片段弓技术矫治Angle Ⅱ~1类深覆合X线头影测量的研究

为研究采用片段弓技术，评价ＡｎｇｌｅⅡ１类深覆牙合矫治后对上颌牙、骨骼及面部软组织的影响，选择ＡｎｇｌｅⅡ１类高角深覆牙合病例２０例，治疗前１２～１４岁，对４个上切牙施加５０ｇ压低力，用腭杆及短口外弓加强支抗，每例患者于初诊时（Ｔ１）、初诊后半年戴矫治器时（Ｔ２）、上前牙压低前（Ｔ３）及压低半年后（Ｔ４）摄取侧位片。选择１７项参数，（Ｔ４－Ｔ３）－（Ｔ２－Ｔ１）表示参数半年机械矫治量。结果表明：单纯机械矫治半年后，上颌第一磨牙无前移，上颌中切牙水平后移量及垂直压低量分别为３．７、３．５ｍｍ，上齿槽座点水平后移及压低量分别为０．７、０．４ｍｍ，上下唇珠点平均后移分别为２．３、３．３ｍｍ。结论：（１）片段弓技术在整体压低上前牙的同时可有效控制后牙的支抗；（２）上中切牙后移量与上唇珠后移量约呈２：１的关系；（３）上齿槽座点骨改形不明显。

CEPHALOMETRCAL EFFECT OF DEEP OVERBITE CORRECTIONIN ANGLE1 CASES WITH SEGMENTED APPROACH

The present study was to evaluate the effect of overbite correction for Class malocclusion. The sample comprised 20 extraction cases with high angle. Cephallograms was taken at the first appointment (T1),six months later(T2),before upper intrusion(T3) and six months intrusion(T4). Parameter(T4-T3)-(T2-T1) represent mechanics correction amounts with segmented approach. Cephalometrically, the upper molar no moved mesially. The upper central incisor retraction was 3.7mm and intrusion was 3.5mm. Upper lip retraction was 2.3mm and lower lip retraction was 3.3mm. While the subspinnale was retracted only 0.7mm. The conclusion show: 1. Segmented approch can effective intrude upper teeth bodily while control anchorage teeth. 2. A ratio of 2:1 was attained between incisor retration and lip change. 3. Changes in the maxillary complex were difficulty.