MIO. ‡Significant decrease in MIO. González-García and Rodríguez-Campo. Temporomandibular Joint Internal Derangement. J Oral Maxillofac Surg 2011.

differences between ALL and OA were observed 1) at 24 months in Wilkes stage II, 2) at 1 month in Wilkes stage III, and 3) at 1 month in Wilkes stage IV. At 1 month in Wilkes stage III and Wilkes stage IV, mouth opening was significantly lower for the OA group in comparison to the ALL group. For Wilkes stage II patients, those undergoing OA showed significantly better MIO values than those undergoing ALL at the second year, although this difference was not evident at any other time point during the follow-up period. For Wilkes stage III patients, preoperative mouth opening was significantly lower in those undergoing OA than those undergoing ALL. This difference per-

sisted at the first month postoperatively but disappeared from the third month forward. For Wilkes stage IV patients, significant lower MIO was observed in the OA group at the first month postoperatively, although this difference did not persist during the rest of the follow-up period. No differences were observed for patients classified as Wilkes stage V during the follow-up period evaluated (Table 6). In relation to pain and function, success rates (percentages) for ALL/OA at each time point of the follow-up period in relation to Wilkes stages are summarized in Table 7. Although some differences were observed, mostly for Wilkes stages II and III, success

Mean VAS values according to Wilkes stage 60

VAS score (0-100)

50 Wilkes II

40

Wilkes III Wilkes IV

30

Wilkes V

Lineal (Wilkes II) Lineal (Wilkes III)

20

Lineal (Wilkes IV) Lineal (Wilkes V)

10

0 Pre-op

1 month

3 months

6 months

9 months

12 months 24 months

FIGURE 1. Evolution of pain according to Wilkes stage. Pre-op, preoperatively. González-García and Rodríguez-Campo. Temporomandibular Joint Internal Derangement. J Oral Maxillofac Surg 2011.

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GONZÁLEZ-GARCÍA AND RODRÍGUEZ-CAMPO

Mean MIO values according to Wilkes stage 50 45

MIO (mm)

40

Wilkes II Wilkes III

35

Wilkes IV Wilkes V

30

Lineal (Wilkes II) Lineal (Wilkes III)

25

Lineal (Wilkes IV) Lineal (Wilkes V)

20 15

Pre-op

1 month

3 months

6 months

9 months

12 months 24 months

FIGURE 2. Evolution of mouth opening according to Wilkes stage. Pre-op, preoperatively. González-García and Rodríguez-Campo. Temporomandibular Joint Internal Derangement. J Oral Maxillofac Surg 2011.

rates for pain and mouth opening did not follow any fixed pattern, globally showing that ALL and OA did not essentially differ in terms of success during the follow-up period. Success rates for pain and MIO were quite similar for ALL and OA during the whole follow-up period for the group of patients classified as Wilkes stage IV. Success rates for patients classified as Wilkes stage V were not considered relevant because of the low number of patients within this group. To compare pain and MIO among Wilkes stages at each time point for each group (ALL and OA), we used 1-way ANOVA. In relation to the decrease in pain for the group of patients treated by ALL, no significant differences between Wilkes stages were observed at any time during the follow-up period. For patients treated by OA, no significant differences between Wilkes stages were observed at any time during the follow-up period, except at 24 months (global P ⫽ .01) between Wilkes stages II and IV (P ⫽ .04) and between Wilkes stages III and IV (P ⫽ .01) (Table 8). In relation to the increase in MIO for the group of patients treated by ALL, significant differences between Wilkes stages were observed preoperatively and at 1, 3, 6, 9, and 12 months postoperatively. These differences disappeared at the end of the follow-up period. In relation to the increase in MIO for the group of patients treated by OA, significant differences between Wilkes stages were observed preoperatively and at 1, 3, and 6 months postoperatively. These differences disappeared at 9 and 12 months but persisted at the end of the follow-up period (Table 8).

