Tardive dyskinesia are involuntary movements, especially of the lower face, that develop after exposure to a group of medications known as neuroleptics. The abnormal movements include tongue thrusting, repetitive chewing, jaw swinging and/or facial grimacing. The most commonly used offending neuroleptics are typical (old generation) antipsychotic medications, such as haloperidol, trifluoperazine, or fluphenazine. They act by blocking dopamine receptors in the brain. The condition may be reversible, if recognized in the earliest stages, by stopping the causative agent, but may be permanent. On occasion, if the anti-psychotics are stopped after the tardive dyskinesia has been present for a long period, the condition may become significantly worse.