The relationship of bone marrow edema pattern in the mandibular condyle with joint pain in patients with temporomandibular joint disorders: longitudinal study with MR imaging

The purpose of this study was to investigate the course of bone marrow edema pattern (decreased signal intensity on T1- or proton-density-weighted images and increased signal intensity on T2-weighted fat-suppressed images) in the mandibular condyle after improvement in clinical symptoms, and to clarify its relationship with temporomandibular joint (TMJ) pain. This study was based on 14 joints of 11 patients (all female, mean age 37.5 years) with TMJ disorders showing condylar bone marrow edema pattern on initial magnetic resonance (MR) images. All joints were re-evaluated clinically and using MR images after relief of joint pain following arthrocentesis combined with non-surgical treatment. The time interval between the initial and follow-up MR images ranged from 14 to 27 months (mean 17 months). Of the 14 joints, 4 joints (28.6%) showed a normal bone marrow signal, whereas 10 joints (71.4%) showed persistent bone marrow edema pattern on follow-up MR images (P = 0.125). Therefore, the reduction in TMJ pain did not correlate with resolution of bone marrow edema pattern in most joints. The results of this study suggest that the bone marrow edema pattern in the mandibular condyle does not always contribute to the occurrence of joint pain in patients with TMJ disorders.