Primary orthostatic tremor in mandible: A rare case report

Primary orthostatic tremor (POT) is a rare movement disorder of unknown pathophysiology, characterized by fast tremor affecting a specific part of the body. The present paper reports a case of POT in mandible, discussing the approach and management. A 37-year-old male patient complained of involuntary mandibular movements, with onset 6 years ago, with no history of precipitating event. Usually, tremors were not present during patient's mastication or phonation. The oscillations presented rhythmically and symmetrically, with high frequency and low range of motion. Surface electromyography revealed an electromyographic discharge pattern bilaterally in the masseters, presenting a mean frequency of 13 Hz, and a predominance of postural type. Based on the history and clinical characteristics and electromyography, a diagnosis of POT was made. Several treatments have been employed over the years. Currently, the patient is being treated with buspirone hydrochloride 10 mg/day with a significant reduction of tremors. It can be concluded that knowledge of the characteristics of this condition is essential for the elaboration of a correct diagnosis and the better management of POT patients.