Three-dimensional finite element analysis in distal en masse movement of the maxillary dentition with the multiloop edgewise archwire.

The purpose of this study was to compare the effects of a multiloop edgewise archwire (MEAW) on distal en masse movement with a continuous plain ideal archwire (IA). Three-dimensional finite element models (FEM) of the maxillary dentition in which the second permanent molars had been extracted were constructed to include the periodontal membrane, alveolar bone, standard edgewise bracket (0.018 x 0.025 inch), stainless steel IA (0.016 x 0.022 inch), and MEAW (0.016 x 0.022 inch). The stress distribution and displacement of the maxillary dentition were analysed when Class II intermaxillary elastics (300 g/side) and 5 degree tip-back bends were applied to the IA and MEAW for distal en masse movement of the maxillary dentition. Compared with the IA, the MEAW showed that the discrepancy in the amount of tooth displacement was lower and individual tooth movement was more uniform and balanced. There was minimal vertical displacement or rotation of the teeth using the MEAW when compared with the IA. The MEAW seems to have advantages for distal en masse movement of the maxillary dentition.