Relationship Between Joint Effusion and Parotid Lymph Nodes in Temporomandibular Disorders

Joint effusion in temporomandibular disorders is a pathological accumulation of synovial fluid caused by inflammatory conditions. However, these is a little attention of the relationship between joint effusion and parotid lymph nodes. The purpose of this study was to examine the relationship between joint effusion in temporomandibular disorders and number and size of parotid lymph nodes using MR imaging.

 This study was approved by the university ethics committee (EC12-009).The study subjects were MR images of 402 TMJs in 201 patients (47 males, 154 females ; age range 8-82 years, mean age 34.3 years) who underwent MRI for suspected temporomandibular joint disorders in the Nihon University School of Dentistry Hospital, Matudo ,Japan, from April 2006 to March 2007. All MR imaging not related to the lymphadenopathy, including anemias, inflammatory diseases, leukemias, lymphomas, and metastatic tumors.MR imaging techniques used included oblique sagittal proton density and T2-weighted imaging and axial short TI inversion recovery (STIR) imaging. Joint effusion was classified according to grading system (Larheim et, al, ) on T2-weighted oblique sagittal image.On axial STIR images, the number and size of parotid lymph nodes were observed on a workstation by 2 radiologists, and they were categorized into without joint effusion and with joint effusion basis of the presence or absence of joint effusion.These analyses were performed with the statistical package SPSS version 21.0 (IBM Japan Inc, Tokyo, Japan). p<0.05 was considered to indicate statistical significance.

 The number and size of parotid lymph nodes was significantly diffrences between with joint effusion groups and without joint effusion groups. The mean values of the number of nodes were 2.3±1.1, 1.0±1.1, corresponding to with joint effusion group, without joint effusion group, respectively (p<0.01). Mean values of the size of nodes were 3.6±0.9 mm, 2.8±0.9 mm, corresponding to with joint effusion group, without joint effusion group, respectively(p<0.01).

 Our result investigated the relationship between the occurrence of joint effusion in temporomandibular disorders and the number and size of lymph nodes in the neck region. These informations suggested that the occurrence of joint effusion in patients with temporomandibular disorders increases the incidence of parotid lymph nodes.

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