<原著>ラット下顎頭の過剰運動による顎関節滑膜の変化

This study investigated changes in temporomandibular joint (TMJ) synovmm in rats caused by condylar hypermobility Forced condylar hypermobility was induced by opening the mouth widely (20mm) under general anesthesia with ether when the rats were 8 weeks of age This procedure was repeated 10 times continuously once a day for 10 or 30 days For the histologic examination three experimental and three control rats were sacrificed at 5 days, 2, 4, 6, 8, 10, and 20 weeks after the treatment Histological changes were mainly observed in the anterior synovium of the upper joint compartment These were characterized by a thickening of the synovial cell layer, an increase in dilated vasculature, fibrin deposit, and synovial adhesion The 10 day treated rats showed more remarkable changes than 30 day treated rats The present procedure for inducing synovitis of the TMJ in rats was considered useful in understanding the pathogenesis of synovitis in human TMJ