Hello, you can still correct your teeth at the age of 20, but the time is longer than that of minors, and the later retention period is longer. Try to prevent your teeth from rebounding. Because the development of alveolar bone is basically stereotyped and the bone density is relatively high after adulthood, especially the ability of bone regeneration will be relatively reduced, so the force of adult orthodontics on teeth should be eased and the retention period should be long.