The Maxillary Sinus Membrane Elevation Procedure: Augmentation of Bone around Dental Implants without Grafts-A Review of a Surgical Technique

Abstract

Background. Long-term edentulism may in many cases result in resorption of the alveolar process. The sinus lift procedure aims to create increased bone volume in the maxillary sinus in order to enable installation of dental implants in the region. The method is over 30 years old, and initially autogenous bone grafts were used and later also different bone substitutes. Since 1997, a limited number of studies have explored the possibility of a graftless procedure where the void under the sinus membrane is filled with a blood clot that enables bone formation. Aim. To describe the evolution of the sinus-lift technique and to review the literature related to the technique with a focus on long-term studies related to the graft-less technique. Methods. The electronic database PubMed was searched, and a systematic review was conducted regarding relevant articles. Results. A relatively few long-term studies using the described technique were found. However, the technique was described as reliable considering the outcome of the existing studies. Conclusion. All investigated studies show high implant survival rates for the graftless technique. The technique is considered to be cost-effective, less time-consuming, and related to lower morbidity since no bone harvesting is needed.

Figure 1

One-week postoperative baseline panoramic view over reconstructed atrophic maxilla. Block bone grafts attached with titanium screws in the anterior and sinus membrane elevation performed in the maxillary sinus floor. Notice the minute amount of bone (1-2 mm) in the sinus floor. The conical shape of the marginal part of the implant represents 5 mm.

Figure 2

3 D reconstruction of CT scan from the same patient as in Figure 1 six months postoperatively, left side. Bone is formed around implants in the maxillary sinus floor.

Figure 3

Situation 3 years postoperatively.

Figure 4

Surgical technique. An osteotomy is performed, and the bony window is temporarily removed. The installed implant is here seen elevating the sinus membrane, and, after blood has filled the created compartment around the implant, the bony window is thereafter replaced.