正畸治疗中，牙在牙弓内进行移动，如果牙根向舌侧移动，则颊侧发生牙龈退缩的风险较小；如果牙根向颊侧移动，当颊侧骨板小于理想厚度时则有可能发生颊侧牙龈退缩。如果患者正畸前没有牙龈退缩，而原有骨板较薄或已有骨开裂/骨开窗时，则无论牙根向何处移动，牙龈退缩的风险均较高。正畸医师在面对牙根移动时，经常处于进退两难的局面。本文从牙周软组织的角度出发，阐述与正畸治疗相关的牙周软组织增量技术及治疗时机。“,”During the orthodontic treatment, if the root moves lingually, the risk of buccal gingival recession is low. On the contrary, if the root moves buccally, the thin buccal bone probably leads to the buccal gingival recession. In patient without gingival recession, bony dehiscence and fenestration make the situation complicated. Both of the directions show high risk of gingival recession. The present article, from the point of view of periodontal soft tissue, introduces the periodontal soft tissue augmentation technique related to orthodontic treatment and the timing of the surgery.