Heo Kyung-Hoi, Lim Young-Jun, Kim Myung-Joo, Kwon Ho-Beom
Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
Dental Research Institute and Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
J Adv Prosthodont. 2018 Apr;10(2):138-146. doi: 10.4047/jap.2018.10.2.138. Epub 2018 Apr 18.
The purpose of this study was to analyze the effects of the splinted implant prosthesis in a reconstructed mandible using three-dimensional finite element analysis.
Three-dimensional finite element models were generated from a patient's computed tomography data. The patient had undergone partial resection of the mandible that covered the area from the left canine to the right condyle. The mandible was reconstructed using a fibula bone graft and dental implants. The left mandibular premolars and molars remained intact. Three types of models were created. The implant-supported prosthesis was splinted and segmented into two or three pieces. Each of these models was further subcategorized into two situations to compare the stress distribution around normal teeth and implants. Oblique loading of 300 N was applied on both sides of the mandible unilaterally. The maximum von Mises stress and displacement of the models were analyzed.
The stress distribution of the natural mandible was more uniform than that of the reconstructed fibula. When the loading was applied to the implant prosthesis of reconstructed fibula, stress was concentrated at the cortical bone around the neck of the implants. The three-piece prosthesis model showed less uniform stress distribution compared to the others. Displacement of the components was positively correlated with the distance from areas of muscle attachment. The three-piece prosthesis model showed the greatest displacement.
The splinted implant prosthesis showed a more favorable stress distribution and less displacement than the separated models in the reconstructed mandible.
本研究旨在通过三维有限元分析，探讨夹板式种植体修复体在重建下颌骨中的效果。
根据患者的计算机断层扫描数据建立三维有限元模型。该患者下颌骨部分切除范围从左尖牙至右髁突。下颌骨采用腓骨移植和牙种植体进行重建。左下颌前磨牙和磨牙保持完整。创建了三种类型的模型。种植体支持的修复体采用夹板固定并分为两段或三段。这些模型中的每一个又进一步细分为两种情况，以比较正常牙齿和种植体周围的应力分布。在下颌骨两侧单侧施加300 N的斜向载荷。分析模型的最大von Mises应力和位移。
天然下颌骨的应力分布比重建的腓骨更均匀。当对重建腓骨的种植体修复体施加载荷时，应力集中在种植体颈部周围的皮质骨。与其他模型相比，三段式修复体模型的应力分布更不均匀。部件的位移与肌肉附着区域的距离呈正相关。三段式修复体模型的位移最大。
在重建下颌骨中，夹板式种植体修复体比分离式模型显示出更有利的应力分布和更小的位移。
