title: Palatal window osteotomy technique improves maxillary sinus augmentation in previously insufficient augmentation case.
abstract: BACKGROUND
  Perforation of the Schneiderian membrane is the most common complication in sinus floor augmentation (SFA). When volume of grafting is qualified to prevent enlargement of the membrane perforation, lack of bone volume may occur in optimal site.
  
  
  METHODS
  SFA was performed in sites #24 to 26 in a 63-year-old male. However, a 10-mm size perforation of the Schneiderian membrane occurred in site #26. Although the sinus cavity was grafted with deproteinized bovine bone mineral (DBBM) after repair of membrane perforation, insufficient bone formation was observed on palatal and distal aspects of site #26 at 5 months after SFA. Although additional SFA was required for implant placement, it seemed to be difficult to elevate the membrane by a conventional lateral approach in the palatal aspect of the sinus floor (site #26). Considering the configuration of new bone formation, it was decided to perform the palatal antrostomy approach. The Schneiderian membrane was elevated without perforation, and the sinus cavity was grafted with DBBM mixed with venous blood. Two 12-mm long, 4.1-mm diameter implants were placed in sites #14 and 16. Four months after implant placement, abutment-connection surgery was successfully performed. The radiographic image indicated improved radiopacity, without obvious bone resorption in site #26.
  
  
  CONCLUSIONS
  The palatal window osteotomy technique could be considered as an alternative method for augmentation of maxillary sinus in cases where difficulty is encountered to elevate a membrane by a conventional approach (e.g., in cases in which buccal bone height is long).
authors.affiliation: Department of Implantology and Periodontology, Kanagawa Dental University, Graduate School of Dentistry, 3-31-6 Tsuruya-cho, Kanagawa-ku, Yokohama, Japan. ueno@kdu.ac.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ueno
authors.affiliation: Unit of Oral and Maxillofacial Implantology, Tsurumi University Dental Hospital, Yokohama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kurokawa
authors.affiliation: Department of Removal Prosthodontics, Kanagawa Dental University, Graduate School of Dentistry, Yokosuka, Japan.
authors.forename: Katsuichiro
authors.initials: K
authors.lastname: Maruo
authors.affiliation: Unit of Oral and Maxillofacial Implantology, Tsurumi University Dental Hospital, Yokohama, Japan.
authors.forename: Tsuneaki
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of General Education, Tsurumi University, School of Dental Medicine, Yokohama, Japan.
authors.forename: Jayanetti Asiri
authors.initials: JA
authors.lastname: Jayawardena
keywords: Dental implants; Palatal osteotomy; Sinus floor augmentation; Surgical technique