Kusp Pediatric Dentistry

Primary Teeth

When do baby teeth start falling out and when does a child start growing permanent teeth?

As pediatric dentists, we often get a lot of questions from parents regarding their child’s baby teeth or permanent teeth. When will my child lose their first tooth? When is it normal to have loose teeth? When will my child get their first permanent molar? Our job as a pediatric dentist is to assess the development of the mouth. There are many dental transitions, and this article can help you understand a little bit more about the differences between permanent and primary (baby) teeth, when baby teeth are lost and when the permanent ones erupt.

I often hear parents say “baby teeth are just going to fall out”…and  that is true (most of the time!) However primary teeth serve several important purposes AND the baby molars actually have to stay in the child’s mouth until they are between 9 and 12 years old. Primary teeth are important for: Chewing/Mastication, Speech and proper word pronunciation, self-esteem and esthetics, and the health of the developing permanent teeth, and they serve as space holders for their permanent tooth replacements. Most importantly, baby teeth give you kids the cutest little smile that keeps you falling in love with your child’s little face, even if they are being naughty.

So, what about baby teeth?

There are 20 total baby teeth. Ten teeth in each arch, top and bottom. There are 4 incisors (front teeth), 2 canines (eye teeth), and 4 molars in each arch. Baby teeth in the US are labeled by letters rather than numbers. Baby teeth start erupting (entering the mouth) anywhere between 4-6 months of age until approximately 6-7 years of age when the child begins losing their baby teeth. Usually this is around kindergarten when kids start having loose, wiggly teeth (and trade secrets about the tooth fairy!)

See also  Over Retained Primary

The second period in a child’s oral development is called the mixed dentition. This is the time in which a child’s first permanent tooth begins to come into the mouth. This is roughly around 6-7 years of age. Here is an example of the first permanent tooth coming in. Sometimes, these permanent teeth come in slightly behind the baby tooth and once the baby tooth falls out, will make its way into the correct position. The mixed dentition is when the child has a “mix” of both baby teeth and permanent teeth. This period is usually between 6 and 12 years of age and usually begins when the child loses their middle/front bottom teeth. Shortly after that, the child will get their first set of permanent molars– we call these the 6- year permanent molars. They sprout behind all the baby molars when the child is around 6 years old.

How are Baby Teeth and Permanent Teeth Different?

Well, there are a lot of myths about baby teeth! Baby teeth have ALL THE PARTS of a permanent tooth: a crown, roots, and nerve tissue! Although not exactly like permanent teeth, baby teeth serve all of the important functions permanent teeth do, and some! 

  • Baby teeth are smaller in size 
  • Whiter enamel in color than permanent teeth
  • Broad, flat contacts between the back molars (this is why is it so important to floss!)
  • Prominent bulge on the side of the molars
  • Smaller crown-to-root ratio than permanent teeth
  • Baby teeth are more narrow

All teeth have three layers of tooth structure, similar to a hard boiled egg. The outer layer being the shell and the hardest portion of the tooth = “enamel”, the white spongy part of the egg is like the second layer of the tooth which is more organic in content, and we call this layer “dentin” and then there is the yolk, and in teeth that is the “pulp” – that is the live part of the tooth where all the nerves and blood vessels live for the tooth. In primary (baby) teeth vs permanent teeth these layers are thinner…so there is less mineralized, hard tooth structure protecting the nerve of the tooth. When dental decay in a baby tooth passes through these layers, this is when children start having dental pain and may need treatment beyond a basic fillings, such as “baby” root canals and extractions.

See also  Apitherapy

Another one of the most common things parents call us about is when their child gets their first permanent incisors (front teeth), they look so yellow! Well, this is actually true… permanent teeth are generally more yellow in color than their primary tooth counterpart. And when the child has both permanent teeth and baby teeth, the color differences are more obvious. There are other differences between primary and permanent teeth. The best treatment for that is getting regular dental cleanings and brushing well every day to keep those new permanent teeth sparkly!

Hope this answers some of the important questions about baby teeth and permanent teeth. Happy Brushing!