Thinning of the lower third of the face using botulinum toxin in the masseter muscle

The width of the lower third of the face is mainly determined by the size and shape of the jawbone, the thickness of the masseter muscle and the volume of adjacent subcutaneous tissue. The ideal, culturally recognized pattern for a male face corresponds to a wider lower third and a mandibular angle tending to 90º, while a female face should have a more oval appearance or the shape of a heart, and the middle third wider than the lower third. In order to achieve these aesthetically ideal proportions, botulinum toxin type A (BoNTA) has been successfully applied in the masseter muscle, which is one of the determinates of the lower face's width. Te present article reviews the current literature on the use of botulinum toxin for this purpose, offering the experience of the authors in this practice, aiming at achieving a more harmonious facial contour.

Keywords: BOTULINUM TOXINS, TYPE A; MASSETER MUSCLE; HYPERTROPHY