Structure and Function of the TMJ Disc and Disc Attachments

The TMJ disc is a fibrocartilage tissue, biconcave and elliptical in shape. The disc provides low friction articulation surfaces in the joint. Moreover, its biconcave profile allows a smooth articulation between two incongruent surfaces of the mandibular condyle and the articular eminence. Without the TMJ disc, the incongruent surfaces would have a small area of contact, creating concentrated stresses in the tissues that can lead to tissue damage. The TMJ disc increases the contact area between opposing articulating surfaces and, thus, distributes lower magnitude stresses to a larger surface area in the joint.