BACKGROUND:During clinical orthodontic correction, the self-ligating bracket is more helpful to maintain the periodontal healthy than the traditional bracket, but previous studies mainly focused on the clinical periodontal index and periodontal pathogens, and whether inflammatory cytokines are involved has not been reported. OBJECTIVE:To analyze the changes of the expression levels of interleukin 1β and tumor necrosis factor α in gingival crevicular fluid before and after the correction using self-ligating bracket and conventional bracket appliance. METHODS:Totaly 38 orthodontic patients without periodontal disease (including 20 males and 18 females; aged 11-25 years) were included in this study. Al the patients were randomly divided into control and test groups (n=19/group) and subjected to orthodontic correction using self-ligating bracket and conventional bracket appliance, respectively. The volumes of gingival crevicular fluid and expression levels of interleukin-1β and tumor necrosis factor-α were detected before correction and at 4, 8 and 12 weeks after correction. RESULTS AND CONCLUSION: The volume of gingival crevicular fluid and expression levels of interleukin-1β and tumor necrosis factor-α after correction were al higher than those before correction (P< 0.05). The volume of gingival crevicular fluid and expression levels of interleukin-1β and tumor necrosis factor-α after correction in the test group were lower than those in the control group (P< 0.05). These results demonstrate that self-ligating bracket appliance is more conducive to protect the periodontal tissue than the conventional bracket appliance.