Diagnostic Value of High-resolution Ultrasound for the Evaluation of Capsular Distension in Temporomandibular Joint Effusion

Abstract

Objectives. The aim of this study was to evaluate if the increased temporomandibular joint (TMJ) capsular thickness, measured by ultrasound (US), is associated with the presence of effusion, diagnosed using MRI imaging.Methods. 102 patients with signs and symptoms of temporomandibular disorders were included in the study. Each patient underwent US and MRI examination, 1 to 7 days following clinical examination. The US was performed with an 8–40 MHz linear transducer operating at 20 MHz. MRI was performed using an 1.5 T MRI device. The ROC curve was analyzed to identify the optimal cut-off value for capsular distention, which can be used as an indirect sign of TMJ effusion.Results. The capsular width values were found to be between 0.7-3.6mm. The best cut-off value was 2.05 mm with sensitivity of 55.9% and specificity of 94.7% (p<0.05). The next optimal cut-off value was 1.75 mm with sensitivity of 67.6% and specificity of 82.4%. The area under the ROC curve was 0.78 (95 % CI 0.68, 0.87). Conclusions. Ultrasound measured capsular width can be used as an indirect sign of TMJ effusion. The most accurate cut-off value obtained in this study was 2.05 mm.