Prevalence of morphological changes in the surfaces of the temporomandibular joint disc associated with internal derangement

Purpose: The purpose of this study was to determine the prevalence of morphological changes in the superior and inferior surfaces in the temporomandibular joint (TMJ) disc and relate them to disc displacement. Materials and Methods: Thirty TMJs obtained from fresh cadavers were studied, The TMJs were dissected, and the superior and inferior surfaces of the disc were inspected and classified as intact, irregular, or perforated. These findings were correlated to the position of the disc. Results: There was a greater prevalence of morphologic changes in the inferior (57%) than in the superior surface (17%) of the disc (P <.001). This was found for joints both with normal disc position and those with disc displacement. There was no relationship between surface irregularities of the inferior surface and the position of the disc. Perforation was seen more frequently in joints with disc displacement than in those with normal disc position. Conclusion: Morphologic changes in the inferior surface of the TMJ disc are more prevalent than those in the superior surface, but this is not related to disc position. However, this needs to be considered when doing arthroscopy of only the superior joint compartment.