Evaluation of Tooth Movement Accuracy with the F22 Aligner System: A Retrospective Study

Background: To investigate the accuracy of an F22 Aligner system, considering the amount of prescribed movement, tooth type, grip points, sex and age. Methods: Digital models of 120 patients (64 females and 56 males; mean age 35.2 years +/- 7.4) affected by mild-to-moderate Class I malocclusion and treated via F22 Aligners, retrospectively selected from the University of Ferrara Orthodontics Clinic's electronic database; post-treatment models were generated, and three angular values per tooth and four linear intra-arch measurements per arch were acquired. For angular measurements, planned (T1) and achieved (T2) values were obtained thorough digital model superimpositions. Linear measurements were acquired from pre-treatment, reference and post-treatment models. Statistical comparisons were performed to assess accuracy among tooth types and prescribed movements, tooth type, grip points, sex and age were investigated via chi-squared automatic interaction detection regression trees. Results: Mean accuracy for inclination and angulation were 86.76% and 88.01%, respectively, whereas rotation was less accurate (61.59%), especially for rounded teeth. All variables investigated influenced accuracy, with the exception of inclination, which was only influenced by age. Regarding linear measurements, good expansive capacity was shown, except for the distance between mandibular second premolars. Conclusions: F22 aligners are a viable solution for the treatment of Class I malocclusion of mild-to-moderate complexity, although clinicians should bear in mind the lower predictability of rotation, as well as the influence of the variables investigated.