Study design and sample
pain
It was a randomized split mouth clinical trial with 1:1 allocation ratio to intervention and control sides conducted in the Department of Orthodontics at the Faculty of Dentistry, Damascus University. The study was approved by the institutional review board (IRB) and ethical review committee of Damascus University (N. 2473). The CONSORT (Consolidated Standards of Reporting Trials) statement was followed as a guide for this study which was registered at Clinicaltrials.gov with the identifier number (NCT03399422). The recruited study participants were patients presenting to the Department of Orthodontics, Faculty of Dentistry, Damascus University. Patients’ inclusion and follow-up is shown in the CONSORT flow chart (Fig. The CONSORT flow chartThe sample size was calculated to investigate the significant differences in pain perception between both sides based on a split-mouth design previous study [