목적: There are two methods of uncinectomy, the classical uncinectomy technique described by Stammberger and the swing-door technique described by Wormald. Although incidence is low, these two methods are at risk for complications. The authors present posterior fontanelle approach of maxillary sinus, which is a modified technique for safe removal of uncinate process and effective access of maxillary sinus. 방법:The posterior fontanelle was found by palpation at the superior portion of posterior end of inferior turbinate with ball probe. After identifying the posterior fontanelle, the iatrogenic maxillary sinus ostium was made with antrum knife on this area. This ostium was enlarged anteriorly until it joined the natural ostium with a back- biting forceps. When lacrimal bone was encountered, tip of back-bite forceps was rotated upward to remove the vertical portion of uncinate process. 결과:There are no complication, such as orbital penetration with fat exposure and naso-lacrimal duct injury, during operation. 결론:We devised a posterior fontanelle approach of uncinectomy and middle meatal antrostomy to reduce complication rate. Orbital injury and naso-lacrimal injury did not occur in this technique. Further study with a randomized controlled trial is required to prove its validity.