Rotational Control and Retraction of Maxillary Canine Using Self-Ligating Empower Brackets: An In Vivo Study

Abstract

Introduction: Interest in self-ligating brackets is generally smoother and more comfortable. Objectives: To compare rate of retraction and rotational control of maxillary canines with self-ligating MBT brackets on one side and conventional MBT brackets on the other side of the maxillary arch. Materials and Methods: Ten subjects with a mean age range of 18 to 25 years were selected. For each patient in the maxillary arch, bonding was performed with 0.022-inch slot conventional MBT brackets on one side and 0.022-inch slot self-ligating MBT brackets on the other side. Stainless steel 0.009-inch ligatures are used for conventional ligation. Retraction of canines was performed with 0.019 × 0.025-inch stainless steel wires using NiTi closed coil springs with eyelets of 12 mm and 9 mm. The force of retraction was measured using a dynamometer. Dental casts were made at each time interval to record the canine retraction rate (in mm) and rotation (in degrees). Results: The mean difference in the retraction rate was 0.045 mm/month between self-ligating and conventional brackets, respectively (P > 0.05). The mean difference of total rotation of canines with self-ligating and conventional brackets was 1.5°, which gives evidence that there was less rotation of canines with self-ligating brackets. Conclusion: There was no statistically significant difference in canine retraction rates between conventional and self-ligating brackets. Secure ligation with the self-ligating brackets showed better rotational control than the conventional brackets.

Keywords

• canine retraction
• conventional bracket
• rotation
• self-ligating bracket