Objective To investigate the clinical effect of non-extraction treatment with self-ligating bracket on anterior teeth crowding.Method 54cases of patients with anterior teeth crowding received in the department of stomatology of our hospital from January 2009to January 2013were divided into the control and self-ligating bracket group with random number table method

27cases in each group.The control group were given non-extraction treatment with traditional MBT straight-wire brackets while the self-ligating bracket group were given non-extraction treatment with Quick self-ligating brackets.Arch width

upper anterior teeth convexity

dentition time and the total correction time were compared in both groups before and after their treatment.Results After the treatment

the premolar width in both groups increased but the improvement level of the selfligating bracket group was higher than that of the control group and the difference was statistically significant（P<0.05）.The levels of upper anterior teeth convexity of patients in both groups were significantly higher after their treatment

but the level of upper anterior teeth convexity of patients in the control group was higher than the self-ligating bracket group and the difference was statistically significant（P<0.05）.The dentition time and the total correction time in the self-ligating bracket group were shorter than the control group and the difference was statistically significant（P<0.05）.Conclusion The effect of non-extraction treatment with selfligating bracket on anterior teeth crowding is better than the non-extraction treatment with traditional MBT straight-wire brackets by extending the arch width of the double peak area to obtain the required space for dentition so as to reduce the anterior teeth lip deformity in the process of teeth alignment

shorten the dentition time and the total correction time and improve the efficiency of its correction.It is worthy of further promotion for the non-extraction treatment.