Abstract: Objective To investigate the dynamic changes of interlukin-1β（IL-1β）and tumor necrosis factor-α （TNF-α） in gingival crevicular fluid（GCF） during orthodontic tooth movement, and to discuss the biological significance. Methods　 Fifteen patients were chosen as subjects. For each patient, upper and lower canines at one side having one treatment for distal movement by elastic chain served as the experimental teeth, whereas the contralateral ones were used as controls. The GCF were taken before activation and at 1, 24, 48, 72, 168 hours respectively after initiation of the experiment. The levels of IL-1β and TNF-α in GCF were determined by radioimmunoassay. Results　 The levels of IL-1β and TNF-α in experimental group began to increase at 24 hours and reached to its peak value at 72 hours after initiation of the experiment, but their levels returned to baseline at 168 hours. Both of them, however, remained at the baseline level in control group. The changes of the two cytokines level were found statistically significant at 48 and 72 hours（P<0.05） between experimental and control group. No statistically significant were observed before activation and at 1, 168 hours after application of orthodontic forces（P>0.05） between experimental and control group. Conclusion　The levels of IL-1β and TNF-α in gingival crevicular fluid experience dynamic changes during the early phase of orthodontic treatment, indicate that they might play an important role in the process of alveolar regeneration and tooth movement.

Key words: gingival crevicular fluid, interlukin-1β, tumor necrosis factor-α, orthodontic tooth movement