Abstract
INTRODUCTION: There is a diverse range of orthodontic appliances available in clinical practice. However, there is also a lack of evidence regarding the effectiveness of different prescriptions on the final positioning of these teeth following rectangular strand insertion into orthodontic molar tubes. This study aimed to determine whether the torque present in the tubes of pre-adjusted devices of different prescriptions would alter the ideal inclination of the first and second lower and upper molars. METHODS: This study utilized plaster models from 30 patients who presented with ideal torque. Four prescriptions with tubes of 0.22x0.028" slot were used: MBT, Roth, Damon, and Edgewise. Tubes were glued on to plaster models on the vestibular side of teeth in the center of the clinical crown. In addition to this gluing position, the position of 1 millimeter below the center of crowns on lower models was evaluated. Gaps between tubes and steel rectangular wires of 0.019x0.025"or 0.021x0.025" thickness were measured, and the effective torque was calculated from these values. CONCLUSIONS: For 0.019x0.025" wires, a higher number of optimal torque maintenances was observed, regardless of the prescription tested, compared to 0.021x0.025" wires. The Roth prescription obtained the values closest to zero in the evaluation of the effective torque, indicating a small average torque change.