【摘要】：雙牙-牙槽前突是臨床上常見的錯牙合畸形之一，通常表現(xiàn)為上下頜骨位置基本正常，切牙牙軸明顯唇傾，牙列多不擁擠或輕度擁擠，雙唇過突。正畸掩飾治療常需要拔除前磨牙，利用拔牙間隙內(nèi)收過于唇傾的前牙，雙唇隨之內(nèi)收，達到良好的面型。拔牙矯治內(nèi)收前牙引起切牙唇傾度及突度的變化，明確二者之間的關(guān)系，運用到病例的VTO分析中，實現(xiàn)矯治目標的可視化，制定適合的矯治計劃，對正畸臨床工作有實際指導(dǎo)意義。 目的：通過測量采用拔牙矯治的40例雙牙 牙槽前突女性患者矯治前后的側(cè)位片，，分析得出矯治前后切牙唇傾度及突度（即切牙矢狀向位置）發(fā)生的變化及二者之間的量化關(guān)系公式。從而為靜態(tài)VTO分析中確定上下切牙目標位置提供新的參考。 方法： 1.選取在吉林大學(xué)口腔醫(yī)院正畸科門診就診的雙牙-牙槽前突的女性患者40例，矯治前年齡≥16周歲，平均年齡為20.5周歲。 2.在矯治前后的頭顱定位側(cè)位片上建立坐標系：將SN以S點為圓心順時針旋轉(zhuǎn)7o作為X軸，過S點做X軸的垂線作為Y軸。選取8個硬組織標記點，主要測量項目包括上中切牙牙軸與SN及NA的交角（U1-SN°、U1-NA°），下中切牙牙軸與MP及NB的交角（L1-MP°、L1-NB°），上下中切牙切點及根尖點的橫坐標（U1c-Xmm，U1r-Xmm、L1c-Xmm、L1r-Xmm），上下中切牙切點及根尖點與NA、NB的距離（U1c-NAmm、U1r-NAmm、L1c-NBmm、L1r-NBmm）。 3.運用SPSS21.0對矯治前后各項目的測量值進行配對T檢驗，對相應(yīng)的線距及角度進行線性回歸分析，并建立回歸方程。 結(jié)果： 1.各測量項目在矯治前后差異顯著，上下切牙唇傾度及突度明顯減小。 2.矯治后MP-SN°輕微增大0.45±1.28°（p=0.0340.05）。 3.切牙唇傾度變化量與突度變化量顯著相關(guān)，具體公式為： ①U1-SN°=0.608+2.627×U1c-Xmm-2.507×U1r-Xmm（R2=0.893）②U1-NA°=0.086+2.636×U1c-NAmm-2.145×U1r-NAmm（R2=0.861）③L1-MP°=2.458+2.644×L1c-Xmm-2.273×L1r-Xmm（R2=0.623）④L1-NB°=0.977+3.208×L1c-NBmm-2.741×L1r-NBmm（R2=0.836）。
[Abstract]:The double tooth-alveolar protrusion is one of the common malocclusion in clinic, which usually shows normal position of upper and lower jaws, obvious labial inclination of incisor axis, uncrowded or mildly crowded dentition, and overprotrusion of both lips. Orthodontic camouflage often requires extraction of premolars. The anterior teeth with excessive lip inclination are extracted from the space between extraction teeth, and the lips are adducted with it to achieve a good face shape. Extraction of teeth causes the change of lip inclination and protrusive degree of incisors, and the relationship between them is clarified. It can be used in the VTO analysis of cases to realize the visualization of orthodontic objectives, and to draw up suitable treatment plans. It is of practical significance to the clinical work of orthodontics. Objective: to measure the lateral radiographs of 40 female patients with alveolar protrusion treated with extraction of teeth before and after orthodontic treatment. The changes of labial inclination and protrusions (sagittal position of incisors) before and after orthodontic treatment were analyzed and the quantitative relations between them were obtained. This provides a new reference for determining the target position of upper and lower incisors in static VTO analysis. Methods: 1. Forty female patients with bicuspid-alveolar protrusion were selected from the Department of Orthodontics, Jilin University Stomatological Hospital. The pre-treatment age was 鈮

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