The evolution of sinus lift techniques

A sinus lift is a surgery that adds bone to the maxilla in the area of the molars and premolars. It’s sometimes called a sinus augmentation. The bone is added between the floor of the maxillary sinus and the Schneiderian membrane. To make room for the bone, the sinus membrane has to be moved upward, or “lifted.” Any dentist who is trained to do it can do a sinus lift. Tatum, the originator of the procedure, is a general dentist.

There are two basic methods for performing the sinus lift technique. The first method is the Lateral window technique, which was described by Boyne in 1960. The procedure was used by Boyne to achieve an optimal intercrestal distance needed for denture making.

The sinus lift techniques have undergone numerous modifications through the years. In 1975, Tatum was the first to perform the lateral window technique in conjunction with autogenous bone grafting for the purpose of placing dental implants in the newly formed bone. Although the lateral window technique is highly invasive, it is a necessary procedure. In 1994, Summers, who was in pursuit of a less invasive sinus lift method, made the surgical protocol easier by offering crestal approach or osteotome technique.

Initially, the osteotome technique was used for compressing the soft maxillary bone to improve primary stability of implants and to increase success rates of implants placed in the posterior maxilla. After a period of success using the technique for bone compression, Summers started floor dilatation of the sinus, thus increasing the length of his implants. When the technique was first introduced, there were two significant disadvantages that limited this technique’s indications.

The first disadvantage was the limited heath that the sinus could be raised. Initially, Summers was able to successfully lift the membrane 1–3 mms. The second limitation was the inability to directly visualize the membrane. The technique was initially performed with convex osteotomes by using the sinus floor to lift the membrane. After the membrane is lifted, bone grafting material is the used to hydraulically lift the Schneiderian membrane. Today, using modern technologies such as piezoelectric units and balloons as well as crestal approach kits, which use saline, we are now able to achieve height gains that rival those of the lateral window technique, with little concern for membrane perforation.

So where are we today? Very few practitioners, including Tatum, routinely use autogenous bone for sinus augmentation. One of the main reasons is there are several excellent alternative bone grafting materials available that don’t require a secondary surgical site and provide very similar results to autogenous bone. So one question that is being asked a lot lately is: Is autogenous bone the “gold standard”? The jury is still out, but there is a lot of evidence out there that suggest it is not. Only time will tell.

The lateral window technique is being used more sparingly these days. There are several methods available that have allowed us to effectively raise the Schneiderian membrane 5–7 mms or more routinely and place the implant simultaneously, as long as we have enough crestal bone to get primary stability. This technique is safer for the patient, and it reduces the chance that an infection will occur.

Lastly, with the evolution of safer and more predictable sinus lift methods, more dentists are able to successfully perform the procedure, which allow more patients to have implants in the posterior maxilla.

Implant dentistry is a discipline that requires the practitioner to possess a wide range of skills. As the technology improves, it will open the door to a wider dissemination of implant dentistry into our society and help to increase the quality of life for many patients that need our help. Technology will never replace knowledge and skill; however, it can and will lower the learning curve and help more practitioners provide state-of-the-art services to their patients.