Temporomandibular joint clicking with nonreducing anterior displacement of the meniscus.

Patients who have temporomandibular joint (TMJ) clicking and pain are assumed to have an anterior displacement of the meniscus with reduction on opening of the jaw. On the basis of this assumption, these patients are treated nonsurgically with splint therapy. Of 301 TMJs examined, 108 (36%) produced clinically audible clicks on opening, closing, or both. Fluoroscopy and arthrotomography studies for 16 (15%) showed anteriorly displaced menisci without reduction. The mean age of this group was 32 years, with a range of 17-51 years. The duration of the patients' symptoms ranged from three months to eight years (mean 3.7 years). Bilateral degenerative joint disease was noted in 8/16 (50%). Operative findings in four patients suggested the cause of the clicking sound as a frictional impact between the degenerated surface of the condyle and the hypertrophied displaced meniscus. These observations demonstrate that an audible click may not imply a reduction of a displaced meniscus.