A randomized clinical trial of thermoplastic retainer wear

Each patient was assigned to one of the groups by random number generation. Clinical records in the form of study models were taken at the start of active treatment (T1), at debond (T2), 6 months into the retention phase (T3), and 1 year post-debond (T4). The irregularity index, intercanine width, intermolar width, arch length, overbite, overjet, and Peer Assessment Rating (PAR) scores were measured on study models using digital callipers. A Mann-Whitney test was used to evaluate the treatment changes within each group. The only statistically significant difference was found to be at T3 and T4 for overbite (P = 0.05 and P = 0.02, respectively). PAR scoring showed more variable changes in group 2. There was good correlation for the measurement method. There was no statistical difference for the two groups for overjet, arch length, intermolar width, intercanine width, and irregularity index at any time point.