Abstract: Objective To explore risk factors of the relapse of post orthodontic treatment so as to help prevent relapse.Methods A total of 128 patients,who finished orthodontic treatment in 2006,were retrospectively examined.A single factor analysis was used for 10 possible risk factors including gender,patient compliance,cheek or tongue position of root,age of finishing treatment,alveolar bone height and periodontal membrane inflammation,patient management after the treatment,retainer type,occlusion,parallel of root,and treatment time.Based on single factor analysis,the multifactor unconditioned logistic regression analysis was made.Results The results of logistic regression analysis revealed 3 statistically significant risk factors:the management for patient after the treatment (OR=7.77),the occlusion at the end of treatment (OR=4.54),and the compliance of patient (OR=3.53).Conclusions Reasonable management after the treatment,stable occlusion,and good compliance contributed to reducing the risks of the orthodontic posttreatment relapse.

Key words: relapse, patient compliance, patient management, unconditioned logistic regression analysis