Why do some children have two rows of teeth?

  • Removal of a baby tooth is painless
  • We recommend all children should see a dentist
  • Regular checks help supervise dental development

We get all kinds of questions as you can imagine, but the one we’re about to post here was one of the most unusual.

Here we go: Why do some children have two rows of teeth?

Commonly, the arrival of second teeth occurs at about six years of age, give or take a few months. Except for the wisdom teeth, the last of the secondary teeth come in around 12 years of age.

Tooth eruption can be variable, with girls getting teeth earlier than boys.

Mostly baby teeth get loose and come out because the permanent teeth that usually grow in directly underneath them shrink the root of the baby tooth, thus making the baby tooth “rootless” so that it becomes loose enough to fall out.

But sometimes things go a little awry for kids with permanent teeth growing in but with their first teeth still in place.

two rows of teeth

A double row of teeth a common occurrence

This occurrence is widespread and it happens if the permanent tooth does not grow in directly underneath the baby tooth. Because the two teeth are not aligned in the socket, the replacement tooth is unable to push out the one that it should be replacing.

It then takes the easier route and grows behind the baby teeth, causing the baby tooth root to take longer to dissolve, and the child is left with two sets of teeth.

Double teeth generally a temporary problem

Most commonly it occurs on the lower front teeth (incisors) between the ages of five and seven, but can also happen with other teeth in the mouth.

For most children, having a second row of teeth will be temporary, as the baby tooth will gradually fall out on their own.

If, however, the baby teeth do not naturally loosen, we would probably recommend extraction so that the permanent tooth can grow into its proper position. Usually, this decision would be made when the permanent incisor is at least halfway erupted, and the baby tooth is not getting looser over time.

the tooth fairy

Tooth Fairy money

If you do have to make that visit to see our dentist, please understand that in these circumstances, removal of a baby tooth is generally a painless and quick procedure that most kids tolerate just fine.

Tooth fairy monies are always a sweetener. See our blog post on the tooth fairy.

We recommend that all children should see their dentist regularly so that oral development can be supervised.

Starting life with 20 teeth

All children are born with 20 teeth known as the child’s baby, or milk, teeth. These teeth usually begin breaking through the gums and exposing when the child is about six-months-old.

They remain in the child’s formative years but begin to fall out as the child develops with the first to arrive being the first to go.

As they start falling out, they are replaced by permanent teeth breaking through the gums. These remain with the child for the rest of their life.

Permanent teeth are more yellow than baby teeth, and they have longer roots. They also feature things called mamelons – these are the bumps on the edge of the permanent teeth which give them a serrated appearance. They are quickly worn away with use.

Great White Shark

Imagine being a shark

If humans get double teeth from time to time, spare a thought for the shark. Sharks average 15 rows of teeth in each jaw and in a lifetime will shed thousands of teeth.

Sharks are born with complete sets of teeth and do not suffer from cavities.