Discussion Under a general approach, several items can be highlighted from the results of our study: 1) patients

with advanced disease, classified as Wilkes stages IV and V, were significantly older than patients with early disease, classified as Wilkes stages II and III; 2) the presence of bilateral involvement of the TMJ was high, occurring in one third of the patients; and 3) the distribution of arthroscopic techniques performed was almost equal, with approximately 50% of the joints treated with each technique (ALL and OA), although no randomization was performed. Although several techniques were used and combined within the group of patients treated with OA, electrocoagulation of the posterior ligament was performed in more than 88% of the cases, thus providing some homogeneity in this otherwise heterogeneous group. However, the objective of our study was not to assess which operative technique was better; our objective was to perform a direct comparison of the overall group with respect to the group of patients treated with isolated ALL. Further randomized controlled studies are necessary to properly assess the effectiveness of each OA technique. The main limitation of this study was its retrospective design and the absence of a controlled randomized distribution of patients for each treatment group. Although a large number of patients in the ALL group had bilateral involvement, selection of patients with the same Wilkes stage may have alleviated a possible selection bias. The main strength of our study was the high number of operated patients. The presence of a high mean VAS score of 54 together with a severe decrease in mean MIO to 29 mm for the whole series validated the inclusion of patients for arthroscopy. Interestingly, no statistically significant differences between mean values were observed for preoperative pain among Wilkes stages, thus indicating that pain may not necessarily be more

2520

Table 5. VAS AND MIO MEAN VALUES FOR ALL AND OA IN WILKES STAGES II THROUGH V

Wilkes Stage II (n ⫽ 57)

Arthroscopic Technique VAS/MIO ALL

VAS MIO

OA

VAS MIO

III (n ⫽ 132)

ALL

VAS MIO

OA

VAS MIO

ALL

VAS MIO

OA

VAS

MIO V (n ⫽ 17)

ALL

VAS MIO

OA

VAS MIO

1 mo

3 mo

6 mo

9 mo

12 mo

24 mo

(mean ⫾ SD)

(mean ⫾ SD)

(mean ⫾ SD)

(mean ⫾ SD)

(mean ⫾ SD)

(mean ⫾ SD)

(mean ⫾ SD)

51.81 ⫾ 24.36 (n ⫽ 26) 38.96 ⫾ 4.60 (n ⫽ 26) 57.61 ⫾ 22.04 (n ⫽ 31) 38.52 ⫾ 4.45 (n ⫽ 31) 55.63 ⫾ 16.30 (n ⫽ 40) 36.63 ⫾ 5.36 (n ⫽ 40) 57.11 ⫾ 23.41 (n ⫽ 92) 34.09 ⫾ 6.25 (n ⫽ 92) 53.39 ⫾ 23.74 (n ⫽ 84) 25.20 ⫾ 5.54 (n ⫽ 84) 53.30 ⫾ 22.95 (n ⫽ 168) 24.42 ⫾ 4.49 (n ⫽ 168) 37.50 ⫾ 31.09 (n ⫽ 6) 29.00 ⫾ 11.41 (n ⫽ 6) 61.73 ⫾ 27.79 (n ⫽ 11) 25.09 ⫾ 4.82 (n ⫽ 11)

30.30 ⫾ 22.8 (n ⫽ 23) 34.17 ⫾ 6.63 (n ⫽ 23) 28.72 ⫾ 22.96 (n ⫽ 25) 32.36 ⫾ 5.95 (n ⫽ 25) 25.75 ⫾ 20.98 (n ⫽ 36) 32.14 ⫾ 5.52 (n ⫽ 36) 32.47 ⫾ 23.17 (n ⫽ 77) 29.06 ⫾ 6.83 (n ⫽ 77) 33.46 ⫾ 24.48 (n ⫽ 69) 30.04 ⫾ 6.78 (n ⫽ 69) 34.98 ⫾ 23.96 (n ⫽ 134) 27.85 ⫾ 5.46 (n ⫽ 134) 43.0 ⫾ 21.30 (n ⫽ 6) 26.50 ⫾ 5.91 (n ⫽ 6) 47.56 ⫾ 20.2 (n ⫽ 9) 28.11 ⫾ 5.79 (n ⫽ 9)

26.80 ⫾ 25.62 (n ⫽ 20) 38.15 ⫾ 5.46 (n ⫽ 20) 20.87 ⫾ 13.22 (n ⫽ 15) 36.07 ⫾ 6.25 (n ⫽ 15) 25.27 ⫾ 23.51 (n ⫽ 26) 35.42 ⫾ 6.07 (n ⫽ 26) 32.33 ⫾ 25.89 (n ⫽ 48) 33.37 ⫾ 7.30 (n ⫽ 48) 27.90 ⫾ 21.46 (n ⫽ 61) 32.31 ⫾ 7.20 (n ⫽ 61) 30.45 ⫾ 25.43 (n ⫽ 98) 30.47 ⫾ 6.92 (n ⫽ 98) 20.33 ⫾ 16.77 (n ⫽ 3) 29.0 ⫾ 9.64 (n ⫽ 3) 32.86 ⫾ 22.98 (n ⫽ 7) 27.0 ⫾ 6.05 (n ⫽ 7)

