Internal derangements of the temporomandibular joint evaluated with direct sagittal CT: a prospective study.

Direct sagittal computed tomography (CT) was performed in 454 patients thought to have internal derangement of the temporomandibular joint (TMJ). Of 905 joints examined, 71 were subsequently studied using arthrography and/or surgery. Sensitivity was 91.8%, accuracy 87.3%, and the positive predictive value 93.3%. Degenerative joint disease was detected in 33.6% of joints with anterior meniscal displacement but no reduction, 15.3% of those with displacement and reduction, and 5.0% of those with no identifiable meniscal abnormality. It is concluded that direct sagittal CT is a sensitive and effective method of detecting and characterizing displacement of the TMJ meniscus as well as underlying degenerative joint disease.