Effect of Loop Geometry on Horizontal Forces of Vertical Loops: A Finite Element Analysis

Alignment of the teeth as the first stage of comprehensive orthodontic treatment has widely been addressed. Several methods such as using super elastic arch wires, multi-strand wires and incorporation of various loops into the round stainless steel wires have been suggested in this stage. The aim of this study was to investigate and compare the horizontal forces produced by six various loop designs in different amounts of activation using the finite element method. The Finite Element Model (FEM) was used to design and compare the horizontal forces of round 0.014 inches stainless steel vertical open loop, vertical closed loop, vertical helical open loop, vertical helical closed loop, plain vertical loop and the squash loop. The forces were measured at 0.1, 0.4, 0.8 and 1mm activations. For all activations, vertical open loop had the highest horizontal force; while vertical helical closed loop showed the lowest force. The design of vertical loops influences the horizontal force in all activations, immensely.