Magnetic resonance imaging findings of internal derangement and effusion in patients with unilateral temporomandibular joint pain

Objectives. The purpose of this study was to investigate the relationship b etween the presence of temporomandibular joint (TMJ) pain and the magnetic resonance (MR) imaging findings of internal derangement (ID) and effusion. Study design. The study was comprised of 41 consecutive patients with TMJ p ain. Criteria for including a patient were report of unilateral pain near t he TMJ, with the presence of unilateral TMJ pain during palpation, function , and/or unassisted or assisted mandibular opening, and the absence of a sp ecific clinical TMJ-related diagnosis of disk displacement with or without reduction. Bilateral sagittal and coronal MR images were obtained to establ ish the presence or absence of TMJ ID or effusion, or both. Results. Comparison of the TMJ side-related data showed a significant relat ionship between the clinical finding of TMJ pain and the MR imaging diagnos es of TMJ ID (P =.001), and TMJ effusion (P =.004). Furthermore, there was a significant relationship between the MR imaging diagnosis of TMJ ID and T MJ effusion (P =.000). Use of the kappa statistic test indicated poor diagn ostic agreement between the presence of TMJ pain and the MR imaging diagnos is of TMJ ID (kappa =0.34), TMJ effusion (kappa =0.32), and TMJ ID and effu sion (kappa =0.27). Conclusions. The study's findings suggest that although clinical pain is co rrelated with TMJ-related MR imaging findings, clinical pain in and of itse lf is not reliable for predicting the presence of TMJ ID or effusion, or bo th. Therefore, MR imaging appears to be a warranted and necessary supplemen t to the clinical findings.