Lower facial remodeling with botulinum toxin type A for the treatment of masseter hypertrophy

• Main Authors: Fernanda Homem de Mello de Souza Klein (Author), Fabiane Mulinari Brenner (Author), Maurício Shigeru Sato (Author), Fernanda Manfron Batista Rosas Robert (Author), Karin Adriane Helmer (Author)
• Format: Book
• Published: Sociedade Brasileira de Dermatologia, 2014-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 0365-0596; 10.1590/abd1806-4841.20143200
• Keywords: Botulinum toxins, type A; Face; Masseter muscle; Dermatology; RL1-803
• Source: Anais Brasileiros de Dermatologia, Vol 89, Iss 6, Pp 878-884 (2014)

BACKGROUND: Masseter hypertrophy has been treated with botulinum toxin injections because of esthetic complaints especially in Asians. OBJECTIVES: The goal of the present study was to evaluate the efficacy of abobotulin toxin use in masseter hipertrophy treatment in Brazilians. METHODS: Ten Brazilian female patients with masseter hypertrophy were subjected to injections of 90U of abobotulinum toxin A applied on each side respecting the safety zone stabilished in literature and were followed up for 24 weeks. RESULTS: When analyzing the coefficients between measures of middle and lower third of the face obtained from standardized photographs, an increase was observed, with statistical significance at 2 weeks (p=0.005) and 12 weeks (p=0.001). The progression of lower third reduction was 3.94%, 5.26%, 11.99%, and 5.47% (2, 4, 12, and 24 weeks respectively). All patients showed improvement in bruxism after treatment. Observed adverse effects were masticatory fatigue, smile limitation, and smile asymmetry. CONCLUSION: The use of abobotulinum toxin A for masseter hypertrophy is effective in Brazilians and reached its maximum effect of facial thinning at 12 weeks. Smile limitation had a higher incidence compared to that reported in the literature and may result from risorius muscle blockage caused by toxin dissemination. Despite its side effects, 80% of the patients would like to repeat the treatment.