What happens to your jaw when a tooth is lost
Dr Pushkar SobtiAll-on-X implantologist, Delhi
One sentence I hear in the clinic almost every week is: "It's only one tooth at the back. Nobody can see it." I understand why people think that. A missing back tooth doesn't hurt, and it doesn't show when you smile.
But the gap doesn't stay the same. Over the months and years that follow, the bone shrinks, the teeth around the gap start to move and the bite changes. Many of the complex cases I treat today started as "only one tooth" ten or fifteen years earlier.
The bone starts to shrink
A tooth root does more than hold the tooth. Every time you chew, the root passes pressure into the jawbone, and that pressure tells the bone it is needed. When the root is gone, the bone loses that signal and the body starts to reabsorb it.
It happens fast. Studies that measured extraction sites found the bone ridge can lose around half of its width within the first year, and most of that loss happens in the first three months. After that the shrinking slows, but it doesn't stop.
On a CBCT scan I can see this clearly. A ridge that was once wide and rounded becomes thin, like a knife edge. That is the bone an implant later has to sit in.
The neighbouring teeth move
Teeth are held in place partly by their neighbours. When one goes, the teeth on either side slowly tilt into the gap. The tooth above or below it, which no longer has anything to bite against, gradually grows out of its socket towards the space.
The result is a bite that no longer fits together properly. Food gets trapped in new gaps, cleaning becomes harder, and the tilted teeth are more likely to develop decay and gum problems. One missing tooth can put two or three others at risk.
Chewing and the face change
When back teeth are missing, people chew more on the other side or with their front teeth, which were never designed for that load. Over time this can wear and crack the remaining teeth and strain the jaw joint.
When several teeth are lost, the effect shows on the face. Shrinking bone and missing teeth reduce the support for the lips and cheeks. The lower face becomes shorter, the lips thin and lines deepen around the mouth. This is the "sunken" look many people associate with old age, and much of it is really caused by bone loss.
Why bridges and dentures don't stop it
A bridge or a denture replaces the tooth you can see, and both have their place. But neither puts any load into the bone where the root used to be, so the bone under them keeps shrinking. A denture can even speed this up, because it presses on the gum and the bone beneath it. This is why dentures that fitted well at first often become loose after a few years.
An implant is the only replacement that sits inside the bone and loads it the way a natural root does. That is what helps preserve the bone around it.
What to do if you have lost a tooth
- If the tooth is about to be removed, ask whether an implant can be placed on the same day. When the bone allows it, this is the best way to protect it.
- If it has been removed recently, the space can often be grafted at the same visit to preserve the bone until an implant is placed.
- If it was removed years ago, it is usually not too late. A CBCT scan shows exactly how much bone is left, and there are good options even when it is thin.
The sooner a missing tooth is replaced, the simpler the treatment tends to be. If you have a gap you have been meaning to deal with, send me your X-ray on WhatsApp and I will tell you where you stand.
Questions
How quickly does bone shrink after a tooth is removed?
Most of the change happens in the first few months. Studies of extraction sites show the bone ridge can lose around half of its width within the first year, with most of that in the first three months.
Is it too late for an implant if my tooth was removed years ago?
Usually not. A CBCT scan shows how much bone is left. If it has thinned, options include bone grafting, a sinus lift, tilted implants as in All-on-4, or zygomatic and pterygoid implants.
Does a bridge or denture stop bone loss?
No. A bridge or denture replaces the visible tooth but puts no load into the bone where the root was, so the bone under it keeps shrinking. An implant loads the bone the way a root does.
Next · Mon 26 Oct
Implants, bridges or dentures: an honest comparison. What each option is good at, what it costs and how long it lasts.