Gurian Kaita N, Guatelli-Steinberg Debra, McGraw W Scott, Rychel Jess, O'Hara Mackie C
Department of Anthropology, Ohio State University, Columbus, Ohio, USA.
School of Medicine, West Virginia University, Morgantown, West Virginia, USA.
Am J Biol Anthropol. 2025 Feb;186(2):e70001. doi: 10.1002/ajpa.70001.
Sharing micro-computed tomographic (μCT) scans of teeth increases data accessibility and reduces the need for repeated scans of any given specimen. However, the use of the same TIFF stacks or DICOMs by multiple individuals has the potential to introduce new sources of error. Here, we explore whether use of the same μCT scans by different persons produces comparable results.
Worn (N = 11) and unworn (N = 4) Cercocebus atys upper molars (UM1 N = 8, UM2 N = 7) were μCT scanned using a Bruker Skyscan 1172 High Resolution Ex Vivo Scanner at a resolution of 22 μm. Two individuals (K.N.G. and M.C.O.) created a 2D mesial slice for each TIFF stack (tooth). Worn teeth were reconstructed by K.N.G. and M.C.O. Three researchers (M.C.O., K.N.G., and J.R.) measured tooth shape, linear enamel thickness, average enamel thickness, and relative enamel thickness (AET and RET). Inter-observer percent error was calculated for each measurement. Univariate ANOVAs were calculated to evaluate variance due to slice maker, reconstructor, tooth, and measurer when percent error averaged > 5%.
For unworn teeth, error was generally low and largely due to the person doing the measurement. For worn teeth, wear reconstructor was a statistically significant source of variation for AET and RET.
We found that (1) inter-observer error was generally low, (2) linear measurements are prone to error, (3) worn teeth did not present an additional source of error as compared to unworn teeth, and (4) different people can use the same μCT scans to reliably reconstruct, slice, and measure teeth.
共享牙齿的微型计算机断层扫描（μCT）图像可提高数据的可及性，并减少对任何给定标本进行重复扫描的需求。然而，多人使用相同的TIFF堆栈或DICOM文件有可能引入新的误差来源。在此，我们探讨不同人员使用相同的μCT扫描是否会产生可比的结果。
使用布鲁克Skyscan 1172高分辨率离体扫描仪，以22μm的分辨率对磨损的（N = 11）和未磨损的（N = 4）黑冠白睑猴上臼齿（UM1 N = 8，UM2 N = 7）进行μCT扫描。两名人员（K.N.G.和M.C.O.）为每个TIFF堆栈（牙齿）创建一个二维近中切片。磨损的牙齿由K.N.G.和M.C.O.进行重建。三名研究人员（M.C.O.、K.N.G.和J.R.）测量牙齿形状、釉质线性厚度、平均釉质厚度和相对釉质厚度（AET和RET）。计算每次测量的观察者间百分比误差。当百分比误差平均>5%时，计算单因素方差分析以评估切片制作者、重建者、牙齿和测量者引起的方差。
对于未磨损的牙齿，误差通常较低，且主要归因于进行测量的人员。对于磨损的牙齿，磨损重建者是AET和RET的一个具有统计学意义的变异来源。
我们发现：（1）观察者间误差通常较低；（2）线性测量容易产生误差；（3）与未磨损的牙齿相比，磨损的牙齿并未带来额外的误差来源；（4）不同的人可以使用相同的μCT扫描来可靠地重建、切片和测量牙齿。
