Orthodontics is not isolated, it is very closely related to many disciplines. The incidence of temporomandibular joint disease is high, and the orthodontic factor is an important cause of its development. Oral orthodontics is an important tool for the correction of temporomandibular joint disorder syndrome, and conversely, the wrong orthodontic force may also cause joint disorder syndrome. Malocclusion causes dental trauma and periodontal damage, which is an important cause of periodontal disease, and improper treatment is also important for periodontal damage. Severe bony malocclusion requires a combination of orthognathic surgery and oral orthodontics, and early detection can prevent treatment failure. Orthodontic force is a key factor in the correction of malocclusion, once the wrong force is used, things will backfire. Tooth movement is an important biological process in orthodontics, and the way, speed and control of tooth movement have an important relationship with the skill level of the doctor. New developments in material science have greatly contributed to orthodontics. Therefore, the doctor’s skill level is the key to the quality of orthodontics and whether it will produce undesirable negative effects.