Darwish Noor A, El Hadidi Yasser N, Sayed Taha Moustafa M
Oral and Maxillofacial Surgery, Faculty of Dentistry, Ain Shams University, Cairo, Egypt.
J Craniofac Surg. 2025 May 22. doi: 10.1097/SCS.0000000000011507.
This study was aimed to evaluate 3-dimensional finite element analysis (FEA) of stress distribution in zygomatic and pterygoid implants in atrophic posterior maxilla. A 3D FEA model of an edentulous, atrophic maxilla was developed using cone-beam computed tomography (CBCT) scans. Four different implant configurations were evaluated: 2 zygomatic+2 pterygoid+3 anterior implants, 2 zygomatic+3 anterior implants, 2 zygomatic+2 pterygoid+2 anterior implants, and 2 zygomatic+2 anterior implants. Virtual implants were placed and a prosthetic superstructure was designed for each model. FEA was conducted to analyze stress distribution within the bone, implants, and prosthesis under simulated masticatory loads. Stress distribution in the peri-implant bone, abutments, and prosthetic framework was visualized through von Mises stress maps, while maximum principal stresses and micromotion were evaluated to determine implant stability and osseointegration potential. FEA revealed notable variations in stress distribution among the 4 models. Model 4 exhibited the highest peri-implant bone stress on the zygomatic left implant. Micromovement was lowest in model 4 and highest in model 2. Abutment-level stress analysis in model 3 showed the lowest stress on zygomatic implants and pterygoid implants, whereas model 4 recorded the highest stresses on zygomatic implants. Prosthetic framework stress was highest in model 2, while prosthetic superstructure stress showed minimal variation across models. Inclusion of pterygoid implants alongside zygomatic and anterior implants effectively reduces stress concentrations and micromovements in the atrophic maxilla, enhancing biomechanical stability and load distribution. Models without pterygoid implants showed increased stress on zygomatic implants, potentially compromising long-term stability.
本研究旨在评估三维有限元分析（FEA）在萎缩性上颌后牙区颧骨种植体和翼突种植体应力分布中的应用。利用锥形束计算机断层扫描（CBCT）扫描建立了无牙颌、萎缩性上颌骨的三维有限元分析模型。评估了四种不同的种植体配置：2颗颧骨种植体+2颗翼突种植体+3颗前牙种植体、2颗颧骨种植体+3颗前牙种植体、2颗颧骨种植体+2颗翼突种植体+2颗前牙种植体、2颗颧骨种植体+2颗前牙种植体。植入虚拟种植体，并为每个模型设计修复上部结构。进行有限元分析以分析在模拟咀嚼负荷下骨、种植体和修复体中的应力分布。通过冯·米塞斯应力图可视化种植体周围骨、基台和修复框架中的应力分布，同时评估最大主应力和微动以确定种植体稳定性和骨结合潜力。有限元分析显示4种模型的应力分布存在显著差异。模型4在左侧颧骨种植体上表现出最高的种植体周围骨应力。模型4中的微动最低，模型2中的微动最高。模型3的基台水平应力分析显示颧骨种植体和翼突种植体上的应力最低，而模型4记录的颧骨种植体上的应力最高。修复框架应力在模型2中最高，而修复上部结构应力在各模型之间变化最小。在颧骨种植体和前牙种植体旁加入翼突种植体可有效降低萎缩性上颌骨中的应力集中和微动，增强生物力学稳定性和负荷分布。没有翼突种植体的模型显示颧骨种植体上的应力增加，可能会影响长期稳定性。
