One of the features that differentiates a feminine from a masculine face is the width of the face at the jawline.
We may accept a masculine face where the lower face is wider than the upper but a wide lower face is considered to detract from feminine beauty.
In many cases, the excessive width of the lower face is caused by overdevelopment of the large chewing muscles in the cheek, called the masseters. In the past, the bulk of the muscle was reduced with surgery but now Botox is being used safely and painlessly to shrink the muscle.
After an initial dose of 25 – 50 units of botox per side, most patients experienced the maximal reduction in the muscle mass at the 3 month mark.
Botox effects are visible for longer with masseter injections than cosmetic use. Muscle reduction commonly remains visible for 6 – 12 months.