# Dislocation of the jaw
The normal range of motion of the jaw joint is kept within normal limits by anatomical structures such as bony ledges, ligaments, and muscles. If the jaw joint dislocates e.g. slides and goes beyond its anatomical limits, it may get stuck in this position, and the clinical expression will be of "stuck" open mouth. This is usually painful and accompanied by feeling of a hard bulge in front of the ear.
The cause of the disorder can be weakness of the joint ligaments or weakness of the jaw-closing muscles. Alternatively, the cause could be drug treatment (for example medications from the phenothiazine family) that predispose the patient to jaw dislocation, or even the habit of opening the mouth excessively. The diagnosis is made after taking patient history and clinical evaluation.
The immediate treatment for a dislocation of the jaw joint is to reduce the joint into its normal place by a relatively simple manual manipulation. When the dislocation events become frequent, open joint surgery is indicated (a procedure called eminectomy). Alternatively, the disorder can be temporarily alleviated by injecting botulinum toxin into the jaw-opening muscles.