Maxillary sinus membrane perforation commonly occurs during extraction, mostly during an impacted tooth extraction. If left untreated, maxillary sinus perforation can cause several complications. Here, we describe a closure technique of an oroantral fistula using a bone fragment. During the extraction of an impacted maxillary second premolar, the tooth fell into the maxillary sinus. The tooth was removed from the sinus using a transantral approach. A bone fragment of the tooth was obtained and placed in the extraction socket via the transantral entrance and fixed with fibrin glue (Greenplast; Green Cross, Yongin, Korea) to close the oroantral fistula. After 5 months, an immature bone was formed in the sealed area where the bone graft was placed, without any complications.