Crestal endoscopic approach for evaluating sinus membrane elevation technique

Abstract

Closed sinus lifting is a unique technique in being simple and less invasive (Summers, Compendium 15(6):698, 1994). However, it is blind to assess the safety of sinus lining during lifting without perforation. Previously, sinus membrane was assessed endoscopically in an invasive way. We aimed to judge clinically the sinus membrane integrity after crestal elevation by a direct simple less invasive endoscopic visual assessment through the crestal osteotomy site. To confirm undetected perforation, the sinus membrane was monitored dynamically by introducing the endoscope through a trephined opening in the lateral wall of the sinus (Nkenke et al., Int J Oral Maxillofac Implants 17(4):557–66, 2002).PatientsTwelve patients suffering atrophic posterior maxillae ranging 3–5 mm bone height below the sinus membrane were included to perform closed sinus lifting with simultaneous immediate implant placement under direct endoscopic assessment.ResultsThe floor was lifted without perforation in 83.33% of cases. However, it varied according to its thickness. Minor perforations occurred in two cases (16.67%). Both perforations were detected from the crestal endoscopic view while one of them was detected from the lateral endoscopic approach.ConclusionCrestal endoscopic access gives better direct vision to the membrane than the induced opening in the lateral wall of the maxillary sinus. Moreover, it uses the same prepared osteotomy site without doing any extra procedures. Perforation depends on the thickness of sinus lining and its ability to stretch during elevation. Intact crestal sinus floor elevation can never be guaranteed under endoscopic monitoring especially with thin irregular membranes.

The endoscopically assisted transcrestal sinus floor elevation with platelet-rich fibrin at an immediate implantation of periapical lesion site

“…The integrity of the mucosa, hemorrhage of the sinus floor and height of the surrounding bone wall can be explored, and microscopic perforations can be precisely detected. [15]…”

Complications in sinus lifting procedures: Classification and management

“…has been proposed to use small-diameter endoscopic devices that can be introduced through the crestal osteotomy and allow checking membrane integrity with no need for a second osteotomy into the sinus at an apical position. 69 Once the perforation has occurred, and in order to restore the sinus floor lining, several approaches can be followed. Some authors recommend using platelet aggregates to seal the communication before inserting the implant, 69 whereas others suggest the placement of a small piece of resorbable membrane through the crestal osteotomy to separate the sinus cavity from the implant, especially when implant placement is performed in conjunction with a bone graft.…”

“…Sinus lining integrity can be controlled intrasurgically by endoscopy through an osteotomy in the lateral wall of the sinus; however, this procedure involves the perforation of the lateral wall of the sinus. Recently, it has been proposed to use small‐diameter endoscopic devices that can be introduced through the crestal osteotomy and allow checking membrane integrity with no need for a second osteotomy into the sinus at an apical position 69 . Once the perforation has occurred, and in order to restore the sinus floor lining, several approaches can be followed.…”

“… 24,67‐69 Such membrane perforations are usually associated with either anatomical or surgical technique factors. It has been reported that the thinner the membrane is, the higher the risk of tears during elevation 69 . These perforations are more frequent when the sinus floor is oblique and when the sinus membrane is elevated more than 3 mm 24,70 (Figure 8).…”

“…Its reported rate ranges between 0% and 17% (Table 3). 24,[67][68][69] Such membrane perforations are usually associated with either anatomical or surgical technique factors. It has been reported that the thinner the membrane is, the higher the risk of tears during elevation.…”