Analysis Of The Relationship Between Distal Width Of Arch Wire And Angulation Of Gable Bend For Transmission Straight Wire Appliance With3-d Finite Element

Objective:To establish three-dimensional finite element model of transmission straight wire appliance with better biological and mechanical similarity, and try to obtain the relationship between distal width and angulation of gable bend of main arch wire to guide clinical operations. Methods:By using scanning of spiral CT with64rows, the sectional image data in DICOM format of maxillary dentition and maxillae of the volunteer (ClassⅡ, division1) were obtained. With the help of Ansys workbench13.0, Mimics10.01, Unigraphics NX and Geomagic Studio8.0softwares, the three-dimensional finite element model included transmission straight wire appliance, bend, Australian Orthodontic Wire, maxillae, maxillary tooth and periodontal ligament was established in Windows XP Service Pack3system. The results of the analysis, the import Matlab7.12scientific computing software, get the relevant variables linear equations, and ultimately come to the main arch wire backward bend angle and width of the relationship between the posterior segment.Results:A three-dimensional finite element model of transmission straight wire appliance was established, which consisted of250929elements and657766nodes. Furthermore, three-dimensional finite element model had higher geometric similarity and mechanical similarity, as well as the advantages of adding or subtracting components according to the requirement of the research. The model was conductive to analyze the mechanical system of transmission straight wire appliance and guide the clinical application and appliance modification.Conclusion:A more accurate preliminary experiments, clinical reference value after the main arch wire segment width and bend backward qualitative relationship between the angle that the maxillary first molar in the arch wire segments have not been widened after the backward bend under the effect of crown showing the tongue to move far in the trend. This indicates that maxillary first molar crowns in just being the main arch wire bending backward under the action of a distal and lingual inclination tendency to tilt, causing arch width decreases. Preliminary try and get that under certain conditions, the main arch wire backward bending angle and the main arch wire segment after the quantitative relationship between the width, D3=(0.10178*θ-0.7867) D1/D2+1.7764(D1as a springboard to resistance molar buccolingual center distance, D2as a springboard to the center of molar occlusal gingival resistance to the distance, D3-based arch wire ends enlarged molar buccal tube from the horizontal distance,θ-based backward bending angle arch wire). Also suggest that the width of the main arch wire posterior segment not only with the close relationship between the angle of gable bend, but also closely related with the molar morphology.