Insofar as they are mobile, coupled organs of the masticatory system, the two human temporomandibular joints, true membranous sutures, are bound by their relations with the central nervous system and by the general laws of osteoarticular biomechanics. Certain invariants of temporomandibular morphogenesis are described, these concerning human cephalization phenomena, and more particularly the role of the neural crests in the elaboration of the temporomandibular relationship, its biomechanical features, and articular kinematics. The role of Marsch Robinson's theory, neurocristopathic malformations, and total temporomandibular joint prostheses are discussed. Fundamentally biomechanical in nature, dentomaxillofacial, and by extension, cephalic orthopedics require a multidisciplinary approach.