Many people don’t understand the effect of complete dentures on the jaw.
There is a natural reaction of the body when a tooth is extracted. When a tooth is gone, the body perceives this and causes the bone that had supported that tooth to be resorbed—dissolved away. The body senses that this bone is no longer needed, and the calcium and phosphorous are taken into the bloodstream and used other places in the body.
This shrinking takes place in any area of the jaw where there are missing teeth. Its effects are most dramatic in the lower jaw. When all the lower teeth are gone, the entire mandible (lower jawbone) is affected. Over a period of about twenty years, as this dissolving of the bone goes on, the shrinking of the lower jaw can become severe. This causes several problems:
- As the bone becomes thin, it becomes difficult to rest a complete denture on it. The denture will be unstable because it has nothing to hang onto.
- When the teeth are gone, the bone will develop a sharp ridge. When a denture is rested on this ridge, it can easily become sore. When jaw resorption is severe, it becomes very difficult to make a comfortable denture that stays in place.
- The risk of breaking this lower jaw can become great, because it is so thin.
- The jaw shrinking tends to give your face a collapsed look. The distance between your nose and your chin gets smaller and smaller, and your chin begins to look more pointed. To the right is a famous drawing of an old man by Leonardo daVinci. This is the typical collapsed face look of a person who has had no teeth for a long time.
One option for people who have had dentures for a long time so that their jaw has shrunk is to get soft dentures, with a soft liner that is more comfortable. Another option is dental implants. The presence of dental implants will actually prevent jaw shrinkage.