Get to know your Teeth

Our teeth do a lot more than just help us chew our food. They also play a role in talking, smiling and even digesting food, but what’s the deal with baby teeth and adult teeth? Let’s break it down.

Everyone develops two sets of teeth during the first 21 years of life.

Baby Teeth: The Basics

Eruption Timeline

  • Baby teeth typically begin to emerge around 6 months of age (this can vary). By the age of 2, most children have a full set of 20 primary/baby/milk teeth. Usually, the first ones to erupt are the lower central incisors (around 6 months old but this can vary from child to child). The last ones to appear are usually the upper second molars (around 21 to 30 months old).


  • Baby teeth are smaller and whiter than adult teeth. They have thinner enamel and sometimes smoother, rounded edges.

Tooth Loss

  • Around 6-7 years old, baby teeth start falling out as adult teeth take their place. In some cases, a person may retain a baby tooth in adulthood.

Adult Teeth: The Transition

The transition from baby teeth to permanent ones is gradual and spans a person’s childhood.

Infancy to Age 2/3 – Baby teeth develop during pregnancy, with the first ones appearing around 6 months.

By age 2/3, a child has all 20 baby teeth and their first dental appointments are recommended around 1 year’s old.

At ages 3 to 6, adult molars begin developing under the gums.

At ages 6 to 9, the first primary teeth (lower central and lateral incisors) loosen and fall out and the adult first molars erupt at the back of the mouth.

From ages 9 to 12, more baby teeth are lost and replaced by permanent ones and the adult premolars emerge.

From ages 12 to 18, wisdom teeth (third molars) usually appear last, between 17 and 21.

    Dentists have their own way of numbering teeth. In this system, the permanent teeth are given two numbers, the first number indicating the quadrant and the second number identifying each tooth in the quadrant. For example, the upper right quadrant of your mouth is referred to as 1, then each tooth in this quadrant is numbered from 1 to 8, moving from the incisors back to the molars.

    The quadrant numbers are

    Upper Right – 1 Upper Left – 2

    Lower Left – 3  Lower Right – 4

    Remember, it’s your left or right, not the dentists!