A comparison of the rate of en-masse space closure using conventional and passive self-ligating brackets with closed-coil springs

Abstract

Malocclusion prevalence is high, and an orthodontist needs to be effective and efficient in treating malocclusion. Self-ligating brackets are claimed to be more effective and efficient, and to have less friction in ortodontic movement than do conventional brackets. The objective of this study is to compare the rate of mandibular en-masse space closure retraction and loss of anchorage between passive self-ligating brackets and conventional brackets using closed-coil springs. The study design was a prospective randomized controlled clinical trial with split-mouth technique. Twenty two mandibular quadrants in patients that were ready for en-masse space closure retraction were placed with conventional brackets MBT Agile 3M slot.022” in a whole quadrant, while the contra lateral was placed with passive self-ligating brackets Damon Q standar torque Ormco. The en-masse space closure retraction rate and loss of anchorage were measured in study models at 4 and 8 weeks. The results indicated there was significant difference between passive self-ligating brackets and conventional brackets regarding the en-masse space closure retraction rate and loss of anchorage rate. Self-ligating brackets were faster in en-masse space closure with a mean rate 0.58mm in 4 weeks and 0.74mm in 8 weeks and they were more resistant to loss of anchorage. The split-mouth technique was effective for comparison of the rate of mandibular en-masse retraction and loss of anchorage between self-ligating brackets and conventional brackets using closed-coil springs, where individual variability was minimized.