Accuracy of a clear aligner hybrid approach in managing severe rotations of rounded teeth : A retrospective cohort...

The aim of this retrospective study was to evaluate the accuracy of rotational movements of maxillary and mandibular canines and premolars achieved using clear aligners combined with a segmental lingual appliance, as planned in the digital setup, and to compare these results with those obtained using clear aligners alone.

This retrospective cohort study included 40 adult patients, analyzing 40 teeth (20 canines and 20 premolars), each presenting at least 15° of rotation. The sample was divided into two groups: a study group treated with F22 aligners (Sweden & Martina, Due Carrare, Padua, Italy) combined with a segmental lingual appliance to correct rotation without attachments and a control group treated with F22 aligners using vestibular attachments to facilitate the rotational movement. Digital models acquired at three stages-pretreatment (T0), ideal posttreatment (T1), and actual posttreatment (T2)-were analyzed using visual aesthetic malocclusion (VAM, Vectra, Canfield Scientific, Fairfield, NJ, USA) software to assess rotation values and calculate imprecision and accuracy for each tooth. Statistical analysis was conducted to compare the two groups.

The study group showed significantly higher accuracy in rotational movements compared to the control group. The mean accuracy was 88.3% for the hybrid approach, versus 55.7% for clear aligners with attachments alone, and this difference was statistically significant (p < 0.01). This improvement was consistent across both canines and premolars, with statistically significant differences in all subgroups.

The combination of clear aligners with a segmental lingual appliance provided superior control in managing severe rotations of rounded teeth, resulting in greater predictability compared with aligners alone.