Botulinum Toxin Type A for the Treatment of Masseter Muscle Prominence in Asian Populations

: In Asian populations, an oval face shape with a slimmer lower face is considered favorable. Botulinum toxin type A (BoNT-A) treatment of the lower face for aesthetic purposes is widely performed in Asia, although it is not officially approved for this indication in any country. In this review, the authors highlight recent research describing injection techniques, mechanism of action, clinical efficacy, and key learning points to safely treat benign masseter muscle prominence (MMP) in Asian populations using BoNT-A. To support the existing literature, clinical examples are provided that demonstrate individualized treatment plans for patients with asymmetric vs symmetric MMP and an observed complication after treatment. This review provides insights for optimizing clinical outcomes and for designing future studies investigating the safety and efficacy of BoNT-A for treating MMP. LEVEL OF EVIDENCE: 5: [Image: see text]