Skeletal and dentoalveolar effects of different hyrax maxillary expansion protocols compared with novel magnetic expansion: a CBCT-based study

This study aimed to compare the skeletal, dentoalveolar, and dental effects of rapid (RME), slow (SME) maxillary expansion, and magnetic maxillary expansion (MME) in adolescents with transverse maxillary deficiency using cone-beam computed tomography (CBCT). A retrospective analysis was conducted on 39 patients (24 males, 15 females; mean age 12.8 ± 0.9 years), equally divided into three groups (N = 13 each) based on the expansion protocol: RME, SME using hyrax expander appliance, or MME. All patients underwent CBCT imaging at baseline (T1), post-expansion (T2), and after a three-month retention period (T3) were extracted. Skeletal, dentoalveolar, and dental parameters, including maxillary basal widths, alveolar inclination, posterior tooth inclination, vertical dental height, and maxillary molar volume, were measured. Statistical analysis was performed using paired t-tests and ANOVA with Tukey’s post-hoc test (p < 0.05). All three protocols produced significant skeletal and dental expansion from T1 to T2 (p < 0.001). RME achieved the greatest skeletal widening, particularly at the nasal floor (p = 0.013), but was associated with more buccal tipping, molar volume reduction, and significantly greater relapse at the nasal floor during retention (p = 0.006). SME provided moderate but stable outcomes with fewer side effects. MME demonstrated skeletal expansion comparable to SME and, in some parameters, to RME, while showing less relapse and smaller reductions in molar volume. Vertical dental height changes were significant across groups. All expansion methods successfully addressed maxillary constriction. RME delivers quick skeletal corrections but presents a higher risk of relapse and dentoalveolar complications. SME yields stable, gradual results, whereas MME shows promise as a viable alternative, offering effective skeletal expansion with fewer negative effects and potential biological benefits.