Abstract: Gingival invagination is a type of gingival cleft that occurs during orthodontic space closure in some of the orthodontic patients who received tooth extraction. Clinical manifestations may be fine folds in attached gingiva surface, or deep cleft that penetrates the interdental papilla from the buccal to the lingual alveolar process. Gingival invagination can affect the health of local periodontal tissues, the effect and stability of orthodontic treatment. This article reviews the research progress of gingival invagination studies, including the definition, manifestations, causes, influencing factors and effects.