Xin Feng1, Yicheng Chen2, Kristina Hellén-Halme3, Weihua Cai4, Xie-Qi Shi5,6. 1. Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Årstadveien 19, 5009, Bergen, Norway. 2. School of Energy Science and Engineering, Harbin Institute of Technology, Xi Da Zhi Street, Nangang, 150001, Harbin, People's Republic of China. 3. Department of Oral and Maxillofacial Radiology, Faculty of Odontology, Malmö University, 205 06, Malmö, Sweden. 4. School of Energy and Power Engineering, Northeast Electric Power University, Changchun Road 169, Changchun, 132012, Jilin, People's Republic of China. 5. Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Årstadveien 19, 5009, Bergen, Norway. xieqi.shi@uib.no. 6. Department of Oral and Maxillofacial Radiology, Faculty of Odontology, Malmö University, 205 06, Malmö, Sweden. xieqi.shi@uib.no.
Abstract
BACKGROUND: The effect of rapid maxillary expansion (RME) on the upper airway (UA) has been studied earlier but without a consistent conclusion. This study aims to evaluate the outcome of RME on the UA function in terms of aerodynamic characteristics by applying a computational fluid dynamics (CFD) simulation. METHODS: This retrospective cohort study consists of seventeen cases with two consecutive CBCT scans obtained before (T0) and after (T1) RME. Patients were divided into two groups with respect to patency of the nasopharyngeal airway as expressed in the adenoidal nasopharyngeal ratio (AN): group 1 was comprised of patients with an AN ratio < 0.6 and group 2 encompassing those with an AN ratio ≥ 0.6. CFD simulation at inspiration and expiration were performed based on the three-dimensional (3D) models of the UA segmented from the CBCT images. The aerodynamic characteristics in terms of pressure drop (ΔP), maximum midsagittal velocity (Vms), and maximum wall shear stress (Pws) were compared by paired t-test and Wilcoxon test according to the normality test at T0 and T1. RESULTS: The aerodynamic characteristics in UA revealed no statistically significant difference after RME. The maximum Vms (m/s) decreased from 2.79 to 2.28 at expiration after RME (P = 0.057). CONCLUSION: The aerodynamic characteristics were not significantly changed after RME. Further CFD studies with more cases are warranted.
BACKGROUND: The effect of rapid maxillary expansion (RME) on the upper airway (UA) has been studied earlier but without a consistent conclusion. This study aims to evaluate the outcome of RME on the UA function in terms of aerodynamic characteristics by applying a computational fluid dynamics (CFD) simulation. METHODS: This retrospective cohort study consists of seventeen cases with two consecutive CBCT scans obtained before (T0) and after (T1) RME. Patients were divided into two groups with respect to patency of the nasopharyngeal airway as expressed in the adenoidal nasopharyngeal ratio (AN): group 1 was comprised of patients with an AN ratio < 0.6 and group 2 encompassing those with an AN ratio ≥ 0.6. CFD simulation at inspiration and expiration were performed based on the three-dimensional (3D) models of the UA segmented from the CBCT images. The aerodynamic characteristics in terms of pressure drop (ΔP), maximum midsagittal velocity (Vms), and maximum wall shear stress (Pws) were compared by paired t-test and Wilcoxon test according to the normality test at T0 and T1. RESULTS: The aerodynamic characteristics in UA revealed no statistically significant difference after RME. The maximum Vms (m/s) decreased from 2.79 to 2.28 at expiration after RME (P = 0.057). CONCLUSION: The aerodynamic characteristics were not significantly changed after RME. Further CFD studies with more cases are warranted.
Authors: Fabio Pagella; Mara De Amici; Alessandro Pusateri; Guido Tinelli; Elina Matti; Marco Benazzo; Amelia Licari; Sabrina Nigrisoli; Silvana Quaglini; Giorgio Ciprandi; Gian Luigi Marseglia Journal: Int J Pediatr Otorhinolaryngol Date: 2015-10-08 Impact factor: 1.675
Authors: Hui Chen; Yingguang Li; Johan Hc Reiber; Jan de Lange; Shengxian Tu; Paul van der Stelt; Frank Lobbezoo; Ghizlane Aarab Journal: Dentomaxillofac Radiol Date: 2018-01-02 Impact factor: 2.419