The masseter muscle runs down the rear of the cheek to the lower jaw, it may become enlarged if there is frequent clenching or grinding of the teeth – known as bruxism.
This can cause facial asymmetries, or increased muscle bulk offering a masculine, squared look to the lower face. Injecting Botulinum toxin into this muscle will relax it, offering relief from teeth grinding and headaches due to the clenched jaw, reduce and slim down a square jaw, offering a more feminine contour to the lower face.