[Research progress in bone marrow edema in the temporomandibular joint]

Bone marrow edema (BME) of the temporomandibular joint is an abnormal change within the bone marrow that appears as low signal intensity on T1-weighted images and high signal intensity on T2-weighted images in MRI. It is commonly seen in patients with temporomandibular joint osteoarthritis. Studies have shown that BME is closely related to joint pain, disc displacement and bony degeneration, but its specific mechanism is not yet fully understood, potentially involving abnormal mechanical loading, inflammatory responses and imbalances in bone metabolism. Although BME is considered an early sign of osteoarthritis, BME persists in approximately 71.4% of patients after pain resolution , suggesting the complexity of its association with clinical symptoms. In recent years, advanced MRI techniques (such as T2 mapping and fat suppression sequences) have improved the detection rate of BME and facilitated the assessment of its dynamic changes. However, the exact role of BME in temporomandibular disorders remains controversial. This article reviews the etiology and mechanism, pathology, imaging characteristics, and correlation with clinical symptoms of BME in the temporomandibular joint, and proposing future research directions to to elucidate its significance in disease progression and to provide guidance for clinical diagnosis and treatment.