| Objective Construct a three-dimensional finite element model of the mandible, temporomandibular joint, the upper airway and the adjacent structure of an Obstructive sleep apnea hypopnea syndrome patient and regulate protrusion of mandibular, Articular disc displacement and surface stress distribution changes observed OSAHS patients due to mandibular advancement By gradually loaded quantitative mandibular advancement.the position changes of articular disc and its relationship with the mandibular protrusion can be observed and analysized which providing theoretical basis for mechanism studies of treatment to OSAHS with mandibular protraction.And provide the basis for theoretical aspects of parameters from the temporomandibular joint.Methods DICOM format image information of an OSAHS patient’s upper airway and temporomandibular joint obtained by thin—section CT scanning and digital image processing were utilized to construct a three—dimensional finite element model by Mimics and Ansys software. And then titrated mandibular advancement, the changes and the law of articular disc observed by biomechanics and displacement.Results Construct a three-dimensional finite element model of the mandible, temporomandibular joint, the upper airway and the adjacent structure of an Obstructive sleep apnea hypopnea syndrome patient and regulate protrusion of mandibular,which is formed by solid92 tetrahedral unit of a 10-node mesh. The model has cluded cortical bone, the total number of units and the total number of nodes in cancellous bone, muscle and airway total: 280,360 units and 590,195 nodes.Protrusive mandible by gradual displacement of the articular disc dimensional direction increases,Overall articular disc displacement increases, the occurrence of a downward move forward.The statistical regression analysis between the mandible and the articular disc protrusion overall position related changes, and draw the regression coefficient equation: y = 0.01885x-0.00056.The entire loading process, the articular disc stress distribution which is substantially removed 4.4mm 11.00 mm and a larger gap between the two sites, other sites of stress more evenly, and the stress reaches a maximum when 11.00 mm.Conclusion Application of spiral CT combined use Mimics, Imageware and Ansys finite element analysis software to establish OSAHS patients under the jaw, temporomandibular joint, upper airway dimensional finite element model of the structure and its surroundings.Through real and effective software validation model, the use of flexible,By gradually lower jaw protrusion, articular disc displacement in three dimensions were changed, and the inconsistencies in the lateral direction,and the surface of the articular disc displacement changes the stress distribution analysis found that the mandible forward articular disc distribution area of maximum stress at different distances basically unchanged,Stress values at different distances when articular disk stress mandible forward when 4.4mm and 11.00.mm larger changes, taking into account the clinical need of the patient’s tolerance.Mandibular joint disc protrusion and move forward down a positive correlation, confirmed: articular disc position as mandibular advancement determine the size of the important reference index. |
