Abstract: Objective: To explore the role of enlarging ostium maxilare on chronic maxillary sinusitis in endoscopic sinus surgery. Methods: A total of 218 cases suffering from chronic maxillary sinusitis and receiving endoscopic sinus surgery were divided into two groups at random. In group A, both uncinate process and ethmoidal bulla were excised, and anterior and posterior ethmoid cells were opened, ostium frontale was opened, ostium maxilare was enlarged, mostly plump middle turbinate was excised. In group B, uncinate process and ethmoidal bulla were resected, anterior ethmoid cells were opened, and ostium maxilare and middle turbinate were reserved. Results: On the standard of 1997(Haikou), the cure rate was 92% in group A and 91% in group B, and the mend rate was 8% in group A and 9% in group B in a followup of more than one year. There was no significant difference between the two groups. Conclusion: The key for transnasal endoscopic surgery is resection of the anatomical variation of ostiomeatal complex but not enlargement of the ostium maxillary.

Key words: Maxillary sinusitis, Ostium enlargement operation , Endoscopy