Effect of patterns of stainless steel ligation on orthodontic bracket with contact boundary conditions using finite element analysis

Abstract

The objective of this work was to analyse the stress and deformation in the orthodontic bracket and archwire with different patterns of ligature tying namely full round pattern I (P-I), the figure of eight pattern II (P-II) and figure of eight pattern III (P-III) using finite element analysis (FEA). A standard edgewise stainless steel (SS) maxillary right central incisor orthodontic bracket was measured using profile projector. Solid models of the bracket, archwire and three patterns of ligature tie were done. The archwire was modelled and assembled into the bracket slot. The FE model of the assembly was done. Effect of three patterns of ligation on the archwire and bracket was analysed by applying archwire torque as a couple. The stress in the bracket and archwire for the patterns of ligation P-I, P-II and P-III were noted. The maximum deformation of the bracket and archwire for the patterns of ligation P-I, P-II and P-III were obtained. From the analysis, it was concluded that the magnitude of stress in the archwire and the deformation value in the bracket was high in P-I pattern. Ligature pattern P-II developed the least amount of stress and deflection in the bracket and archwire.