Long-term stability of maxillary anterior alignment in non-extraction cases.

OBJECTIVE The purpose of this retrospective study was to evaluate long-term stability of maxillary incisors alignment in cases submitted to non-extraction orthodontic treatment. METHODS The sample comprised 23 patients (13 female; 10 male) at a mean initial age of 13.36 years (SD = 1.81 years), treated with fixed appliances. Dental cast measurements were obtained at three different time points (T1 - pretreatment, T2 - posttreatment and T3 - long-term posttreatment). Variables assessed in maxillary arch were Little Irregularity Index, intercanine, interpremolar and intermolar widths, arch length and perimeter. The statistical analysis was performed by one-way ANOVA and Tukey tests when necessary. Pearson' correlation coefficients were used to investigate possible associations between the evaluated variables. RESULTS There was no significant change in most arch dimension measurements during and after treatment, however, during the long-term posttreatment period, it was observed a significant maxillary incisors crowding relapse. CONCLUSIONS The maxillary incisors irregularity increased significantly (1.52 mm) during long-term posttreatment. None of the studied clinical factors demonstrated to be predictive of the maxillary crowding relapse.