Key Laboratory of E&M (Zhejiang University of Technology), Ministry of Education & Zhejiang Province, Hangzhou, Zhejiang, 310014, China.
Key Laboratory of E&M (Zhejiang University of Technology), Ministry of Education & Zhejiang Province, Hangzhou, Zhejiang, 310014, China.
J Mech Behav Biomed Mater. 2020 Jul;107:103758. doi: 10.1016/j.jmbbm.2020.103758. Epub 2020 Apr 5.
The purpose of this study was to analyze mechanical behaviors of a topologically optimized and 3D-printed mandibular bone block with polyetherketoneketone (PEKK) for surgical mandibular reconstruction.
3D virtual mandibular models were reconstructed from cone beam computed tomography images. A proposed mandibular resection of the mandibular body (40 mm anterior-posteriorly) was segmented. Internal structure of the resected bone was designed with topological optimization. Dental implants and implant-supported crowns were integrated into the design. A second 3D virtual model was created with the same size and location of the defect but was reconstructed with a fibular graft and implant-supported crowns. The biomechanical behaviors of the two models were compared by finite element method (FEM) under the same boundary constraints and three loading locations, namely, central incisors, lower left and right side first molar areas.
The FEM results showed the maximum stresses and displacements of the topology optimized model were much lower than those of the model with fibular bone graft. The highest stress of the optimized mandibular model was located on the lower edge of the posterior border of bone analog, and fixation screws. The maximum displacement occurred at the lower edge of the proximal mandibular stump or the lower edge of the distal mandibular body on the contralateral site. Under the same three loading locations, the maximum stress of the optimized model significantly decreased by 67.9%, 71.9% and 68.6% compared to the fibular graft model.
The 3D printed bone analog with topological optimization is patient-specific and has advantages over the conventional fibular bone graft for surgical mandibular reconstruction. The optimized PEKK bone analog model creates more normal stress-strain trajectories than the fibular graft model and likely provides better functional and cosmetic outcomes.
本研究旨在分析聚醚酮酮（PEKK）拓扑优化和 3D 打印下颌骨块的力学行为，用于下颌骨外科重建。
从锥形束 CT 图像重建 3D 虚拟下颌模型。对下颌体进行了拟议的下颌切除术（前后 40mm），并进行了分割。对切除骨的内部结构进行了拓扑优化设计。将牙种植体和种植体支持的牙冠集成到设计中。使用相同大小和位置的缺损，但使用腓骨移植物和种植体支持的牙冠，创建了第二个 3D 虚拟模型。通过有限元法（FEM），在相同的边界约束和三个加载位置（中切牙、左下和右下第一磨牙区）下比较了两种模型的生物力学行为。
FEM 结果表明，拓扑优化模型的最大应力和位移远低于腓骨骨移植模型。优化下颌模型的最高应力位于骨模拟后缘和固定螺钉的下缘。最大位移发生在近下颌残端的下缘或对侧下颌体远端的下缘。在相同的三个加载位置下，与腓骨移植物模型相比，优化模型的最大应力显著降低了 67.9%、71.9%和 68.6%。
具有拓扑优化的 3D 打印骨模拟是针对患者个体的，并且在外科下颌骨重建方面优于传统的腓骨移植物。优化的 PEKK 骨模拟模型比腓骨移植物模型产生更正常的应力-应变轨迹，并且可能提供更好的功能和美容效果。
