The maxillary sinus is a hollow cavity, lined by a thin blanket (Schneiderian membrane), located on both sides of the upper jaw. It’s purpose is to: provide humidification of air, serve as a ” crumple zone” in trauma, and enhance vocal resonance. When the posterior teeth are extracted, the sinus “pneumatizes” or expands, decreasing the available height of bone. A sinus graft procedure augments the vertical height of bone for dental implant placement. This made be done before or in conjunction with dental implant placement.
Internal (Osteotome) Sinus Lift
The internal or osteotome sinus lift is performed usually at the time of implant placement. A minimum of 3-5 mm of vertical bone height is recommended. The bone is prepared to just beneath the floor of the sinus, which is then gently tapped/infractured. Bone graft is introduced through the osteotomy (drilled hole), lifting the Schneiderian membrane from the walls of the sinus. An implant fixture can be placed simultaneously.
Lateral Window (Modified Caldwell Luc) Sinus Lift
In severely resorbed/atrophic ridges, there is inadequate vertical bone remaining, requiring more bone grafting into the sinus. A small window is prepared on the side of the maxillary sinus, and the Schneiderian membrane is gently elevated from the surrounding walls. Bone graft is placed and the window is covered with a barrier membrane and the tissue sutured. A 6-9 month maturation period is required prior to implant surgery.