Some people have a square jawline or very wide broad faces. Sometimes this occurs because of the way the mandibular bone is shaped, along the jaw. But other times it is due to a bulky muscle called Masseter which is actually used for chewing. If someone is chewing gum all the time or having food which is really hard or if the person is also clenching their teeth at night unknowingly, the masseter muscle gets bulkier. This bulk can be reduced with the help of botox injections. The muscle size reduces after 4 to 6 weeks of injection and the contour of the face becomes narrower. As a result, this square jaw actually disappears and the face becomes nice and oval in shape. It is very safe to do masseter injections but it should be done by a trained professional. So by giving tiny amounts of botox, you can actually achieve a chiseled jawline without undergoing any surgery.