- The maxillary sinus is an air pocket above the upper back teeth. It is not a disease; everyone has one.
- When this pocket is large, the jawbone below it is thin. This is an issue for upper molar implants in particular.
- A sinus lift gently raises the floor of that pocket and builds bone underneath it.
- Whether you need a sinus lift can be known from an X-ray, not by touch. We explain it at our clinic in Busan with numbers.
Some patients tell us that another consultation added a bone graft and a sinus lift to their plan. At Reset Dental Clinic in Seomyeon, Busan, we understand why a growing plan raises doubts. For patients living in or visiting Korea, we provide 1:1 English interpretation from your first consultation through the end of treatment.
This column explains what the sinus is and why this topic comes up for upper back teeth. It also shows how to tell whether a sinus lift is really needed in your case.
What is the maxillary sinus?
Look at the bones of the face and you will find the upper jawbone. Above it, near the cheekbone, is an empty space about the size of an egg.
This is the maxillary sinus. It is one of the sinuses beside the nose, a pocket filled with air.
What matters is that this pocket sits very close to the upper jawbone. In some people, the root tips of the upper molars almost touch the floor of the sinus.
It is not a disease. Everyone has one, and it would be odd not to.
But its size differs from person to person. If yours is large, the bone left below it is thin.
That thin layer of bone is exactly where an upper molar implant has to go. This is why the sinus comes up in implant planning at all.
Why is it an issue for upper back teeth?
The lower jaw has no maxillary sinus. In the lower jaw, the challenge is avoiding the nerve canal.
In the upper jaw, the challenge is that the sinus leaves too little bone height. That is where the sinus lift comes in.
An implant's root must be fully surrounded by bone. If the bone is too short, the lower part sits in bone and the upper part is left outside it.
The exposed part has nothing holding it, so its grip is weak. If inflammation starts there, it can gradually melt the bone that was holding the implant.
Upper jawbone is also softer than lower jawbone to begin with. So even in similar conditions, we take more care with upper molars.
Both problems, low height and soft bone, add up in the same place. A sinus lift deals with the first one by giving the implant enough bone to sit in.
What does a sinus lift actually do?
The name sounds hard, but the idea is simple. A sinus lift gently lifts the thin membrane on the sinus floor and fills the new space with bone graft material.
Over time, that material turns into your own jawbone. Once the bone height has risen, a long and wide enough implant can be placed properly, instead of a short, less stable one.
Several graft materials are used, such as synthetic bone and bone of animal origin. We choose according to the site and situation.
So it is hard to say that one material is always better. A costly imported material is not always the answer either.
Is the implant placed on the same day as the sinus lift? It depends on the remaining bone height.
| Remaining bone | Plan | Why |
|---|---|---|
| Some bone left, enough for initial stability | Graft and place the implant in the same surgery | The implant can grip firmly from the start |
| Almost no bone left | Build bone first, place the implant after it heals | There is nothing yet for the implant to grip |
We decide this from the X-ray. The grafted bone usually needs a few months to settle. The time depends on several things:
- How much bone was grafted
- Where it was grafted
- Your age
- Your general health
We check with X-rays along the way and set the timing of the next step from them.
Do you need a sinus lift?
In the lower jaw, you can sometimes get a sense by touch. If the gap where a tooth was lost feels sunken when pressed, the bone has been absorbed.
But you cannot tell anything about the sinus by touch. It shows up on an X-ray alone.
So if you are facing an upper molar implant, the first step is to look at the images. Here are the common reasons bone runs short:
| Situation | Why the bone is short |
|---|---|
| The sinus is naturally large | Less bone is left below it |
| Severe gum disease in the past | Gum disease itself is a disease that melts the jawbone |
| The tooth was removed long ago | With no chewing force, the bone keeps being absorbed |
| Dentures worn for many years | The jawbone loses its job and shrinks a lot |
| Infection at a root tip in the past | Bone where infection has passed is uneven and thin |
More than one of these can apply to the same person. The X-ray shows the combined result as a single number: the bone height that remains.
Why not use a short implant instead of a sinus lift?
It is possible. Some dentists do avoid a sinus lift this way. But we look very carefully at this option for upper molars.
| Option | What it does | Our concern |
|---|---|---|
| Sinus lift | Builds bone height, then a full-length implant | More involved surgery, needs careful planning |
| Short implant | Fits into the bone that is there | May not hold up for long under molar chewing force |
| Placing it deeper | Sets the implant lower in the bone | Poor crown shape, food traps, peri-implantitis |
Research papers report that short implants do not cause major problems. What we see in the clinic is different.
Upper jawbone is soft, and molars carry the heaviest chewing force. We have seen short implants fail to hold up over time many times. Once inflammation starts, there is no margin, and they easily wobble and come out.
