Karadeniz Technical University Faculty of Dentistry, Department of Oral Diagnosis and Radiology, 61080 Trabzon,Turkiye.
Dentomaxillofac Radiol. 2011 Mar;40(3):165-9. doi: 10.1259/dmfr/23067462.
The Cavalieri principle of stereological methods is widely used to estimate the volume of structures. Recently in clinical practice, it has become common to use this approach for daily routine purposes. The Cavalieri principle provides quantitative and unbiased volume estimates which are independent of the observer. In the present study, the efficacy of using the Cavalieri principle to estimate the volume of sheep mandibular defects on cone beam CT (CBCT) scans was tested.
24 differently sized defects were created on 4 sheep mandibles. Before the defects were created, the outer boundaries of the defects were determined using plaster casts. CBCT scans of the defects were taken. The scans were reconstructed in the coronal plane and sections of 0.2 mm thickness with 0.2 mm and 0.4 mm intervals were obtained. The volume of each defect was estimated using the Cavalieri principle. The models were created using light-body silicone for the estimation of the actual volume of each defect. They were immersed in water using a pycnometer and the actual volumes were obtained on the basis of the Archimedean principle. The actual and estimated volumes of the defects were compared using the Wilcoxon signed-rank test.
The results showed that the volumes from the Cavalieri estimates did not differ from the actual volumes of the defects (P > 0.05).
We concluded that the volume of mandibular defects can be accurately estimated using the Cavalieri principle on images from a CBCT scan.
体视学方法的 Cavalieri 原理被广泛用于估计结构的体积。最近在临床实践中，这种方法已成为日常常规目的的常用方法。 Cavalieri 原理提供了定量且无偏的体积估计值，这些估计值与观察者无关。在本研究中，测试了使用 Cavalieri 原理来估计绵羊下颌骨缺损的体积的效果。
在 4 只绵羊下颌骨上创建了 24 个不同大小的缺损。在创建缺陷之前，使用石膏模型确定了缺陷的外边界。对缺陷进行了 CBCT 扫描。对扫描进行了冠状平面重建，并以 0.2mm 的间隔获得了 0.2mm 和 0.4mm 厚度的切片。使用 Cavalieri 原理估计每个缺陷的体积。使用轻体硅酮创建了模型，以估算每个缺陷的实际体积。将模型浸入水中，使用比重瓶获得了基于阿基米德原理的实际体积。使用 Wilcoxon 符号秩检验比较了缺陷的实际和估计体积。
结果表明，Cavalieri 估计值的体积与缺陷的实际体积无差异（P＞0.05）。
我们得出结论，使用 CBCT 扫描图像上的 Cavalieri 原理可以准确估计下颌骨缺损的体积。
