Adaptation and remodeling of the mandibular condyle following vertical ramus osteotomy in dogs.

This experiment investigated the effects of vertical ramus osteotomy (VRO) on normal mandibular condyles and those altered surgically to simulate trauma to the articular surface. Four dogs that received unilateral vertical ramus osteotomy to reposition the condyle downward and forward responded with progressive remodeling of the articular cartilage. A second group of four dogs that had grooves cut into the articular surfaces of both condyles showed more rapid healing on the side receiving VRO. In a third group (n = 4), vertical ramus osteotomy appeared to protect the articular cartilage from regressive remodeling after extraction of the molar teeth and prevent decreased vertical dimension of occlusion. The articular cartilage on the side with the vertical ramus osteotomy remained healthy, while the untreated side developed a narrower joint space and showed histologic evidence of thinning and degeneration of the fibrocartilage and increased density of the subchondral bone.