Face-slimming needles are essentially the use of botulinum toxin injections to treat masseter muscle hypertrophy. Women consider an oval face to be beautiful, but they often require plastic surgery due to enlargement of the mandibular angle. More than 90% of these patients have benign masseter muscle hypertrophy and hope to reduce it at the same time. Since it is difficult to control the amount and depth of muscle resection during mandibular angle surgery, not only is the effect unsatisfactory, but it also easily increases the chances of bleeding, hematoma, and infection, resulting in asymmetry on both sides of the face, trismus, and long-term muscle spasm. and other serious complications. Botulinum toxin injection causes the masseter muscle to atrophy and become smaller through denervating neurotrophic effects, making the treatment more thorough.