不同固位技术修复单侧上颌骨缺损的生物力学研究

Biomechanical study on unilateral maxilla restoration using different retention methods

目的采用三维有限元分析方法研究卡环、附着体以及颧种植体3种不同固位技术对上颌骨单侧缺损修复的生物力学影响。方法利用医学图像处理软件Mimics重建单侧缺损上颌骨模型,采用镜像技术生成修复体模型,并建立使用不同固位技术修复的上颌骨有限元模型,模拟口腔咬合状态下上颌骨受力状态。结果采用颧种植体固位修复的上颌骨健侧及修复侧上腭应力最大,分别为7.399、4.864 MPa;而且采用颧种植固位使得健侧及修复侧上颌骨应力最小,分别为10.46和10.86 MPa;颧种植体自身应力也最小,为15.25 MPa。结论不同固位技术修复对单侧上颌骨缺损修复效果影响较大。卡环固位及附着体固位由于带有支架可用于分担作用上腭的力,颧种植体固位可通过传递力至颧骨,故可分担作用于上颌骨的力。

Objective To study the biomechanical effects of 3 different retention methods （clasp, attachment or zygomatic implants） on repairing unilateral maxillary defects by using 3D finite element analysis method. Methods The maxillary unilateral defect model was reconstructed by the medical image processing software Mimics. The prosthesis was generated by mirroring technology. After processing, the finite element model of maxillary model by the three different retention methods was established to simulate stress distributions of maxilla during occlu- sion. Results Compared with the other methods, by using zygomatic implant retention method, stresses on af- fected and unaffected palate were the largest as 7. 399 and 4.864 MPa, respectively, while those on affected and unaffected maxilla were the smallest as 10.46 and 10.86 MPa, respectively. Stress on zygomatic implant itself was 15.25 MPa, which was also the smallest. Conclusions Different retention methods had an obvious impact on unilateral maxillary defect restoration. The clasp and attachment retention methods could share the stress on palate by carrying bracket. The zygomatic implant retention method could also share the stress on maxilla by passing the stress to the zygoma.