SINUS LIFT IMPLANT
If you have been told your upper molar bone height is insufficient, whether you need a sinus lift and by what method is decided by the CBCT measurements.
Why Diagnosis Matters
A sinus lift (sinus bone graft) is surgery that lifts the membrane at the floor of the maxillary sinus, the empty space above the upper molars, and adds bone graft material to create the bone height for placing an implant. This is because when an upper molar is extracted, the jawbone resorbs and the maxillary sinus expands downward, so the remaining bone shrinks to a few millimeters. Yeonhap Dental Clinic considers a sinus lift when the remaining bone is under 7 mm on the 3D CBCT. It is not needed for lower molars or front teeth, which have no maxillary sinus.
Consultation Checklist
At the first consultation, we check the five points below on a 3D CBCT and then decide the method.
Treatment Options
A sinus lift is surgery that raises the floor of the maxillary sinus above an upper molar to create space for bone graft material, and we consider it when the remaining bone is under 7 mm. Yeonhap Dental Clinic looks at the condition of the sinus membrane and first tries the less painful crestal approach, switching to the lateral approach the same day if a perforation is confirmed.
It is surgery that raises the floor of the maxillary sinus above an upper molar to create space for bone graft material. It is done when the bone has become low after a tooth was extracted and the implant length cannot be achieved, and we consider it when the remaining bone is under 7 mm.
The crestal approach is a method of hydraulically pushing up the membrane at the sinus floor through the hole where the implant will be placed and adding bone graft material. With no incision or only a minimal one, recovery is fast, and if the membrane is healthy and initial stability is secured, placement is done on the same day. Even with only 1–2 mm of remaining bone, we try it first if the sinus membrane is healthy.
The lateral approach is a method of making a small window in the cheek-side bone and lifting the sinus membrane while looking at it directly. We choose it from the start when the membrane is thin or there is a radiopaque lesion in the sinus; for sinusitis, we treat it first and then consider the lateral approach; and if the perforation signal during the crestal approach is ambiguous or confirmed, we switch to the lateral approach that day and, if initial stability is secured, finish through to placement.
Planning Points
We expect about 4–5 months or 6–7 months to the final prosthesis, depending on the remaining bone and the stability and healing. If the sinus lift is done first and the implant is placed later, it is about 7–8 months. The timing of the second-stage surgery and whether a temporary tooth is used are decided by condition.
Even at sites where the lateral approach would be easier because the remaining bone is small, Yeonhap Dental Clinic first tries the less painful crestal approach, and if the perforation signal is ambiguous or a perforation occurs, switches to the lateral approach the same day. If the membrane is thin or a lesion is seen in the sinus, we consider the lateral approach from the start, sinusitis is treated first, and if initial stability is not achieved, we do only the sinus lift first.
If the remaining bone and the stability and healing are good, the treatment may be completed in about 4–5 months. If bone formation and gradual loading adaptation are needed, it usually goes through a second-stage surgery after 5 months and about 1 month with a temporary tooth before the final prosthesis.
Before Visit
If you organize the points below and bring them, at the first consultation we can tell you the method and even the time frame.
Remaining bone of 7 mm: If there is less than 7 mm up to the floor of the maxillary sinus, we consider a sinus lift. This is not a value from the literature but Yeonhap Dental Clinic's clinical standard. Approach: If the sinus membrane is healthy, we first try the crestal approach (hydraulic lift) even when the remaining bone is small, and if the perforation signal is ambiguous or a perforation occurs, we switch to the lateral approach the same day. A thin membrane or a lesion in the sinus means the lateral approach from the start, and sinusitis is treated first and then reconsidered. Number of surgeries: The two-stage method is the baseline, with the second-stage surgery usually at 5 months, or at 4 months if the remaining bone is 4–5 mm. Use of a temporary tooth is decided by condition, and the one-stage method, in which a healing component is placed right away, applies only when done on the same day as extraction. Cost: A sinus lift is a separate item from the cost of the implant and is non-covered even for NHI-covered implants.
What divides the results of a sinus lift is not the size of the surgery but the conditions. The estimated 3-year survival rate of implants at sinus lift sites is reported as 92.8% for the crestal approach (19 studies) and 90.1% for the lateral approach (48 studies, 12,020 implants) (Tan 2008, Pjetursson 2008), and with remaining bone of 6 mm or less, the two approaches showed no significant difference in survival, membrane perforation, or marginal bone loss (meta-analysis of 7 randomized studies, Shi 2023). For this reason, even at sites where the lateral approach would be easier because the remaining bone is small, Yeonhap Dental Clinic first tries the much less painful crestal approach, spreads the force across the whole membrane with hydraulic pressure instead of a tapping instrument, and if the perforation signal is ambiguous or a perforation occurs, switches to the lateral approach on the spot and finishes the same day (if initial stability is not achieved, placement is postponed). The method is decided not by bone height but by the condition of the sinus membrane and the perforation signal during surgery. References: Tan 2008, systematic review of 19 studies: estimated 3-year survival of implants with the crestal approach sinus lift, 92.8% · Pjetursson 2008, estimated 3-year survival of implants with the lateral approach sinus lift, 90.1%, 48 studies and 12,020 implants · Shi 2023, meta-analysis comparing crestal and lateral approaches with remaining bone of 6 mm or less (no significant difference in survival, perforation, or marginal bone loss) Treatment results may vary by individual oral condition.
Learn more
Learn more
Last updated:
Leave a few details on our consultation page and we'll get back to you promptly.