What is a sinus lift and why is it needed?

Directly above the upper molars and premolars lie the air-filled maxillary sinuses. When these teeth are lost, two processes happen together: the jawbone resorbs from below, and the sinus expands downwards from above (pneumatisation). As a result, the bone height between the sinus floor and the mouth that would support an implant decreases.

A sinus lift (sinus floor augmentation) means separating the thin membrane lining the sinus (the Schneiderian membrane) from the bone, lifting it upwards and placing bone graft in the space created. The graft is placed not “inside” the sinus but beneath the membrane, on the mouth side; the ventilation function of the sinus is preserved.

How is a closed sinus lift performed?

In the closed technique (crestal or osteotome technique), no separate window is made. The implant site is prepared up to 1–2 mm below the sinus floor. Then special hand instruments with concave tips (osteotomes) are used to push the thin bone of the sinus floor upwards in a controlled way, lifting the membrane. If necessary, a small amount of graft is added through the site and the implant is placed in the same session.

• Suitable when: The remaining bone height is enough to stabilise the implant, but a few extra millimetres of height are needed.
• Advantage: Smaller surgery, usually less swelling and implant placement in the same session.
• Limitation: The procedure is done without directly seeing the sinus membrane, so the height that can be gained is limited.

How is an open sinus lift performed?

In the open technique (lateral window technique), the gum is lifted and a small window is made in the bone wall of the sinus on the cheek side. Through this window, the sinus membrane is visible and is gently separated from the bone and lifted. Bone graft is placed in the space created, the window is usually covered with a collagen membrane and the gum is stitched.

If the remaining bone is enough to stabilise the implant, it can be placed in the same session. If there is very little bone, the graft is first allowed to mature and the implant is placed in a second session. For more on membranes, see our article on GBR and membrane choice.

Open or closed? A decision based on remaining bone height

According to a classification widely used in implant literature, the decision is largely based on the bone height between the sinus floor and the ridge. The table below is a general framework; bone density, width and sinus health are also assessed.

Different sources give slightly different limits; today, short implants and other surgical techniques are also among the options. In full-arch treatments, angled implant placement can reduce the need for a sinus lift in some patients.

What tests are done before a sinus lift?

Planning is based on a 3D dental CT scan. The scan measures the remaining bone height and width and shows the shape of the sinus floor, bony partitions inside the sinus (septa), membrane thickness and findings such as thickening of the sinus lining or cysts. The position of blood vessels in the sinus wall is also assessed to determine where the window will be placed in the open technique.

If you have a history of frequent sinusitis, nasal congestion or sinus surgery, an ear, nose and throat specialist’s opinion may be obtained before the procedure. Your general health, medications and smoking habits are also part of the planning.

Which graft is used in a sinus lift?

At the sinus floor, the patient’s own bone, processed human bone (allograft), animal-derived bone mineral (xenograft) or synthetic grafts can be used alone or as a mixture. Bovine mineral resorbs very slowly, so it maintains volume for a long time; your own bone can speed up bone formation. For the differences between materials, see our article on bone graft types.

Who is it not suitable for?

• People with untreated active sinusitis or a suspected cyst/tumour in the sinus (ENT assessment is needed first),
• People with systemic diseases that impair wound healing, such as uncontrolled diabetes,
• Heavy smokers (risk increases; a break before and after the procedure is recommended),
• People who have had radiotherapy to the head and neck or take certain drugs that affect bone metabolism (individual assessment required).

Healing after a sinus lift

• First 2–3 days: There may be swelling and bruising of the cheek; a light nosebleed is sometimes seen. Use a cold compress and take the prescribed medication regularly.
• First 1–2 weeks: Avoid anything that increases pressure in the sinus. Stitches are removed during this period.
• Following months: The graft turns into bone. Textbooks report times ranging from about 4 to 10 months, depending on the amount of bone, for the graft to mature and the implant to integrate.

Should the implant be placed in the same session or later?

In an open sinus lift, placing the implant in the same session as the graft shortens the overall treatment time. However, textbooks point out some advantages of placing the implant a few months after grafting: how the graft has healed can be seen before the implant, a possible graft infection is easier to manage while there is no implant yet, and the angle and position of the implant can be planned more freely. The decision is made by assessing bone height, bone quality, the condition of the sinus membrane and the patient’s general health together. If the sinus membrane tears during the procedure, postponing the implant may be the safer option.

What are the risks?

• Tear of the sinus membrane: If noticed during the procedure, it is usually repaired with a resorbable membrane; with large tears the procedure may be postponed.
• Graft infection: Textbooks report the infection rate of sinus grafts as slightly higher than for standard implant surgery (about 3–5%). Increasing pain, swelling, a bad smell or nasal discharge should be reported to your dentist.
• Sinusitis: Can occur especially in people with previous sinus problems.
• Graft granules coming from the nose: May indicate membrane damage; contact the clinic.

Frequently asked questions

Related pages

Medically reviewed by: Dr. Dt. Mehmet Fuat BozabaSpecialist in periodontology · September 2026

For an examination and assessment: Message us on WhatsApp or call 0544 289 66 33. Yayla Dental Akademi, Bahçelievler / Istanbul.

Sources: Misch CE. Contemporary Implant Dentistry, 3rd ed. Mosby Elsevier, 2008; Hupp JR, Ellis E III, Tucker MR. Contemporary Oral and Maxillofacial Surgery, 6th ed. Elsevier Mosby, 2014; Buser D (ed). 20 Years of Guided Bone Regeneration in Implant Dentistry, 2nd ed. Quintessence Publishing, 2009.

This article is for information only; a diagnosis and treatment plan can only be made by a dentist after an examination.