Effect of Bracket’s Slot Size on Canine Position and Space Closure Rate (A Typodont Study)
Abstract
This study aimed to determine the effect of newly introduced 0.020 slot size brackets on di-mensional positions and space closure ratio of mandibular canine. Material and Methods: The study includes six groups according to slot sizes (0.018, 0.020 and 0.022) and materials of canine retrac-tion (elastomeric power chain and closed coil spring). A 200 gm of retraction force was used on 0.017 X 0.025 stainless steel wire ligated to brackets by elastomeric ligatures along 13 mm available space. After immersion of the typodont in water bath with (50-55) C for 5 minutes, the rate of space closure were measured in millimeter using vernier (from the distal wings of canine bracket and the mesial wings of the second premolar), In both vertical and horizontal directions, digital images were taken by camera and the angle between canine extension bar )C B) and bite plane extension bar (BPB) was measured by protractor to determine tipping and rotation. Results: The results showed that 0.022 slot bracket groups had highest amount of rate of space clo-sure tipping and rotation, while 0.020 slot brackets groups had higher space closure rate than 0.018 slot brackets groups. Conclusions: bracket slot 0.022 groups showed higher tipping, rotation and space closure rate, while 0.020 slot brackets groups had higher rate of space closure with same or bet-ter rotation and tipping control in comparison with 0.018 slot bracket groups
