Temporomandibular joint model: anatomical comparison between human and rat

Aim: To compare the features of human and rat TMJ anatomically.

Objective: To analyze and evaluate human and rat TMJ from an anatomical point of view and make a comparison between them to set an alternate and easy model of TMJ.

Background: The human TMJ is a group of anatomical structures that with a special group of muscles, is responsible for the movement of the mandible during mastication. This joint has a unique structure and function as compared with other diarthrodial joints. TMJ disorders and other related pathologies are very common and little is known about their underlying pathogenesis. Invitro studies and animal models may be used for these purposes. In particular, rats may be used since they are easy to handle and inexpensive to maintain in a bioterium, making them a convenient animal for use in experimental studies.

Materials and Methods: Formalin fixed twelve adult male Wistar Albino rat specimens were used in this procedure. The various anatomical structures of TMJ were evaluated such as condyle, mandibular fossa, disc, articular tubercle and temporal bone of rat was compared to that of humans.

Results: The TMJ is surrounded by a thin capsule, consisting of fibrous tissue and a synovial lining. The mandibular angle has a prominent shape. The glenoid fossa is flat, with no eminences.

Conclusion: Morphologically the articular structure of rats is, on the whole, similar to that of humans. In these animals there is no articular eminence.