Diagnostic Accuracy of Dynamic High-Resolution Ultrasonography in Assessing Anterior Disc Displacement in Temporomandibular Joint Disorders: A Prospective Observational Study

<b>Objective:</b> The objective of this study was to assess the diagnostic efficacy of dynamic high-resolution ultrasonography (HRUS) in detecting anterior disc displacement with reduction (ADDWR) and anterior disc displacement without reduction (ADDWoR) in the temporomandibular joint (TMJ). <b>Methods:</b> A total of 144 TMJs was categorized into three groups according to the magnetic resonance imaging (MRI) findings, which served as the reference standard: the normal disc position (NDP) group, the ADDWR group, and the ADDWoR group. Static images of the TMJ in full opening and maximum intercuspal positions, along with dynamic sequences during jaw opening, were obtained utilizing a 14 MHz L-shaped linear array transducer. The diagnostic efficacy of dynamic HRUS for identifying ADDWR and ADDWoR was evaluated in terms of accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic odds ratio (DOR), and the Youden index. <b>Results:</b> According to the MRI findings, the NDP, ADDWR, and ADDWoR groups consisted of 42 (29.2%), 47 (32.6%), and 55 (38.2%) TMJs, respectively. HRUS data revealed 54 TMJs (37.5%) in the NDP group, 26 TMJs (18.1%) in the ADDWR group, and 64 TMJs (44.4%) in the ADDWoR group. With MRI as the reference standard, HRUS exhibited a diagnostic accuracy of 71.4%, sensitivity of 51.4%, and specificity of 91.4% for ADDWR. For the ADDWoR, HRUS attained a diagnostic accuracy of 86.5%, sensitivity of 90.0%, and specificity of 82.1%. <b>Conclusions:</b> With MRI serving as the reference standard, dynamic HRUS has high diagnostic value for ADDWoR, with better diagnostic accuracy than ADDWR. Ultrasonography has the potential to be used as a highly effective and non-invasive imaging modality for the early screening of ADD in future clinical practice.