Tissue reactions associated with internal derangement of the temporomandibular joint. A radiographic, cryomorphologic, and histologic study.

Ten temporomandibular joint specimens, five with clinical signs of arthropathology and five without, were examined by means of tomography, double-contrast tomography, and serial cryosectioning combined with histologic staining of sections for tissue identification. Of the five joints with signs of arthropathology four demonstrated disc displacement. The fifth joint showed a post-traumatic condition. Four of the joints with clinical signs of arthropathology demonstrated hyperplastic connective tissue retaining contrast medium in the posterior part of the fossa. This hyperplastic connective tissue contained extravasated blood and enlarged cavernous structures lacking endothelial lining. Extravasated blood is one probable source of temporomandibular joint pain. All joints with permanently displaced discs demonstrated perforation of a hyalinized posterior disc attachment. Without tissue identification such an attachment is likely to be misinterpreted as being the disc itself.