Objective To investigate the upper airway three-dimensional CT changes after wearing Silensor oral appliance in obstructive sleep apnea syndrome（OSAS）. Methods 30 OSAS patients were studied with polysomnography and three-dimensional CT scan before and after wearing Silensor oral appliance four weeks, to compare the three-dimensional CT changes of upper airway and the results of polysomnography before and after treatment. Results After wearing Silensor oral appliance, the size of upper airway（beside nasopharynx） was enlarged significantly, apnea-hypopnea index had decreased, SaO2 had increased, the mean apnea time had decreased, snoring sound index had decreased. Conclusion The upper airways of OSAS patients were enlarged significantly by Silensor oral appliance, especially the velopharynx and glossopharyngeum, so it worked with the effect of enlarging upper airway.
