下颌逐步前伸对阻塞性睡眠呼吸暂停低通气综合征患者软腭末端截面影响的三维有限元分析

The three- dimensional finite element analysis on OSAHS patients palatopharyngeal part with the titrated mandibular advancement

目的加载阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者上气道及其周围结构三维有限元模型下颌骨逐步前伸,观察上气道软腭末端截面形态学及生物力学变化,为OSAHS患者下颌前伸矫治器治疗机制研究提供一种新方法。方法应用螺旋CT对OSAHS患者上气道扫描,结合工程软件Mimics10.0、Imageware10.0及Ansys8.0建立三维有限元模型,并加载下颌骨依次前伸2、4、6、8 mm,观察软腭末端截面形态学及生物力学变化。结果软腭末端截面随下颌骨逐步前伸其矢状径减小,横径增加;平均应力变化不明显,分布均匀;拉应力有增加的趋势,但其分布位置无明显改变。结论螺旋CT技术结合Mimics,Imageware、Ansys等有限元分析软件可以建立几何相似性好、使用方便的OSAHS患者上气道及其周围结构三维有限元模型,证实随下颌逐步前伸软腭末端截面积增大,截面拉应力增加,为下颌前伸矫治器治疗OSAHS的机制研究提供一种新方法。

Objective To construct a three- dimensional finite element model of an obstructive sleep apnea hypopnea syndrome（ OSAHS） patients ＇ upper airway and adjacent structure,titrated mandibular advancement,and to observe the biomechanics and morphologic changes of the palatopharyngeal part. Methods Obtained the OSAHS patients CT scanning date,a three- dimensional finite element model of an OSAHS patients＇ upper airway and adjacent structure,titrated mandibular advancement were constructed by using the Mimics10. 0,Imageware10. 0 and Ansys8. 0 software,the biomechanics and morphologic changes of glossopharyngeal part were observed.Results With titrated mandibular advancement,glossopharyngeal part of three- dimensional finite element of OSAHS changed significantly,the greatest increase when the mandible advanced by 8cm. The sagittal diameter of palatopharyngeal were decreased significantly as the transverse diameter increased correspondingly. With titrated mandibular advancement,the palatopharyngeal stress did not change significantly. The first principal stress（ s1） increased with the increasing of distance,but the location of principal stress concentration did not change significantly. Conclusion This study shows that the joint use of spiral CT technology and Mimics software,Imageware software,Ansys software could provide a more accurate mode for establishment the upper airway and vicinity structure of OSAHS patient than only use CT scanning. And it provide a theoretical basis for treatment of OSAHS with Mandibular advancement appliance and laying a good foundation for the follow- up study of upper airway in OSAHS patients with biomechanical analysis.