With the improvement of living standards and the increasing awareness of self-care of people, more and more adults are joining the ranks of orthodontics. Some were not treated when they were young for various reasons and now have the time, energy, and can afford to undergo orthodontic treatment; others are referred by other departments to improve aesthetics and function through combined treatment of orthodontics and other disciplines. Adults can still receive orthodontic treatment even though their growth is at a standstill, because the alveolar bone that surrounds the teeth has a lifelong capacity for active remodeling, and under orthodontic forces, the bone on the pressure side will resorb and the bone on the tension side will deposit so that the teeth can move to a new position and still remain stable. Of course, adult orthodontics has its limitations compared to children, such as the presence of periodontal disease, joint disease, etc., which often requires combined treatment from multiple departments, and if there is significant jaw disproportion, it may also need to be combined with orthognathic surgery to achieve functional and aesthetic harmony.