Do baby teeth have roots?

A baby tooth showing the root

This is a question that many parents ask me in the dental office while pointing at a panoramic x-ray of their children, as it is something that most people are unaware of and that usually surprises them when they discover it. Yes, primary teeth have roots, just like permanent teeth.

Here you can see the root of the primary teeth and how the primary tooth forms underneath.

In fact, it is underneath this milk tooth, specifically between its roots, inside the bone, that the permanent tooth that will replace it is formed, as can be seen thanks to x-rays. In fact, this is the reason why primary teeth fall out. As the space in the jaws is limited, the more tooth or root is formed from the permanent tooth, the less remains of the deciduous tooth. As the permanent tooth develops, it 'takes over' the space occupied by the root of the primary tooth, until it disappears completely and eventually loses its hold, finally falling out and giving way to the adult tooth.

What does it mean when baby teeth have roots?

Difference between the root of the permanent tooth (left) and the temporary tooth (right).

The fact that the primary teeth also have roots is not merely a scientific curiosity, but involves a number of things:

  • Caries. When it reaches the root, a cavity in a temporary tooth will hurt and become infected in exactly the same way as a permanent adult tooth, hence the importance of treating caries in primary teeth, as we have explained in other articles. In addition, if the infection appears at the root ends of the primary tooth, it can damage the formation of the permanent tooth.
  • Eruption. Sometimes, the permanent tooth deviates from its trajectory during growth, so it does not 'push' or 'push' the roots of the primary tooth, so the latter does not fall out. This is what we call an ectopic eruption, because the permanent tooth erupts next to the primary tooth and the latter does not fall out by itself, as it still retains part of its root. Consequently, the primary tooth has to be extracted.
  • Pulpectomy. The fact that they have their own pulp or 'nerve' completely independent of the permanent tooth that forms underneath, also means that if a pulpectomy (the equivalent of a root canal or 'nerve kill' on an adult tooth) has to be performed, it would not affect the nerve of the permanent tooth.
  • Space maintainer. If we have to extract a temporary tooth early and, when doing so, we observe that it has a lot of root, it means that the permanent tooth will take a long time to appear, so we will probably have to use a space maintainer, something we already talked about in this another blog post.