P L Westesson1, T A Larheim, H Tanaka. 1. Department of Radiology, University of Rochester School of Medicine and Dentistry, NY, USA.
Abstract
PURPOSE: The purpose of this study was to describe the imaging characteristics of posterior disc displacement of the temporomandibular joint (TMJ). MATERIALS AND METHODS: The study was based on 35 joints with posterior disc displacement and a control material of bilateral TMJ images of 62 healthy volunteers. The images were analyzed, and criteria for posterior disc displacement were developed. RESULTS: Posterior disc displacement was characterized by the disc or a major part of the disc being located posterior to the superior prominence of the condyle. Three subcategories of posterior disc displacement could be identified: a thin flat disc, a grossly posteriorly displaced disc, and a perforated disc with a portion of the disc displaced posteriorly. Posterior disc displacement was not seen in any of the asymptomatic volunteers. CONCLUSION: Posterior disc displacement of the TMJ is rare but has probably been overlooked in the past because of a lack of well-defined imaging characteristics.
PURPOSE: The purpose of this study was to describe the imaging characteristics of posterior disc displacement of the temporomandibular joint (TMJ). MATERIALS AND METHODS: The study was based on 35 joints with posterior disc displacement and a control material of bilateral TMJ images of 62 healthy volunteers. The images were analyzed, and criteria for posterior disc displacement were developed. RESULTS: Posterior disc displacement was characterized by the disc or a major part of the disc being located posterior to the superior prominence of the condyle. Three subcategories of posterior disc displacement could be identified: a thin flat disc, a grossly posteriorly displaced disc, and a perforated disc with a portion of the disc displaced posteriorly. Posterior disc displacement was not seen in any of the asymptomatic volunteers. CONCLUSION: Posterior disc displacement of the TMJ is rare but has probably been overlooked in the past because of a lack of well-defined imaging characteristics.