Abstract
A surgery for the frontal sinus mucocele is one of the most difficult operations among endoscopic sinus surgery (ESS), because of the high incidence of the recurrence. The Frontal trephination is originally developed to point out nasofrontal duct during ESS. We used the frontal trephination to treat the frontal sinus mucocele. The instrument enabled to clean up nasofrontal duct after surgery and to keep patency of the duct.