Another approach is to place the implant deeper. But if it goes too deep, the crown on top cannot take a good shape. Food gets trapped, cleaning gets harder and peri-implantitis becomes more likely.
Some patients come to us a few years later because such an implant has loosened. Then we do a sinus lift and bone graft from the start, build bone and place a new implant.
If a short upper implant placed elsewhere is loose, have it checked soon. Left loose for long, it can melt the remaining bone too, and how much is left decides whether we can rebuild.
Doing it properly once is clearly better than doing twice the work years later. The reverse is also true: grafting where there is enough bone is not right either. We do as much as is needed.
Is a sinus lift a difficult surgery?
To be honest, it is one of the more demanding implant procedures.
Better equipment and techniques have made it much easier than before. Even so, it takes more anatomical knowledge than a standard placement, and side effects are possible.
That is why it is a surgery to go into well informed. After surgery, please follow these points:
- Do not blow your nose hard for a while.
- If you sneeze, keep your mouth open.
- If you smoke, stop at least around the surgery, because poor blood flow hinders the graft.
- Follow the other instructions we give you after surgery.
Swelling is usually more than with a standard implant. Today we open as little as needed, so recovery is much easier than before, and most people feel clearly better within a few days.
If you have diabetes that is under control, we usually go ahead. Healing is slower, so we plan more time, and please tell us your medicines and recent blood sugar levels.
Does it affect the nose? When done normally, it does not affect how your nose works. It lifts a thin membrane on the sinus floor, not the whole pocket, but tell us if you have rhinitis or sinusitis.
How can you tell whether a sinus lift is really needed in Busan?
This is the question we hear most. When a plan suddenly grows, it is natural to wonder whether extras are being added. There is a way to tell.
A sinus lift is needed when the remaining bone height is low. That height is visible on a panoramic X-ray.
These are signs of a real need.
- The dentist goes through the X-ray with you.
- You are told in numbers how many millimeters of bone there are.
- They explain what implant length is needed and how many millimeters must be built.
On the other hand, if you are told "you need a bone graft here" with no image shown, it is fair to ask again. Grafts are sometimes suggested where there is clearly enough bone.
To be clear, this is not about criticizing other dentists. It is simply to help you protect yourself.
Ask these three questions at any consultation:
- "How many millimeters of bone do I have?" See whether you get a number while looking at the X-ray.
- "Is there a way without a bone graft, and what would be different?" See whether the options are explained or one is pushed.
- "How long after the sinus lift is the implant placed?" Ask whether it is done together or in stages, and what the overall schedule is.
Frequently asked questions
Is a sinus lift very painful?
There is usually more swelling than with a standard implant. Because we open as little as needed, recovery is easier than it used to be. Most people feel clearly better within a few days.
How long does the grafted bone take to settle?
Usually a few months. It varies with the amount, site, age and general health, and we set the next step after checking with X-rays.
Is smoking a problem?
Yes, especially for grafting. Poor blood flow in the gums makes it harder for the graft to settle, so we advise stopping at least around the surgery.
Can I have a sinus lift consultation in English in Busan?
Yes. We offer 1:1 English interpretation from the first consultation through the end of treatment. The clinic is near Seomyeon Station Exit 2 (5-min walk), opposite Lotte Hotel Busan, and you can call 010-8555-2854 (+82-10-8555-2854 from abroad).
A sinus lift is not a way to make the plan bigger.
It builds the ground high enough for the post to stand in.
Doing it when it is not needed is a loss.
Avoiding it when it is needed is a loss too.
We have often seen short implants placed to avoid it return years later as a bigger surgery.
If you need an upper molar implant in Busan, Reset Dental Clinic measures the remaining bone in millimeters with a panoramic X-ray and 3D CT before any sinus lift. We offer 1:1 English interpretation throughout, and you can call 010-8555-2854 to book a consultation.
References
- KDCA National Health Information Portal, "Dental Implants" — when a bone graft is needed, healing time and conditions for placement
- KDA newspaper Dailydental (Chiui Sinbo), "65% of Implant Patients Have Experienced Peri-Implant Disease" (Korean Academy of Periodontology, 17th Gum Day) — risk factors for peri-implant disease and maintenance
- KDCA National Health Information Portal, "Gum Disease (Periodontal Disease)" — how gum disease destroys the jawbone
- KDCA National Health Information Portal, "Systemic Disease and Periodontal Treatment" — how smoking, diabetes and other whole-body factors affect tissue healing
- KDA newspaper Dailydental (Chiui Sinbo), "Implant Patients Aged 65 and Over Pass 800,000 Last Year" — the growing number of implant patients in Korea
Written by Reset Dental Clinic Support Team
Medical review Dr. Na In-chae, Head Dentist · Periodontics Specialist
Last updated: September 19, 2026
This column is for general information and does not replace diagnosis or treatment for individual patients. If you have symptoms, please see a dentist.
