August 9, 2019

About Primary Teeth and Dental Anatomy

What are dentists talking about when they speak about canines, incisors, and teeth eruptions?

This guide is for parents eager to learn about dental anatomy to make sure their child is developing on schedule. Most babies get their first tooth between the ages of four and seven months of age. We know the central incisors, located at the bottom front, are the first primary teeth to poke through the gums. There are rare cases of infants being born with one or more teeth. This unique set of teeth are nothing to worry about unless they interfere with feeding or become a choking hazard. Ask your pediatrician for advice if you do experience any issues.

Primary Dentition Key Terms: 

The primary dentition is the first collection of teeth to erupt in the oral cavity
The primary dentition is comprised of 20 teeth
The primary dentition is also referred to as deciduous teeth. 
In each arch of the mouth, there are two central incisors, two lateral incisors, two canines, and four molars. 
Exfoliation is when primary teeth get ready to fall out and make room for primary teeth.
Maxillary is the upper jaw
Mandibular is the lower jaw

What is happening inside the mouth?

Let’s begin with the top of the jaw, also known as the Maxillary and learn more about the deciduous teeth.


Eruption Dates: The central incisors erupt between 8-12 months and are joined by the lateral incisors sometime between 9-13 months. The canines erupt between 12- 22 months, and on average the 1st molar pokes through between 12 – 19 months. The 2nd molar pokes through the gumline between 25-33 months.

Exfoliation Dates: The central incisors exfoliate between 6- 7 years of age. The lateral incisors are lost between 7-8 years of age. The canines are next and are lost between the ages of 10-12 years old. Expect the first molars to make room for permanent teeth between ages 9-11 years old. The 2nd molars will be lost by age 10-12 years old.


Eruption Dates: The lower jaw, also known as the Mandibular, is on a distinctive schedule. The central incisor emerges between 6 – 10 months of age, lateral incisor poke through between 10-16 months, the canines erupt between 17-23 months, 1st molar between 14 – 18 months, 2nd molar, erupt between 22-31 months.

Exfoliation Dates: Much like their Maxillary counterparts, the central incisor is lost around 6-7years old. It’s the same with the lateral incisors as they make room at about 7-8 years of age. The canines are lost around age 9 to 12 years of age. The 1st molar is lost between 9-11 years of age. The 2nd molar makes room for permanent teeth at 10-12 years of age.

Other Primary Tooth Eruption Facts

A common rule is that for every 6 months of life, approximately four teeth will emerge.
Boys lag behind girls in tooth eruption
Lower teeth typically emerge before upper teeth
Teeth in both jaws usually erupt in pairs
Primary teeth are smaller and whiter in color than permanent teeth
All primary teeth should have erupted by the time your child is 2 to 3 years of age

Coping With New Teeth

If your child is experiencing discomfort you can massage the gums with a clean finger, or massage the gums with the back of a small, cold spoon.

“I am extremely happy with our experience, all the staff we have met are extremely friendly and helpful. Dr Ella Choi and her staff have been wonderful and patient with my son that has an anxiety disorder and have done all they can to try to calm him. All dental work and costs that have been needed have been explained in detail and they take the time to make sure you understand what is involved. I have been to other Pediatric Dentistry Clinics and have often felt rushed. Thank you all at Playtime Pediatric Dentistry I appreciate all you have done for us. - Daniella D.”