压低辅弓增加后牙支抗的临床应用研究

Clinical Investigation of Posterior Segment Anchorage Reinforcement Effect of Intrusion Arch

目的:研究压低辅弓在尖牙远移过程中增加后牙支抗的临床效果。方法:选择需要强支抗,上颌减数第一双尖牙的患者30例,随机分为研究组和对照组,每组15例,研究组采用上颌NANCE弓,配合0.017"×0.025"TMA压低辅弓,30°后倾弯,150g力远中牵引尖牙至第二双尖牙,对照组采用上颌NANCE弓,配合口外弓。将矫治前后的头颅侧位定位片和三维模型进行对比分析,其变化量进行独立t检验。结果:研究组在尖牙远中移动的过程中,右侧上颌第一磨牙近中移动0.77mm,近中腭向扭转8.9°;左侧上颌第一磨牙近中移动约0.72mm,近中腭向扭转8.8°;右侧上颌尖牙远中移动约5.5mm,远中腭向扭转10.3°;左侧上颌尖牙远中移动约5.71mm,远中腭向扭转15.1°。与对照组相比无显著性差异。且第一磨牙在前后向的位移与尖牙的位移和磨牙的扭转存在高度相关性。结论:30°后倾弯的压低辅弓在远中移动尖牙过程中,可以为后牙提供强支抗。

Objective： To investigate posterior segment anchorage reinforcement effect of intrusion arch.Methods： 24 extraction cases,maximum anchorage requirement,were selected.Within these cases,upper canines were retracted distally with 150g force,with 30 degree tip-back activation of intrusion arch,0.017＂×0.025＂TMA,as posterior segment anchorage reinforcement.The x-ray film and digital models,before and after treatment,were compared statistically.Results： During canine retraction,upper right 1st molar translated mesially 0.77mm,rotated mesially and palatal 8.9 degree;and left right 1st molar translated mesially 0.72mm,rotated mesially and palatal 8.8degree.Upper right canine retracted distally 5.5mm,and rotated distally and palatal 10.3 degree.Upper left canine retracted distally 5.71mm,and rotated distally and palatal 15.1 degree.Statistical analysis showed the translation of upper 1st molar was correlated with molar rotation significantly.Conclusion： During canine retraction,30 degree tip back activation of intrusion arch could provide enough posterior anchorage reinforcement and prevent the side effect.