Putting Torque on 4 Incisor Teeth
By Dr. Michel Champagne
To continue on the torque subject, I want to discuss 2 techniques to modify the torque of upper or lower incisor teeth in the finishing phase of treatment. I am thinking of a situation where you take your pre finishing ceph and you see that you need to change the torque of all 4 incisors ( we have discussed in earlier blogs the ways to change the torque of a single tooth). Technique A : using a set of Tweed pliers you may change the angle of the wire by the same degrees at the distal of both laterals. Place the pliers facing one to the other at the distal of one lateral, apply the torque and do the same at the distal of the other lateral tooth. This should be done on a big enough wire which engages the horizontal walls of the brackets. The wire should not be too stiff to avoid any unwanted pain to the patient; a TMA .019 x .025 in a bracket slot of .022 x .028 is a good choice and should be activated by 20 degrees at the first activation (Figure 1). Technique B : you can also use an auxiliary root torque (ART) spring. The ART is a prefabricated device that you can insert over the base arch to increase the torque of 4 incisors. Depending on the orientation you choose to insert it, you can apply buccal or lingual root torque (Figure 2).
Figure 1. Using Tweed torquing pliers
Figure 2. ART applying a lingual root torque