How to remember primary teeth eruption times

Updated February 21, 2017

Children have two sets of teeth. Their baby teeth -- or milk teeth -- erupt between six months and two years of age. There are 20 baby teeth in total. As the milk teeth fall out, they are replaced by a set of permanent teeth. This process usually begins happening at age 6 and continues to age 14. Wisdom teeth generally erupt between ages 17 and 25. It is important that parents care for their children's teeth and teach them how to brush both baby and adult teeth.

Remember the 7+4 rule. By 7 months, a baby should have experienced his first tooth eruption. Four months later, at age 11 months, he should have four teeth. Every four months after that, he gets four new teeth. So, at age 15 months, babies have 12 teeth, at 19 months they have 16 teeth and finally, at 22 months they have their full set of 20 primary teeth.

Visualise the order of arrival. Unlike eating utensils which start on the outside, teeth arrive from the centre of the mouth and move outwards. Teeth are like steps moving from down to up; the bottom teeth arrive first and then the top. This process repeats until all 20 teeth have arrived.

Print and post a chart showing the order and timing of teeth eruptions (see Resources). Note your baby's progress on the chart to see how she compares.

Pay attention to abonormalities and decay. Milk teeth still need good dental care. No two children's teeth will arrive at exactly the same time but if your child has no teeth by 12 months, talk to your dentist or doctor.


Girls' teeth usually arrive earlier than boys' teeth.

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About the Author

Based in Toronto, Tanya Gulliver has been writing professionally for more than 20 years. She is pursuing a doctorate in environmental studies focusing on catastrophic disasters. She was first published as a pre-teen, co-writing a weekly events column for her local paper where her goal was to frequently mention her friends and family in the paper.