If your tooth, or teeth, have been missing for a while, the jawbone starts to recede in that area. The bone is preserved by the pressure and movement from chewing, and when that no longer occurs, the jawbone is resorbed into the body. Most of this bone loss, about 25% of it, happens in the first year, and that continues the longer you leave it. If you’ve had dentures for a number of years and wish to convert to implants, this may be problematic due to bone resorption.
Bone loss can also be caused by periodontitis. Bacteria eat away at the jawbone under your teeth, so if you’ve had gum disease or long term poor oral care, you may have compromised the bones around your teeth.
The other thing that can happen is that the bone can become porous, and lower in density. This is due to a range of diet, hormone, lifestyle and disease factors, as well as tooth loss.
While these are far from ideal, if you can get a bone graft, this may resolve the problem. Bone can be harvested from somewhere else in your body, or synthetic bone (called xenografts) can be used. This replaces lost bone and also stimulates growth in the jawbone. As bone density increases, so does the likelihood of success of the implants.