Botulinum Toxin for Temporomandibular Disorder: Current Evidence, Clinical Applications, and Future Perspectives

Temporomandibular disorders (TMDs) are heterogeneous musculoskeletal conditions frequently characterized by pain, impaired mandibular function, and reduced quality of life. Botulinum neurotoxin type A (BoNT-A) has emerged as a potential therapeutic option, particularly for persistent myogenous TMDs associated with masticatory muscle hyperactivity. This narrative review critically examines the mechanisms of action, current clinical evidence, therapeutic applications, and safety profile of BoNT-A in TMD management. Available evidence suggests that BoNT-A can reliably reduce masticatory muscle activity and may provide pain relief in selected patients with refractory myogenous TMDs; however, its superiority over placebo or established conservative treatments remains inconsistent. Considerable heterogeneity in patient selection, injected muscles, dosing regimens, injection techniques, and outcome assessment currently prevents the definition of standardized treatment protocols. Although short-term adverse events are generally mild and transient, repeated injections may induce muscle atrophy, reduced bite force, and potentially mandibular skeletal changes, whose long-term clinical relevance remains uncertain. Therefore, BoNT-A should not be considered a first-line treatment but rather a carefully selected adjunct within a multimodal rehabilitation strategy after appropriate conservative management has failed. Future phenotype-stratified comparative trials with standardized protocols and long-term structural safety outcomes are warranted.