Dental malocclusion causes more problems to the life and communication of more patients. For different types of malocclusion, the clinical need to choose different orthodontic periods and methods of treatment: 1, the period of milk teeth: that is, when the child is 4-5 years old. If the child has bad habits such as tongue sticking out, lip biting, etc., it needs timely orthodontic treatment. At this time, orthodontic treatment of the anterior jaws can avoid abnormal development of the jaws and prevent the jaws in the permanent dentition period; 2. Teething period: i.e., when the girl is 8-10 years old or the boy is 9-12 years old. Hospital, looking for orthodontic professionals to examine the child to determine whether intervention is needed; 3, the early permanent teeth: that is, about 11-12 years old for girls or 13-15 years old for boys, the child at this time just completed the tooth replacement, and in a period of relatively vigorous growth and development. Orthodontic treatment at this time can maximize the coordination of the upper and lower jaws, and improve the face and appearance of the child, the course of treatment is shorter, and the results are relatively good; 4, adult period: that is, after the age of 18, the clinical routine orthodontic treatment to improve the aesthetics and function, and severe bony malocclusion patients can also be combined with surgery, combined orthodontic orthognathic treatment.