Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
Department of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA, USA.
Biomech Model Mechanobiol. 2022 Aug;21(4):1251-1265. doi: 10.1007/s10237-022-01588-z. Epub 2022 Jun 6.
Cranial sutures are complex soft tissue structures whose mechanics are often studied due to their link with bone growth in the skull. Researchers will often use a cross-sectional two-dimensional slice to define suture geometry when studying morphometry and/or mechanical response to loading. However, using a single cross section neglects the full suture complexity and may introduce significant errors when defining their form. This study aims to determine trends in suture path variability through skull thickness in a swine model and the implications of using a 'representative' cross section on mechanical modeling. To explore these questions, a mixture of quantitative analysis of computed tomography images and finite element models was used. The linear interdigitation and width of coronal and sagittal sutures were analyzed on offset transverse planes through the skull thickness. It was found that sagittal suture width and interdigitation were largely consistent through the skull thickness, whereas the coronal suture showed significant variation in both. The finite element study found that average values of displacement and strain were similar between the two-dimensionally variable and three-dimensionally variable models. Larger ranges and more complex distributions of strain were found in the three-dimensionally variable model. Outcomes of this study indicate that the appropriateness of using a representative cross section to describe suture morphometry and predict mechanical response should depend on specific research questions and goals. Two-dimensional approximations can be sufficient for less-interdigitated sutures and when bulk site mechanics are of interest, while taking the true three-dimensional geometry into account is necessary when considering spatial variability and local mechanical response.
颅骨缝是复杂的软组织结构，由于它们与颅骨生长有关，因此经常研究其力学特性。研究人员在研究形态计量学和/或对加载的机械响应时，通常会使用横截面二维切片来定义缝线几何形状。然而，使用单个横截面会忽略缝线的全部复杂性，并在定义其形状时引入重大误差。本研究旨在确定猪模型中颅骨厚度变化对缝线路径变化的趋势，以及在机械建模中使用“代表性”横截面的影响。为了探讨这些问题，使用了计算机断层扫描图像和有限元模型的定量分析混合方法。在颅骨厚度上通过偏移横向平面分析冠状缝和矢状缝的线性交错和宽度。结果发现，矢状缝的宽度和交错在颅骨厚度上基本一致，而冠状缝则存在明显的变化。有限元研究发现，二维变化和三维变化模型之间的位移和应变平均值相似。在三维变化模型中，应变的范围更大且分布更复杂。本研究的结果表明，使用代表性横截面来描述缝线形态计量学和预测机械响应的适当性应取决于具体的研究问题和目标。对于交错较少的缝线和当关注整体部位力学时，二维近似值可能就足够了，而在考虑空间变异性和局部力学响应时，有必要考虑真实的三维几何形状。
