Orthodontics studies the etiology, treatment, and prevention of abnormalities of the maxillofacial and dental system. The main task of orthodontic treatment is to improve the shape of the jaw-dental system — displacement of teeth or tooth rows. Regulation of occlusion, adjustment of lower jaw joint function, activation of masticatory muscle function, and others. For orthodontic treatment, fixed and removable appliances are used. Removable appliances include aligners and plates, while fixed appliances include the bracket system.