Scanning electron microscopy
Sinonasal mucosa specimens were dehydrated with different concentrations of graded ethanol for 10 minutes each. The dehydrated specimens were soaked in 100% acetone for 20 minutes and then in pure isoamyl acetate for 30 minutes. All samples were dried in a carbon dioxide critical point dryer, then sputtered with gold, and examined by SEM (QUANTA 2000; FEI; Czech republic) at the accelerated voltage of 10kV.