The best age for orthodontic treatment varies from person to person. 1.Some of the malocclusions such as “enamel”, lip biting and finger sucking need early orthodontic treatment (3-5 years old). 2.Dental and jaw deformities usually start to show up during the replacement of milk teeth and permanent teeth (6-12 years old), so regular dental checkups and consultations with professional orthodontists can identify some problems that need to be solved early. Children at this stage are in the pre-growth peak or growth spurt, which is the best period for functional orthopedic treatment of mild skeletal deformities. 3, usually, the best age for fixed orthodontic treatment is after the complete replacement of baby teeth by permanent teeth (12-14 years old), at this stage of adolescents in the growth spurt, bone tissue remodeling is active, the teeth embedded in the alveolar bone can produce faster movement under the action of lighter orthodontic forces, easy to achieve fast, comfortable and ideal orthodontic results. 4, adult patients due to the end of bone development, bone remodeling is slower, tooth movement slowed down, coupled with often accompanied by periodontal, dental and other diseases, making the orthodontic difficulty factor increased, the course of treatment extended. However, there is no strict age limit for adult orthodontics, in principle, as long as the periodontal tissue is healthy, they can receive orthodontic treatment. 5.For patients with serious bone deformity, orthodontic-surgical combination treatment can only be carried out after adulthood.