The authors prospectively analysed 50 patients with chronic anterior disc displacement without reduction, who underwent arthroscopic lysis and lavage of the temporomandibular joint (TMJ). Patients with symptoms lasting less than 1 year were assigned to Group A ( n = 28) and patients with symptoms lasting more than 1 year to Group B ( n = 22). The most common problems were inflammatory changes of synovial and retrodiscal tissue (Group A, 71%; Group B, 82%). Fibrous adhesions were present in 14% of Group A patients and 45% of Group B patients. Degenerative changes of the disc and articular surface were present in 4% of Group A patients and 32% of Group B patients. Mouth opening increased 123% from baseline in Group A, and 112% in Group B ( P < 0.05). Pain decreased significantly in both groups (Group A, 2.5 points; Group B, 1.68 points; P < 0.05). In conclusion, almost all patients with chronic anterior disc displacement without reduction benefited from arthroscopic lysis and lavage of the TMJ. Patients with a shorter duration of symptoms problems benefited more than those with a longer duration. Arthroscopic lysis and lavage of the TMJ is safe and beneficial in chronic anterior disc displacement without reduction.
Anterior disc displacement of the temporomandibular joint (TMJ) represents an intracapsular dysfunction, where the disc is displaced anteriorly to the condyle . Two different conditions are recognized: anterior disc displacement with reduction, where the proper relationship between the disc and condyle is restored during maximum mouth opening; and anterior disc displacement without reduction, where the disc stays anterior to the condyle and prevents maximum mouth opening. Anterior disc displacement without reduction is clinically apparent by reduced mandibular movement and pain. It is often preceded by disc displacement with reduction, where the sound phenomenon (clicking) in the affected TMJ dominates .
Long-term disc displacement without reduction can progress to anterior band atrophy, flattening and thinning of the dorsal band of the disc, decreased innervation and vascularization of the retrodiscal tissue, and degenerative changes of the articular surfaces, including the development of subchondral cysts . The treatment of anterior disc displacement is usually conservative (biting splints, physiotherapy). If conservative treatment fails, minimally invasive procedures (arthrocentesis) or surgery (arthroscopic lavage and lysis, arthroscopic surgery, open surgery) may be necessary .
Arthroscopy of the TMJ was first described by Ohnishi in 1975. In 1986, S anders described arthroscopic lysis and lavage as a minimally invasive treatment . The effect of arthroscopic lysis and lavage in anterior disc displacement lies primarily in the irrigation of the joint, washout of inflammatory cytokines, and lysis of adhesions. Arthroscopic lysis and lavage is an effective treatment modality for chronic anterior disc displacement without reduction, with an approximately 80% success rate .
The aim of this prospective study was to evaluate the intraarticular changes in anterior disc dislocation without reduction in patients with TMJ symptoms for less than 1 year, compared with those whose complaints persisted beyond 1 year.
Materials and methods
Fifty patients with anterior disc displacement without reduction were prospectively analysed. Inclusion criteria were: a verified diagnosis of anterior disc displacement without reduction by physical examination, X-ray examination, and magnetic resonance imaging of the TMJ and sonography or computed tomography employed when necessary; a 3-month trial of conservative treatment (including occlusal splint and physiotherapy) with unsatisfactory results; unilateral disorder; and a patient without comorbidities, especially endocrine, rheumatological or skeletal diseases. Exclusion criteria were: inability to meet any of the inclusion criteria; inability to evaluate the patient during the entire follow-up period; diagnosis of any medical disorder in the follow-up period; incomplete documentation; and occurrence of any other temporomandibular disorder besides unilateral anterior disc displacement without reduction. Data about the patients’ past and current subjective TMJ problems were acquired using a detailed questionnaire. According to the authors’ experience, the maximum duration of the patients’ subjective problems was 2 years. Patients with symptoms for less than 1 year were assigned to Group A ( n = 28) and patients with symptoms lasting more than 1 year to Group B ( n = 22). Before surgery, pain level and maximum mouth opening were recorded. Pain was evaluated on a 6-point scale (0, no pain; 1, minimal pain; 2, mild pain; 3, moderate pain; 4, severe pain; 5, intolerable pain). Maximum mouth opening was measured as the distance between the upper and lower incisors.
