Team photograph of Dr Axelrad & staff

Ankylosis

Posted on by Dr. Robert Axelrad (Brampton Dentist)

Ankylosis

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In the last blog, we looked at what we need to do when a primary tooth ‘falls out’ too early.

In this entry, we’ll look at the opposite scenario; that is, what happens when a primary tooth doesn’t fall out…yes, this can happen!

There are different situations when a primary tooth doesn’t fall out when it’s supposed to, but for our purposes we’ll look at when an adult tooth is absent.

The Lowdown
When a primary tooth falls out, it’s because there is a permanent tooth that is ready to erupt into the mouth…review Anatomy of Your Child’s Jaw, posted on November 18, 2012.

The pressure from the permanent tooth ‘eats’ away at the roots of the primary tooth. If there are no roots present on the primary tooth, then it becomes loose and falls out.
This is pre-programmed to occur in all of us. At a certain age, the adult teeth are ‘programmed’ to erupt into the mouth and they do so by ‘kind of’ pushing the primary tooth out.

At times however, there is no permanent tooth present. It may be congenitally missing (this means that the adult tooth is just not present in the jaw).

So, if there is no permanent tooth to eat away at the roots of the primary tooth then the primary tooth will not fall out. The primary tooth remains anchored into the bone, because its roots are still present.

Anatomy Lesson
As mentioned previously, the roots of a tooth are embedded in the jaw bone. However, the roots are not attached directly to the bone.

There are microscopic fibers, called Periodontal Ligament Fibers (P.D.L) which attaches the roots to the bone. This is important for the following reason: The periodontal fibers act as shock absorbers which take the force when the tooth is under pressure. In addition, because these fibers are present, the tooth has a little bit of movement. If the P.D.L fibers are not present, then the tooth has no movement.

When an adult tooth is not present, then the roots of the baby teeth don’t get eaten (resorbed) away. In these cases where the roots remain, the periodontal fibers around the roots of the primary tooth disappear and the roots become ‘cemented’ to the bone. This is called ‘Ankylosis’. The roots of the retained baby tooth are cemented to the bone.

Remember, if the P.D.L fibers give the tooth some mobility, if they’re not present anymore, the teeth become cemented in.

The image above (panorex) shows a primary tooth (that can be seen on the lower right) that is ankylosed in the bone.

No adult tooth was present to ‘eat away’ at its roots.

These ankylosed baby teeth don’t stay around forever. Eventually the roots do get ‘resorbed’ by an inflammatory process and the teeth fall out.

This usually happens by the age of 35-40. So, sometimes these retained primary teeth stay around well into adulthood.

There does come a time when we do need to deal with these stubborn primary teeth that don’t fall out when they are supposed to and yes, an ideal solution would be an Implant.

Got dental questions or concerns?  We have answers and can help.  Call us today at (905) 791-3867 or visit us at Bestgate Professional Center, 40 Finchgate Boulevard, Suite 121, Brampton, Ontario. New patients, walk-ins and Emergencies are always welcome.

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