Introduction
Torque correction is one of the most difficult and critical procedures performed during orthodontic treatment.1 Post alignment of palatally or labially blocked out tooth, requires labial or lingual root torque.2 In this article a simple and easy method to construct a torquing cantilever which is a composite of two different gauges of TMA wire to provide stability and maintain a high moment: force ratio for a single tooth to achieve labial or lingual root torque.3
Procedure
The technique is illustrated on an. 019" × .025" stainless steel base archwire.
Welding of a 0.019×0.025 TMA wire with a 0.017×0.025 TMA wire (or less gauge TMA wire) was done and adapted to the arch form.
Based on the tooth to be torqued the length of the wire is adjusted.
In the auxiliary tube of molar band 0.019×0.025 TMA wire was used.
Anteriorly in the 0.017×0.025 TMA wire (or less gauge wire) a 90° vertical bend was given towards the tooth and another 90° horizontal bend was given that falls into the bracket slot (Figure 1).
In the example, the cantilever is twisted towards the incisal edge for labial root torque in the mandibular tooth below the base archwire and ligated tightly (Vice versa in maxillary tooth) (Figure 2).
Likewise, the cantilever can be twisted towards the gingiva for lingual root torque in the mandibular tooth (Vice versa in maxillary tooth).
Figure 3 shows the effect of the torquing auxillary.
Discussion
For root torque, moment: force ratio should be high (12:1) and force level should be low.3 A higher gauge 0.019×0.025 TMA wire was used for rigidity and 0.017×0.025 TMA or lesser gauge wire for torquing as it has low load deflection rate and long range of action, thus inducing greater moment: force ratio.
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