Güngör Enes, Doğan Mehmet Sinan
Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Zirve University, 21100 Gaziantep, Turkey.
Department of Pediatrics, Faculty of Dentistry, Dicle University, 04100 Diyarbakır, Turkey.
J Dent Sci. 2017 Jun;12(2):145-150. doi: 10.1016/j.jds.2016.11.004. Epub 2017 Mar 31.
BACKGROUND/PURPOSE: The reliability and accuracy of linear distance and voxel density (VD) measurements are very important in dentistry. The purpose of this study was to assess the accuracy and reliability of linear distances and VD measurements of cone-beam computed tomography (CBCT) at different voxel sizes.
Eighteen-millimeter linears of size 40 gutta-percha were prepared in fresh sheep head. The head was scanned using CBCT with 0.25, 0.3, and 0.40 voxel sizes. Standard linear distances of gutta-percha were measured in panoramic CBCT images at 0.25, 0.3, and 0.4 voxel sizes. VD measurements were made separately on spongeous bone of palatal surfaces of the roots of teeth 4, 5, and 6 of maxilla and on cortical bone of teeth 4, 5, and 6 regions of the left and right hemimandibles through cross-sectional imaging.
We found that linear distance measurements on panoramic image of CBCT were slightly lower than physical measurements. A significant difference was not found for the gutta-percha linear distances and cortical VD measurements at different voxel sizes (P ≥ 0.05). The correlation between measurements of VD at different voxels in cortical bone was greater than 0.85 (P = 0.000).
Linear distance measurements on the sheep head cadaver of 0.25, 0.3, and 0.4 voxel sizes were similar and reliable when compared with physical measurements. In minimizing radiation exposure, VD measurement of cortical bone at 0.4 voxel-based CBCT could be used to estimate cortical bone density. However, studies should be performed on the human head cadaver.
背景/目的：线性距离和体素密度（VD）测量的可靠性和准确性在牙科领域非常重要。本研究的目的是评估不同体素大小下锥形束计算机断层扫描（CBCT）的线性距离和VD测量的准确性和可靠性。
在新鲜羊头中制备40号牙胶尖的18毫米线性样本。使用体素大小为0.25、0.3和0.40的CBCT对羊头进行扫描。在全景CBCT图像中测量体素大小为0.25、0.3和0.4时牙胶尖的标准线性距离。通过横断面成像分别对上颌牙齿4、5和6牙根腭侧的海绵骨以及左右半下颌牙齿4、5和6区域的皮质骨进行VD测量。
我们发现CBCT全景图像上的线性距离测量值略低于实际测量值。不同体素大小下牙胶尖线性距离和皮质VD测量值之间未发现显著差异（P≥0.05）。皮质骨中不同体素的VD测量值之间的相关性大于0.85（P = 0.000）。
与实际测量相比，体素大小为0.25、0.3和0.4的羊头尸体上的线性距离测量结果相似且可靠。为了尽量减少辐射暴露，基于0.4体素的CBCT对皮质骨的VD测量可用于估计皮质骨密度。然而，应在人类尸体头部上进行研究。
