The proportion of adolescents suffering from malocclusion is very high, mainly in the form of uneven teeth, severe misalignment of teeth (such as “small tiger teeth”), buck teeth (whistling teeth), small chin and grounded teeth, etc., which not only affects the aesthetics, but also affects dental health. Teenagers have many advantages for orthodontic treatment, mainly in the following aspects: 1, to reduce the occurrence of dental caries and gingivitis. Early orthodontic treatment of uneven teeth, buck teeth or misaligned teeth is beneficial to adolescents in maintaining oral hygiene and reducing the occurrence of dental caries and gingivitis. 2.It is beneficial to the normal development of jaw and face. Severe malocclusion affects the normal development of jawbone, and early treatment is beneficial to the growth of jawbone in the normal direction. 3.It is beneficial to the correction of patients’ pronunciation. Gaps in the teeth (gaps) affect the pronunciation of adolescents, and early treatment helps to correct the pronunciation of patients. 4. Misalignment such as uneven teeth, buck teeth or diastema affects chewing efficiency. 5. Maintain the psychological health of adolescents. The psychological health of patients is affected by malocclusion such as uneven teeth, buck teeth, and enameled teeth, especially for adolescents during their puberty. 6. Teenagers have very good alveolar bone conditions. After the tooth replacement, the alveolar bone is elastic, the body has a strong metabolism and has a certain growth potential, so the teeth are easy to move and the alveolar bone is quickly rebuilt during the tooth movement. The teeth move quickly and well. Patients feel more comfortable and pain-free.