The biological concept of "internal derangement and osteoarthrosis": a diagnostic approach in patients with temporomandibular joint pain?

OBJECTIVES We sought to investigate whether the finding of temporomandibular joint (TMJ)-related pain may be linked to magnetic resonance (MR) imaging findings of TMJ internal derangement and TMJ osteoarthrosis. STUDY DESIGN The study consisted of 194 consecutive TMJ patients. Criteria for including a patient with a painful TMJ were as follow: report of orofacial pain in the TMJ, with the presence of unilateral or bilateral TMJ pain during palpation, function, and unassisted or assisted mandibular opening. Criteria for including a patient with a nonpainful TMJ were as follow: absence of a TMJ with pain during palpation, function, and unassisted or assisted mandibular opening. Application of the criteria resulted in a study group of 150 patients with unilateral TMJ pain, 10 with bilateral TMJ pain, and 34 without TMJ pain. Bilateral sagittal and coronal MR images were obtained to establish the presence or absence of TMJ internal derangement or osteoarthrosis, or both. RESULTS A comparison of the TMJ-related data showed a significant relationship between the clinical finding of TMJ pain and the MR imaging diagnoses of TMJ internal derangement (P =.002) and TMJ osteoarthrosis (P =.004). Significant increases in risk of pain occurred with "disk displacement without reduction and osteoarthrosis" (P =.000), "disk displacement without reduction and absence of osteoarthrosis" (P =.000), and "disk displacement with reduction and osteoarthrosis" (P =.036). CONCLUSIONS The results suggest that TMJ-related pain is correlated with TMJ-related MR imaging diagnoses of internal derangement and osteoarthrosis. The data confirm the biological concept of "internal derangement and osteoarthrosis," yet re-emphasize that internal derangement and osteoarthrosis may not be regarded as the unique and dominant factors in the definition of TMJ pain.