Efficiency evaluation of rapid maxillary expansion treatment on nasal septal deviation using tortuosity ratio from cone-beam computer tomography images

Background and objective: This study aims to assess the effect of Rapid Maxillary Expansion (RME) on Nasal Septal Deviation (NSD) changes from three-dimensional (3D) images. Methods: In this study, conebeam computed tomography (CBCT) images from 15 patients with maxillary constriction (mean age 12 +/- 1.6 years) were included. RME treatment with Hyrax appliance was performed in all patients. CBCT scans were taken at three different times; before appliance insertion (T0), after active expansion (T1) and 3 months after appliance insertion (T2). We developed a novel Matlab-based application to quantify NSD based on the tortuosity ratio by dividing the actual length of the septum by the ideal length in the midsagittal plane by using this application. Results: Tortuosity ratio (TR) values were found as 1.03 +/- 0.03 (T0), 1.02 +/- 0.02 (T1), and 1.02 +/- 0.02 (T2). Differences of TR values among these groups were evaluated using the statistical method of ANOVA (ANalysis Of VAriance) for repeated measures with the significance level of p <= .05. Results showed significant reductions in TR values between T0-T1 (p <= .05) and between T0-T2 (p <= .05). Nonetheless, a significant difference between T1-T2 was not determined (p > .05). Conclusions: As a result, we can conclude that the NSD degree is affected by the RME treatment. The developed application can be used for both educational and research purposes. (C) 2019 Elsevier B.V. All rights reserved.