Effectiveness, Safety, and Predictors of Response to Botulinum Toxin Type A in Refractory Masticatory Myalgia: A Retrospective Study

BoT-A therapy provides significant relief for approximately one third of patients with refractory masticatory muscle pain. Therapy is associated with a mild risk of adverse effects. The presence of muscle hypertrophy, occurrence of an adverse effect, and concurrent use of opioid analgesics were found to be predictors of outcome response.