Bruxism is nonfunctional jaw movement that includes clenching, grinding and gnashing of teeth. It usually occurs during sleep, but with functional abnormality of brain, it can be seen during consciousness. Oromandibular dystonia (OMD) can involve the masticatory, lower facial, and tongue muscles and may result in trismus, bruxism, involuntary jaw opening or closure, and involuntary tongue movement. Its prevalence in the general population is 21%, but its incidence after brain injury is unknown, Untreated, bruxism and OMD cause masseter hypertrophy, headache, temporomandibular joint destruction and total dental wear. We report a case of successful treatment of bruxism and OMD after brain injury treated with botulinum toxin A and occlusal appliance. The patient was a 59-year-old man with operation history of frontal craniotomy and removal of malformed vessel secondary to cerebral arteriovenous malfomation. We injected with a total 60 units of botulinum toxin A each masseteric muscle and took impression for occlusal appliance fabrication under general anesthesia. On follow up 2 weeks and 2 months, the patient remained almost free of bruxism. We propose that botulinum toxin A and occlusal appliances be considered as a treatment for bruxism and OMD after brain injury.