Initial effect of multiloop edgewise archwire on the mandibular dentition in Class III malocclusion subjects. A three-dimensional finite element study.

The purpose of this study was to compare the effect of a multiloop edgewise archwire (MEAW) with a plain ideal archwire (IA) on distal en masse movement of the mandibular dentition. A three-dimensional finite element model (3D FEM) of the mandibular dentition, without third permanent molars, was constructed to include the periodontal membrane (PDM), 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). Stress distribution and displacement of the mandibular dentition were analyzed when Class III intermaxillary elastics (300 g/side) and 5 degree tip-back bends from the first premolar to the second molar were applied to the IA and the MEAW for distal en masse movement of the mandibular dentition. Compared with the IA, the discrepancy in the amount of tooth displacement was less and individual tooth movement with the MEAW was more uniform and balanced. There was minimal vertical displacement or rotation of the teeth with the MEAW when compared with the IA. The MEAW seems to have advantages for distal en masse movement of the mandibular dentition.