Protraction Archwire:effectively protruding incisors and alignment

目的:探讨唇倾排齐弓丝在临床治疗中唇倾并排齐下前牙的效率和效果。方法:临床筛选36例(19例女性,17例男性)适应病例,分为两组:唇倾弓丝组和镍钛丝排齐组。按照唇倾弓丝组的排齐时间计算,分阶段留取牙颌石膏模型,并拍摄术前术后头颅定位侧位片。分别测量石膏模型尖牙宽度,磨牙宽度和牙弓宽度。同时在侧位片上测量术前术后的下前牙与下颌平面的倾斜角度。以α=0.05为基准,采用Stata统计软件对上述测量数据进行显著性比较分析。结果:唇倾弓丝完成唇倾并排齐下前牙的时间显著性少于镍钛丝排齐组,唇倾弓丝的排齐效率为0.106 mm/d,镍钛丝的排齐效率为0.047 mm/d。模型测量和侧位片测量表明,唇倾弓丝对于尖牙宽度,磨牙宽度和牙弓宽度和下前牙与下颌平面夹角的改变较镍钛丝排齐更显著。结论:与镍钛丝排齐相比,唇倾弓丝唇倾并排齐下前牙的效率更好,临床操作更简便。

Objective： To investigate the aligning and proclining efficiency of protraction archwire over treatment time.Methods： 36 patients（19 females and 17 males） were divided into two groups;protraction archwire group and conventional NI-Ti group.Mandibular dental study casts were taken according to the time of mandibular incisor alignment.Changes in arch dimensions were measured from dental study casts,by the intercanine and intermolar widths as well as arch length.Changes in arch length were represented by mandibular incisor inclination to the mandibular plane measured from serial cephalograms at T1 and T3（the alignment time in protraction archwire group）.All data were analyzed with Stata statistical software with significance predetermined at α=0.05.Results： The mean time to final alignment（T1-T3） was significantly less for the protraction archwire group compared with the conventional Ni-Ti group.This gave mean rates of 0.106 mm per day（SD,0.022） for protraction arch and 0.047 mm per day（SD,0.038） for conventional Ni-Ti group,and more intercanine width,intermolar width,lower incisor proclination were presented in the protraction archwire group.Conclusion： The protraction arch is much simpler,more efficient in proclining mandibular incisors than conventional Ni-Ti archwire and vertical loops.