ABSTRACT
Objective:To analyse the change of morphology and internal air flow in upper airway by the use of oral appliance(OA)in patients with obstructive sleep apnea hypopnea syndrome (OSAHS).Methods:A 46-year-old male patient with OSAHS accepted CT scan before and three months after use of OA.Computational fluid dynamics(CFD)model was built on the base of CT scans by Mimics 10.01 and ANSYS ICEMCFD14.0.The internal flow of upper respiratory tract was simulated by ANSYS-FLUENT 14.0 and the re-sults was analyzed by ANSYS-CFD-Post14.0.Results:The most narrow area of upper airway was located in the lower bound of pha-ryngopalatiae,and it augmented from 0.119 4 cm2 to 0.409 9 cm2 after wearing OA;the maximum air velocity was decreased from 11 . 087 m/s to 8.204 m/s,the minimum negative pressure was decreased from -83 Pa to -59 Pa,the resistance of cavum pharyngis de-creased from 250 Pas/L to 145 Pas/L.Conclusion:Application of OA may expanse the upper respiratory tract,decrease the negative pressure and resistance of the upper respiratory tract in narrow area,reduce the collapsibility of the upper airway and maintain the pa-tency of the airflow.