Association between high signal intensity in the posterior disc attachment seen on T₂ weighted fat-suppressed images and temporomandibular joint pain

Objectives: We sought to determine whether high signal intensity in the posterior disc attachment (PDA) seen on T₂ weighted fat-suppressed MRI is associated with temporomandibular joint (TMJ) pain and joint pathology. Methods: This study was based on 283 TMJs of 177 patients (31 males and 146 females, mean age 32.7 years) with TMJ disorders showing anterior disc displacement. MRI evaluation included assessment of signal intensity in the PDA and TMJ status (disc displacement with reduction, disc displacement without reduction and disc displacement with bone changes). Clinical criteria that were considered positive indicators of TMJ pain included the presence of pre-auricular pain during palpation, jaw function and assisted or unassisted mandibular opening. Association of signal intensity in the PDA with joint pain and TMJ status was analysed using χ² test. Results: Joint pain was reported in 47 (77.0%) out of 61 joints with high signal intensity in the PDA and in 97 (43.7%) out of 222 joints with low signal intensity in the PDA (P < 0.0001). High signal intensity in the PDA correlated closely with more advanced joint pathology. In joints with anterior disc displacement with bone changes, TMJ pain was more commonly reported in joints with high signal intensity in the PDA than with low signal intensity in the PDA (P < 0.0001). Conclusions: High signal intensity in the PDA on T² weighted fat-suppressed MRI is associated with TMJ pain in TMJ disorders with anterior disc displacement with bone changes in the mandibular condyles.