The Masseter Muscle and Its Role in Facial Contouring, Aging, and Quality of Life: A Literature Review

BACKGROUND: Masseter muscle hypertrophy manifests itself as enlargement of masseter muscle. It can be associated with square shaped lower face, pain, dental attrition, maxillary and mandibular bone resorption, and accelerated aging process of the lower face. OBJECTIVE: Is to assess efficacy and safety of botulinum toxin type A in contouring the masseter and its impact on quality of life, the aging process of the lower face, and it's role in full face rejuvenation. METHODS: A PubMed search was conducted for articles on masseter treatment with botulinum toxin type A, masseter muscle hypertrophy, and aging process of the lower face. Key studies are reviewed and findings are summarized. RESULTS: Botulinum toxin type A can be injected in the lower posterior aspect of the masseter muscle. Treatment decreases muscle bulk and reshapes the lower face. Furthermore, patient quality of life measures, including pain and symptoms of grinding and clenching are improved. Treatment can decrease shear stress on maxillary and mandibular bones and can possibly prevent tooth loss and progressive bone resorption of the lower face. Adverse effects are minimal and short lasting. CONCLUSION: Botulinum toxin type A is a safe and effective treatment of masseter hypertrophy. The treatment results in improvement of functionality, cosmesis and restoring facial harmony. Financial Disclosure: This manuscript received no financial support. Sabrina G. Fabi is an investigator and consultant for Allergan, Merz, Galderma, and Revance. Corresponding author: Rawaa M. Almukhtar, MD, MPH, Louisiana State University, Department of Dermatology, 1542 Tulane Ave., Ste. 639 , New Orleans, LA 70112, Email: ralmuk@lsuhsc.edu ©2018American Society of Plastic Surgeons