下顎頭のbone marrow edemaと骨形態との関連

―縦断的観察―

抄録

Decreased signal intensity on T1 or proton-density weighted images and increased signal intensity on T2 weighted magnetic resonance images (MRI) in the bone marrow space are considered to represent bone marrow edema (BME). The purpose of this study was to determine whether condyle BME is associated with condyle bone changes.
The study group consisted of 65 temporomandibular joints (TMJs) of 57 patients with TMJ disorders showing condyle BME on initial MRI. Condyle bone changes were compared between TMJs that showed a persistent BME pattern (BME-persistent group; 43 TMJs of 40 patients) and TMJs that showed a normal bone marrow signal (BME-disappeared group; 21 TMJs of 22 patients) on follow-up MRI.
(1) In the TMJs which were normal shaped condyle on initial MRI, follow-up MRI showed that condyle bone changes had occurred in 53.9% of the BME-persistent group, whereas normal shaped condyle had continued in all of the BME-disappeared group. (2) In the TMJs which showed condyle erosion on initial MRI, follow-up MRI showed that condyle erosion had continued in 35.7% of the BME-persistent group, whereas condyle erosion had disappeared in all of the BME-disappeared group. (3) In the TMJs which were condyle osteophyte on initial MRI, follow-up MRI showed that condyle erosion had occurred in 22.2% of the BME-persistent group, whereas condyle osteophyte had continued in all of the BME-disappeared group.
The longitudinal study showed that condyle BME was associated with condyle bone changes. Furthermore, it was suggested that condyle BME could cause condyle erosion.