Arthroscopic treatment of temporomandibular joint locking resulting from disc derangement: two-year results. This article reports 2-year postarthroscopic surgical treatment data for 18 subjects (17 female and 1 male) who had a diagnosis of restricted mandibular movement due to an internal derangement of the temporomandibular joint (TMJ). These subjects had been treated by an average of 2.1 +/- 1.1 doctors for their TMJ problem before seeing the surgeon for arthroscopic treatment. The subjects' mean pain score at the final time point (21 to 30 months after surgery) was decreased by 57% in usual pain intensity. Jaw function showed an average improvement of 67%. These subjects also showed a 13-mm mean increase in their maximum active opening ability at the 2-year postsurgical time point. Slight to definite clicking noises were present presurgically in 11 of 18 patients, and similar joint noises were reported in 14 of 18 patients postsurgically. The mean overall improvement was rated as 8.18 +/- 2.4, with 10 the highest possible rating. One subject rated her improvement as 0, two subjects rated their improvement as 6 out of 10. No significant morbidity was reported by the subjects as a result of their surgery. 