To compare canine retraction using NiTi closed coil springs vs elastomeric chains comprehensively in a split-mouth randomized controlled trial.
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.
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.
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.
Resident, Department of Orthodontics and Dentofacial Orthopedics, Faculty of Dentistry, Future University in Egypt, Cairo, Egypt.
Associate Professor, Department of Orthodontics & Pediatric Dentistry, Oral and Dental Research Division, National Research Centre, Giza, Egypt; and Adjunct Assistant Professor, Department of Epidemiology & Health Promotion, College of Dentistry, New York University, New York, NY, USA.
Associate Professor, Department of Orthodontics and Dentofacial Orthopedics, Faculty of Dentistry, Cairo University, Cairo, Egypt.
Professor and Orthodontic Residency Director. Case Western Reserve University School of Dental Medicine, Cleveland, OH, USA.
Professor and Chairman, Department of Orthodontics and Dentofacial Orthopedics, Faculty of Dentistry, Future University in Egypt, Cairo, Egypt.