The Anatomy of the Temporomandibular Joint

Temporomandibular joint (TMJ) is a freely movable diarthrodial joint with great importance due to its functions regarding the masticatory system and speech. This chapter aims to provide an informative review of the anatomy of the TMJ. Main structures that make up the temporomandibular joint are bones, ligaments, muscle groups, disc, fibrous capsule, synovial fluid, and the synovial membrane. The TMJ has two primary articular surfaces. The temporal bone includes the cranial component comprising the articular eminence, tuberculum articulare, and the fossa mandibularis. The mandible includes the processus condylaris. A synovial membrane covers the fibrous membrane of the articular surfaces, and the synovial fluid manages the metabolic needs of the tissues, and also acts as a lubricant during function. An articular disc is located within the joint cavity, between the fossa mandibularis and the caput mandibula. Main ligaments of the TMJ complex are the medial and lateral collateral ligaments, the temporomandibular (lateral) ligament, the sphenomandibular ligament, and the stylomandibular ligament. Several accessory ligaments are also defined including the pterygomandibular ligament, the anterior malleolar ligament, the retinacular ligament, and the Tanaka ligament. Finally, the muscles of mastication, the suprahyoid and infrahyoid muscles, and the neurovascular structures supplying the TMJ are also mentioned within this chapter.