[Abstract] Objective To investigate the occurrence and related factors of gingival atrophy in two types of occlusal inferior teeth in orthodontic treatment. Methods From March 2016 to March 2018， 110 patients who received orthodontic treatment in this hospital were convenient selected and further divided into 55 cases open teeth (the treatment site was open teeth) and 55 cases， the lower teeth group (lower teeth in the treatment site) and 55 cases normal teeth were selected as the control group according to the treatment site. The occurrence of gingival recession after treatment of open teeth ......