Photoelastic analysis of movement tendency of lower teeth using multiloop edgewise archwire with vertical elastics in anterior teeth area

To investigate the movement tendency of lower teeth using multiloop edgewise archwire (MEAW) with vertical elastics in anterior teeth area by three-dimensions photoelastic analysis. The photoelastical model of full teeth as human body on physical parameter and dimension was established and loaded by MEAW with vertical elastics in anterior teeth area similar with clinic. Every freezing model-tooth was bladed by anteroposterior axes and vertical axes, the stress of every point of alveolar bone was calculated by three-dimensions shear-equation method. The stress distribution regularity of per-tooth was analyzed to describe their move tendency. The lower second molar was intrused and rotated to distal and inclined as negative torque. The lower first molar moved and rotated to distal, the mesial rotate to buccally and the distal rotate to lingually. The lower second pre-molar was extruded and inclined as crown to mesial and root to distal, inclined as negative torque. The lower canine was intrused slightly and inc