The cross-sectional effects of ribbon arch wires on Class II malocclusion intermaxillary traction: A three-dimensional finite element analysis

Abstract

Background: The application of intermaxillary traction is often accompanied by the unexpected movement of dentition, especially anchorage teeth. The aim of this study was to comprehensively compare the influence of cross-sectional shape of ribbon arch wires with edgewise and round wires on intermaxillary traction in Class II malocclusion treatment using FEA simulation.Methods: The dentofacial structure was simulated in finite element software. A retraction force of 1.5 N was applied to different cross-sectional orthodontic arch wires: a ribbon wire (0.025×0.017-inch and 0.025×0.019-inch), a rectangular wire (0.017×0.025-inch and 0.019×0.025-inch) and a round wire (Φ 0.018-inch and Φ 0.020-inch).Results: Among the three groups, ribbon wire (0.025×0.017-inch and 0.025×0.019-inch) exhibited the lowest displacement in the X-axis (12.61 μm and 12.77 μm, respectively) and Z-axis (8.99 μm and 9.06 μm, respectively). However, the 0.025×0.017-inch ribbon wire showed the highest Y-axis displacement. In the round wire group, Φ 0.020-inch wire displayed less rotation than Φ 0.018-inch wire, where the sagittal, frontal and occlusal rotation of Φ 0.020-inch wire was almost half of that of Φ 0.018-inch wire. The movement of the first molar region was intermediate between the ribbon arch group and the round wire group. Notably, the values of the 0.025×0.017-inch arch wire displacement, which were much higher than those of any other group, peaked at 0.019 mm in the central incisor region with a spike-like shape. The deformation range of the Φ 0.018-inch wire group was the largest in this study.Conclusions: The cross-section of the arch wire influenced force delivery in Class II intermaxillary traction. With the same shape, a larger cross-sectional area would lead to less mandibular dentition movement. For the rectangular arch wire and ribbon arch wire groups, since the height and width were inverted, the vertical displacement of anchorage teeth in the ribbon wire group was significantly reduced, but the possibility of buccal tipping in mandibular anterior teeth also increased.

Effects of Rigid and Nonrigid Connections between the Miniscrew and Anchorage Tooth on Dynamics, Efficacy, and Adverse Effects of Maxillary Second Molar Protraction: A Finite Element Analysis

“…In previous studies, different values were reported for the elastic modulus of this wire: it was reported 8500 MPa, 130000 MPa for 0.007-inch diameter, and 140000 MPa for 0.011-inch diameter [34]. In various FEA studies, different moduli of elasticity had been used, such as 160 gigapascals [35], 168 gigapascals [36], 176 gigapascals [37], 180 gigapascals [38], and 200 gigapascals [39,40]. In the present study, with increasing ligature rigidity, the palatal and distal movements of the premolars decreased and their intrusive movement increased.…”

“…Since various elastic moduli had been stated for the ligature wire in the literature [34][35][36][37][38][39][40], we also simulated a range of elastic moduli in model 3 and reported the effects of parametric changes in the ligature wire rigidity on stresses and displacements of model elements. The bone, tooth, and PDL models were modeled in Mimics 3D image processing software (Mimics Research 21; Materialise NV; Brussels, Belgium) and 3-Matic (Materialise).…”

Efficacy of a four-curve auxiliary arch at preventing maxillary central incisor linguoclination during orthodontic treatment: A finite element analysis

“…It has nothing to do with the length or con guration design of the arch wire. It represents the bending rigidity of the arch wire, and its size depends on the material properties of the bow wire (such as elastic modulus) and cross section properties (such as the distance of inertia).Orthodontists can change the stiffness of the whole or local orthodontic appliance by selecting different materials of the arch wire, different cross section sizes, and designing different span of the arch wire and the con guration of the bend, to achieve accurate control of the orthodontic force [11][12][13]. To achieve good control of maxillary anterior teeth torque angle during the correction process, we proposed a new type of torque auxiliary bow device: self-made four-curvature auxiliary arch, which is used in the early stage of treatment (Patent No: ZL 201420113873.9) [14].…”