24.08 ⫾ 19.94 (n ⫽ 12) 37.75 ⫾ 5.72 (n ⫽ 12) 17.78 ⫾ 17.30 (n ⫽ 9) 42.0 ⫾ 4.79 (n ⫽ 9) 26.35 ⫾ 24.82 (n ⫽ 26) 37.88 ⫾ 6.32 (n ⫽ 26) 26.53 ⫾ 21.88 (n ⫽ 40) 35.60 ⫾ 5.47 (n ⫽ 40) 24.77 ⫾ 23.02 (n ⫽ 47) 34.89 ⫾ 6.04 (n ⫽ 47) 26.09 ⫾ 24.51 (n ⫽ 85) 34.82 ⫾ 6.56 (n ⫽ 85) 17.0 ⫾ 19.27 (n ⫽ 5) 28.20 ⫾ 6.18 (n ⫽ 5) 13.40 ⫾ 9.18 (n ⫽ 5) 30.40 ⫾ 1.51 (n ⫽ 5)

33.57 ⫾ 25.33 (n ⫽ 7) 39.29 ⫾ 16.32 (n ⫽ 7) 33.60 ⫾ 29.97 (n ⫽ 10) 38.90 ⫾ 5.23 (n ⫽ 10) 18.40 ⫾ 21.78 (n ⫽ 15) 39.67 ⫾ 5.79 (n ⫽ 15) 34.15 ⫾ 23.05 (n ⫽ 26) 36.96 ⫾ 6.37 (n ⫽ 26) 19.69 ⫾ 18.34 (n ⫽ 45) 34.91 ⫾ 7.43 (n ⫽ 45) 23.52 ⫾ 24.43 (n ⫽ 52) 34.75 ⫾ 7.17 (n ⫽ 52) —

35.63 ⫾ 28.5 (n ⫽ 16) 39.19 ⫾ 5.18 (n ⫽ 16) 34.92 ⫾ 32.99 (n ⫽ 12) 39.92 ⫾ 7.45 (n ⫽ 12) 26.52 ⫾ 24.56 (n ⫽ 23) 38.17 ⫾ 5.64 (n ⫽ 23) 22.34 ⫾ 20.68 (n ⫽ 44) 36.86 ⫾ 5.70 (n ⫽ 44) 22.09 ⫾ 23.21 (n ⫽ 53) 35.44 ⫾ 6.38 (n ⫽ 53) 19.97 ⫾ 22.10 (n ⫽ 86) 35.56 ⫾ 6.84 (n ⫽ 86) —

20.27 ⫾ 20.62 (n ⫽ 15) 38.20 ⫾ 5.00 (n ⫽ 15) 29.82 ⫾ 28.56 (n ⫽ 11) 42.91 ⫾ 5.39 (n ⫽ 11) 22.81 ⫾ 24.70 (n ⫽ 16) 39.31 ⫾ 5.10 (n ⫽ 16) 27.48 ⫾ 25.48 (n ⫽ 31) 38.06 ⫾ 6.11 (n ⫽ 31) 17.27 ⫾ 21.18 (n ⫽ 33) 37.88 ⫾ 7.03 (n ⫽ 33) 15.35 ⫾ 16.88 (n ⫽ 57) 37.74 ⫾ 5.82 (n ⫽ 57) —

—

—

—

—

—

—

—

—

—

NOTE. Numbers in parentheses indicate the number of patients with available data for each group and period of time. González-García and Rodríguez-Campo. Temporomandibular Joint Internal Derangement. J Oral Maxillofac Surg 2011.

