[Biomechanics of temporomandibular joint]

Temporomandibular joint (TMJ) is one of the most intricate and complicate loading joints in the human body. Articular cartilage is characteristic of low infiltrative, porous viscoelastic material. In physiological condition, there is a stress-absorbing architecture system in the TMJ cartilage, which consists of collagen-proteoglycan-water gel network. TMJ disc is a specific connective tissue as stress concentration absorber between condyle and articular fossa, but it does not belong to fibrocartilage. Retrodiscal tissue has high compliance of which the role is to play volume-compensating mechanism in joint movement. Lateral wall is a complexed structure out of ligament and capsule with weak tensile strength and tensile rigidity. Therefore, prolonged oral parafunction will result in joint fatigue and failure.