State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Orthognathic and TMJ Surgery, Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China.
Oral and Maxillofacial Surgery Center, Guangdong Hanfei Plastic Surgery Hospital, Guangzhou City, Guangdong, China.
Med Eng Phys. 2024 Jul;129:104176. doi: 10.1016/j.medengphy.2024.104176. Epub 2024 May 8.
To evaluate and compare the biomechanical behavior of three-dimensionally (3D) printed patient-specific Ti6Al4V with commercially made titanium mini plates following Lefort-I osteotomy using finite element analysis.
Le Fort I osteotomy was virtually simulated with a 5 mm maxillary advancement and mediolateral rotation in the coronal plane, resulting in a 3 mm gap on the left side's posterior. Two fixation methods were modeled using software to compare 3D-printed Ti6Al4V and commercial titanium mini plates, both featuring a 4-hole l-shape with thicknesses of 0.5 mm and 0.7 mm at the strategic piriform rim and zygomaticomaxillary buttress locations. Using ANSYS R19.2, finite element models were developed to assess the fixation plates and maxilla's stress, strain, and displacement responses under occlusal forces of 125, 250, and 500 N/mm².
This comparative analysis revealed slight variation in stress, strain, and displacement between the two models under varying loading conditions. Stress analysis indicated maximum stress concentrations at the vertical change in the left posterior area between maxillary segments, with the Ti6Al4V model exhibiting slightly higher stress values (187 MPa, 375 MPa, and 750 MPa) compared to the commercial titanium model (175 MPa, 351 MPa, and 702 MPa). Strain analysis showed that the commercial titanium model recorded higher strain values at the bending area of the l-shaped miniplate. Moreover, displacement analysis revealed a maximum of 3 mm in the left posterior maxilla, with the Ti6Al4V model demonstrating slightly lower displacement values under equivalent forces.
The maximum stress, strain, and segment displacement of both fixation models were predominantly concentrated in the area of the gap between the maxillary segments. Notably, both fixation models exhibited remarkably close values, which can be attributed to the similar design of the fixation plates.
通过有限元分析评估并比较三种（3D）打印的患者特异性 Ti6Al4V 与商业制造的钛制微型板在 LeFort-I 截骨术后的生物力学行为。
虚拟模拟 LeFort I 截骨术，上颌骨前突 5mm，冠状面左右旋转，导致左侧后缘出现 3mm 间隙。使用软件模拟两种固定方法，比较 3D 打印 Ti6Al4V 和商业钛制微型板，均采用 4 孔 L 形，在 strategic piriform rim 和 zygomaticomaxillary buttress 位置的厚度分别为 0.5mm 和 0.7mm。使用 ANSYS R19.2 开发有限元模型，评估固定钢板和上颌骨在 125、250 和 500 N/mm² 咬合力下的应力、应变和位移响应。
在不同的加载条件下，两种模型的应力、应变和位移之间存在微小差异。应力分析表明，在最大的上颌骨节段之间的左侧后缘垂直变化处，最大的应力集中在钛 6 铝 4 钒模型（187 MPa、375 MPa 和 750 MPa），略高于商业钛模型（175 MPa、351 MPa 和 702 MPa）。应变分析表明，在 L 形微型板的弯曲区域，商业钛模型记录的应变值较高。此外，位移分析显示左侧上颌骨后缘最大位移为 3mm，在等效力下 Ti6Al4V 模型的位移值略低。
两种固定模型的最大应力、应变和节段位移主要集中在上颌骨节段之间的间隙区域。值得注意的是，两种固定模型的固定值非常接近，这可以归因于固定钢板的相似设计。