TEMPOROMANDIBULAR JOINT INTERNAL DERANGEMENT

IV (n ⫽ 252)

Preoperative

2521

GONZÁLEZ-GARCÍA AND RODRÍGUEZ-CAMPO

Table 6. COMPARISON OF VAS AND MIO BETWEEN ALL AND OA FOR WILKES STAGES II THROUGH V DETERMINED WITH STUDENT t TEST FOR UNPAIRED DATA (P VALUES)

Wilkes Stage

P Value Preoperative

1 mo

3 mo

6 mo

9 mo

12 mo

24 mo

VAS MIO

.34 .71

.81 .32

.42 .30

.45 .08

.99 .88

.95 .76

.33 .03*

VAS MIO

.87 .02*

.14 .02*

.25 .22

.97 .12

.03* .18

.46 .37

.55 .48

VAS MIO

.97 .23

.67 .01*

.49 .11

.76 .95

.38 .91

.58 .92

.63 .91

VAS MIO

.12 .45

.71 .65

.42 .69

.72 .47

II III IV V

*Statistically significant (P ⬍ .05).

pain values for Wilkes stages III and IV in comparison to Wilkes stage II, but also with a higher decrease in pain for Wilkes stages III and IV than for Wilkes stage II. It seems that arthroscopy ultimately shows less benefit for stage II than for the more severely affected stages (ie, stages III and IV). Improvement in relation to pain was not followed by a parallel significant increase in mouth opening for Wilkes stage II at any time during the follow-up period, as well as for Wilkes stage III before 9 months. In contrast, a highly significant increase in mouth opening was observed for the group of patients classified as Wilkes stage IV from the first month postoperatively. These results are quite similar to previously published data in patients affected by CCL of the TMJ and classified as Wilkes stage IV.5,6 Figure 2 shows how the increase in mouth opening was more pronounced in Wilkes stage IV than in Wilkes stage II or III, thus leading to similar

González-García and Rodríguez-Campo. Temporomandibular Joint Internal Derangement. J Oral Maxillofac Surg 2011.

severe in advanced stages than in early stages. In relation to preoperative mouth opening, a highly statistically significant difference (P ⬍ .001) was observed for both ALL and OA among Wilkes stages, with advanced stages showing progressively lower MIO values. In relation to arthroscopic findings, despite the presence of clinical symptoms and signs, in up to 6% of the cases, no morphologic or structural alteration within the upper joint space was observed after arthroscopy. In a previous study by our group concerning the influence of the upper joint surface and synovial lining in 257 patients affected by CCL of the TMJ treated with arthroscopy, grade I or II synovitis and grade III or IV synovitis were present in 50.58% and 41.86% of patients, respectively.8 These results contrast with lower percentages for grade I or II synovitis and grade III or IV synovitis observed in the present study, when considering all Wilkes stages and not only stage IV. It can be concluded that both scarce and severe involvement of the synovial lining seem to be more frequent in advanced disease, such as cases with CCL of the TMJ. Otherwise, severe chondromalacia has been reported to occur in approximately 31% of the cases affected by CCL of the TMJ. In this study 24.09% of the joints showed severe chondromalacia, also indicating that severe involvement of the upper joint surface seems to be present more frequently in advanced stages. A significant decrease (P ⬍ .001) in pain was observed from the first month postoperatively to the end of the follow-up period in all Wilkes stages. As depicted in Figure 1, evolution of pain according to Wilkes stage showed some particularities, with higher

Table 7. SUCCESS RATE (VAS SCORE <20, MIO >30 MM) ACCORDING TO AMERICAN ASSOCIATION OF ORAL AND MAXILLOFACIAL SURGEONS CRITERIA FOR ALL AND OA AT EACH TIME POINT DURING FOLLOW-UP PERIOD IN RELATION TO WILKES STAGE

Wilkes Stage

1 mo

3 mo

6 mo

12 mo

24 mo

38% 58%

61% 70%

75% 61%

60% 75%

88% 74%

43% 40%

65% 66%

91% 91%

74% 71%

78% 91%

56% 33%

71% 68%

71% 73%

75% 79%

86% 78%

40% 20%

59% 50%

69% 64%

69% 74%

74% 74%

46% 21%

57% 35%

71% 52%

73% 61%

87% 66%

40% 11%

61% 29%

69% 53%

76% 62%

86% 71%

— —

— —

— —

— —

— —

— —

— —

— —

— —

— —

II ALL VAS MIO OA VAS MIO III ALL VAS MIO OA VAS MIO IV ALL VAS MIO OA VAS MIO V* ALL VAS MIO OA VAS MIO

*Success rates in group with Wilkes stage V were not considered because of the small number of patients within this group. González-García and Rodríguez-Campo. Temporomandibular Joint Internal Derangement. J Oral Maxillofac Surg 2011.

