According to different ages and different orthodontic techniques, there are functional orthodontics, fixed orthodontics, invisible orthodontics and surgical orthodontics. 1. Functional orthodontics: It is mainly applied to the inner growth of teeth in childhood, and coordinates the position of upper and lower jaws and trains the function of maxillofacial muscles through the devices such as functional orthodontic appliances. 2. 2. Fixed orthodontics: the orthodontic appliances are bonded to the tooth surface and cannot be removed during the correction process, with a wide range of indications. The effect is more reliable for complex teeth. 3. Invisible Orthodontics: Invisible orthodontics can be used for those who have aesthetic requirements in the process of orthodontics. 4. Surgical correction: If the development is completed with serious osteogenic deformity of the teeth, surgical methods can be used to correct. Due to the age difference, the material, size and technology of braces, the time and effect of correction may also vary, and it is recommended that patients with long inner teeth follow the advice of specialists when undergoing orthodontic treatment.