Disc displacement is often accompanied by a loss of structural integrity of the posterior, medial, and lateral supporting ligaments. Previously reported clinical results of surgical TMJ discrepositioning procedures have been variable, with failures related to a lack of long-term stability, indicating a need for improved methods of disc stabilization ( 4, 5). Some patients with pathological internal derangement of the TMJ, however, are asymptomatic or have relatively innocuous clinical symptoms. Some common clinical symptoms of TMJ dysfunction include TMJ sounds/noises, TMJ pain, facial pain, headaches, limited range of mandibular movement, change in occlusion, masticatory difficulty, earaches, tinnitus, vertigo, and neck, shoulder, and back pain. These changes can lead to progressive worsening of jaw function and pain. The disc or, more commonly, the bilaminar tissue posterior to the disc, can perforate, and intracapsular adhesions can develop. Chronic disc displacement can lead to deformation of the disc, loss of flexibility, vascularization of the disc (a normal disc is avascular), and breakdown of the fibrocartilage covering the condyle and fossa. Displacement of the TMJ articular disc can result in decreased joint space clicking, popping, or crepitation during jaw function arthritis condylar resorption jaw deformities malocclusion inflammation and compression of the bilaminar tissue- all of which can cause various degrees of pain and dysfunction ( 3). The most common cause of TMJ dysfunction is anterior and/or medial displacement of the articular disc (also known as internal derangement of the TMJ) (Figure (Figure1b 1b). TMJ dysfunction occurs more frequently in women than men (8:1 ratio). TMJ dysfunction is a relatively common condition: an estimated 12% to 87% of the US population has at least 1 sign of TMJ dysfunction ( 1, 2). (b) The disc is anteriorly displaced, with the bilaminar tissues interposed between the condyle and fossa. (a) Normal temporomandibular joint anatomy with a harmonious disc-condyle relationship. The joint is circumferentially surrounded by a fibrous capsule and has multiple ligamentous attachments that provide stability, especially in a lateral direction. ![]() The disc is attached to the condylar neck by ligamentous soft tissue attachments. ![]() The disc and condyle are in a normal anatomic relationship if the posterior band of the disc is located above the condylar head when the mandibular condyle is centrically positioned in the fossa (Figure (Figure1a 1a). This disc divides the joint into superior and inferior joint compartments, which normally do not communicate with each other. Interposed between the condyle and the fossa is a piece of dense, avascular fibrous connective tissue, the TMJ articular disc. The joint is formed by the bony articulations of the mandibular condyle and the temporal bone (glenoid fossa and articular eminence). This unique joint can perform both hinge and sliding functions and is the only synovial joint in humans whose articulating surfaces are covered by fibrocartilage. The temporomandibular joint (TMJ) is a bilateral diarthrodial joint of the jaws in the human skeleton.
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