Bone grafting and sinus lifts, for when there isn’t enough bone

Why the bone disappeared

Bone in the jaw exists to hold teeth. When the tooth goes, the bone that surrounded it has no function, and the body reclaims it.

The pace is well documented: around a quarter of the width of the ridge is lost in the first year, and it carries on more slowly thereafter without ever quite stopping. Someone who lost a molar at forty and comes to us at sixty has a ridge that is a good deal narrower than the one they had. That is not neglect — it is simply what bone does.

Two other things accelerate it. Gum disease destroys bone while the tooth is still present, so the ridge was already reduced before the extraction. And a denture pressing on the ridge for years speeds up resorption rather than protecting it, which is one of the more counterintuitive facts in dentistry.

The upper back jaw, and the sinus

The maxillary sinus is an air space that sits above the upper back teeth, and it behaves in a way that catches people out: as the molar roots are lost, the sinus expands downwards into the vacated space.

So the height of bone between the ridge and the sinus floor, which might have been twelve millimetres when the tooth was there, can be three or four a decade later. Three or four is not enough to hold an implant.

A sinus lift adds it back. The membrane lining the sinus is carefully elevated — lifted like a tent lining, not cut — and graft material is placed in the space created underneath. After four to six months that space is bone, and an implant of a proper length can go into it.

Where the shortfall is small, this is done through the implant site itself at the same appointment. Where it is larger, it is done as a separate procedure through a small window in the side of the jaw.

What “we’ll graft it” should always come with

A number, and a reason.

If you have been told you need a graft, the questions worth asking are: how many millimetres of bone are there now, how many are needed, and what measurement is that based on. If the answer does not include figures from a 3D scan, the recommendation is an estimate.

We put the measurements in the written plan. Sometimes they show a graft is unnecessary because a slightly different implant position solves it. Sometimes they show the shortfall is greater than a flat X-ray suggested. Either way, you can take that plan and those numbers elsewhere for a second opinion, which we encourage rather than discourage.

Smoking, specifically

We are direct about this here because grafting is where it matters most.

A graft depends on new blood vessels growing into the material in the first few weeks. Smoking constricts exactly those vessels, and graft failure rates in smokers are substantially higher than in non-smokers — considerably worse than the difference for implants alone.

We ask for two weeks before and eight weeks after. Cutting down is not the same thing, and vaping is not a solution. If somebody is not going to stop, we will still often treat them, but the plan changes and the honest odds change with it, and we would rather say that than take the money and hope.