復位を伴う円板前方転位が復位を伴わない円板前方転位へ移行した症例のMR画像所見

摘要

This study was designed to evaluate the suggestion that the clinical findings and MR image findings of anterior disc displacement with reduction cases could not reduce the disc displacement within the follow-up period.We selected 26 joints without remarkable bone changes in the condylar head or glenoid fossa in which reduction disappeared during follow-up. Clinical evaluation focused on temporomandibular pain,trismus, and joint sound. MR imaging was targeted for configuration of articular disc, degree of disc displacement, and condylar head position.Clinical signs observed with progression of the condition were disappearance of joint sound in 12/26 joints(46.1%), temporomandibular pain in 15/26 joints (57.6%),and decreased distance of opening mouth in 19/26 joints (73%). MR image findings were disc configuration changes in 12/26 joints (46.1%), increased degree of anterior displacement of disc in 20/26 joints (76.9%),and condylar head position changes in 9/26 joints (34.6%).It is suggested that the advanced stage of internal derangement is closely associated with the degree of disc displacement.