Daily exercise usually can’t make the biting muscle thin down, usually rely on the injection of “thin face” that is, botulinum toxin to make the biting muscle thin down, but it is not recommended to use routinely. The principle of botulinum toxin injection is to block the signal transmission between muscle nerve and muscle papilla, leading to muscle atrophy, so as to achieve the effect of biting muscle thinning down, usually after 2 months after the effect, the maintenance cycle of about one year, after one year, the muscle will gradually return to normal, so it will not have an impact on our health. General injection of botulinum toxin is surface anesthesia after subcutaneous injection, for patients with large bite muscles, take multi-point injection, it is recommended to go to the regular medical institutions for injection, under the operation of the doctor.