Prognostic factors in arthrocentesis of the temporomandibular joint: Evaluation of 100 patients with internal derangement

Purpose: The goal of this study was to analyze the prognostic factors for successful arthrocentesis for internal derangement (ID) of the temporomandibular joint (TMJ). Patients and Methods: Arthrocentesis was carried out as the initial treatment in 103 TMJs of 100 patients with ID. The effectiveness of the treatment was evaluated in terms of the postoperative range of maximal mouth opening (MMO) and the degree of preoperative pain on a visual analog scale (VAS). Prognostic factors analyzed were age, sex, duration of painful locking, preoperative and postoperative range of MMO, preoperative degree of pain, preoperative clicking on opening mouth before becoming locked, and magnetic resonance imaging (MRI) findings. These factors were statistically analyzed. Results: Seventy-three cases (71%) satisfied the criteria for success. One week after the procedure, the mean range of MMO in the successful cases (43.8 +/- 5.5 mm) was significantly greater than that in unsuccessful cases (36.9 +/- 6.6 mm) (P < .05). The mean preoperative degree of pain on a VAS in successful cases (4.7 +/- 2.9) was significantly smaller than that in unsuccessful cases (6.2 +/- 2.1) (P < .05). The preoperative incidence of morphologic changes in the mandibular condyle seen on MRI of successful cases was significantly less than that in unsuccessful cases (P < .05). Conclusion: Severe preoperative pain, relapse in the amount of mouth opening within 1 week after arthrocentesis, and preoperative bony changes in the condyle may be predictors of the effectiveness of arthrocentesis for ID of the TMJ. (C) 2001 American Association of Oral and Maxillofacial Surgeons.