Hsien-Li Peter Peng1, Jui-Hui Peng2. 1. P-Skin Professional Clinic, Kaohsiung, Taiwan. 2. National Yang-Ming University School of Medicine, Taipei, Taiwan.
Abstract
BACKGROUND: Masseter hypertrophy is a common, prominent feature in many Asian patients, and correction procedures are often requested for esthetic reasons. Toxin masseter injections have a high efficacy and safety profile, but the risks of a variety of side effects or complications remain. OBJECTIVES: The categorization of various complications was based on etiology, with a presentation of the author's own incidence rates for consideration and comparison. METHODS: Six hundred and eighty patients received a total of 2036 sessions of toxin injection for masseter hypertrophy from 2011 to 2016, and complications or complaints were recorded through follow-up on a by-treatment basis. Complications were grouped together based on etiology and discussed. RESULTS: Of 2036 sessions, temporary mastication force decrease was reported after 611 (30%), bruising after 51 (2.5%), headaches after 12 (0.58%), smile limitation after 3 (0.15%), paradoxical bulging after 10 (0.49%), sunken cheeks (subzygomatic volume loss) after 9 (0.44%), and sagging after 4 (0.20%). CONCLUSIONS: Masseter injections remain very safe. To further decrease the incidence rate, injections should only be inside the recommended safety zone, a quadrilateral within the muscle that avoids most important local structures. Keeping injections inside the safe zone, and ideally in 3-4 different locations at least 1 cm from any border, is crucial for the prevention of complications.
BACKGROUND:Masseter hypertrophy is a common, prominent feature in many Asian patients, and correction procedures are often requested for esthetic reasons. Toxin masseter injections have a high efficacy and safety profile, but the risks of a variety of side effects or complications remain. OBJECTIVES: The categorization of various complications was based on etiology, with a presentation of the author's own incidence rates for consideration and comparison. METHODS: Six hundred and eighty patients received a total of 2036 sessions of toxin injection for masseter hypertrophy from 2011 to 2016, and complications or complaints were recorded through follow-up on a by-treatment basis. Complications were grouped together based on etiology and discussed. RESULTS: Of 2036 sessions, temporary mastication force decrease was reported after 611 (30%), bruising after 51 (2.5%), headaches after 12 (0.58%), smile limitation after 3 (0.15%), paradoxical bulging after 10 (0.49%), sunken cheeks (subzygomatic volume loss) after 9 (0.44%), and sagging after 4 (0.20%). CONCLUSIONS: Masseter injections remain very safe. To further decrease the incidence rate, injections should only be inside the recommended safety zone, a quadrilateral within the muscle that avoids most important local structures. Keeping injections inside the safe zone, and ideally in 3-4 different locations at least 1 cm from any border, is crucial for the prevention of complications.