Periago Danielle R, Scarfe William C, Moshiri Mazyar, Scheetz James P, Silveira Anibal M, Farman Allan G
Department of Orthodontic and Pediatric Dentistry, University of Louisville School of Dentistry, Louisville, KY, USA.
Angle Orthod. 2008 May;78(3):387-95. doi: 10.2319/122106-52.1.
To compare accuracy of linear measurements made on cone beam computed tomographic (CBCT) derived 3-dimensional (3D) surface rendered volumetric images to direct measurements made on human skulls.
Twenty orthodontic linear measurements between anatomical landmarks on 23 human skulls were measured by observers using a digital caliper. The skulls were imaged with CBCT and Dolphin 3D (version 2.3) software used to generate 3D volumetric reconstructions (3DCBCT). The linear measurements between landmarks were computed by a single observer three times and compared to anatomic dimensions using Student's t-test (P < or = .05). The intraclass correlation coefficient (ICC) and absolute linear and percentage error were calculated.
The ICC for 3DCBCT (0.975 +/- 0.016) was significantly less than for skull (0.996 +/- 0.007) measurements. Mean percentage measurement error for 3DCBCT (2.31% +/- 2.11%) was significantly higher than replicate skull measurements (0.63% +/- 0.51%). Statistical differences between 3DCBCT means and true dimensions were found for all of the midsagittal measurements except Na-A and six of the 12 bilateral measurements. The mean percentage difference between the mean skull and 3D-based linear measurements was -1.13% (SD +/- 1.47%). Ninety percent of mean differences were less than 2 mm, and 95% confidence intervals were all less than 2 mm except for Ba-ANS (3.32 mm) and Pog-Go(left) (2.42 mm).
While many linear measurements between cephalometric landmarks on 3D volumetric surface renderings obtained using Dolphin 3D software generated from CBCT datasets may be statistically significantly different from anatomic dimensions, most can be considered to be sufficiently clinically accurate for craniofacial analyses.
比较在锥形束计算机断层扫描（CBCT）生成的三维（3D）表面渲染容积图像上进行的线性测量与在人类颅骨上进行的直接测量的准确性。
观察者使用数字卡尺对23个人类颅骨上的解剖标志之间进行20项正畸线性测量。对颅骨进行CBCT成像，并使用Dolphin 3D（2.3版）软件生成3D容积重建（3DCBCT）。由一名观察者对标志之间的线性测量进行三次计算，并使用学生t检验（P≤0.05）与解剖尺寸进行比较。计算组内相关系数（ICC）以及绝对线性误差和百分比误差。
3DCBCT的ICC（0.975±0.016）显著低于颅骨测量的ICC（0.996±0.007）。3DCBCT的平均百分比测量误差（2.31%±2.11%）显著高于重复颅骨测量的误差（0.63%±0.51%）。除了Na-A以及12项双侧测量中的6项外，所有矢状面测量的3DCBCT平均值与真实尺寸之间均存在统计学差异。颅骨平均尺寸与基于3D的线性测量之间的平均百分比差异为-1.13%（标准差±1.47%）。90%的平均差异小于2 mm，除了Ba-ANS（3.32 mm）和Pog-Go（左侧）（2.42 mm）外，95%的置信区间均小于2 mm。
虽然使用CBCT数据集通过Dolphin 3D软件获得的3D容积表面渲染上的许多头影测量标志之间的线性测量在统计学上可能与解剖尺寸有显著差异，但大多数对于颅面分析而言在临床上可认为具有足够的准确性。
