Oromandibular dystonia—functional and clinical characteristics: a report on 21 cases

Objectives. The objectives of this study were to describe subtypes, characteristics, and orofacial function of patients with oromandibular dystonia and report results of special dental importance. Study Design. Symptoms, signs, and function were evaluated by questionnaires, video, and clinical and physiological examinations in 21 patients with primary and secondary dystonia (13 focal, 7 segmental, 1 multifocal). Results. A mixture of 2 or more subtypes of jaw movements was most common (43%), and the dystonic electromyographic activity was frequent in the anterior digastric (62%) and temporal and lateral pterygoid (48%) muscles. The impact from the oromandibular dystonia was marked. The prevalence of problems with mastication and swallowing was high, as well as with hyposalivation, dental attrition, and other dental problems. Conclusions. Patients with oromandibular dystonia may present to dentists with involuntary jaw movements and other severe functional problems. Care must be adapted to the neurological disorder and may be complicated by the condition itself. (Oral Surg Oral Med Oral Pathol Oral Radiol 2013;115:e21-e26) Oromandibular dystonia (OMD) is a rare focal neurological disorder affecting the lower part of the face and jaws. The dystonic activity may look similar to idiopathic sleep bruxism but usually ceases during sleep. It is characterized by sustained or repetitive involuntary jaw and tongue movements and facial grimacing caused by involuntary spasms of the masticatory, facial, pharyngeal, lingual, and lip muscles. 1–3 OMD is typically classified as jaw opening, jaw closing, jaw deviating, or lingual dystonia or combinations of these. 2,4,5 The combination of OMD, blepharospasms, and dystonic movements of the upper face is known as Meige’s syndrome. 6 Oral function has been reported to be compromised in most cases of OMD. Such dysfunction may lead to social embarrassment, reduced quality of life, depression, and weight loss. 7–13 OMD often interferes with normal orofacial function, such as chewing and control of food bolus, swallowing, breathing, and both verbal and nonverbal communication. Electromyographic (EMG) recordings have shown deviating masticatory muscle activity, such as cocontractions of antagonists and loss of rhythmicity during chewing. 7,14 Depending on the subtype, OMD may also be accompanied by trismus, bruxism, and forceful involuntary jaw closure or temporomandibular joint dislocation, which may lead to trauma and damage of the structures of the oral cavity, dental restorations, and dentures. 2,15 Thus, jawclosing dystonia may result in excessive dental wear, dental fractures, and trauma of the lips, gums, and tongue, whereas jaw-opening dystonia may be associ