Part II: Temporomandibular Joint (TMJ)—Regeneration, Degeneration, and Adaptation

Purpose of Review Elucidate temporomandibular joint (TMJ) development and pathophysiology relative to regeneration, degeneration, and adaption. Recent Findings The pharyngeal arch produces a highly conserved stomatognathic system that supports airway and masticatory function. An induced subperiosteal layer of fibrocartilage cushions TMJ functional and parafunctional loads. If the fibrocartilage disc is present, a fractured mandibular condyle (MC) regenerates near the eminence of the fossa via a blastema emanating from the medial periosteal surface of the ramus. TMJ degenerative joint disease (DJD) is a relatively painless osteoarthrosis, resulting in extensive sclerosis, disc destruction, and lytic lesions. Facial form and symmetry may be affected, but the residual bone is vital because distraction continues to lengthen the MC with anabolic bone modeling. Extensive TMJ adaptive, healing, and regenerative potential maintains optimal, life support functions over a lifetime. Summary Unique aspects of TMJ development, function, and pathophysiology may be useful for innovative management of other joints.