Selective Torques

One of the biggest advantages of passive self-ligation is to maintain play in the mechanical system during all phases of treatment. It has become very apparent that it is undesirable to totally seat the archwire against the base of the archwire slot during orthodontic treatment with very few exceptions. Obviously, it is an advantage if the intent of the clinician is not to move teeth along the archwire. With conventional mechanics and active self-ligation, the archwire is totally seated against the base of the bracket slot during some or all phases of treatment. This binding and friction obviously makes closing spaces, leveling, arch form changes, closing openbites, and the finishing, settling and detailing of the occlusion far more challenging. To best utilize the clinical advantage of passive self-ligation brackets, it is strongly recommended not to exceed .019 x .025 archwire dimension in an .022 bracket slot. This needed play allows for 7° of torque play in both directions. The intent of using multiple bracket torques is to help maintain torque control while keeping play in the mechanical system. The impact of using selective torques is shorter treatment times through greater torque control.

Example:
In first bicuspid extraction cases, the upper and lower cuspids have the tendency to tip lingually as the space is closed. To prevent the clinical crown from tipping, select +7° of torque. With 7° of torque play between an .019 x .025 archwire and the .022 slot, the position of the cuspid will be maintained at the desired 0°, keeping the root in medullary bone and in excellent position without having to bend the archwire.