The purpose of this study was to evaluate the relationship between magnetic resonance imaging (MRI) findings and the relative signal intensity (RSI) of retrodiscal tissue in patients with temporomandibular joint disorders (TMDs) and to determine the usefulness of RSI as a diagnostic marker.
One hundred and thirty-two temporomandibular joints in 66 TMD patients were analyzed. The signal intensities of regions of interest (ROIs) in retrodiscal tissues were measured using T2-weighted MRI. The RSIs of retrodiscal tissues were referenced to the signal intensities of the ROIs of brain gray matter. The relationships between the RSI of retrodiscal tissue and condylar degenerative change (Wilcoxon rank sum test), joint effusion (Wilcoxon rank sum test), disc position (Kruskal-Wallis test), pain (Wilcoxon rank sum test), and limited mouth opening (Wilcoxon rank sum test) were determined.
A strong association was seen between retrodiscal-tissue RSI and disc displacement, joint effusion, condylar degenerative change, and joint pain. Limited mouth opening did not significantly correlate with retrodiscal-tissue RSI.
The retrodiscal-tissue RSI for T2-weighted MRI is a valuable noninvasive tool for monitoring the progression of TMD. Additional clinical studies are warranted.