Orthodontic treatment for children can be done at different ages such as milky teeth, mixed teeth and permanent teeth according to different degrees of malocclusion of teeth, such as anterior antomandibular, multifunctional malocclusion and bony malocclusion, and there is no optimal age for orthodontic treatment. 1. Anterior teeth antomandibular: the appearance of anterior teeth antomandibular can be corrected during the child’s milk teeth period. The roots of baby teeth are fully developed around 4 years old and have not begun to resorb, so the correction is effective. If the correction is too early, the child often can not cooperate, and if the correction is too late, the roots of the milk teeth begin to resorb, and the milk teeth are easy to fall off when the force is applied. 2. Multi-functional malocclusion: functional or bony malocclusion can be corrected in the child’s mixed dentition malocclusion, and generally should be corrected at the age of 8 to 9 years old when the roots of permanent incisors are basically fully developed. 3. Bone malocclusion: this type of malocclusion should be in the child’s permanent teeth period, the body is in the growth of the peak period before the growth spurt, growth spurt, generally girls 10 to 12 years old, boys 11 to 13 years old before the correction. Children’s orthodontic should be under the guidance of the doctor to improve the comprehensive diagnosis to determine, it is recommended to take the child to the regular hospital regularly, as early as possible to intervene in the orthodontic.