RME Effect On Nasal And Palatal Morphology In Class II

To analyze effects of rapid maxillary expansion (RME) on three-dimensional (3D) changes in the maxilla and nasal cavity in adolescents, and to further elucidate the relationship between midfacial underdevelopment and transverse maxillary growth. A total of 37 adolescent patients with skeletal Class II malocclusion and transverse maxillary deficiency requiring expansion therapy were included. The patients, aged 12–15 years (mean age: 12.6 years), were in cervical vertebral maturation (CVM) stages II–III. RME was performed using a Hyrax appliance in combination with fixed orthodontic treatment. Pre- and post-treatment cone-beam computed tomography (CBCT) images were obtained to evaluate the 3D morphological changes in the maxilla and nasal cavity. Correlations among 3D parameters were analyzed using SPSS 22.0 for statistical processing. After treatment, palatal widths, nasal dimensions, PVA, and maxillary length increased significantly, while palatal height decreased and the maxilla moved forward (P < 0.001). Nasal septal deviation angle decreased, indicating improved alignment (P < 0.05). U6-D strongly correlated with palatal widths; PVA showed strong negative correlation with PVH and positive with NW, while NWmax was weakly associated with maxillary advancement. Rapid maxillary expansion in adolescents significantly enhances transverse maxillary growth. Furthermore, it indirectly influences the balance of vertical and sagittal growth by inducing morphological changes in the palate and nasal cavity, contributing to improved craniofacial development.