Comparative evaluation of the maxillary canine retraction rate and anchorage loss between two types of self-ligating...

To evaluate the maxillary canine retraction rate and anchorage loss with active and passive self-ligating brackets (SLBs).

The study was conducted on 10 patients whose age ranged from 14-20 years. The patients had minimal to no crowding with a dental protrusion of maxillary incisor that required the extraction of maxillary first premolars and retraction of canines. The maxillary canines had to be in a good alignment and level before treatment to ensure that canine retraction had started from the same point bilaterally. A cone beam computed tomography (CBCT) had been taken for each patient's maxilla before treatment initiation and after complete canine retraction. Using nickel titanium, close-coil spring canine retraction on both sides and the rate of canine movement was measured.

The patients were checked every 2 weeks to measure the retraction rate and ensure that a constant force (150 g) was being delivered to both canines. The pre- and post-canine retractions CBCT were superimposed to evaluate the pattern and rate of canine movement and anchorage loss. The result of this study showed no statistically significant difference between the two groups.

The type of SLB, either active or passive, does not affect the rate or type of canine movement during its retraction in the orthodontic extraction cases, and the anchorage loss of the upper molars was nearly the same in both type.