When is the lateral window sinus lift chosen?
The lateral window sinus lift is used when so little bone is left below the floor of the sinus that an implant would not hold there, so that considerably more height has to be gained. Cambridge University Hospitals calls it the “external approach”: the graft material is added from the cheek side beneath the sinus membrane. If there is hardly any bone, the implant usually follows after healing in a second procedure; if some bone is present, it can be placed in the same session.
What a sinus lift is in general, why bone is missing at the back of the upper jaw and how healing and its rules work are explained in our guide sinus lift before dental implants. The approach through the implant site is described in crestal sinus lift. This page covers only the lateral procedure.
How is the lateral window sinus lift done step by step?
According to the patient information of Cambridge University Hospitals, Cork University Dental School and Hospital and the American Academy of Periodontology (AAP), the procedure runs in this order:
- Anaesthesia: the area is numbed. According to Cambridge, the procedure is usually done awake as an outpatient; sedation or general anaesthetic is reserved there for difficult or combined procedures. In Cork, by contrast, it is normally done under general anaesthetic as a day case.
- Opening the gum: an incision is made in the gum over the toothless section and the bone is exposed.
- Making the bone window: a small window is cut in the side wall of the bone. The AAP describes this piece of bone being raised into the sinus “much like a trap door”.
- Lifting the membrane: the thin membrane lining the sinus (the Schneiderian membrane) is carefully separated from the bone and pushed upwards.
- Placing the material: the space created is packed with bone graft granules, which can be your own bone, a bone substitute or a mixture. The materials are compared in our guide types of bone grafting.
- Covering: according to Cambridge, the window can be covered with a resorbable membrane if needed.
- Stitching: according to Cork, the gum is closed with dissolvable stitches. If enough bone remains, the implant is placed in the same session before the gum is closed.
How long does the procedure take?
Cambridge University Hospitals gives 45 minutes to two hours, depending on extent; the patient information of Ege University in İzmir gives 90 to 120 minutes. According to Cambridge, an antibiotic may be given shortly before surgery; whether you need one is decided by your dentist. After a procedure under local anaesthetic you can return to your accommodation the same day.
What happens if the sinus membrane tears?
A tear or perforation of the membrane is the most common complication during a lateral window sinus lift and is usually repaired in the same session. How often it happens varies by source:
- In the systematic review by Stacchi and colleagues (2017), a perforation occurred in 195 of 1,240 procedures (around 15.7 percent). The rate depended on the instrument: 20.1 percent with rotary instruments, 10.9 percent with ultrasonic devices and 6 percent with hand instruments.
- Cambridge University Hospitals gives 19 percent for the external approach.
- The meta-analysis by Egido-Moreno and colleagues (2024) reports ranges of 7 to 56 percent in the literature.
According to Stacchi, most documented perforations occurred while the membrane was being detached; bony septa inside the sinus and scarring from earlier sinus surgery increased the risk. This is why the sinus is assessed beforehand on a cone-beam CT (CBCT) scan.
Small tears are usually closed with a resorbable collagen membrane and the procedure continues. If the tear cannot be closed, Cambridge explains that the surgeon may stop and redo the sinus lift once the membrane has healed, usually after a few months; Ege University describes the same option for larger tears. In one study cited by Stacchi, 10 percent of perforations could not be repaired.
A repaired tear usually does not worsen the implant’s prospects: in the meta-analysis by Egido-Moreno, implant survival was 97.1 percent after repaired perforations and 97.7 percent without perforation, with no significant difference.
What other risks are there?
Infection, graft exposure and failure of bone to form are rare. Cambridge University Hospitals gives these figures:
| Risk | Figure given by Cambridge University Hospitals |
|---|---|
| Sinus membrane tear (external) | 19 percent |
| Infection (external) | 2.9 percent |
| Graft exposure | 3 percent |
| No graft present after maturation (external) | 1.9 percent |
| Too little bone for an implant | 1 percent |
The same source lists swelling, pain, bleeding including nosebleeds and a feeling of fullness in the sinus for some weeks; a connection between mouth and sinus and a persistent infection requiring removal of the graft are rare but serious. How sinusitis relates to a sinus lift is explained in our guide sinusitis and dental implants.
Long-term results are good. The systematic review by Pjetursson and colleagues (2008), covering 48 studies and 12,020 implants, calculated a three-year survival rate of 90.1 percent for implants placed after a lateral window sinus lift; with rough-surfaced implants and a membrane over the window it rose to 98.3 percent. Smoking is among the main risk factors for graft failure; see smoking and dental implants.
How long does the graft mature, and when is the implant placed?
The material usually needs 4 to 12 months to become a scaffold on which your own bone grows. The sources are close together:
- Cambridge University Hospitals: maturation 4 to 12 months; with the external approach, the wait before the implant is usually 4 to 9 months; from the procedure to the final tooth takes 6 to 12 months, sometimes longer.
- Cork University Dental School: the graft is usually left alone for six months so it can integrate with your own bone.
- American Academy of Periodontology: individual, usually four to 12 months.
Cork points out that the body may absorb the graft over time if the implant is not placed at the right moment. Whether the implant is placed at once or later depends on the remaining bone; the criteria are explained in sinus lift and implant in one session.
What does a lateral window sinus lift mean for your trip to Türkiye?
Two things change compared with a straightforward implant: the first stay gets longer, and with the two-stage approach a stay is usually added. A 2023 article in the British Dental Journal gives two weeks after a sinus lift as the earliest point to fly, provided there is no pain, swelling or bleeding, and recommends six weeks; the authors stress that research is limited and advise watching for sinus symptoms before flying. So book your return flight only once your plan is fixed after the examination and CBCT scan, and choose a flexible ticket.
Because the operation can turn out differently from the plan, for example with a tear that cannot be closed, ask in advance what that would mean for your dates; see also how many days in Türkiye for dental implants.
How do we plan a lateral window sinus lift at Rönesans?
At our clinic in Serdivan, the bone height below the sinus and the anatomy of the sinus are assessed in three dimensions on a CBCT scan before the procedure. We carry out sinus lifts and bone grafting at the clinic, under general anaesthetic if needed. Whether you need the lateral approach, and whether the implant is placed in the same session or after maturation, is assessed at the examination; our dentists work out the plan together, and one dentist accompanies you through the treatment.
Before treatment begins you receive a written treatment and cost plan listing the procedures for each tooth and the number of stays; transfer from Istanbul and accommodation in Sapanca are included in the treatment price. Before you leave we check wound healing and give you copies of your treatment summary and X-rays. For a preliminary assessment you can send existing X-rays on WhatsApp to +90 532 363 49 54; how stays with us are organised is described on our dental treatment in Türkiye page.