三维有限元模型分析OSAHS患者下颌不同前伸位置舌体变化的研究
【摘要】
目的：建立阻塞性睡眠呼吸暂停低通气综合征（OSAHS）患者上气道及毗邻结构的三维有限元模型，通过下颌逐步前伸，观察患者舌体及舌后气道的形态学改变，为OSAHS的口腔矫治器治疗提供依据。
方法：对OSAHS患者上气道行薄层CT扫描，获得患者上气道DICOM格式的图像信息，采用Mimics三维建模软件、Imageware逆向工程软件、Ansys有限元分析软件建立上气道及毗邻结构的三维有限元模型，然后通过加载下颌骨逐步前伸，观察患者舌体及舌后气道的形态变化及规律。
结果：建立了OSAHS患者上气道及毗邻结构的三维有限元模型，单元类型采用10节点的Solid 92四面体单元，划分网格后，骨密质、骨松质、肌肉和气道得到的单元数和节点数分别为：562920、50141、336789个单元，544929、84869、303134个节点。通过下颌骨前伸，舌体及舌后气道相应发生形态变化，主要表现为舌体前移，舌后气道平面矢状径增大，横径相对减小。
结论：应用螺旋CT技术并联合使用Mimics三维建模软件、Imageware软件、Ansys有限元分析软件建立OSAHS患者上气道及毗邻结构的三维有限元模型，证实通过CT可建立准确、可灵活模拟操作的OSAHS患者上气道及其周围结构的三维有限元模型，其建模效率高、速度快，模型的几何相似性较好，使用灵活；通过对有限元模型下颌进行不同前伸位置的加载，证实有限元分析方法的有效性，为下颌前伸矫治器治疗OSAHS提供理论依据，同时为后续研究患者上气道生物力学分析打下良好基础。
【关键词】阻塞性睡眠呼吸暂停低通气综合征；三维有限元法；下颌前伸；舌体
The investigation of analysis on OSAHS patient mandibular protrusion position of the tongue changing through 3-D FEM model(https://www.daowen.com)
ABSTRACT
Objective：A three-dimensional finite element（FEM）model of the Upper airway and adjacent structure of an Obstructive sleep apnea hypopnea syndrome patient for OSAHS biomechanical analysis was constructed.And the changes of tongue part and airway of OSAHS patient were observed by biomechanics and morphologic with the mandibular protruding，which provided the basis for the treatment of Oral appliance for OSAHS patients.
Methods：DICOM format image informations of an OSAHS patient’s upper airway obtained by thin-section CT scanning and digital image processing were utilized to construct a three-dimensional finite element model by Mimics，Imageware and Ansys software.And the changes and the law of tongue part and airway were observed with the mandibular protruding.
Results：A case of OSAHS and the adjacent upper airway structure of threedimensional finite element model is constructed which is formed by solid 92 tetrahedral unit of a 10-node element.The model has bone cortical 562920 elements，and 544929 nodes，cancellous bone 50141 elements and 84869 nodes，muscle and upper airway 336789 elements and 303134 nodes.After titrated mandibular protruding，tongue part of three-dimensional finite element of OSAHS change accordingly.The main manifestations are that the tongue forward，the transverse diameter and cross-sectional area of retroglossal region are decreased correspondingly，the sagittal diameter is increased significantly after model loading.
Conclusion：The three-dimensional finite element model of the upper airway and vicinity structure of the OSAHS patient was established using spiral CT technology and combined using Imageware，Mimics software and Ansys software，which confirmed the 3-D FEM model could be established through CT.The model has good geometric similarity and good flexibility.The validity of FEM analysis was confirmed through the loading of different protruding position of mandible in FEM model，which provided the theoretical basis for the treatment of OSAHS with mandibular protruding appliance and laying a good foundation for the follow-up study of upper airway of OSAHS patients with biomechanical analysis.
Key words：Obstructive sleep apnea hypopnea syndrome；three-dimensional finite element method；Mandibular advancement；tongue