Introduction
Maxillary sinus augmentation (or sinus lift) is a very effective surgical procedure used to increase bone in the posterior maxilla and, therefore, allow placement of dental implants. The complications most frequently encountered during this type of surgery are laceration of an intraosseous artery (causing bleeding) and perforation of the Schneiderian membrane (the membrane lining the maxillary sinus cavity). In case of bleeding, the procedure has to be suspended (sometimes aborted) until the bleeding is controlled. In case of perforation of the Schneiderian membrane, a repair must be attempted, increasing considerably the length of the procedure and consequently the postoperative discomfort and incidence of complications. The conventional technique for maxillary sinus augmentation involves the use of a high-speed handpiece for the removal of the thin cortical plate that constitutes the lateral wall of the maxillary sinus. In the vast majority of the cases, this bony wall is less than 1 mm (Neiva et al 2004). With the conventional technique, perforation of the Schneiderian membrane occurs in approximately 40% of the sinus lift procedures. A recently developed technique (Geminiani et al 2011) significantly reduces the incidence of this type of complications (Geminiani et al, in press).
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Description of the technique
1. A full-thickness flap is reflected to gain access to the lateral wall of the maxillary sinus (Fig. 1). In this area the bone is normally very thin, usually less than 1 mm.Fig. 12. The sonic handpiece (Fig. 2) is the ideal device for the preparation of the lateral window. The diamond-coated insert does not rotate, but vibrates (at 6 kHz). This allows a precise and safe osteotomy, reducing significantly the incidence of perforations (Weitz et al, in press).
Fig. 34. The sinus membrane is separated from the bony wall. Perforations of the membrane occur frequently during this phase. To increase safety and reduce complications, the air-driven sonic handpiece is used, coupled with the discoid insert. The insert is activated (vibrating and irrigated by the water spray) and then placed between the lateral bone wall and the Schneiderian membrane (Fig. 4).
Fig. 56. Primary closure is fundamental for the success of this procedure (Fig. 6). If primary closure cannot be achieved by flap replacement, a periosteal releasing incision is indicated. More details on how to perform a safe and effective periosteal releasing incision can be found in an excellent article recently published (Romanos 2010).