Osseodensified Crestal Sinus Window: A Replacement Technique for the Lateral Window Approach

Introduction:

A novel transcrestal window sinus lift technique (osseodensification) offers a safe, effective alternative to traditional transalveolar augmentation, achieving bone height gains comparable to lateral window approaches while avoiding their limitations.

Methods:

A healthy patient presented with an edentulous posterior maxilla with large pneumatized maxillary sinus. Preoperative radiographs and 3D CBCT imaging determined bone volume and ruled out sinus pathology prior to surgery. The sinus floor & sinus membrane were found to be perforated.

Two osteotomy positions were confirmed with gutta percha markers. Two 5.0-mm osteotomy sites were made through the sinus floor with  Osseodensification burs diameter 3.0, 4.0, and 5.0. mm. The Schneiderian membrane was sealed with a long-lasting collagen membrane. The osteotomy sites were  filled with hydrated mineralized cancellous allograft. Osseodensification Bur Ø 5.0 mm was used counterclockwise at low speed (150 RPM) and no irrigation to gently propel the allograft into the sinus under the sinus membrane.

Digital radiographs during the procedure verified intact Schneiderian membrane fully containing allograft graft volume.

Results:

Healing was rapid and uneventful, with minimal discomfort, bleeding, and no swelling. No Schneiderian sinus membrane perforation or surgical complications occurred.

The initial (pre-op) bone height was 0.5 mm. The final (post-op) vertical bone gain was 17 mm.

Discussion:

The lateral window technique has traditionally been the preferred approach for sinus augmentation when the residual bone height (RBH) is less than 5 mm. However, the osseodensified crestal sinus window technique may offer a viable alternative or potential replacement in all such cases. Its safety and effectiveness rely heavily on careful case planning and the expertise of a well-trained dental surgeon.

Further research is needed to statistically compare its vertical bone gain outcomes to those achieved with the conventional lateral window approach.