Abstract Background The interceptive treatment of Class II malocclusion using clear aligners is still debatable. This retrospective study analyzes the short-term occlusal and cephalometric effects in 40 growing patients with Class II malocclusion. Methods The sample was divided into 2 groups: Following the dentoalveolar expansion protocol, the first group was treated with clear aligners (GI). The second group was untreated (GN). Dental arches were scanned before and 1 year after the therapy. Similarly, linear measurements on digital casts and cephalometric ones on lateral X-rays were compared. Maxillary (Lmax), mandibular intermolar length (Lmand), and posterior transverse intermolar discrepancy (DIT) were evaluated. The distance between the mesiobuccal cusp of the upper first molar and the buccal groove of the first lower molar was considered at both sides (Cdx and Csx). The statistical descriptive analysis of T0 and T1 values was performed using a paired t-test, setting a p value