Objectives. To Illustrate the characteristics of the bi-dimensional technique in case of previous anchor by asymmetric closure of spaces. Design and method. In the bi-dimensional technique, brackets are commonly used with different sizes of slot (0.018 × 0.25) in the front teeth and in the lateral and posterior teeth (0.022 × 0.028). This setting allows to easily obtain a good three-dimensional control of the front teeth through the use of arches with total vertical thickness (0.018 × 0.022), which can fully express the torque information and optimize the management of the anterior anchorage. Conclusions. Even in cases of unilateral protraction of the subsequent sectors through the mechanics of sliding, this combination of bracket features and dimensions of the arches, associated with the use of an upright spring placed into the additional vertical slot on the bracket of the canine and the arc torque (5°), guarantees a good control of the position of the incisors.
(Rev Esp Ortod. 2012;42(4):247-251)