微结构拓扑变化调控下颌骨重建支架力学适配性的研究

Many causes can lead to segmental mandibular defects, which will affect mastication, swallowing and other important physiological functions, but its functional reconstruction is still a challenge. It is possible to solve this problem by using 3D printing 3D mesh metal scaffold combined with bone graft material in the mode of concrete, and excellent biomechanical adaptability between the scaffold and host bone is particularly important. In the previous study, the biomechanical effects of the topological configuration of the scaffold microstructure were studied, but the mechanism of mechanical regulation between microstructures and host bones under specific mechnical conditions is still unclear. For this reason, based on the principle of "Mechanostat", the applicant proposes a hypothesis that affect the mechanical adaptability of microstructure. On the basis of previous research, the corresponding numerical model and animal model are constructed, and three parts of research contents are designed to verify the hypothesis by using the technical means of biomechanics and mechanobiology. 1)Simulation of bone growth and remodeling between microstructures based on bone functional adaptability theory; 2)Study on topological configuration change of microstructure in combination of simulation and animal experiment; 3)Analysis of mechanical adaptability of mandibular reconstructive mesh scaffolds under physiological loading. This project can provide the theoretical basis and design criterion for the mechanical optimization of 3D mesh scaffold for bone defect repair by exploring the mechanism of mechanical regulation of microstructure adaptation. It is important to study the functional reconstruction of mandibular defect.

多种病因均可导致下颌骨节段性缺损，将影响咀嚼、吞咽等重要生理机能，其功能性重建仍然是个挑战。利用3D打印网状支架再结合植骨材料的混凝土式修复可望解决该难题，而支架与宿主骨之间良好的生物力学适配性尤为重要。项目组前期就支架微结构拓扑构型的生物力学影响进行了研究，认为特定受力环境下微结构与宿主骨之间的力学调控机制还不甚明了。为此，申请人基于“力学调控系统”原理提出了影响微结构力学适配性的科学假设，并在前期研究基础上，构建相应数值模型和动物模型，利用生物力学和力生物学的技术手段，设计了3部分研究内容来验证假设：1）基于骨功能适应性理论模拟微结构间骨长入和重建；2）结合仿真和动物试验分析微结构拓扑构型变化；3）生理负载下分析下颌骨重建网状支架的力学适配性。本项目通过探讨微结构适配性的力学调控机制，可为骨缺损修复三维网状支架的力学优化提供理论依据和设计准则，对下颌骨缺损的功能性重建具有重要研究意义。

本项目针对颌骨大面积截断性缺损精准重建和功能重建困难的临床核心问题，利用激光增材制造三维网状支架再结合植骨材料的耦合修复重建，通过生物力学研究其核心科学规律，以期解决临床问题。.本着从易到难的原则，首先从牙槽骨缺损入手，完成了用于牙槽骨增量个性化支网的生物力学研究，基于不同多孔钛构型成骨性能，完成了对比研究，并且在受载情况下完成了3D打印多孔钛的生物力学研究。然后在前期完成数值仿真模拟研究的基础上，完成了比格犬动物试验，选择临床急需的病例，基于前期研究工作的基础上，推进完成面向上颌牙槽骨严重缺损倾斜种植修复的生物力学仿真研究及临床评价，进而完成个性化人工颞下颌关节植入体固位模式的生物力学研究。再后通过重庆医科大学附属口腔医院伦理委员会批准，选择临床急需的病例，初步进行了临床研究，共计完成了100余例口腔牙槽骨缺损重建生物支架的临床验证性研究；在本项目收官阶段，整理总结前期研究结果和经验，形成面向口腔颅颌面大面积缺损精准修复和功能重建的创新解决方案，形成标准工作流程和规范，基于临床试验验证，为后续临床转化奠定基础。. 本项目研究目标是基于微结构拓扑变化调控研究下颌骨重建支架力学适配性，通过数值仿真、工艺验证、动物试验、临床评价等多个研究环节，本项目达到既定研究目标。因为充分利用研究单位重庆医科大学附属口腔医院的优势，增加了临床研究验证部分，为后续临床转化积累工作经验和研究基础。