Botulinum toxin injection for the treatment of oromandibular dystonia.

Dystonia is a neurologic disorder characterized by abnormal, involuntary movements causing twisting and turning postures; it is postulated to be a disorder of central motor processing. The dystonias, when classified by region of the body involved, have been characterized as focal, segmental, and generalized. Focal dystonia can affect jaw mechanics, leading to forceful contraction of the jaw muscles and resulting in inappropriate deviation of the jaw. Localized injections of botulinum toxin have been used successfully in the management of other focal or segmental dystonias. We have treated 20 oromandibular dystonia patients with botulinum toxin. Six patients had only jaw and tongue involvement; 11 had blepharospasm and jaw involvement; and three had jaw involvement as part of a more generalized dystonia. Five patients had been diagnosed originally and treated as having temporomandibular joint syndrome. All but one of the patients had improvement of their symptoms with the toxin injections. The patients averaged 47% improvement with the injections.