dental disorders
Internal Temporomandibular Joint (TMJ) Derangement
Introduction
The most common form of internal temporomandibular joint derangement is an anterior displacement of the articular disk in relation to the condyle. Often, joint pain and popping/clicking occur and the disk returns to normal position on jaw opening. Less frequently, the disk remains displaced and jaw opening is restricted. Diagnosis is based on history and physical examination. Treatment is with analgesics, jaw rest, muscle relaxation, physical therapy, and oral appliance therapy. If these methods fail, surgery may be necessary. Early treatment greatly improves results. (See also Overview of Temporomandibular Disorders (TMDs) .) Internal derangements may occur if the morphology of the disk is altered and the diskal ligaments become elongated. The severity of the derangement depends on the extent of the disk and ligament changes. If the disk remains anterior to the condyle, the derangement is said to be without reduction. Restricted jaw opening (locked jaw) and pain in the ear and around the temporomandibular joint (TMJ) may result. If at some point in the joint’s excursion the disk returns to the head of the condyle, the derangement is said to be with reduction. Nonpainful derangement with reduction occurs in about one third of the population at some point. All types of derangement can cause capsulitis (or synovitis), which is inflammation of the tissues surrounding the joint (eg, tendons, ligaments, connective tissue, synovium). Capsulitis can also occur spontaneously or result from arthritis, trauma, or infection. 