镍钛螺旋推簧加橡皮链远移尖牙的临床效果

Clinical efficacy of combined use of Ni-Ti opening coiling and elastic chain for distalizing canine

目的观察镍钛螺旋推簧加橡皮链远移尖牙的临床效果。方法双侧对称拔除第一双尖牙需要最大支抗的患者32例,随机均分为两组,分别采用镍钛螺旋推簧加橡皮链(A组)和镍钛螺旋拉簧(B组)移动双侧下颌尖牙向远中。每28天测量下颌尖牙向远中移动及下颌磨牙近中移动的距离,直到将尖牙远移结束。结果A组尖牙移动的速度为(1.19±0.07)mm/28d,与B组的(1.10±0.23)mm/28d相仿(P>0.05);A组磨牙近中移动速度慢于B组[(0.21±0.11)mm/28d vs.(0.37±0.31)mm/28d](P<0.05)。结论使用镍钛螺旋推簧加橡皮链或镍钛螺旋拉簧远移尖牙,牙齿移动速度相似,但镍钛螺旋推簧加橡皮链在支抗保护上优于镍钛螺旋拉簧。

Objective To observe clinical efficacy of combined use of Ni-Ti opening coiling and elastic chain for distalizing the canine.Methods The straight archwire fixed appliance technique was applied in the treatment of 32 cases of bimaxillary protrusion,whose four first premolars were extracted and canine distalization was needed according to the treatment protocol.Thirty-two cases were equally randomized into two groups of A（treated with Ni-Ti opening coiling and elastic chain）and B（treated with Ni-Ti closure coiling）.The distance of canine distalization and the mesial movement of the molar in the mandible of all cases were measured every 4weeks till the end of canine movement.Results The mean speed of canine distalization per 4weeks in group A was similar to that in group B[（1.19±0.07）mm/28 dvs.（1.10±0.23）mm/28d]（P〈0.05）,which of molar mesial movement in group A was less than that in group B[（0.21±0.11）mm/28 dvs.（0.37±0.31）mm/28d]（P〈0.05）.Conclusion The speed of canine distal movement by combined use of Ni-Ti opening coiling and elastic chain is similar to that by Ni-Ti closure coiling.However,combined use of Ni-Ti opening coiling and elastic chain is better than Ni-Ti closure coiling in the anchorage protection.