Orthognathic surgery in Liu Chunming mainly deals with the morphological problems of the jaw caused by overdevelopment/hypoplasia (covering the sky, crooked chin, pulling out the face with shoes, small jaw, Leigong face, etc.). ), and correct the length, thickness and position of the bone through surgery, and finally achieve the function of recovery (some people's bones are so crooked that they can't even bite their teeth together, and they can't eat for more than ten years, which is very miserable).