canine retraction with nickel-titanium coil springs versus elastomeric chains: a systematic review

Objective: canine retraction after first premolar extraction is a prevalent orthodontic procedure. this systematic review aimed to evaluate the efficiency of niti coil springs and elastomeric chains for canine retraction and assess the side effects of each technique.methods: two reviewers conducted an electronic search of online databases (medline, science direct, scopus, and web of science) and a manual search up to may 8th, 2024, without language restrictions. only randomized clinical trials (rcts) were included. the same reviewers assessed the quality of the studies using the cochrane risk of bias tool for randomized trials.  due to the heterogeneity of data, conducting a meta-analysis was not feasible.results: initially, 2400 records were identified. after evaluating the titles and abstracts, the full texts of 40 studies were reviewed. eleven rcts complied with the study selection criteria and were included in the review. the results indicated a faster space closure rate exhibited by niti coil springs compared to elastomeric chains. the rate of anchorage loss varied depending on the anchorage devices used. more tipping and rotation were observed with niti coil springs. there was no statistical difference between the two groups regarding root resorption, pain intensity, and plaque control.conclusions: the results indicated a slightly faster space closure rate with niti coil springs compared to elastomeric chains but at the cost of greater tipping and rotation. no significant differences were observed between the niti closed coil spring and elastomeric chain force delivery systems in the other evaluated parameters.