Replacing temporomandibular joints

The masticatory system plays an important role during biting, chewing, swallowing, speech, singing and other functions, all directly affecting quality of life. For proper functioning, both temporomandibular joints and the connecting mandible, together with the masticatory muscles and contiguous tissue components, play a major role. In a healthy situation, the masticatory muscles supply the mandible with the required movements and biting and chewing forces, while the left and right mandibular condyles slide smoothly along their articular eminences. Disturbances of the masticatory system can lead to a wide range of both muscular and Temporomandibular Joint (TMJ) conditions and pathology, resulting in pain, limited mouth opening, headaches, clicking or popping sounds in the TMJ and impaired masticatory functioning. TMJ disturbances and muscle problems influence each other and may lead to chronic pain and functional impairment. The TMJ prosthesis design is a mixture of well-known and accepted techniques, and new inventions. Among the well-known techniques are screw fixation and the use of proven biocompatible materials. The main new developments are a double articulation, including an inferiorly located centre of rotation, a self-adjusting skull part that is built from stock parts and a rigid screw-prosthesis connection.