No abstract

Objectives To compare canine retraction using NiTi closed coil springs vs elastomeric chains comprehensively in a split-mouth randomized controlled trial. Materials and Methods The canines in 64 quadrants were randomly retracted into the first premolar extraction spaces using NiTi closed coil springs or elastomeric chains, in the maxilla and mandible. The retraction force was 150 g. Cone beam computed tomography scans and study models were obtained before the start of canine retraction and 6 months later. The rate and total amount of canine retraction, canine rotation, tipping, and root resorption were evaluated. A visual analogue scale was used to evaluate patients' pain experience. Results The two methods were statistically similar for dental changes, rate of canine retraction, and root resorption. However, patients reported significantly more days of pain with the elastomeric chain compared to the NiTi closed coil springs. Conclusions Within the constraints of the current study, using either NiTi closed coil springs or elastomeric chains as force delivery systems for canine retraction results in no significant difference in the rate of canine retraction, tipping, rotation, or root resorption. Pain experience during retraction using elastomeric chains is more significant yet needs further investigation.

No abstract

No abstract

Background: The dimensions of the arch wire affect its stiffness and the play between the wire and bracket. Canine retraction over stiffer arch wires limits the degree of canine tipping. However, the greater the wire dimensions, the greater the resistance to sliding. Frictional resistance is known to delay tooth movement. Aim: The aim of this controlled clinical trial was to compare canine retraction rate and angulation with 0.017”X0.025” versus 0.016”X0.022” stainless steel arch wire with a power arm. Materials and Methods: Twenty-four Class II malocclusion patients (age 13.8± 2.6 years) participated in this study. The teeth were leveled and aligned. Bilateral maxillary first premolars were extracted. In group A, the canines were retracted over 0.017”X0.025” wires. In group B, they were retracted using 0.016”X0.022” wires with a vertical power arm. The retraction force was 150g generated by elastomeric chains. The canine retraction rate and angulation were measured at the end of six months. The rates in the two groups were compared with the t-test and the angulation with the Mann Whitney test. Results: canine retraction rate was 4.64±1.5 in group A and 5.24±1.45 in group B. The canine angulation was 6.41±5.14 and 6.73±6.0 for group A and B, respectively. Conclusion: No difference was observed in the canine retraction rate or angulation with 0.017”X0.025” versus 0.016”X0.022” stainless steel arch wire with a power arm.