We generally consider adulthood to occur after the age of 18. Orthodontic treatment for adults is very different compared with that for adolescents, this is due to the fact that the growth and development of adults has been completed, the maxillofacial bone joints have become osseous fusion, plasticity is very low, and the metabolism of adults has become slower, the biological responsiveness is reduced, which increases the difficulty of orthodontic treatment. In recent years, due to the development of oral biology, biomechanics, and material science, it has promoted the continuous improvement and development of orthodontic theory and technology, laying the foundation for adult orthodontics. Age contraindications for orthodontic treatment have been eliminated. At the same time, the number of adults requesting orthodontic treatment is also increasing. It has been said that the improvement of living standards and the extension of the life expectancy of the population are the social background for the development of adult orthodontics. After the basic requirements of life, such as food, clothing, housing and transportation, are met, people begin to pay attention to improving the quality of life and enhancing the concept of aesthetics, which is also one of the manifestations of social progress and increased civilization. Aligning misaligned teeth, obtaining normal oral function and aesthetic appearance have become part of the pursuit of adult life. Zhao Ying, Department of Stomatology, Xuanwu Hospital of Capital Medical University The demand for orthodontic treatment for adults is legitimate and feasible. However, compared with adolescents, adult orthodontics is more complicated. Malocclusion in adults is often accompanied by other oral disorders, such as caries, periodontal disease, missing teeth, tooth wear, residual crowns, residual roots, bad intraoral restorations, and temporomandibular joint disorders. Before starting orthodontic treatment, comprehensive control of periodontal diseases and removal of intraoral restorations are required, otherwise the wearing of orthodontic appliances and tooth movement will be affected. Adults should undergo orthodontic treatment under good oral hygiene conditions, and also pay attention to observe the changes in the periodontal condition of the teeth in the course of treatment. Adult growth and development has stopped, alveolar bone remodeling is slower, tooth movement is relatively slower, the treatment time required is longer. Adults are more prone to relapse after orthodontic treatment, and maintenance after treatment is also more important. Adult orthodontics is categorized into comprehensive treatment and adjunctive treatment. The purpose of the former is the same as that of adolescent orthodontic treatment, which is to improve the aesthetics and function of the teeth. The purpose of the latter is to cooperate with restorative treatments such as veneers and dental implants, as well as the treatment of periodontal disease. Adults, due to subjective and objective factors, it is often difficult to achieve perfection in the treatment effect. Therefore, when adults undergo orthodontic treatment, they should not be in a hurry to achieve success, and they should have a full understanding of the complexity of the treatment and be prepared for it. In addition, adult orthodontic should also consider the impact of systemic health, suffering from rheumatic heart disease, coronary heart disease, hypothyroidism, hyperacidity, diabetes mellitus, arthritis, bleeding disorders, epilepsy and other diseases, the first thing to do is to make these diseases under control. Orthodontic treatment for pregnant women should be done with caution. If there is a history of oral and maxillofacial surgery, radiation therapy, medication history, etc. should take the initiative to explain the situation to the doctor to avoid adverse consequences.