Articular disk of the temporomandibular joint
The articular disk of the temporomandibular joint is a thin, oval plate made of non-vascular fibrous connective tissue located between the mandible's condyloid process and the cranium's mandibular fossa. Its "upper surface" is concavo-convex from before backward, to accommodate itself to the form of the mandibular fossa and the articular tubercle. Its lower surface, in contact with the condyle, is concave. Its circumference is connected to the articular capsule, and in front to the tendon of the lateral pterygoid muscle. It is thicker at its periphery, especially behind, than at  its center. The fibers of which the disc is composed have a concentric arrangement, more apparent at the circumference than at the center. It divides the joint into two cavities, each of which is furnished with a synovial membrane. It is attached as follows. The disc prevents the mandible from moving posteriorly.