EFFECT OF BOTULINUM TOXIN TYPE A ON THE REDUCTION OF MYOFASCIAL PAIN IN PATIENTS WITH TEMPOROMANDIBULAR DISORDERS: A NARRATIVE LITERATURE REVIEW

Abstract

Myofascial pain is the most frequent form of temporomandibular disorder (TMD), and botulinum toxin type A (BoNT-A) has been used in cases refractory to conservative treatment. This study aimed to analyze the evidence on the effect of BoNT-A on the reduction of myofascial pain in adults with TMD. This is a narrative review with a structured search of PubMed/MEDLINE and Europe PMC, including primary studies published between 2014 and 2026 with freely available full texts. Twenty-eight publications were included, corresponding to 25 studies from 15 countries, 13 of which were randomized clinical trials. Uncontrolled studies almost always reported pain reduction. Among the ten placebo-controlled trials that assessed pain, six showed superiority of BoNT-A and four, all published from 2024 onwards, found no difference. Compared with active therapies, such as occlusal splints, low-level laser, acupuncture and percutaneous electrolysis, BoNT-A performed similarly. Adverse effects were generally mild, but included reduced bite force and, at higher doses, loss of mandibular bone volume. BoNT-A may reduce myofascial pain, but the evidence is heterogeneous, and its use should be reserved for refractory cases, at low doses.