After the orthodontic treatment is completed, retainers must be worn to ensure the corrective effect. Retainers generally need to be worn for two years, and for simpler orthodontics, at least one year. The first six months need to wear morning and evening. The second half of the year can be changed to wear at night, not during the day, the next year, every week need to wear 2-3 times, night wear can be. In a few difficult or complex patients, it is necessary to wear the retainer for a long time or for life. The exact length of time the retainer should be worn is subject to regular review under the doctor’s guidance, so the doctor will continue to follow up after the correction is completed. It is important to follow the doctor’s instructions for regular review at the hospital, just not as frequently.