Tricks of the trade: enhancing performance of Ni-Ti auxiliary archwires

The mechanics involved in orthodontic alignment of impacted teeth can be challenging.¹ Traction to unerupted teeth that have had a closed exposure is often achieved with nickel-titanium (Ni-Ti) auxiliary archwires, supported by a stainless steel base archwire (‘piggy-back’ archwires).² This method provides good vertical anchorage and utilizes the super-elastic properties of the Ni-Ti archwires to apply a light force to the tooth.⁵ Ideally, this force should be light and remain active for a long period before reactivation is necessary,^1,2,3,4 but a drawback of this technique is the range of deflection of the auxiliary wire is often limited, resulting in the force becoming inactive relatively quickly.

To overcome this issue, the auxiliary wire can be placed over the occlusal aspect of the orthodontic brackets bonded to the adjacent teeth. This provides a greater deflection of the auxiliary wire that will remain active for a longer duration (Figure 1).