Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Luigi Mangiagalli 31, 20133, Milan, Italy.
U.O. Laboratorio di Morfologia Umana Applicata, IRCCS Policlinico San Donato, 20097, San Donato Milanese, Italy.
Sci Rep. 2024 Jun 7;14(1):13149. doi: 10.1038/s41598-024-63029-4.
In forensic commingled contexts, when the disarticulation occurs uniquely at the atlantoaxial joint, the correct match of atlas and axis may lead to the desirable assembly of the entire body. Notwithstanding the importance of this joint in such scenarios, no study has so far explored three-dimensional (3D) methodologies to match these two adjoining bones. In the present study, we investigated the potential of re-associating atlas and axis through 3D-3D superimposition by testing their articular surfaces congruency in terms of point-to-point distance (Root Mean Square, RMS). We analysed vertebrae either from the same individual (match) and from different individuals (mismatch). The RMS distance values were assessed for both groups (matches and mismatches) and a threshold value was determined to discriminate matches with a sensitivity of 100%. The atlas and the corresponding axis from 41 documented skeletons (18 males and 23 females), in addition to unpaired elements (the atlas or the axis) from 5 individuals, were superimposed, resulting in 41 matches and 1851 mismatches (joining and non-joining elements). No sex-related significant differences were found in matches and mismatches (p = 0.270 and p = 0.210, respectively), allowing to pool together the two sexes in each group. RMS values ranged between 0.41 to 0.77 mm for matches and between 0.37 and 2.18 mm for mismatches. Significant differences were found comparing the two groups (p < 0.001) and the highest RMS of matches (0.77 mm) was used as the discriminative value that provided a sensitivity of 100% and a specificity of 41%. In conclusion, the 3D-3D superimposition of the atlanto-axial articular facets cannot be considered as a re-association method per se, but rather as a screening one. However, further research on the validation of the 3D approach and on its application to other joints might provide clues to the complex topic of the reassociation of crucial adjoining bones.
在法医混杂情况下，当关节分离仅发生在寰枢关节时，正确匹配寰椎和枢椎可能导致整个身体的理想组装。尽管这个关节在这种情况下非常重要，但迄今为止还没有研究探索过将这两个相邻骨骼匹配的三维 (3D) 方法。在本研究中，我们通过测试关节面的点到点距离（均方根，RMS）来研究通过 3D-3D 叠加重新关联寰椎和枢椎的潜力。我们分析了来自同一个体（匹配）和不同个体（不匹配）的椎体。评估了两组（匹配和不匹配）的 RMS 距离值，并确定了一个阈值来区分具有 100%灵敏度的匹配。将 41 具记录在案的骨骼（18 名男性和 23 名女性）的寰椎和相应的枢椎，以及 5 名个体的未配对元素（寰椎或枢椎）进行叠加，得到 41 个匹配和 1851 个不匹配（连接和不连接元素）。在匹配和不匹配中未发现与性别相关的显著差异（p=0.270 和 p=0.210），允许在每个组中将两性混合在一起。匹配的 RMS 值范围为 0.41 至 0.77mm，不匹配的 RMS 值范围为 0.37 至 2.18mm。两组之间的 RMS 值存在显著差异（p<0.001），并且使用最高的匹配 RMS（0.77mm）作为区分值，提供了 100%的灵敏度和 41%的特异性。总之，寰枢关节关节面的 3D-3D 叠加本身不能被视为重新关联方法，而只能作为一种筛选方法。然而，进一步研究 3D 方法的验证及其在其他关节中的应用可能为解决关键相邻骨骼重新关联这一复杂问题提供线索。
