Clinical, Etiological, and Therapeutic Features of Jaw-opening and Jaw-closing Oromandibular Dystonias: A Decade of Experience at a Single Treatment Center

BACKGROUND: Dystonia is a heterogeneous hyperkinetic disorder. The anatomical location of the dystonia helps clinicians guide their evaluation and treatment plan. When dystonia involves masticatory, lingual, and pharyngeal muscles, it is referred to as oromandibular dystonia (OMD). METHODS: We identified patients diagnosed with OMD in a Movement Disorders Clinic and Laryngeal Movement Disorders Clinic from a single institution. Demographic, etiological, clinical, and therapeutic information was retrospectively reviewed for patients with jaw-opening (O-OMD) and jaw-closing (C-OMD) OMD. RESULTS: Twenty-seven patients were included. Their average age of onset was in the sixth decade of life and there was a female predominance. Etiological factors linked in this study to OMD included a family history of dystonia or essential tremor, occupation, cerebellar disease, a dental disorder, and tardive syndrome. Clinically, patients with C-OMD presented with more prominent feeding difficulties, but seemed to respond better to therapy than those with O-OMD. In addition to the known benefits of botulinum toxin therapy, patients who described sensory tricks obtained benefit from the use of customized dental prosthesis. DISCUSSION: This works provides useful information on potential etiological factors for OMD and its response to therapy, and highlights the potential benefit of dental prosthesis for the treatment of OMD.