Customized lingual brackets vs. conventional labial brackets for initial alignment : A randomized clinical trial

The aim of this randomized prospective clinical study was to determine whether there are differences between customized lingual brackets and conventional labial brackets regarding the alignment of the mandibular arch and a reduction of the irregularity index during an 18-week treatment interval.

A total of 20 patients who presented with class I malocclusion for scheduled orthodontic treatment without tooth extraction were included. The patients were randomly assigned by numbered, opaque, sealed envelopes to treatment with customized lingual brackets or conventional labial brackets. During the initial alignment (T0), 0.012″ (T1), 0.014″ (T2), and 0.016″ (T3) nickel-titanium archwires were applied, respectively, and the control visits were scheduled at 6‑week intervals. In all sessions, digital models were obtained by an intraoral scanning device after removal of the archwire and were analyzed by software. Little's irregularity index, intercanine width, intermolar width and arch length were evaluated at three time points and were statistically analyzed with a repeated measures analysis of variance (ANOVA). Changes in these measurements at the three intervals (T1-T0, T2-T1, T3-T2) and overall treatment effects were also compared using the Student t‑test.

Comparing the two treatments regimes, intergroup mean values at T0, T1, T2, and T3 were not significantly different regarding the irregularity index, intercanine width, intermolar width and arch length.

In this pilot study, no differences between the two treatment approaches could be detected for the phase of initial mandibular alignment.