The Three-dimensional Finite Element Model Analysis Of Obstructive Sleep Apnea Hypopnea Syndrome Patient’s Condylar Position Changes And Changes In Surface Stress With Mandibular Protrusion Gradually

Objective To construct a three-dimensional finite element model of the mandibularand temporomandibular joint of an Obstructive sleep apnea hypopnea syndrome patient. Andthen titrated mandibular advancement, observation OSAHS patients condylar positionchanges and changes in surface stress distributionprovide, find information for the treatmentof OSAHS from the temporomandibular joint.Methods DICOM format image information of an OSAHS patient’s upper airwayobtained by thin—section CT scanning and digital image processing were utilized to constructa three-dimensional finite element model by Mimics、Imageware and Ansys software．Andthen titrated mandibular advancement, observed OSAHS patients condylar position changesand stress distribution law.Results A case of OSAHS and the mandible and temporomandibular joint (contains theupper airway and surrounding structures) of three-dimensional finite element model isconstructed which is formed by solid92tetrahedral unit of a10-node element. The model hasbone cortical562920elements, and544929nodes, cancellous bone50141elements and84869nodes, muscle and upper airway336789elements and303134nodes. After titratedmandibular protruding, condylar position and surface stress change accordingly, mainly asfollows: the change of position joint space (the anterior、superior and posterior) and there arevarious of condylar displacement and surface stress changes.Conclusions The three-dimensional finite element model of the temporomandibular joint and mandible of the OSAHS patient was established using spiral CT technology andcombined using Mimics,Imageware software and Ansys software, which confirmed the3-DFEM model could be established through CT. The model has good geometric similarity andgood flexibility. The model through mechanical similarity verification to prove effectivemodel geometric similarity is better, and the use of flexible; through the lower jaw graduallyprotrusive condylar position changes and surface stress distribution analysis, effectiveshowcase mandible protrusion relationship between condylar position changes and stressdistribution law, and confirmed the feasibility of the research methods to provide a theoreticalbasis for the clinical use of oral appliance treatment of OSAHS from temporomandibularjoint.