THE FINE VASCULATURE OF THE RAT MANDIBULAR JOINT

There is no detailed description of the fine vasculature of the rat ma ndibular joint in the literature. The gross vasculature of the cephali c area and of the mandible is known, but without particular emphasis o n the joint itself, This article describes the fine vasculature of the rat mandibular joint, using transverse (coronal) and sagittal thick s ections of specimens injected with India ink and analyzed with light m icroscopy. The main vascular supply to the joint comes from the rostra l and caudal. aspects. Medially, the joint is directly vascularized by vessels from the lateral pterygoid muscle. Rostrally, the synovial me mbrane and the bilaminar zone of the disc are supplied by articular br anches from the rostral deep temporal vessels, terminal branches of th e maxillary artery. Caudally, the rich synovium of the retrodiscal pad and the bilaminar zone are supplied by the articular branches of the caudal deep temporal artery, a branch of the maxillary artery. Venous return is into the short, but large retroarticular vein which empties into the maxillary vein together with the vein from the transverse sin us exiting from the postglenoid foramen. Intra-articular synovial memb ranes own rich venous plexuses, and are lined by a dense capillary net work. The central part of the fibrous articular disc is avascular in a dult rats, and is circumferentially lined by a rim of capillaries from the bilaminar zone.