Performing crestal sinus floor elevation with collagen sponge simultaneously with implant placement may hesitate in endosinus bone gain limited to the height of the implant apex, because the
Schneiderian membrane might collapse on it [41], as demonstrated by the mesial implant.
The bone was removed and the
schneiderian membrane was exposed and elevated from bone.
The ectodermally derived epithelium that lines these ingrowths forms the
schneiderian membrane. The fundus of these pits eventually meets the rostral end of the developing endodermlined pharynx.
In contrast, the other three types are derived from the
schneiderian membrane; their origins are different from the origins of the membranes that line the remainder of the respiratory tract.
A perforation of inferior alveolar bone of the right sinus was discovered during the procedure but the
schneiderian membrane of internal space was still preserved and not torn.