Hypertrophic and big masseter muscles can make the jaw
wider and appear as what is known as "square jaw" which contributes
to more of a masculine look. With Botox injection, we can cause shrinkage
of this muscle and make the jawline oblique (V-shape) which is more of
feminine look. This procedure is called jaw slimming by Botox and the result typically
lasts for 8 to 10 months. If done carefully by an experienced physician, there
won't be any interference with normal chewing, eating or smiling. Depending on
the strength and size of the muscle, I usually inject between 20 to
35 units of Botox in each side. By the way, like every other muscles in our
body, continuous usage and "exercise" makes the masseter muscle bulkier
and more noticeable. Chewing gum is a common "exercise" for masseter
muscle that can lead to a square jaw, and hence I always advise my patients who
prefer a more feminine jaw line to avoid chewing gums.
I hope it helps and good luck!