Ankylosis is a dental condition that occurs when the small ligaments surrounding the roots of primary teeth are damaged and the roots become fused directly to the bone. Sometimes trauma can play a part in causing ankylosis, but the cause is not always known. It is seen fairly often, especially in lower primary molars.

Ankylosis Can Cause Problems
When an ankylosed tooth is fused to the bone, it cannot erupt normally and will appear to sink into the jaw. The teeth on each side of the ankylosed tooth can lean into the gap formed and narrow the space needed for the permanent tooth to grow into. The ankylosis may also cause gum or periodontal disease because there is no way to clean under the leaning teeth. The tooth opposite the ankylosed tooth can erupt too far (see figure 1). Finally, ankylosed primary teeth may block the normal growth of the permanent tooth because the roots will not dissolve normally (see figure 2).

How do we treat Ankylosis?
Ankylosed teeth usually fall out normally. However, if any of these problems are found, extracting the ankylosed tooth, possibly by an oral surgeon, is the usual treatment. Timing of the extraction depends upon the permanent tooth development as well as other factors, so regular examinations and x-rays are necessary.