Lovald Scott T, Wagner Jon D, Baack Bret
Mechanical Engineering Department, University of New Mexico, Albuquerque, NM, USA.
J Oral Maxillofac Surg. 2009 May;67(5):973-85. doi: 10.1016/j.joms.2008.12.032.
To design and optimize a bone plate for fractures of the mandibular body that will provide maximum fracture stability with minimal implanted volume and patient intrusion. The design will be driven by the unique biomechanics specific to this fracture location.
A finite element model of a fractured human mandible was created using tomography scans. Material properties were assigned to the cortical bone, cancellous bone, and dental region. Boundary conditions included simulating a unilateral molar clench and incisal loading. The bone plate design process included a shape optimization routine and design parameter analysis using the model. The optimized bone plate design was finally compared with standard bone plate configurations based on stress and strain measures.
For incisal loading, the newly designed InterFlex II plate has 69% of the fracture strain and only 34% of the plate stress of an 8-hole strut plate. For unilateral molar loading, those numbers improve even further to 59% and 27%, respectively. InterFlex II plate stresses are less than or equal to the paired plate configuration, and fracture strain is within 10% of the corresponding paired plate strain under both loading scenarios. In terms of mechanical performance, InterFlex II is in the same class as the commonly used paired plate configuration, despite having only 55% of the implanted volume.
A design process focused on shape and design variable optimization can produce bone plates that provide maximum fracture stability with minimum implanted volume.
设计并优化一种用于下颌体骨折的接骨板，使其在植入体积最小且对患者影响最小的情况下提供最大的骨折稳定性。该设计将由该骨折部位特有的独特生物力学驱动。
使用断层扫描创建了一个骨折人类下颌骨的有限元模型。为皮质骨、松质骨和牙齿区域指定了材料属性。边界条件包括模拟单侧磨牙咬紧和切牙加载。接骨板设计过程包括形状优化程序和使用该模型的设计参数分析。最后根据应力和应变测量结果将优化后的接骨板设计与标准接骨板配置进行比较。
对于切牙加载，新设计的InterFlex II接骨板的骨折应变是8孔支柱接骨板的69%，接骨板应力仅为其34%。对于单侧磨牙加载，这些数字分别进一步提高到59%和27%。在两种加载情况下，InterFlex II接骨板的应力小于或等于配对接骨板配置，骨折应变在相应配对接骨板应变的10%以内。在力学性能方面，InterFlex II与常用的配对接骨板配置属于同一类别，尽管其植入体积仅为55%。
专注于形状和设计变量优化的设计过程可以生产出在植入体积最小的情况下提供最大骨折稳定性的接骨板。
