Oromandibular dystonia (OMD) is a form of focal dystonia that involves the masticatory, lower facial, labial and lingual musculature affected by the trigeminal, facial and hypoglossal cranial nerves. OMD can be classified into various subtypes, which include jaw-opening, jaw-closing, jaw-deviating, lingual, perioral and/or pharyngeal dystonia. Dystonic spasms may result in clenching, or trismus; grinding of the teeth, or bruxism; tongue thrusting; lip pursing; and other movements.

Evidence-based reviews and clinical experience strongly regard botulinum neurotoxin (BoNT) injection as the first-line treatment for OMD. Patients with OMD require careful examination to determine the particular muscles involved and their pattern of contraction to enable proper selection and targeting for BoNT injection. This chapter enumerates the particular muscles involved in each subtype of OMD, discusses localization and approach for injection and use of guidance techniques where applicable, and tabulates typical dose ranges for different formulations of BoNT. Typical adverse events and techniques to avoid them are discussed.