Botulinum Toxin Type A in Myogenic Temporomandibular Disorders: A Scoping Review of Clinical Applications, Outcomes, and Current Limitations

Background. Myogenic temporomandibular disorders (TMD) represent one of the most prevalent causes of chronic orofacial pain in dental practice. Botulinum toxin type A (BoNT-A) has been increasingly explored as an adjunctive therapeutic option for refractory myofascial pain; however, clinical protocols and reported outcomes remain heterogeneous. Objective This scoping review aimed to map and critically evaluate the current clinical evidence regarding the use of botulinum toxin type A in adult patients with myogenic temporomandibular disorders, with emphasis on therapeutic protocols, clinical outcomes, safety considerations, and existing methodological limitations. Methods A comprehensive literature search was conducted across PubMed/MEDLINE, Scopus, Web of Science, EBSCOhost, SciELO, Redalyc, and LILACS from database inception to January 2026. Clinical studies evaluating intramuscular BoNT-A injections in adult patients with myogenic TMD were considered eligible. Data regarding study characteristics, injection protocols, outcome measures, follow-up periods, and adverse events were extracted and narratively synthesized. Results The available literature demonstrated considerable heterogeneity in study design, diagnostic criteria, BoNT-A dosing protocols, targeted muscles, and outcome assessment methods. Most studies reported short-term reductions in pain intensity and improvements in patient-reported quality of life following BoNT-A injections. However, methodological limitations, including small sample sizes, absence of standardized protocols, limited follow-up periods, and variability in comparator groups, restricted the strength and generalizability of the evidence. Reported adverse effects were generally mild and transient. Conclusions. Current evidence suggests that BoNT-A may provide short-term symptom improvement in selected patients with refractory myogenic temporomandibular disorders. Nevertheless, the literature remains methodologically heterogeneous, and high-quality randomized clinical trials are still needed to establish standardized protocols, long-term safety, and definitive clinical indications. BoNT-A should currently be considered an adjunctive rather than first-line therapeutic option within multidisciplinary TMD management.