Parotid Lymphadenopathy Is Associated With Joint Effusion in Non-Neoplastic Temporomandibular Disorders

Purpose Lymphadenopathy often occurs in the setting of inflammation, with or without infection. We sought to elucidate any association of parotid lymphadenopathy with joint effusion in temporomandibular joint (TMJ) disorders. Materials and Methods We performed a retrospective cohort study. We analyzed the magnetic resonance imaging studies of patients with suspected TMJ disorders performed from April 2006 to March 2007. The degree of joint effusion was graded on sagittal T₂-weighted spin echo images according to a commonly used system. On axial short T₁-weighted short inversion recovery images, the number and short-axis diameter of the parotid lymph nodes were recorded. We performed analyses of the cluster-correlated data using the Mann-Whitney U test and Spearman's correlation coefficients. P <.05 was considered to indicate significance. To assess the possible predictive value of certain variables, a generalized linear model (generalized estimation equation) was constructed, considering the multiple measurements. Results A total of 402 TMJ disorders were analyzed from 201 patients during the study period. The number and size of the parotid lymph nodes identified was significantly greater in the patients with TMJ effusion (P <.01) than in those without effusion. Conclusion In the present study, we found an association between parotid lymphadenopathy and joint effusion in TMJ disorders. These findings indicate that lymphadenopathy should be considered as an inflammation condition commonly associated with joint effusion in TMJ disorders.