安氏I类错儿童上颌切牙唇腭侧齿槽厚度的CBCT研究

Maxillary incisors' dento-alveolar analysis of class I children using cone-beam CT

目的:采用CBCT影像测量安氏I类错患儿上颌前牙唇倾度及前牙唇腭侧齿槽骨的厚度,探讨上颌切牙与其支持骨的空间位置关系。方法:选取深圳市儿童医院口腔正畸科2010.1～2012.1年间就诊的正畸患儿25名,年龄11～14岁,平均12.5岁,男9例,女16例。Angle I类轻度错畸形。上前牙排列良好,无严重拥挤。所有病例均拍摄CBCT影像,在重建后的图像下进行定量测量。测定上切牙唇腭向的倾斜度,上切牙不同层面唇腭侧齿槽骨的厚度,上切牙根尖上方唇侧齿槽骨的曲度以及上切牙根尖距唇侧齿槽骨最凹点的距离。测量得到的数据采用SPSS13.0软件进行统计分析。结果:釉牙骨质界下2 mm唇侧骨板的厚度:中切牙(0.96±0.32)mm,侧切牙(0.78±0.32)mm。釉牙骨质界下2 mm腭侧骨板的厚度:中切牙(1.53±0.40)mm,侧切牙(1.12±0.48)mm。中切牙与腭平面的角度为114.59°±5.25°,侧切牙与腭平面的角度为111.75°±5.98°。切牙根尖上方唇侧齿槽骨的曲度:中切牙145.70°±11.09°,侧切牙156.92°±8.33°。切牙根尖距其上方唇侧齿槽骨最凹点的距离:中切牙(2.88±1.49)mm,侧切牙(2.69±0.99)mm。结论:上颌中切牙较侧切牙更加唇倾,切牙唇侧骨板均较薄,腭侧骨板相对较厚。切牙根尖位置更接近齿槽骨的唇侧。

Objective： The aim of this study was to evaluate the thickness of labial and palatal alveolar bone and labial bony curvature in maxillary anterior teeth of children using CBCT images. Method： Twenty-five patients （9 males, 16 females）, with mean age of 12.5 years were included in this study. Three-dimensional （3D） images were reformatted through CBCT. The incisor labio-palatal inclination, the thickness of labial and palatal alveolar bone, the labial bony curvature angle below root apex and the distance from root apex to the deepest point of labial bony curvature were measured using New Tom NNT programme. Paired t test was performed using SPSS 13.0 software package for Windows. Result： Mean thickness of labial plate 2 mm below CEJ was （0.96±0.32）mm at central incisor, （0.78±0.32）mm at lateral incisor. Mean thickness of palatal plate 2 mm below CEJ was （1.53±0.40）mm of central incisor, （1.12±0.48）mm of lateral incisor. Labio-palatal inclination was 114.59 ±5.25 of central incisor, 111.75±5.98 of lateral incisor. Labial bony curvature angle was 145.70°± 11.09° and 156.92°±8.33°, respectively. Distance between root apex and the deepest point of labial bony curvature of central incisor was （2.88±1.49）mm, （2.69±0.99）mm of lateral incisor. Conclusion：The central incisor is more labial inclination than the lateral incisor. The thickness of maxillary anterior labial plate was very thin and the palatal plate was relatively thick. The maxillary incisor root apex was closer to the labial cortical bone than to the palatal cortical bone.