Subluxation of temporomandibular joint- A clinical view

In the temporomandibular joint (TMJ) with physiological disc position, the disc rotates posteriorly on the condyle to the maximum degree and the condyle translates to the maximum degree, which occurs simultaneously at the maximum mouth opening movement. Condylar hypermobility in the position of maximally open mouth leads to the subluxation of the joint, and the two terms can thus be considered synonyms. The predisposition of the morphological relations of the zenith of the articular eminence and the contours of the articular surfaces lead to an excessive anterior displacement of the condyle over the zenith eminence. In addition, the irregular movement of the disc-condylar complex can also occur. The aim of this paper is to explain the hyperextension of TMJ which may, along with anatomical predisposition to the maximally open mouth position, lead to subluxation or luxation of the joint. Subluxation is not associated with a specific pathological characteristic of the joint. However, apart from discomfort, a subluxation can also cause pain. The excursory movement of the condyle close to and over the individual opening limit can lead to stiffness of joints and the inability to open the mouth (open lock), which is a prominent clinical sign of TMJ luxation. Electronic axiography can show pathological hyperextension of the condyle, while x-ray diagnostics records the condition of subluxation. A spontaneous luxation is clinically evident and therefore radiological diagnosis is used only to confirm the condition. Magnetic resonance imaging shows the disc and in the position of the maximally open mouth, thus giving the responses of the disk relation to the hypermobile condyle. Therapeutic modalities include occlusal splints and oral appliances, physiotherapy, and the mouth opening self-control. The goal of the treatment is relaxation of the masticatory muscles, removal of pain in the joint and muscles, and better coordination of movement, particularly in cases when there is a predisposition of spontaneous luxation.