Evaluation of efficacy, treatment outcome, and stability of tooth movement with clear aligner treatment (Mysmartalign) - Clinical study

Abstract

The study was conducted to evaluate the efficacy, treatment outcomes, and stability of tooth movement with clear aligner therapy. Fifty subjects were selected for aligner treatment and followed a retention protocol as instructed by the orthodontist. To calculate efficacy, changes in Little's Irregularity Index from T0 to T4, T0 to T6, and T0 to T8 of clinical plaster models were compared with STL models for both the maxilla and mandible. A comparison of pre-treatment and posttreatment PAR scores was performed to assess treatment outcomes. Stability was evaluated using the PAR score by comparing post-treatment and one-year follow-up study casts. An independent t-test was used to compare the mean values acquired from the same sample. The mean change in Little's Irregularity Index from T0 to T4, T0 to T6, and T0 to T8 of clinical plaster models was compared with software STL models for both the maxilla and mandible. It was observed that the mean change was greater in the clinical models at each stage. Treatment outcomes showed significant improvement for 16 subjects (32%), while 34 subjects (68%) also showed improvement. A paired t-test was conducted to assess stability between post-treatment and the one-year follow-up, and the results were not statistically significant. The software models overestimated alignment and the resolution of crowding when compared to the actual clinical plaster models. Consequently, the PAR score assessment indicated successful treatment outcomes. However, regarding stability, mild relapses were observed after the one-year follow-up.