2522

TEMPOROMANDIBULAR JOINT INTERNAL DERANGEMENT

Table 8. ONE-WAY ANOVA FOR COMPARISON OF PAIN AND MIO AMONG WILKES STAGES AT EACH TIME POINT IN EACH GROUP (ALL AND OA) (P VALUES)

P Values Preoperative

ALL VAS MIO Wilkes Wilkes Wilkes Wilkes Wilkes Wilkes OA VAS MIO Wilkes Wilkes Wilkes Wilkes Wilkes Wilkes

stage stage stage stage stage stage

stage stage stage stage stage stage

1 mo

3 mo

II vs stage III II vs stage IV II vs stage V III vs stage IV III vs stage V IV vs stage V

.32 ⬍ .001* — ⬍ .001* — ⬍ .001* — —

.24 .01* — .04* — — — —

.66 .002* — — — — — —

II vs stage III II vs stage IV II vs stage V III vs stage IV III vs stage V IV vs stage V

.53 ⬍ .001* ⬍ .001* ⬍ .001 — ⬍ .001* .001* —

.26 .007* — .04* — — — —

.46 .001* — .02* .008* — .04* —

6 mo

9 mo

12 mo

24 mo

.83 .01* — — — — .04* —

.20 .04* — — — .02* — —

.16 .02* — .02* — — — —

.59 .62 NA NA NA NA NA NA

.47 .003* .02* — ⬍ .001* .01* — .002*

.15 .13 NA NA NA NA NA NA

.10 .08 NA NA NA NA NA NA

.01*† .02* — .02* — — — —

NOTE. Wilkes stages II, III, IV, and V were compared preoperatively and at 1, 3, and 6 months. Wilkes stages II, III, and IV were compared at 9, 12, and 24 months. Wilkes stage V was not included for evaluation at 9, 12, and 24 months because of the low number of patients within this group at these time points. Global P values are given for VAS and MIO. Specific P values resulting from paired comparison of Wilkes stages for significant MIO values are also shown below the global P value for MIO. Dashes indicate no significant difference for a specific Wilkes stage pair. Abbreviation: NA, not applicable. *Statistically significant (P ⬍ .05). †Specific P values resulting from paired comparison of Wilkes stages for significant VAS score at 24 months were as follows: P ⫽ .04 for comparison of Wilkes stages II and IV and P ⫽ .01 for comparison of Wilkes stages III and IV. González-García and Rodríguez-Campo. Temporomandibular Joint Internal Derangement. J Oral Maxillofac Surg 2011.

mean MIO values at the end of the follow-up period despite the fact that preoperative MIO values were significantly lower. Maximum effectiveness regarding both decrease in pain and increase in mouth opening makes arthroscopy especially suitable for the treatment of Wilkes stage IV internal derangement of the TMJ. The fact that no significant increase in MIO values was observed at any time during the follow-up period for patients classified as Wilkes stage V would lead us to conclude that arthroscopy, though effective in terms of pain relief, seems to be not effective when considering mandibular function within this group. However, caution has to be maintained in relation to this finding because of the low number of patients classified as Wilkes stage V in this study. From the ANOVA test, it can be concluded that mean VAS values did not statistically differ among Wilkes stages for patients treated with ALL. A similar conclusion can be assumed for the group of patients treated with OA in relation to pain, except for mean VAS values at 24 months, which statistically differed between Wilkes stages II and IV (29.82 and 15.35, respectively; P ⫽ .04) and between Wilkes stages III and IV (27.48 and 15.35, respectively; P ⫽ .01). These

results also confirm, as depicted in Figure 1, that although pain relief was a fact for all Wilkes stages; it reached the highest amount of decrease for patients with CCL at Wilkes stage IV. In relation to variance of mean MIO values among Wilkes stages, significant differences were observed preoperatively and at different time points for both ALL and OA. In the ALL group, the most important contrasts were observed between Wilkes stages II and IV preoperatively and at 1 and 12 months and between Wilkes stages III and IV preoperatively and at 6 months. In both cases, significantly lower mean MIO values were observed for Wilkes stage IV. These lower MIO values at particular time points did not appear during the other periods of follow-up, and ultimately, the differences among stages disappeared. However, the presence of lower mean MIO values for Wilkes stage IV in comparison to Wilkes stages II and III at particular time points seems comprehensible because the mean preoperative MIO value for stage IV was much lower. Moreover, the lineal increase in MIO for Wilkes stage IV is considerably higher than that for Wilkes stages II and III, with a global disappearance of any significant difference at the end of the follow-up period (Fig 2).

