The jawline slimming/teeth grinding (bruxism) treatment uses a series of micro-injections of Botulinum toxin, also known as Botox, to weaken the contracting facial muscles. The masseter muscle aids in chewing, talking, grinding and clenching of the teeth which can lead to a masculine and square jawline. Botox will work to reduce the activity within the masseter so that the muscle isn't able to clench and tense so strongly, which in turn will help to reduce the size of the jawline.