Study Of The Non-extraction Crowed Cases Treatment By Using Different Straight Wire Appliance System

Objectives:Through the study of non-extraction treatment plan for mild to moderate crowding, the effects of anterior teeth from different straight wire system, thereby guiding the clinical rational use of the bracket system. Methods:45 cases with Angle Class I, skeletal Class I, the non-extraction treatment for mild to moderate crowding were selected, 15 cases were treated with traditional bracket system, 15 cases were treated with active self-ligating bracket system and the last 15 cases were treated with passive self-ligating bracket system, taken the cephalograms before and after treatment in patients, than the cephalograms were measurement by using WinCeph7.0 software, The SPSS17.0 software was applied to analysis of measurement results. Results:Three groups of patients were with angle Class I, skeletal Class I malocclusion, mild to moderate crowding, measurement the aech crowding, soft and hard tissue before treatment cephalometric on three groups of patients with SNK-q test, The patients in the three groups in any of the two group mean equal, they have the comparability. After treatment, three groups of patients with dental crowding were relieved, the cephalometric indexes of before and after treatment were analyzed in each group by paired t-test, results showed changes(P < 0.05); the cephalometric indexes amount of change before and after treatment were analyzed in each group by LSD-t test, the results of∠SNA,∠SNB,∠ANB was not significantly different between each groups(P>0.05); traditional bracket group is difference from active self-ligating bracket group and passive self-ligating bracket group on ∠U1-SN,∠U1-NA(P<0.05), traditional bracket group variation is greater than the active self-ligating group and passive self-ligating group; passive self-ligating bracket group is difference from traditional brackets group and active self-ligating bracket group on ∠U1-L1,U1-NA(P<0.05),traditional bracket group variation and active self-ligating group is greater than the passive self-ligating group; L1-NB,∠L1-NB,∠L1-MP,Z Angle,UL-EP,LL-EP were different between the groups of each other(P<0.05), the variation is traditional bracket group greater than active self-ligating group greater than passive self-ligating group. Conclusions:1.Three kinds of straight wire appliance system for patients who have mild to moderate crowding can be relieved, and also lead the anterior teeth inclination to labial 2.The changes of the upper and lower anterior teeth inclination to labial, passive self-ligating bracket is less than traditional brackets, active self-ligating bracket is centered; Changes in the bony indicators, three kinds of straight wire appliance system has no significant difference; Changes in the uper and lower lip, passive self-ligating bracket is less than traditional brackets, active self-ligating bracket is centered.