Faculty of Biomedical Engineering, Sahand University of Technology, Tabriz, Iran.
Mechanical Engineering Department, Sahand University of Technology, Tabriz, Iran.
Comput Methods Biomech Biomed Engin. 2021 Oct;24(13):1437-1449. doi: 10.1080/10255842.2021.1892660. Epub 2021 Oct 16.
The aim of this study was to design for mandibular reconstruction of large lateral defect with minimum target reliability with designated confidence interval under bite force range of 300 ± 102 N. The performance of the models has been evaluated by numerical analysis considering the uncertainty of input parameters. Computer-Aided design was used to develop the models of three designs according to the patient's anatomy and to achieve to near symmetry of the mandible. Stress-strength modeling was utilized for the probabilistic physics of failure analysis under assumption of a quasi-static load. Monte-Carlo simulation was also applied for probabilistic finite element analysis and reliability assessment. The sensitivity analysis of the models was developed to reflect the significance of the variables in the models. The deterministic stress analysis shows that the highest stress and the second maximum stress are 110 MPa and 85 MPa for cortical bone around the screws, respectively. Also, it is determined that the maximum plate stress of the titanium conventional plate model is 580 MPa. The reconstruction system success rate was improved in all models by observing the anatomy of the patient's mandible in the plate designs by computer-aided design and additive manufacturing techniques. Based on the results, the reliability of plate strength and pull-out screws strength are 99.99% and 96.71% for the fibula free flap model, respectively, and 99.99% and 94.17%, respectively, for the customized prosthesis model. Probability sensitivity factors showed that uncertainty in the elastic modulus of the cortical bone has the greatest effect on the probability of screws loosening.
本研究旨在设计用于下颌骨大外侧缺损重建的模型，以在 300±102N 咬合力范围内实现最小目标可靠性，同时具有指定的置信区间。通过考虑输入参数的不确定性的数值分析来评估模型的性能。计算机辅助设计用于根据患者的解剖结构开发三种设计模型，以实现下颌骨的近乎对称。应力-强度建模用于在准静态载荷假设下进行失效分析的概率物理。还应用了蒙特卡罗模拟进行概率有限元分析和可靠性评估。开发了模型的灵敏度分析，以反映模型中变量的重要性。确定性应力分析表明，螺钉周围皮质骨的最高应力和第二高应力分别为 110MPa 和 85MPa。此外，确定钛常规板模型的最大板应力为 580MPa。通过计算机辅助设计和增材制造技术观察患者下颌骨的解剖结构，所有模型中的重建系统成功率都得到了提高。基于这些结果，游离腓骨瓣模型的板强度和拔出螺钉强度的可靠性分别为 99.99%和 96.71%，定制假体模型的可靠性分别为 99.99%和 94.17%。概率灵敏度因素表明，皮质骨弹性模量的不确定性对螺钉松动的概率影响最大。
