Early pain perception and dentoalveolar changes during the leveling-alignment phase: a retrospective comparison of Damon Ultima and conventional bracket systems

Abstract Background Pain is among the most frequently reported adverse effects of fixed orthodontic appliances. Self-ligating systems are promoted as offering reduced friction and more favorable early tooth movement, and the Damon Ultima system is additionally claimed to improve torque expression through a modified slot, but clinical evidence remains limited. Because each bracket system is used with its own archwire sequence, this study compared complete treatment systems rather than bracket design alone. Methods Retrospective analysis of prospectively collected, routinely recorded clinical data from 44 consecutive patients (22 per group) treated with non-extraction fixed appliances between September 2023 and December 2024. The appliance system was selected by the patient and family rather than allocated at random. Pain was recorded at six time points from baseline to day 7 on a standardized departmental form using a 0–10 cm visual analog scale. Cephalometric and digital model analyses were performed at T0 (before treatment) and T1 (after the 20-week leveling-alignment phase). Mann-Whitney U tests, Friedman tests with Durbin-Conover post hoc comparisons, and independent samples t-tests were used, with Bonferroni, Benjamini-Hochberg, and Holm adjustments within three predefined families of tests. Results Both groups showed a similar pain trajectory, peaking between 6 h and 2 days and declining by day 7. No baseline cephalometric or digital model variable differed between the groups. Only posterior biting at 2 h reached nominal significance ( p = 0.038; rank-biserial r = 0.368, 95% CI 0.041 to 0.624), which did not survive adjustment (Bonferroni-adjusted p = 0.676). Mandibular incisors proclined, overbite decreased and transverse arch dimensions increased significantly within both groups, except maxillary mesiopalatal intermolar width in the conventional group. No between-group comparison of T1-T0 change was significant (smallest unadjusted p = 0.113 and 0.120 in the cephalometric and digital model families); no effect size exceeded d = 0.49. Conclusions No difference between the Damon Ultima and conventional MBT systems in early pain perception or dentoalveolar change survived adjustment for multiple comparisons. The study was not powered as an equivalence trial, however, so small-to-moderate differences cannot be excluded, and these data provide no evidence of an early clinical advantage for the newer system.