After extraction and debridement at #3, osteotomy is initiated in the mesiobuccal socket free hand.  Since the remaining bone is ~ 2 mm, the sinus floor is perforated suddenly.  Fortunately the sinus membrane is not, as related to its thickening.  Use 2-3.5 mm drills to enlarge the bony perforation (mainly lateral movement), followed by pushing bone graft upstairs with a curette (Fig.1 *); insert a 4x9 mm dummy implant (Fig.1) to determine the length of the final implant (Fig.2,3). 

Thickened Sinus Membrane   Last   Next

Xin Wei, DDS, PhD, MS 1st edition 11/11/2019, last revision 01/25/2020