The purpose of this study was to analyze the expression of bone morphogenetic protein-2 (BMP-2) in patients with internal derangement of the temporomandibular joint.
Twenty-one human temporomandibular joint samples (5 extirpated disks and 16 biopsy specimens of synovitis area from patients with internal derangement of the TMJ) and 2 control temporomandibular joint specimens (2 normal disks obtained by autopsy) were analyzed with specific antibodies through use of an immunohistochemical technique.
BMP-2 was predominantly localized in chondrocytes around the damaged areas of the articular disks. BMP-2 expression was also found in synovial cells and endothelial cells of blood vessels. Control specimens demonstrated BMP-2 staining in synovial lining cells and endothelial cells of blood vessels. However, the chondrocytes in the normal cartilage layers of the control specimens showed no staining.
These findings suggest that BMP-2 may be involved in the pathogenesis of osteoarthritic changes or the repair process of temporomandibular joint internal derangement.