Arthroscopic lysis and lavage
Arthroscopy was performed under general anaesthesia with nasotracheal intubation. The Olympus arthroscope (1.9 mm, 30°) was transbuccally inserted into the upper joint space. A needle for irrigant efflux was inserted into the anterior part of the TMJ . Lavage was performed with more than 1000 ml of Ringer lactate solution. After lavage, patients used a stabilizing occlusal splint. In the first 3 postoperative days, they were instructed to open the mouth as minimally as possible. On the fourth day, physiotherapy was initiated. Analgesics were provided for postoperative pain management.
Pathological and clinical analysis
During arthroscopy, gross macroscopic changes of the articular structures were recorded. For the evaluation of morphological changes, the classification of H olmlund & A xelsson was used ; for the evaluation of fibrous adhesions the Zhang classification was used .
The morphology of the articular surface (normal; fibrillation at the site of the tubercle and/or disc; denudation of the bone and/or disc perforation), the status of the synovial membrane (normal; hypervascularity and/or hyperaemia; synovial hyperplasia), the type of fibrous adhesions (absent, fibres, column, wall), and their location (anterior, by the anterior recessus; medial, by the articular tubercle; posterior) were noted. The results of arthroscopic lavage were evaluated 6 months postoperatively. Level of pain and maximum mouth opening were measured postoperatively. A successful outcome was considered to be a maximum pain level 1 out of 6, and mouth opening of more than 35 mm 6 months postoperatively.
Data are reported as the mean ± standard error of the mean (SEM). A P -value of less than 0.05 between groups was considered statistically significant by the non-paired Student’s t test.
All patients underwent surgery without significant complications. During arthroscopy, Group A patients revealed milder morphological changes than Group B patients. Sixteen percent of all patients had degenerative changes of the articular surface (Group A, 4%; Group B, 32%, Table 1 ). Synovial changes occurred in 76% of all patients (Group A, 71%; Group B, 82%, Table 2 ). Fibrous adhesions occurred in 14 (28%) patients (Group A, 15%; Group B, 45%, Table 3 ). In these 14 patients, 12 (86%) had adhesions localized to the anterior articular compartment, 3 (21%) to the medial compartment, and 4 (29%) to the posterior compartment.
|No pathology||Fibrillation at the site of the tubercle and/or discus||Denudation of the bone, disc perforation||Total|
|Group A||27 (96%)||–||1 (4%)||28 (100%)|
|Group B||15 (68%)||3 (14%)||4 (18%)||22 (100%)|
|Total||42 (84%)||3 (6%)||5 (10%)||50 (100%)|
|No pathology||Hypervascularity hyperaemia||Synovial hyperplasia||Total|
|Group A||8 (29%)||18 (64%)||2 (7%)||28 (100%)|
|Group B||4 (18%)||9 (41%)||9 (41%)||22 (100%)|
|Total||12 (24%)||27 (54%)||11 (22%)||50 (100%)|
|Group A||24 (86%)||3 (11%)||1 (4%)||–||28 (100%)|
|Group B||12 (55%)||4 (18%)||4 (18%)||2 (9%)||22 (100%)|
|Total||36 (72%)||7 (14%)||5 (10%)||2 (4%)||50 (100%)|
The successful outcome of arthroscopic lysis and lavage (maximum pain level 1 out of 6 and mouth opening of more than 35 mm 6 months postoperatively) was observed in 41 out of 50 patients (82%). This result was more apparent in Group A than in Group B patients (89% versus 72%). With regards to mouth opening, Group A patients demonstrated a 123% increase from baseline, whilst Group B patients demonstrated a 112% improvement. These were both significantly improved from their original values, but Group A was significantly better than Group B. Pain decreased significantly in both groups as well (Group A, 2.5 versus Group B, 1.68, P < 0.05, Table 4 ).
|Maximum mouth opening – before (mm)||Maximum mouth opening – after (mm)||Pain – before (0–5)||Pain – after (0–5)|
|Group A||28.25 ± 0.65||34.61 ± 0.57*||3.25 ± 0.18||0.75 ± 0.14*|
|Group B||31.55 ± 0.70||35.41 ± 0.56*||2.27 ± 0.15||0.59 ± 0.17*|
|Total||29.70 ± 0.53||34.96 ± 0.41*||2.82 ± 0.14||0.68 ± 0.11*|
|Difference in mouth opening (mm)||Difference in pain|
|Group A||6.36 ± 0.71 (+23%)||−2.50 ± 0.20 (−77%)|
|Group B||3.86 ± 0.75 (+12%) †||−1.68 ± 0.20 (−74%) †|
|Total||5.26 ± 0.55 (+18%)||−2.14 ± 0.15 (−76%)|