Effusion in magnetic resonance imaging of the temporomandibular joint: A study of 123 joints

Purpose: Effusion is the term used by radiologists for a hyperintensity signal seen inside a joint on magnetic resonance imaging (MRI). The aim of this study was to correlate the clinical and imaging features of this phenomenon, with the ultimate purpose of clarifying its meaning in dysfunctional processes of the temporomandibular joint (TMJ). Patients and Methods: The clinical histories of 111 patients (123 joints) with effusion on MRI were reviewed. Thirty-one patients (46 joints) with articular pathology but without effusion, chosen at randomized, sen ed as a control group. Five clinical variables (articular pain, radiating pain, limited mouth opening, clicking, and clinical stage) and five imaging findings (disc displacement, effusion location, disc morphology, osteophytes, avascular necrosis, and osteochondritis dissecans) were evaluated. Results: Effusion in TMJ could be seen in relation to disc displacement and degenerative changes (osteophytes, avascular necrosis, osteochondritis dissecans). Clicking was more frequently found in TMJs without effusion. Conclusions: These results suggest that effusion may be a marker of articular degeneration in the TMJ.