What is a Sinus Lift?
A “sinus lift” is the term for a special bone augmentation procedure that is performed in the upper jaw.
Years of toothlessness, periodontitis, and/or other diseases lead to the deterioration of the denture-supporting bone. In addition, the maxillary sinus in the upper jaw gets bigger and bigger due to toothlessness. In many cases, there is not enough bone left to support implants. However, both the quality and the quantity of the existing jawbone are crucial for successful implantation. Nowadays, numerous surgical techniques exist for augmenting jawbones in a gentle and painless manner. Sinus lift surgery is a special technique for the upper jaw:
The mucous membrane of the maxillary sinus is lifted through a small window and bone substitute material is inserted between the mucous membrane of the maxillary sinus and the remaining bone. Depending on the bone substitute material used, the foreign substance should turn into bone within 4-8 months, making an implantation possible again.
Depending on the condition and the amount of the patient’s existing remaining jawbone, it is possible to implant immediately during a sinus lift surgery or to place the implants some time after the bone augmentation procedure.
A distinction is made between an internal and an external sinus lift. In an internal sinus lift, the mucous membrane of the maxillary sinus is prepared through the implant’s drill hole. The cavity created is then inserted with bone material. The maxillary sinus’ intact mucous membrane prevents the bone material from getting into the maxillary sinus from the top. The internal sinus lift is particularly suitable if just a few teeth need to be replaced.
The external sinus lift is particularly suitable if a number of teeth need to be replaced and there is very little bone left to work with. In this case, a small lateral window to the maxillary sinus is created. The bone substitute material is inserted through this window. A reconditioning of the bone substitute material with autologous body cells or growth factors is not necessary.
Human bone heals quickly. Finally, everything is sewn up. The patient receives his prosthesis and thus has well-fitting dentures until the time of the implantation.
Alternatives to implant surgery include a different surgical technique or a removable dental prosthesis. If a fixed dental prosthesis is desired, then one could, for instance, also screw a bone block onto the jaw ridgem, not raising the jaw ridge towards the interior as in the sinus lift, but towards the outside. This is known as an onlay plastic. This technique provides better aesthetic results, but carries more risks and is thus usually only used for aesthetic purposes.
Another possibility when there is insufficient bone material for implantation would be to forego fixed dentures and request the preparation of a partial or full prosthesis.
The risks of this procedure are negligible with an experienced surgeon, but complications may nevertheless arise in individual cases, possibly requiring additional measures. Every additional necessary measure that is taken may subsequently be associated with further complications, which may be life-threatening within the course of the procedure. Right now, we will only discuss sinus lift-specific complications, which are as follows:
- The bone substitute material does not turn into bone. In such a case, an implantation is not possible
- The bone substitute material grows into the connective tissue. In such a case, an implantation is not possible either
- A rupture of the mucous membrane of the maxillary sinus leading to the loss of the bone substitute material. An implantation would not be possible in this case
- An inflammation of the augmentation. This inflammation may spread to neighboring structures (maxillary sinus, eyes, etc.). Removal of the augmentation material in a second surgical procedure is often necessary
- Injury to neighboring structures such as nerves, cheeks, and blood vessels, with the respective consequences
- Maxillary sinusitises
- Sensation disturbances in the lip and upper jaw
Fortunately, such complications have become very rare due to positive developments in medicine during the past decades.