Effect of Rapid Maxillary Expansion Treatment on the Nasal Floor and Nasal Soft Tissue: Report on 26 Patients

Objective: Rapid maxillary expansion may result in transverse and sagittal alterations of the maxilla and base of the nose. rapid maxillary expansion-induced changes in soft and skeletal tissues could influence midfacial aesthetics. In this study, we aimed to determine the short-term effects of rapid maxillary expansion on the midface soft and skeletal tissue structures by reviewing cone-beam computed tomography imaging retrospectively. Methods: The study included 26 patients who underwent rapid maxillary expansion, of whom 13 were women and 13 were men (mean age 11.29 years; standard deviation 1.56, range 9.5-14.4 years). All selected patients underwent multi-slice cone-beam computed tomography twice; pre-rapid maxillary expansion (T0) and post-rapid maxillary expansion (T1). To compare the T0 and T1 results, 7 skeletal tissues, 4 soft tissues, and 3 angle variables were evaluated. Results: A statistically significant elevation of all variables related to soft (alar base and alar curvature) and skeletal tissues (N-ANS; P < 0.05) was found. Comparisons between T0 and T1 revealed significant changes in the pyriform aperture width (anterior nasal width, posterior nasal width, and anterior nasal floor width; P < .001). When the beta coefficient was considered in simple regression analysis, the difference in the value of anterior nasal floor revealed a positive effect that was 3.91 times that of the change in the al-al alar base width. Conclusion: Rapid maxillary expansion caused significant positional changes in the soft tissues around the nose of young and growing patients. The maxillary transverse width variable, T1-T0 difference, was found to impact the alar base width owing to the effects on the anterior nasal floor. Therefore, the anticipated changes should be explained to patients with pre-rapid maxillary expansion.