Adults can actively cooperate with the treatment, are sensitive to the reaction, and keep the oral hygiene clean, so the course of treatment is often shorter than expected. However, relatively speaking, adults' adaptation and remodeling ability and bone metabolism ability are not as good as teenagers', teeth move slowly, and the adaptation time of perioral muscle remodeling is longer, so the course of treatment may be relatively prolonged, the recurrence tendency will increase, and the time required to wear retainers will be correspondingly prolonged.