Orthodontics can be divided into cermet invisibility and lingual treatment. Generally speaking, orthodontics takes about one and a half to two years. The time of orthodontics depends on the age and the severity of tooth dislocation. If you suffer from occlusal disorder in childhood, it usually takes about one year to correct it, provided that the patient has no abnormal bone development. If the relationship between maxilla and mandible is not correct, functional correction is needed, which may prolong the cycle. If it is adult correction, the correction cycle is about 2-3 years, and the retainer needs to be worn after correction. Because the adult's bones are fully developed, the displacement of teeth is only a slight movement, so retainers are needed to protect teeth from recurrence.