Prevalence and clinical characteristics of patients with oromandibular dystonia seen in the orofacial pain clinic: a retrospective study

Objective. The aim of this study was to describe the prevalence and clinical characteristics of patients with oromandibular dystonia (OMD) presenting to an academic orofacial pain clinic. OMD diagnosis was based on clinical signs and symptoms, presenting in varied forms and severities. Knowledge of clinical characteristics would help in early diagnosis and treatment of OMD. Study Design. In this retrospective study, we identified patients with OMD (International Classification of Diseases [ICD]-9 diagnostic code 333.82 and ICD-10 code G24.4) who presented at the clinic from October 2012 to December 2017. Additional selection criteria were age greater than 18 years and confirmation of OMD diagnosis with at least 1 follow-up visit. Results. Over a 5-year period, 22 patients with OMD were identified according to the ICD diagnostic codes, and of those, 6 patients met the selection criteria corresponding to a prevalence of 170 per 100,000 (95% confidence interval [CI] 70-390). The most common chief complaint was jaw pain (67%), and all patients had associated diagnosis of myofascial pain of masticatory muscles. Conclusions. The prevalence of patients with OMD in an academic orofacial pain clinic is higher than previously reported in population-based studies. The presentation of OMD often includes temporomandibular disorders (TMDs), with involvement of various masticatory muscles.