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 shortterm 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.