People who have worn full dentures for many years often notice their face has changed — the lower third looks shorter, the chin seems to come forward, and lines around the mouth deepen. It is not simply ageing. It is the jawbone responding to the absence of teeth.
Dr. Jin-Ho Cho at Shine Dental Newington — BDS (University of Sydney, 1987), more than 35 years in practice, over 9,000 implant fixtures placed — assesses bone volume at every implant consultation, and this process is why the timing of treatment matters.
Why does bone disappear after teeth are lost?
Bone is living tissue that responds to the loads placed on it. The bone that surrounds a tooth root — the alveolar bone — exists specifically to support that tooth. It is maintained by the forces transmitted through the root every time you chew.
Remove the tooth and the stimulus goes with it. The body reabsorbs bone it is no longer using. This is a normal biological process, not a disease.
The pattern is fairly predictable. Most change happens in the first six to twelve months after extraction, with the ridge losing both height and width. Loss then continues more slowly, year after year. Someone who lost a molar last year usually has considerably more bone than someone who lost the same tooth fifteen years ago.
How does that show in the face?
The jawbones provide the underlying framework for the lower face. As the ridges shrink, several things follow:
The lower face shortens. With no teeth to set the distance between upper and lower jaws, the chin sits closer to the nose when the mouth is closed.
The chin appears to rotate forward. As vertical height reduces, the lower jaw closes further and the chin comes forward, sometimes giving a more prominent appearance.
Lip support reduces. The upper lip is supported from behind by the teeth and the bone that holds them. Without that, it can appear to fall inward and thin.
Folds around the mouth deepen, because the soft tissue is unchanged in volume while the framework beneath it has reduced.
These changes are gradual and cumulative, which is why they are often attributed entirely to ageing.
Do dentures prevent it?
Conventional dentures restore appearance and function, and for many people they are a reasonable choice. What they do not do is transmit force into the bone the way a root does. A denture rests on the gum, spreading load across the surface rather than through the ridge.
In fact, the pressure of a denture on the ridge can contribute to resorption over time. This is why long-term denture wearers periodically need their dentures relined or remade — the ridge underneath has changed shape.
Do implants change this?
An implant integrates with bone and transmits chewing force into it. That load maintains the bone immediately around the implant in a way a denture does not.
Two honest qualifications. First, an implant maintains bone around itself; it does not regrow bone that has already gone, and it does not preserve areas of the jaw far from where it sits. Second, outcomes vary between individuals and depend on gum health and maintenance, as covered in our article on peri-implantitis.
For a full arch, All-on-X places several implants that carry load across the jaw, which is one reason it is considered where preserving the ridge matters. Our comparison of All-on-X and full dentures sets out the differences.
Does the timing of treatment matter?
Yes, and this is the practical point of the article.
If a tooth is coming out and you already know you want to replace it with an implant, discussing that before the extraction opens options. Socket preservation grafting at the time of removal can reduce the shrinkage that follows — a smaller intervention than rebuilding a ridge later. Our article on bone grafting explains the techniques.
If teeth were lost years ago, that does not close the door. It means the assessment needs to establish what bone remains, which requires a CBCT scan rather than a standard x-ray. Grafting, shorter or angled implants, or a different approach altogether may be workable. Our guide on implants with bone loss covers the options.
What this does not mean
It would be misleading to suggest that implants restore a younger appearance or reverse facial ageing. They do not. Bone that has already been lost is not recovered by placing an implant, and facial appearance is influenced by many factors beyond the jaw.
What can reasonably be said is that maintaining bone in the jaw is one factor in maintaining facial structure, and that the choices made when teeth are lost influence how much bone is retained. Individual results vary.
The other consequences of gaps
Bone change is not the only reason to address missing teeth. Neighbouring teeth drift into the space, the opposing tooth over-erupts, chewing load redistributes and cleaning becomes harder. Our article on the health consequences of missing teeth covers these.
Arranging an assessment
If you are facing an extraction, or have had gaps for some time and want to know where you stand, an assessment with a CBCT scan will show what bone is actually there. You receive a written, itemised quote with item numbers before anything is booked. Consultations run in English or Korean. HICAPS on-the-spot claiming is available, and the practice is a CBHS and NIB preferred provider.
Call (02) 9748 4822, mobile 0430 442 018, or send an enquiry.
Treatment options depend on individual clinical assessment, and outcomes vary between patients.