Libby Joseph, Marghoub Arsalan, Johnson David, Khonsari Roman H, Fagan Michael J, Moazen Mehran
Medical and Biological Engineering, School of Engineering and Computer Science, University of Hull, Hull HU6 7RX, UK.
UCL Mechanical Engineering, University College London, London WC1E 7JE, UK.
J R Soc Interface. 2017 May;14(130). doi: 10.1098/rsif.2017.0202.
During the first year of life, the brain grows rapidly and the neurocranium increases to about 65% of its adult size. Our understanding of the relationship between the biomechanical forces, especially from the growing brain, the craniofacial soft tissue structures and the individual bone plates of the skull vault is still limited. This basic knowledge could help in the future planning of craniofacial surgical operations. The aim of this study was to develop a validated computational model of skull growth, based on the finite-element (FE) method, to help understand the biomechanics of skull growth. To do this, a two-step validation study was carried out. First, an physical three-dimensional printed model and an FE model were created from the same micro-CT scan of an infant skull and loaded with forces from the growing brain from zero to two months of age. The results from the model validated the FE model before it was further developed to expand from 0 to 12 months of age. This second FE model was compared directly with clinical CT scans of infants without craniofacial conditions ( = 56). The various models were compared in terms of predicted skull width, length and circumference, while the overall shape was quantified using three-dimensional distance plots. Statistical analysis yielded no significant differences between the male skull models. All size measurements from the FE model versus the physical model were within 5%, with one exception showing a 7.6% difference. The FE model and data also correlated well, with the largest percentage difference in size being 8.3%. Overall, the FE model results matched well with both the and data. With further development and model refinement, this modelling method could be used to assist in preoperative planning of craniofacial surgery procedures and could help to reduce reoperation rates.
在生命的第一年,大脑迅速生长,脑颅增加到其成年大小的约65%。我们对生物力学力之间的关系,特别是来自生长中的大脑、颅面软组织结构和颅顶单个骨板之间关系的理解仍然有限。这些基础知识可能有助于未来颅面外科手术的规划。本研究的目的是基于有限元(FE)方法开发一个经过验证的颅骨生长计算模型,以帮助理解颅骨生长的生物力学。为此,进行了一项两步验证研究。首先,从婴儿颅骨的同一微CT扫描创建一个物理三维打印模型和一个FE模型,并加载从零到两个月大的生长中大脑产生的力。该模型的结果在FE模型进一步扩展到0至12个月大之前对其进行了验证。将第二个FE模型直接与无颅面疾病婴儿的临床CT扫描(n = 56)进行比较。比较了各种模型预测的颅骨宽度、长度和周长,同时使用三维距离图对整体形状进行量化。统计分析表明男性颅骨模型之间没有显著差异。FE模型与物理模型的所有尺寸测量值相差在5%以内,只有一个例外显示相差7.6%。FE模型和临床数据也具有良好的相关性,尺寸上的最大百分比差异为8.3%。总体而言,FE模型的结果与物理模型和临床数据都匹配良好。随着进一步的开发和模型优化,这种建模方法可用于协助颅面外科手术的术前规划,并有助于降低再次手术率。