dislocation of jaw

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dislocation of jaw

Traumatic or spontaneous displacement of the mandible. Jaw dislocations are uncomfortable and may be psychologically distressing. They may occur on either side, in which instance the tip of the jaw is pointed away from the dislocation. On the unaffected side, just in front of the ear, may be felt a little hollow or depression that is often tender. If both sides of the jaw are dislocated, the jaw is pushed downward and backward. In either event, there is pain and difficulty in speech and the condition is often accompanied by shock. Backward dislocation of the jaw is rare.


Jaw dislocation is usually caused by a blow to the face or by keeping the mouth open for long periods as in dental treatment, but occasionally may be caused by chewing large chunks of food, yawning, or hearty laughing. A fall or blow on the chin could cause dislocation, but backward dislocation seldom occurs without fracture or extreme trauma.


These dislocations are reduced by placing well-padded thumbs inside of the mouth on the lower molar (back) teeth with the fingers running along the outside of the jaw as a lever. The thumbs should press the jaw downward and backward. The jaw will glide posteriorly over the ridge of bone (articular eminence), which can be felt, and just as this occurs the jaw usually snaps into place. When this motion is noted, the thumbs should be moved laterally toward the cheeks to keep them from being crushed between the molars.

This snapping into place is due to an involuntary spasm of the muscles, which pulls the jaw as though an overstretched rubber band were attached to it. Following the reduction, an immobilizing bandage or double cravat should be applied.


It is important that the hands be protected by heavy gloves to prevent trauma by the teeth.
See also: dislocation