APA Dictionary of Psychology

a movement disorder associated with the use of conventional antipsychotic agents and characterized by involuntary movements of the tongue and musculature of the mouth and face. Patients may involuntarily chew, protrude the tongue, or make grimacing or pursing movements of the lips and cheeks. Also called buccal–lingual masticatory syndrome; oral–lingual dyskinesia. See also tardive dyskinesia.