Hyperintensity signal in the joint space of the temporomandibular joint on fat-saturated T2-weighted magnetic resonance imaging

Our aim was to investigate the incidence of a hyperintense signal in the joint space of the temporomandibular joint (TMJ) on fat-saturated T2-weighted magnetic resonance images (MRIs). We studied 112 patients (224 joints) with disorders of the TMJ who were examined by T2-weighted MRI, and recorded the association between displacement of the disc and the hyperintense signal using the K coefficient. A hyperintense signal was found in 4 of 91 joints (4%) when the disc was in the normal position, in all 19 joints with anterior disc displacement with reduction, and in 108 of the 114 joints (95%) with anterior disc displacement without reduction. There was a significant correlation between displacement of the disc and the hyperintense signal (p < 0.001). The kappa Coefficient Was 0.91. Such a signal in the joint space of the TMJ on fat-saturated T2-weighted MRI may indicate the presence of synovial fluid in the joint space with displacement of the disc. (C) 2009 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.