The Investigation Of Analysis On OSAHS Patient Mandibular Protrusion Position Of The Tongue Changing Through3-d Fem Model

Objective A three-dimensional finite element (FEM) model of the Upper airwayand adjacent structure of an Obstructive sleep apnea hypopnea syndrome patient for OSAHSbiomechanical analysis was constructed. And the changes of tongue part and airway ofOSAHS patient were observed by biomechanics and morphologic with the mandibularprotruding, which provided the basis for the treatment of Oral appliance for OSAHS patients.Methods DICOM format image informations of an OSAHS patient’s upperairway obtained by thin-section CT scanning and digital image processing were utilized toconstruct a three-dimensional finite element model by Mimics, Imageware and Ansyssoftware．And the changes and the law of tongue part and airway were observed with themandibular protruding.Results A case of OSAHS and the adjacent upper airway structure ofthree-dimensional finite element model is constructed which is formed by solid92tetrahedralunit of a10-node element. The model has bone cortical562920elements, and544929nodes,cancellous bone50141elements and84869nodes, muscle and upper airway336789elementsand303134nodes. After titrated mandibular protruding, tongue part of three-dimensionalfinite element of OSAHS change accordingly, The main manifestations are that the tongueforward, the transverse diameter and cross-sectional area of retroglossal region aredecreased correspondingly, the sagittal diameter is increased significantly after modelloading. Conclusions The three-dimensional finite element model of the upper airway andvicinity structure of the OSAHS patient was established using spiral CT technology andcombined using Imageware, Mimics software and Ansys software, which confirmed the3-DFEM model could be established through CT. The model has good geometric similarity andgood flexibility. The validity of FEM analysis was confirmed through the loading ofdifferent protruding position of mandible in FEM model, which provided the theoretical basisfor the treatment of OSAHS with mandibular protruding appliance and laying a goodfoundation for the follow-up study of upper airway of OSAHS patients with biomechanicalanalysis.