Cavalcanti M G P, Ruprecht A, Vannier M W
Department of Radiology, Faculty of Odontology, University of São Paulo, Brazil.
Dentomaxillofac Radiol. 2002 Jul;31(4):218-23. doi: 10.1038/sj.dmfr.4600701.
To determine the precision and accuracy of three-dimensional (3D) volume rendering spiral multislice computed tomography (CT)-based linear measurements of the mental foramen for dental implants, in vitro, and their precision, in vivo.
Five cadaver heads were imaged by multislice spiral CT (Toshiba Aquilion) with 0.5 mm thick axial slices (0.5 mm/0.5 s of table feed) at 0.5 mm interval reconstructions. The image data sets were transferred to a networked computer workstation. Using computer graphics the data were analysed with a 3D volume rendering technique using Vitrea software. Two oral and maxillofacial radiologists, independently, made electronic linear measurements from the superior border of the mental foramen to the crest of the alveolar process. The soft tissues were removed and physical measurements made using a 3 Space (Polhemus, Colchester, VT, USA) electromagnetic digitizer with a personal computer running Windows 98. The same linear measurements of 15 patients using the same imaging methodology were performed and the precision was analysed.
The findings showed no statistically significant inter- or intra-observer differences in vitro and in vivo, or between imaging and physical measurements in vitro (P>0.05).
3D multislice spiral CT imaging allows highly accurate measurements for dental implant placement in proximity to the mental foramen. Computer graphics software, using volume rendering is suitable for implant planning.
在体外确定基于三维（3D）容积再现螺旋多层计算机断层扫描（CT）的下颌孔线性测量用于牙种植体的精度和准确性，以及在体内的精度。
使用东芝Aquilion多层螺旋CT对5个尸体头部进行成像，轴向层厚0.5mm（床进速度0.5mm/0.5s），重建间隔0.5mm。将图像数据集传输到联网的计算机工作站。使用计算机图形学，利用Vitrea软件通过3D容积再现技术对数据进行分析。两名口腔颌面放射科医生独立地从下颌孔上缘至牙槽嵴顶进行电子线性测量。去除软组织，使用3Space（美国佛蒙特州科尔切斯特的Polhemus公司）电磁数字化仪和运行Windows 98的个人计算机进行物理测量。对15名患者采用相同的成像方法进行相同的线性测量，并分析其精度。
结果显示，在体外和体内，观察者之间或观察者自身之间，以及体外成像测量与物理测量之间均无统计学显著差异（P>0.05）。
3D多层螺旋CT成像可为靠近下颌孔的牙种植体植入提供高度准确的测量。使用容积再现的计算机图形软件适用于种植体规划。
