J Oral Med Pain.  2021 Dec;46(4):143-149. 10.14476/jomp.2021.46.4.143.

Evaluation of Treatment Outcomes in Oromandibular Dystonia Using Surface Electromyography: A Case Series

• Im YG
• Kim JH
• Kim BG

• KMID: 2552221
• DOI: http://doi.org/10.14476/jomp.2021.46.4.143

Abstract

Purpose
Oromandibular dystonia is a neurological disorder that affects the jaw and lower face muscles, often resulting in abnormal repetitive movement of the jaw and perioral structures. The purpose of this study was to assess the effectiveness of surface electromyography (EMG) in evaluating the treatment outcome of oromandibular dystonia.
Methods
Based on a retrospective review of medical records, we analyzed the data of four patients who received medication or botulinum toxin injection, as well as surface EMG of the jaw muscles before and after treatment. We assessed the patients’ clinical characteristics and the results of surface EMG before and after treatment.
Results
The case series included one female and three males, and the age range was 65- 78 years. Based on the clinical features, two subjects were classified as jaw deviation and the remaining two were as jaw closing. Dystonic patterns revealed by surface EMG varied, including phasic, tonic, and mixed contraction patterns. EMG amplitude after treatment was lower than pre-treatment value in all four subjects, suggesting improved clinical signs and symptoms. One subject who received clonazepam and another who received botulinum toxin injection showed a remarkable reduction in EMG amplitude within a normal range.
Conclusions
Surface EMG can be used to effective evaluate treatment outcomes in patients with oromandibular dystonia. It could be considered as an adjunctive diagnostic tool in managing patients with dystonia.

Keyword

Dystonia; Electromyography; Oromandibular dystonia; Surface electromyography; Treatment outcome