Abstract: Objective: The purpose of this study is to discuss the problems that should be paid attention to in the periodontal surgery for orthodontic patients, taking a surgery on an impacted tooth as an example. Diagnosis and treatment: A 25-year-old male patient presented with gingivitis, malocclusion, and an impacted upper right lateral incisor. The malocclusion included overbite of anterior teeth, distal relationship of bilateral first molars and canines, and there was a gap between the central incisor and canine of right maxillary. First, the teeth were aligned and the gap was widen through orthodontic treatment. Next, non-surgical periodontal therapy was completed. Then, a surgery eruption was carried out, in which a modified incision was designed on the palatal side to preserve all soft tissues as much as possible on the premise of effectively exposing the impacted tooth. At the same time, bone and soft tissue augmentation were performed according to the target position of orthodontic teeth movement. Finally, the right maxillary lateral incisor was aligned after the surgery. Results: The soft and hard tissues of the periodontal complex were kept healthy during orthodontic treatment after rational design of the periodontal surgery. Conclusions: Both orthodontic and periodontic factors should be taken into consideration when designing a periodontal surgery for patients in orthodontic practice.

Key words: combined periodontic-orthodontic treatment, impacted tooth, surgery eruption, orthodontic treatment, periodontal surgery