Abstract

Background: An early torque expression with an optimal buccolingual inclination of the upper and lower incisors in the orthodontic treatment would allow for more efficient, controlled treatments with more predictable results, but it is generally achieved in the final stages of treatment when a stainless steel archwire fills the bracket slot. For this reason, the aim of this study is to evaluate the expression of torque in the initial phases of orthodontic treatment with active self-ligating brackets (ASLB) in upper central incisors (UCI) and lower incisors (LI). Results: Torque expression was measured by the change of buccolingual inclination of UCI and LI in lateral cephalic radiographs. The measures taken were: upper central incisor axis-maxillary occlusal plane, lower incisors axis-maxillary occlusal plane as the base planes; comparing it to reference planes: upper central incisor axis-palatal plane, and lower incisor axis-mandibular plane. These measures were evaluated in 29 patients between 10 and 35 years old, with any type of malocclusion and orthodontic treatment with ASLB at two times, T1: pre-treatment and T2: follow-up cephalic radiograph (after the wires Sentalloy 0.014, Sentalloy 0.018 and Bioforce 0.020×0.020 were expressed). It was observed that UCI and LI showed early torque expression when initiated lingualized and in the norm, and when UCI initiated vestibularized. Conclusions: This study using ASLB with superelastic archwires showed an early torque expression in UCI and LI when they started lingualized, when they started vestibularized or in the standard, they were able to obtain a better inclination compared to the initial.