RESUMEN
This study was conducted on a group of 30 patients suffering from chronic sinusitis and control group of 15 patients in a period of two years. Chronic sinusitis group was evaluated by pre-operative C.T. scan. Which was performed with [General electric scan 9800]. Post-operative C.T. scans were taken for follow up.Diagnostic nasal endoscopy was performed at the time of the initial evaluation at the out patient clinic. Evaluation was performed under topical an aesthesia After decision had been made to proceed with F.E.S.S. the first biopsy was taken during surgery and the second biopsy was taken after improvement from O. M.C. ordinary histologic examination with haematoxyline, eosin and toluidine blue ultrastructural examination by Transmission Electron microscopy and Scannng Electron Microscopy results concluded that: use of functional endoscopic sinus surgery to remove the local pathological lesion [affecting Ostio Meatal complex] is a main factor in gradual regeneration of the paranasal sinus mucosa