青少年高角双颌前突患者拔牙矫治前后的Ricketts X线头影测量分析

A Cephalometric study using Ricketts Analysis before and after orthodontic treatment with four premolars extracted in High-angle Bimaxillary Protrusion in Adolescents

目的研究拔牙矫治对青少年高角双颌前突患者硬组织生长发育的影响。方法对沈阳市口腔医院正畸科2002年7月至2004年8月收治的31例青少年高角双颌前突患者,在拔除4个第一双尖牙后,采用滑动直丝弓矫治技术进行矫治,然后以矫治前头影测量图为模板绘制2年后生长预测图,用Ricketts分析法对矫治后与生长预测图上的测量项目进行比较分析。结果矫治后各测量项目的结果与根据生长预测图得到的结果比较:(1)面轴角、面平面角、突度距、上颌深度角和下颌体弧度角改变差异无统计学意义。(2)上下中切牙轴倾角、下切牙高度距、下切牙突度距及唇突度距减小(P<0.05)。(3)下面高度角减小(P<0.05)。结论拔牙矫治可改变青少年双颌前突患者上下切牙的轴倾度和突度,不能改变颌骨的生长发育方向和生长速度。

Objective To study influences in the development of hard tissue after orthodontic treatment with four premolars extracted in bimaxillary protrusion in adolescents.Methods 31 High-angle bimaxillary protrusion adolescents were selected with four premolars extracted.Draw the picture of two years later without orthodontic treatment on the basis of before orthodontic treatment using Ricketts analysis.15 angular and linear measurements were compaired after orthodontic treatment and two years later without orthodontic treatment with paired t-test.Results(1)NBa-PtGn,FH-NPo,A-NPo,FH-NA,DcXi-PmXi were not have statistically changes.(2)U1-APo(°),L1-APo(°),L1-APo(mm),L1-OP,Li-EP showed significant decrease.(3)ANS-Xi-Pm showed decrease.Conclusions Orthodontic treatment with extraction of four premolars could change the axial gradient and convexity of incisor tooth in high-angle bimaxillary protrusion in adolescents;but the development and growth rate of jaw bones were not changed.