Oromandibular dystonia is a type of focal dystonia characterized by involuntary spasms of the jaw. The jaw can be pulled down (jaw-opening dystonia), pulled closed (jaw-clenching dystonia), and/or moved laterally. It is sometimes accompanied by lingual dystonia with abnormal movements of the tongue. Typical symptoms include difficulty opening the mouth, clenching or grinding of the teeth, jaw movements or pain, chin thrusting, tongue protrusion, lip pursing, or platysma contraction. In some cases, symptoms may only appear with action. Symptoms can result in difficulty speaking, chewing, or swallowing.

It may be associated with blepharospasm, cervical dystonia, and/or spasmodic dysphonia. The cause is unknown, although these movements may occur in the setting of tardive syndrome as a result of dopamine-blocking medications. Peak onset of symptoms occurs at 50-60 years of age. The condition is rare and more common in women than in men. There is no cure.