Where is the sinus, and what does it have to do with the upper back teeth?
The maxillary sinus is an air-filled space inside the upper jawbone. According to the patient information from Cambridge University Hospitals, the sinuses sit either side of the nose, above the upper premolars and molars and below the eyes. Inside, they are lined with a thin membrane. Because of this close relationship, the position of the sinus is always taken into account when implants are planned at the back of the upper jaw.
Why is bone height at the back of the upper jaw often insufficient?
After the upper back teeth are lost, two changes often coincide:
- The bone shrinks: after an extraction, the bone around the former socket becomes narrower and lower over time. We describe this in our guide bone graft before implants.
- The sinus expands downwards: according to the patient information of Ege University’s dental hospital in İzmir, the sinus enlarges downwards after the loss of the back teeth and comes closer to the mouth.
Together, this can leave too little bone between the sinus floor and the mouth for an implant. The American Academy of Periodontology (AAP) therefore counts the back of the upper jaw among the areas traditionally considered the most difficult for implants, because of limited bone quantity and quality and the closeness of the sinus.
When is a sinus lift needed?
A sinus lift comes into question when implants are planned at the back of the upper jaw and there is not enough bone height below the sinus floor. According to Cambridge University Hospitals, the aim is to create enough bone under the sinus for an implant. The membrane lining the sinus is gently lifted and the space created is filled with bone graft material. The decision usually takes into account:
- the bone height below the sinus floor measured on the cone-beam CT (CBCT) scan
- the number of missing teeth and planned implants
- smoking and general health
- alternatives such as a bridge or a removable denture
- any history of sinusitis, so please tell us about it before planning
What is the difference between a lateral window and an internal sinus lift?
There are two basic approaches. Which one is chosen depends mainly on the existing bone height and on how much extra bone is needed.
| Feature | Lateral window (external) sinus lift | Internal (crestal) sinus lift |
|---|---|---|
| Access | Small window in the side wall of the jaw | Through the hole drilled for the implant |
| When? | When considerably more bone height is needed | When a little extra height is enough |
| Implant | At once if there is enough remaining bone, otherwise in a second operation after the graft has healed | Usually in the same operation |
Cambridge University Hospitals describes the lateral window approach like this: the gum is opened, a window is made in the bone, the membrane is lifted, graft material is packed in and the gum is closed with dissolving stitches; Cork University Dental School and Hospital describes the same steps.
With the internal approach, according to Cambridge University Hospitals, the sinus floor is gently tapped upwards through the implant site, graft material is pushed in if needed and the implant is placed in the same operation. The same source says this approach is suitable when only about 3 millimetres of extra bone height is needed.
How does healing progress after a sinus lift?
Cambridge University Hospitals describes the normal course like this:
- Swelling usually peaks on the second day.
- Bruising on the cheek can spread down to the lower jaw.
- From around day ten, when any non-dissolving stitches are removed, most people feel better.
- After two to three weeks, most people feel back to normal.
According to the oral and maxillofacial surgery department of McGill University, slight oozing is possible in the first 24 to 48 hours, and small granules of graft material can occasionally come out of the mouth in the following days and weeks.
It takes longer for the graft to fuse with your own bone. When the implant is placed in a second operation, Cambridge University Hospitals gives 4 to 9 months for this and Cork University Dental School about six months. The timing is individual and set after a check-up and X-ray.
What should you avoid after a sinus lift?
According to the Rize Oral and Dental Health Centre of the Turkish Ministry of Health, blowing your nose raises the pressure in the sinus; this can increase bleeding and shift the graft material. In the first weeks, anything that builds pressure in the sinus is therefore avoided:
- Do not blow your nose: Cambridge University Hospitals advises two weeks, McGill at least one week. If needed, gently dab your nose.
- Sneeze with your mouth open: McGill and the Rize centre both advise against sneezing with your mouth closed or nose pinched.
- No straws, no vigorous rinsing, no wind instruments: McGill recommends avoiding all three for at least a week.
- Postpone air travel and strenuous exercise: McGill advises two weeks for both (more on flying in the next section).
- Do not smoke: according to Cambridge University Hospitals, the graft fails more often in smokers; see our guide smoking and dental implants.
Because the sources give different time limits, the instructions of your own dentist apply to you.
When can you fly after a sinus lift?
There is little research on flying after dental surgery. A 2023 article by Felkai and colleagues in the British Dental Journal points out that most of the data come from military aircrew, and offers its guidance as a starting point for the dentist’s decision. For more complex procedures such as a sinus lift or bone graft it gives two weeks as the earliest point, provided there is no pain, swelling or bleeding. As a recommendation, the article’s summary gives six weeks after a sinus lift.
Book your return flight only once the schedule is fixed, and choose a flexible ticket if you can. How a sinus lift and bone grafting affect the number and length of your trips is explained in our guide how many days in Türkiye for dental implants.
Which signs mean you should get in touch?
According to Cambridge University Hospitals and McGill University, do not wait for your check-up if:
- pain or swelling increases after the first days instead of settling
- bright red blood keeps flowing (slow, dark oozing is expected)
- you feel that something has shifted after sneezing or blowing your nose
- you develop a fever (McGill gives 38 °C as the threshold) or feel generally unwell
- air seems to pass through the wound
Ege University points out that if there is a connection between the sinus and the mouth, fluid can come out of the nose. If drinks run out of your nose, please contact us without delay. If you are already at home, a dentist or the emergency dental service near you is the first point of contact for acute problems; also send us a message with photos on WhatsApp (see aftercare and follow-up).
How do we plan a sinus lift at Rönesans?
At our clinic in Serdivan, bone height, bone width and the distance to the sinus are assessed on a CBCT scan. We carry out bone grafting and sinus lifts at our clinic; treatment under general anaesthetic is possible if needed. For a preliminary assessment you can send any existing X-rays on WhatsApp to +90 532 363 49 54, but only the CBCT scan on site shows for certain whether a sinus lift is needed.
Whether and which technique is suitable, and whether the implant can be placed in the same operation, is discussed with you after the examination. This sets the number and length of your trips, which we plan around your travel dates. Before treatment starts you receive a written treatment and cost plan; transfer from Istanbul and accommodation in Sapanca are included in the treatment price. On departure you receive copies of your treatment summary and X-rays for your dentist at home. The procedure itself is described on our dental implants page.