GONZÁLEZ-GARCÍA AND RODRÍGUEZ-CAMPO

The aim of performing an analysis of success rate according to the stage of internal derangement is based on variable results previously reported in the literature. Bronstein and Merrill3 observed a success rate of 96% for stage II, 83% for stage III, 88% for stage IV, and 63% for stage V. Holmlund et al16 reported a success rate of only 50% for patients with CCL with osteoarthrosis, corresponding to Wilkes stage V, whereas Murakami et al17 reported a success rate of approximately 90% for ALL in stages III and IV, and needed OA for a success rate of 93% in stage V. In our study, with strict success criteria of a VAS pain score of less than 20 and mouth opening of 35 mm or greater, we observed an increasing success rate for both ALL and OA at each time point of the follow-up period. From the results of this study, it can be concluded that both ALL and OA are equally effective at decreasing pain in patients with TMJ internal derangement at any Wilkes stage. Moreover, ALL and OA did not differ with respect to mouth opening from the first month postoperatively for Wilkes stages II and V and from the third month postoperatively for Wilkes stages III and IV. Within these results, significantly lower MIO values for OA at 1 month postoperatively could be attributable to the higher inflammatory response within the upper compartment of the TMJ after more complex arthroscopic maneuvers. Similar conclusions can be highlighted from success rates in relation to pain and function for ALL and OA among Wilkes stages. Recently, Smolka and Iizuka,18 in a study of 26 joints that underwent ALL, found an acceptable overall success rate of 78.3%, although the treatment was less successful for stages IV and V (71.4% and 75%, respectively) than for stages II and III (80% and 85.7%, respectively). OA was introduced as anterior release of the joint capsule or the pterygoid muscle to allow for posterior repositioning of the disc, as well as electrocautery of the posterior ligament. Good preliminary results with OA were obtained by Davis et al,7 McCain and de la Rua,19 and Tarro,20 although direct comparison studies between OA and ALL were still absent. In a subsequent study by Indresano,10 103 of 188 patients who underwent ALL and 121 of 212 patients who underwent OA were evaluated and compared with regard to pain and function. Within the group of patients with ALL who were followed up for 8.3 years, pain was reduced by 71% and disability was reduced by 66%. In comparison, patients undergoing OA, with a mean follow-up of 4.8 years, showed a pain reduction of 81% and a disability improvement of 86%. The differences were statistically significant. Interestingly, within the ALL group, 37% of the patients had further surgery and, therefore, the first procedure had failed, in contrast to only 9% of the patients in the OA group. Although the study was retrospective, the

2523 results were consistent with previously published data. In contrast, Miyamoto et al,21 in a comparison study of 41 joints treated with ALL and 73 joints treated with arthroscopic anterolateral capsular release (AALCR) in patients with advanced internal derangement (Wilkes stages III through V), found similar good results in terms of pain and function for both treatment modalities, except for MIO at 1 month after surgery, with AALCR providing significantly better results. They concluded that ALL within the superior joint space was suitable and effective for patients with advanced internal derangement with locking and that AALCR was necessary only if early wide mouth opening was required. These results are in concordance with data previously published by González-García et al5 on the treatment of patients with Wilkes stage IV internal derangement and CCL, in which no statistical differences were observed between both arthroscopic techniques at any time point. Moreover, the results from the present study confirm these observations among all Wilkes stages. White,22 in a recent review of articles published in the last few years, supports the idea that despite the use of advanced arthroscopic techniques for internal derangement, no definitive differences in outcome—range of motion, postoperative pain, or time required to rehabilitate the joint—were observed, whether these procedures were used or only ALL was used. In contrast to Miyamoto et al,21 we observed slightly significantly lower values for mouth opening in patients undergoing OA in comparison to patients undergoing ALL in Wilkes stages III and IV in the early postoperative period, as well as lower success rates. However, these differences did not persist at the third month after surgery and later. One explanation that should be considered is the presence of a higher joint inflammatory response after OA that may limit mouth opening in the early postoperative period. Both ALL and OA are equally effective at decreasing pain in patients with TMJ internal derangement at any Wilkes stage. A highly significant increase in mouth opening was observed in the group of patients classified as Wilkes stage IV from the first month postoperatively. While directly comparing ALL and OA, we found that both techniques did not differ with respect to mouth opening from the first month postoperatively for Wilkes stages II and V and from 3 months for Wilkes stages III and IV. Patients classified as Wilkes stage IV presenting with CCL of the TMJ had the highest decrease in pain and the highest increase in mouth opening among the stages, thus confirming that these patients are the best candidates for arthroscopy.

