Comparison of the Predictability of Dentoalveolar Expansion with Different Aligner Systems in Orthodontics: A Longitudinal Clinical Study in Adult Patients

Aligners represent a therapeutic option in orthodontics, offering advantages such as aesthetics, comfort, and individualized prescriptions for each patient. However, the predictability of maxillary expansion is subject to variability. The objective of this article is to evaluate the efficacy and predictability of aligners in maxillary expansion. One hundred adult patients were included in this study, divided into four groups, each assigned to a different brand of clear aligners: Angel Aligners, Invisalign, Spark, or Hey Smile. Digital models were obtained at three stages: initial STL (T1), prediction (T2), and final (T3) (before the first refinement). The models were measured to obtain linear distances between canines, first bicuspids, second bicuspids, and first molars. Statistical analysis was performed using SPSS 28.0. The best predictability was obtained in the lower arch (68.900%) for second bicuspids, while the worst accuracy was for canines (39.290% in the upper arch using Invisalign). Angel aligner showed the highest percentage of predictability (60.002%) among the evaluated brands, followed by Hey Smile (59.895%), Spark (59.275%), and Invisalign (57.153%). The results show that clear aligners are an effective treatment for transverse movements in both arches. However, further research is needed to improve predictability.