(A) Periodontal examination should be conducted before orthodontic treatment 1. Periodontists evaluate the periodontal health condition of patients and carry out corresponding technical treatment, including supragingival scaling, subgingival scraping, root surface leveling, etc. Usually, orthodontic treatment can be started only after the periodontal inflammation is controlled and the condition is stable for 4-6 months. 2.Patients should learn knowledge and methods about periodontal hygiene self-protection. (B) Periodontal maintenance in orthodontic treatment 1, periodontal specialist regular follow-up. Orthodontic patients with mild or moderate periodontitis should have a periodontal review once in 3-6 months. 2, orthodontic treatment, once the performance of inflammation, should immediately see a periodontal specialist, timely control of inflammation. 3.Carefully clean the area between the aligner brackets, band rings and gingival margin, maintain good oral hygiene, and maintain the stability of periodontal inflammation.