It is often found that the child’s circumcision needs to be corrected, and the earlier it is corrected, the better. When the milk teeth and jaws form antimandibular, you can wear movable orthodontic appliances to correct the anterior or posterior antimandibular, and the hazards of pericoronation include the following points: 1, limiting the space for tongue movement, which may result in ambiguous pronunciation and affect the communication.2, the upper anterior antimandibular can cause the upper anterior teeth to be overly abraded on the labial side, which will result in sensitivity and affect the appearance.3, the posterior region of the antimandibular can form the occlusal interference and jaw trauma, which will result in the resorption of tooth roots and the emergence of tooth Loosening, and can induce temporomandibular joint dysfunction.4. The circumcision will make the maxilla underdeveloped and the mandible over-extended, thus forming a crescent-shaped face, which seriously affects the aesthetics.