All-on-4®全口重建用於全口無牙患者的重建治療相當盛行，相較於傳統植牙手術，能以較低的手術花費以達成患者的全口重建。臨床上得知，雖然All-on-4®已是相當成熟的技術，但是仍會發生嚴重程度不一的併發症，影響患者術後的日常生活，並增加醫療成本。然而其贋復物的製作皆仰賴牙醫師的經驗，並無統一的標準或方法可供依循。
本研究分為兩部份，第一部分為利用全域最佳化方法(粒子點群法)，找尋植體配置的最佳化設計，以降低骨骼的應力與高應變區域總體積；第二部分是以第一部分的植體設計參數為基礎，並修改支架的截面設計，使其包含內外兩層材料，分別模擬支架與外層所包覆的贋復物，使模型能應用至此部分的最佳化方法，並使用拓樸最佳化(雙向演進式結構式最佳化)，降低支架設計的順從性。兩者皆與自動化建模和有限元素分析結合，開發出一套自動化最佳化流程，能應用於不同外形的下顎骨，找尋最適合該下顎骨的All-on-4®設計。
第一部分的結果顯示，針對不同外形的下顎骨，其最佳化後的高應變區域總體積下降幅度為61 %～68 %，其骨骼等效應力的平均下降幅度為13 %～20 %。第二部分的支架順從性的下降幅度為17 %～26 %，同時植體周圍的骨骼有較佳的生物力學反應。
本研究以最佳化方法和有限元素分析，找尋適合患者下顎骨的贋復物設計，提供不同以往且客觀的設計，以供牙科醫師不同方面的植體配置做參考，並發展出創新的支架外型設計，以增進整體牙科贋復物的製作。

All-on-4® is a popular reconstructive treatment for edentulous patients and can be performed with lower surgical cost than traditional implant surgery. Although All-on-4® is a mature technology, complications of varying severity can still occur to affect patient's daily live after surgery and increase medical costs. However, the preparation of prothesis is based on the dentist’s experience, and there is no standard method to follow.
This research proposed a computational approach for All-on-4® design optimization from the biomechanical perspective. The approach was composed of two modules. The first part was to find the optimal design of the configuration of implants using the particle swarm optimization technique to reduce the total bone volume with high strain and stress. With the optimal configuration of implants, the second module modified the structural design of the All-on-4® framework by considering all parts, including the mandibular, framework, and dental prosthesis. The bi-directional evolutionary structured optimization technique was used to modify the arrangement of framework materials and reduce the compliance of the framework structure under specified loads. Both modules were integrated into an automated modeling workflow that can be applied to different mandibles to customize All-on-4® designs for patients.
The first modules showed that the total volume in the high-strain region was reduced by 61 % to 68 % after optimization in the mandibles studied. The average reduction in bone stress was 13 % to 20 % in the second module. The framework compliance was reduced by 17 % to 26 %, while the peri-implant bone showed better biomechanics.
This study incorporated robust optimization methods and finite element analysis to find an optimal prothesis design for the patient's mandible. The approach can be implemented as a clinical tool to offer dentists new insight from the biomechanical point of view when making decision for a treatment plan.

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