Botulinum Toxin in the Management of Temporo-mandibular Related Myalgia: a Prospective Study

All participants will receive a solution of BTX-A (Xeomin, Merz Pharma GmbH, Frankfurt am Main, Germany) in the masseter and temporalis muscles (total of 100 units reconstituted with 4cc unpreserved 0.9% sodium chloride). The injection will be provided by the same maxillofacial surgeon. The participants are asked to clench their teeth to determine the site of the most intense muscle activity in the masseter and temporal muscles with palpation. Intramuscular BTX-A injections are administered on both sides at the location of the most intense muscle activity of the masseter (80 units) and temporalis (20 units).