All-on-4 concept為目前使用人工植體進行全口重建時較新的方法，其優勢在於能以較少的植體及手術次數與較低的費用，來達成製作全口固定式贋復物(fixed dental prosthesis)，以重建咬合功能的目的。為避免人工植體在承受咬合力後，植體周圍齒槽骨所受之壓應變過高導致骨吸收(absorption)現象發生，因此植體的配置對於齒槽骨之力學影響勢必經過通盤的分析。
本研究將All-on-4所使用之四根植體的位置與角度參數化，並定義出下顎骨神經與植體參數之相對關係，進行植體位置配置最佳化。力學分析採用有限元素法(Finite Elements Method)並且建立自動化電腦建模與分析流程，求得結構在受到咬合力後齒槽骨的應力分佈，接著利用上述分析流程，匯入下顎骨3D數位模型進行研究，利用最佳化方法計算出最佳植體配置設計，並以力學實驗驗證此分析流程之正確性。
其結果顯示，經過本研究之最佳化分析流程，兩側植遠心端植體周圍最小主應變小於-0.004之體積總和改善幅度為40.15%。根據結果進一步分析可知，遠心端植體位置應靠近下顎骨神經，在力學表現上會有較佳的結果。在使用All-on-4植體擺放位置設計時，傾斜植體所造成之應力增加與贋復物懸臂長度縮短造成之應力降低需同時考慮。

This study aims to optimize the placement and configuration of dental implants used in all-on-4 treatment concept by a numerical approach in which the finite element analysis (FEA) and design optimization techniques are integrated to minimize the peri-implant stress for reducing the risk of early bone loss.
In the finite elements model, eight parameters including tilt angles, length, diameter, and position of both side of the distal implants are concerned. A computational framework for automatic finite element model generation and design optimization is developed to search for the optimal configuration of the distal implants. A mechanical experiment is conducted to validate the result of the optimization.
The initial design of the optimization process is a design currently used in clinical practice. After the optimization process, the sum of the volume with a minimum principal strain below -0.004 in peri-implant region reduced by 40.15% compared to the initial one. The experimental result is successful to validate the
This research developed an automated framework for optimizing the implants placement based on the FEA and optimal design search algorithm. The results of the case study showed that the optimization process can find the optimal design.

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