The most effective method of square chin is currently surgical treatment. The pathologic basis of square chin deformity is wide jaw angle and hypertrophied biting muscle, so the surgery is mostly focused on the jaw angle and biting muscle. There are three main surgical approaches, namely, extra-oral approach, intra-oral approach and combined intra- and extra-oral approach. Surgical methods include jaw angle osteotomy, partial excision of biting muscle and simultaneous osteotomy and muscle excision. Botulinum toxin is an exotoxin produced by the bacterium Clostridium difficile, and there are 8 subtypes of botulinum toxin. There are 8 subtypes of Botulinum toxin. Currently, Botulinum toxin type A is the main type of Botulinum toxin used in the clinic, which is initially used for the treatment of myasthenia gravis, blepharospasm, and hemifacial spasms, etc. Later, some people have found that injecting Botulinum toxin into the localized wrinkles of the face has better temporary wrinkle removal effect. Side effects after Botox injection are rare, mainly pain at the injection site, which may affect pronunciation and difficulty in swallowing. Botulinum toxin injection may be an effective alternative to surgery for square face reshaping, but its effect does not last long and the recurrence rate is high.