Older adults can usually undergo orthodontic treatment, need to treat other diseases in the mouth before orthodontic treatment, such as periodontitis, pulpitis, etc. If there is severe periodontitis in the mouth, excessive alveolar bone resorption is not suitable for orthodontic treatment, as follows. Human alveolar bone can be remodeled throughout life, so adults can undergo orthodontic treatment. Before orthodontic treatment, other diseases in the mouth should be treated accordingly, including extraction of blocked wisdom teeth that repeatedly cause pericoronitis, perfect periodontal sequence treatment for periodontitis, root canal treatment for pulpitis and apical periapical inflammation, and repair of dental defects. If the patient has uncontrollable and severe periodontitis, which leads to excessive resorption of the alveolar bone and symptoms of tooth loosening, orthodontic treatment is usually not appropriate. It is recommended to visit a regular medical institution to receive professional treatment.