Comparative evaluation of the efficiency of segmental maxillary canine retraction using Burstone T-loops versus elastomeric chains: a split-mouth randomized clinical trial.

Objective: The aim of this study was to evaluate and compare the effectiveness of elastomeric power chains and T-loop springs in retracting the maxillary canine with a time frame of four months.

Material and methods: The study included 16 patients (8 women and 8 men), with a mean age of 19.06±2.22 years. These patients were recommended to bilateral maxillary first premolars extraction. A split-mouth design was used to randomly assign opposing quadrants to either power chains or T-loops. Study models and panoramic radiographs were acquired before and after canines retraction. The rate of canine retraction, rotation, tipping (primary outcome), and molar anchorage loss (secondary outcome) were measured using study models and panoramic radiograph, after retraction. All data was subjected to appropriate statistical analysis.

Results: The average retraction for T-loops was 4.76 ± 1.02 mm, while for power chains it was 4.28 ± 0.81 mm. T-loops showed faster canine retraction (1.19 ± 0.08 mm/month) than power chains (1.07 ± 0.06 mm/month). T-loops had a significantly higher canine rotation (17.28±2.62°) than power chains (10.62±4.15°) (p<0.005). The sliding side showed greater tipping than the loop side, with statistically significant difference. Anchorage loss was not statistically different between both mechanics.

Conclusion: T-loops offered the highest degree of canine retraction with minimal tipping, while power chains used for sectional canine retraction resulted in less canine rotation. However, there was no significant difference in the amount of anchorage loss between both mechanics.