2524

References 1. Dolwick MF, Riggs RR: Diagnosis and treatment of internal derangements of the temporomandibular joint. Dent Clin North Am 27:561, 1983 2. Wilkes CH: Structural and functional alterations of the temporomandibular joint. Northwest Dent 57:287, 1978 3. Bronstein SL, Merrill RG: Clinical staging for TMJ internal derangement: Application to arthroscopy. J Craniomandib Disord 6:7, 1992 4. Sanders B: Arthroscopic surgery of the temporomandibular joint: Treatment of internal derangement with persistent closed lock. Oral Surg Oral Med Oral Pathol 62:361, 1986 5. González-García R, Rodríguez-Campo FJ, Monje F, et al: Operative versus simple arthroscopic surgery for chronic closed lock of the temporomandibular joint: A clinical study of 344 arthroscopic procedures. Int J Oral Maxillofac Surg 37:790, 2008 6. González-García R, Rodríguez-Campo FJ, Monje F, et al: The influence of the upper joint surface and synovial lining in the outcome of chronic closed lock of the TMJ treated with arthroscopy. Int J Oral Maxillofac Surg 68:35, 2010 7. Davis CL, Kaminishi RM, Marshall MW: Arthroscopic surgery for treatment of closed lock. J Oral Maxillofac Surg 49:704, 1991 8. Laskin DM: Internal derangements, in Laskin DM, Greene CS, Hylander W (eds): Temporomandibular Disorders: An Evidence-Based Approach to Diagnosis and Treatment. Chicago, IL, Quintessence Publishing, 2006, pp 253-259 9. Laskin DM: Arthrocentesis for the treatment of internal derangements of the temporomandibular joint. Alpha Omegan 102:46, 2009 10. Indresano AT: Surgical arthroscopy as the preferred treatment for internal derangements of the temporomandibular joint. J Oral Maxillofac Surg 59:308, 2001 11. Moses JJ, Poker ID: TMJ arthroscopic surgery: An analysis of 237 patients. J Oral Maxillofac Surg 47:790, 1989

TEMPOROMANDIBULAR JOINT INTERNAL DERANGEMENT 12. Segami N, Murakami K, Hosaka H, et al: Arthroscopic anterolateral capsular release for internal derangement of the temporomandibular joint. Jpn Arthrosc Assoc 18:105, 1993 13. Dolwick MF, Reid S, Sanders B, et al: Criteria for TMJ Meniscus Surgery. Chicago, IL, American Association of Oral and Maxillofacial Surgeons, 1984, p 31 14. Eriksson L, Westesson PL: Temporomandibular joint diskectomy. No positive effect of temporary silicone implant in a 5-year follow-up. Oral Surg Oral Med Oral Pathol 74:259, 1992 15. Sanders B, Buoncristiani R: Diagnostic and surgical arthroscopy of the temporomandibular joint: Clinical experience with 137 procedures over a 2-year period. J Craniomandib Disord 1:202, 1987 16. Holmlund A, Gynther G, Axelsson S: Efficacy of arthroscopic lysis and lavage in patients with chronic locking of the temporomandibular joint. Int J Oral Maxillofac Surg 23:262, 1994 17. Murakami K, Moriya Y, Goto K, et al: Four-year follow-up study of temporomandibular joint arthroscopic surgery for advanced stage internal derangements. J Oral Maxillofac Surg 54:285, 1996 18. Smolka W, Iizuka T: Arthroscopic lysis and lavage in different stages of internal derangement of the temporomandibular joint: Correlation of preoperative staging to arthroscopic findings and treatment outcome. J Oral Maxillofac Surg 63:471, 2005 19. McCain JP, de la Rua H: Principles and practice of operative arthroscopy of the human temporomandibular joint. Oral Maxillofac Surg Clin North Am 1:135, 1989 20. Tarro AW: Arthroscopic treatment of anterior disc displacement: A preliminary report. J Oral Maxillofac Surg 47:353, 1989 21. Miyamoto H, Sakashita H, Miyata M, et al: Arthroscopic surgery of the temporomandibular joint: Comparison of two successful techniques. Br J Oral Maxillofac Surg 37:397, 1999 22. White RD: Arthroscopic lysis and lavage as the preferred treatment for internal derangement of the temporomandibular joint. J Oral Maxillofac Surg 59:313, 2001