Biphasic Injection for Masseter Muscle Reduction with Botulinum Toxin

Masseter Muscle Hypertrophy (MMH) is a well-known clinical benign condition that not gender-specific and it can be monolateral or bilateral. Botulinum Toxin type A (BoNTA) injection has been widely described for MMH treatment non-surgical facial slimming. BoNTA masseter injections have high efficacy safety profile, but the risks of side effects remain. Muscular bulging during mastication complication due to superficial overcompensation masseteric fibers in response neurotoxic weakening deep masseter. We present biphasic-injection technique administration, based following anatomical concept developed order prevent paradoxical bulging. total 98 treatments from 2015 2020 were performed with this technique. No remarkable complications occurred our study. cases loss full smile, difficulty mouth opening, dizziness, headache, neurapraxia, xerostomia reported. case asymmetric smiling was self-resolved within week. patient claimed transient muscle weakness as distressing. observed. Extensive knowledge muscular anatomy appropriate are key factors achieving desired result avoiding complications. feel sharing tip could helpful all physicians involved BoNTA.