Sinus lift (also termed sinus floor augmentation, sinus graft or sinus procedure) is a surgical procedure which aims to increase the amount of bone in the posterior maxilla (upper jaw bone), in the area of premolar and molar teeth, by sacrificing some of the volume of the maxillary sinus.
The two maxillary sinuses are tiny air-filled holes located below the cheeks, above the back teeth (molar and premolars) and on the sides of the nose.
While there may be a number of reasons for wanting a greater volume of bone in the posterior maxilla, the most common reason in contemporary dental treatment planning is to prepare the site for the future placement of dental implants.
A number of different factors may cause the lowering of the sinuses:
Long-term tooth loss without the required treatment
When a natural tooth is lost, whether due to dental decay, periodontal disease or dental trauma, the alveolar process begins to remodel.
Usually, the toothless area (termed as edentulous ridge), will lose both height and width over time. Furthermore, the level of the floor of the maxillary sinus gradually becomes lower.
In advance stages of the periodontal disease, the amount of bone loss is normally higher.
Overall, this leads to a loss of volume of bone which is available for implantation of dental implants, which rely on osseointegration.
Inflammation of the maxillary sinuses
Sometimes, an inflammatory condition of the maxillary sinuses (called sinusitis) may lead to bone resorption and the lowering of the sinuses floor.
Some patients may have the maxillary sinuses enlarged from birth due to a genetic defect.
Other causes can include enhanced bone resorption at this level, missing teeth due to genetics or birth defect, trauma etc.
Sinus augmentation (sinus lift) is performed when the floor of the sinus is too close to an area where dental implants are to be placed. This procedure is performed to ensure a secure place for the implants while protecting the sinus.
a situation where sinus lift is indicated
Prior to undergoing sinus augmentation, diagnostics are run to determine the health of the patient's sinuses, general health and other local conditions.
All procedures involve a bone graft used to add bone volume to the sinus floor. Various materials can be utilized:
- autogenous bone: a bone graft, taken from elsewhere on the individual's body, e.g. the back of the head, iliac crest etc
- biomaterials: artificial substances that replace human bone e.g. calcium sulfate, hydroxyapatite
Normally, the procedure is performed under general anesthesia.
Tooth loss leads to bone loss
Over time, the sinus will expand into the area previously occupied by bone and teeth
If a dental implant is placed into the inadequate bone, it will move, shift and eventually fail
The sinus lift procedure begins with a temporary opening in one of the two possible areas
With an instrument, the sinus membrane is carefully lifted to its previous position, providing clearance for the placement of the substitute bone (the bone graft)
Adequate bone is placed to provide support for the dental implant
Over time, the implant and substitute bone will heal creating a strong bond
The implant-supported crown has a stable foundation
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Let's take a look at a sinus lift procedure before and after:
Sinus lift complications
A major risk of a sinus augmentation is that the sinus membrane could be pierced or ripped (most often during step 5). Should this occur, the therapeutic remedies include stitching the tear or placing a patch over it.
In some cases, the surgery is stopped altogether and the tear is given time to heal. Often, the sinus membrane grows back thicker and stronger, making success more likely on the second operation.
There are other risks involved including infection, inflammation, hematoma, pain, graft failure, sinusitis etc.
However, the overall success rate of a proper sinus lift procedure is excellent (95 to 97%).
Last review and update: February 2019