Japan. Both the United States and Japan have very strong orthodontic technology, but in Japan, because the dental problems of local people are more serious, the orthodontic technology is more mature, so Japan's protruding mouth surgery is strong. The protruding mouth is a common facial shape in clinical practice, especially in the south. It is a typical protruding mouth facial shape. It manifests as protrusion of the teeth and maxillary and mandibular bones, causing the lips to curl up, which has a great impact on the appearance.