Potencial terapêutico de diferentes marcas de neurotoxina botulínica para tratamento de dor orofacial em humanos: uma revisão da Literatura

Abstract

Chronic orofacial pain, including temporomandibular disorders (TMDs), myofascial pain, trigeminal neuralgia, and occipital neuralgia, represents a frequent therapeutic challenge in clinical practice, often exhibiting limited responsiveness to conventional treatments. In this context, botulinum toxin type A (BTX-A) has emerged as a promising therapeutic alternative. However, despite the wide availability of different commercial formulations, there is still no standardization regarding dosages, treatment protocols, or conversion ratios among products, which may influence clinical outcomes. Therefore, this study conducted a comprehensive literature review using the PubMed, Scopus, Web of Science, EMBASE, LILACS, and Google Scholar databases to identify human clinical studies investigating the use of BTX-A for the management of orofacial pain. Animal studies, reviews, study protocols, commentaries, conference abstracts, and case reports were excluded. Following duplicate removal using EndNote Web and Rayyan platforms, 1,069 records underwent screening by two independent reviewers, resulting in 84 eligible articles for full-text assessment. After the final selection process, 32 studies were included for in-depth analysis. The findings suggest that different botulinum toxin type A formulations—including OnabotulinumtoxinA (Botox®), AbobotulinumtoxinA (Dysport®), IncobotulinumtoxinA (Xeomin®), as well as products such as Hengli®, Botulax®, LetibotulinumtoxinA, and LanbotulinumtoxinA—demonstrate significant efficacy in reducing pain intensity, improving Visual Analog Scale (VAS) scores, decreasing the frequency of painful episodes, and enhancing patients’ quality of life. The most frequently investigated conditions were myofascial pain and TMD (18 studies, 688 patients), trigeminal neuralgia (14 studies, 700 patients), and occipital neuralgia (2 studies, 14 patients). Efficacy was consistently observed, particularly in myofascial pain/TMD and trigeminal neuralgia, whereas evidence for occipital neuralgia, although promising, remains limited. Regarding safety, BTX-A exhibited a favorable profile, with adverse events generally being mild and transient. Reported side effects included dysphagia, speech difficulties, facial asymmetry, muscle weakness, as well as isolated cases of hematoma, local erythema, xerostomia, diplopia, and headache. In conclusion, botulinum toxin type A appears to be an effective and safe therapeutic option for the management of chronic orofacial pain, particularly myofascial pain/TMD and trigeminal neuralgia. Nevertheless, methodological heterogeneity, small sample sizes, and the lack of standardization among different formulations continue to limit the comparability of findings. Further randomized controlled trials with larger sample sizes and standardized treatment protocols are required to establish more robust evidence and support clinical guidelines.