Morphologic differences between superior and inferior disc surfaces in chronic internal derangement of the temporomandibular joint.

This study examines the morphologic differences between the superior and inferior disc surfaces in patients with chronic internal derangement of the temporomandibular joint. Forty-two discs were removed in 33 patients when morphologic or qualitative tissue changes made a reparative procedure impossible. Eighty-three percent of the joints operated in this series showed late opening (grade III) clicking or were considered clinically locked. Specific differences between superior and inferior disc surface anatomy were demonstrated in these cases of long-standing internal derangement.