Masticatory muscle hypertrophy is a kind of jaw angle hypertrophy, the jaw angle is obviously enlarged, turned out, and the face is national or trapezoidal. The jaw angle is prominent and asymmetrical on both sides. The ratio of the upper and lower facial width is not coordinated, and the distance between the two jaw angles is too wide. The causes of masticatory muscle hypertrophy are generally divided into the following three kinds: 1, human masticatory muscle including the bite muscle, temporalis muscle, pterygoid muscle, pterygoid muscle, etc., so the occurrence of bite muscle hypertrophy is generally considered to be related to human chewing habits and eating habits. Such as diet often eat hard food or snacking, chewing gum habits related. 2, bite muscle hypertrophy and genetic factors, in fact, from the clinical point of view, there are indeed familial bite muscle hypertrophy phenomenon. 3, the cause of the bite muscle hypertrophy is accompanied by the jaw angle hypertrophy, jaw angle outward and so on, so clinically will be bite muscle hypertrophy called jaw angle hypertrophy or bite muscle benign hypertrophy. Benign hypertrophy of the masticatory muscle mandibular angle is a common facial deformity in the Oriental population. The facial shape of this group of people is often wind-shaped and use-shaped. The lower third of the face is significantly wider. In severe cases, the mandibular angle protrudes backward and downward, and some are accompanied by shortening of the lower third of the face. Patients have visible or palpable hypertrophic bulging chewing muscle strips when biting. Most of the cases have bilateral onset, and a few are unilateral.