An evaluation of the torsional moments developed in orthodontic applications. An in vitro study

Dimensional accuracy of ceramic self-ligating brackets and estimates of theoretical torsional play

“…The accuracy of Meling's equation for calculating theoretical torsional play has been confirmed in previous studies. For instance, Odegaard et al 15 compared measured torque with that derived from Meling et al, 12 and they found 0.6 degrees of difference between measured and calculated torsional play in a 0.016 3 0.022-inch wire inside a 0.018-inch standard edgewise bracket. Similar results were reported by FischerBrandies et al 13 who also compared measured torsional play with that derived using Meling's formula.…”

“…Furthermore, theoretical torque is an estimate when there is no loading. 16 As torsional play increases with loading, 15,17 the effects of loading on the amount of torsional play may provide valuable information. This warrants further research.…”

Comparison of Torquing Ability of 0.019” × 0.025” Nickel Titanium and Fiber Composite Archwires -A Cone Beam Computed Tomography Study

“…The current literature on torque expression in orthodontic brackets consists of theoretical models, discussions and in-vitro studies employing various measurement devices, brackets, and wire dimensions (12)(13)(14)18). Despite the abundance of empirical and research data on Iran J Ortho.…”

“…Future studies should also evaluate torque expression of 0.021" × 0.025" wires to evaluate the maximum torque expressed when the third order clearance / play is least, between the wire and the bracket slot. On considering the previous literature it was also found that stainless steel wires were taken as standard for comparison (12,13,18). This study could have considered a third group having stainless steel wire to evaluate their efficacy in delivering torque and then comparing NiTi and fiber composite wire with stainless steel wire taking it as a reference.…”

“…So the expression of the in-built torque of a bracket is a matter of sequentially increasing the wire dimension till the bracket slot is fully filled. However, torque expression is a result of the interaction of many factors: bracket design (12), wire / slot play (engagement angle) (12), mode of ligation, 12 bracket deformation (13), wire stiffness (12,14), magnitude of wire torsion and dimension (13,(15)(16)(17), and wire edge beveling (18)(19)(20)(21)(22). Clinical factors such as initial tooth inclination13 bracket position (14,23), and tooth anatomy (24)(25)(26)(27) are also determinants of torque expression.…”