Baby Teeth

When They Come In, When They Fall Out

A baby's teeth start to erupt when the baby is about six months old. Baby teeth will later be lost one by one. This makes space for the adult permanent teeth. By the age of 21, a person usually has all of his or her adult teeth.

The charts below tell the names of baby (primary) and adult (permanent) teeth. The pictures show when each tooth usually erupts and is shed. However, not all children get the same teeth at the same times. Your child’s teeth may erupt earlier or later than these charts.

As seen from the chart, the first teeth begin to break through the gums at about 6 months of age. Usually, the first two teeth to erupt are the two bottom central incisors (the two bottom front teeth). Next, the top four front teeth emerge. After that, other teeth slowly begin to fill in, usually in pairs -- one each side of the upper or lower jaw -- until all 20 teeth (10 in the upper jaw and 10 in the lower jaw) have come in by the time the child is 2 ½ to 3 years old.

The complete set of primary teeth is in the mouth from the age of 2 ½ to 3 years of age to 6 to 7 years of age.

Other primary tooth eruption facts:

A general rule of thumb is that for every 6 months of life, approximately 4 teeth will erupt
Girls generally precede boys in tooth eruption
Lower teeth usually erupt before upper teeth
Teeth in both jaws usually erupt in pairs -- one on the right and one on the left
Primary teeth are smaller in size and whiter in colour than the permanent teeth that will follow
By the time a child is 2 to 3 years of age, all primary teeth should have erupted

Shortly after age 4, the jaw and facial bones of the child begin to grow, creating spaces between the primary teeth. This is a perfectly natural growth process that provides the necessary space for the larger permanent teeth to emerge. Between the ages of 6 and 12, a mixture of both primary teeth and permanent teeth reside in the mouth.

If baby teeth fall out after a couple of years, why is it important to care for them?

While it’s true that primary teeth are only in the mouth a short period of time, they play a vital role in the following ways:

They reserve space for their permanent counterparts
They give the face its normal appearance
They aid in the development of clear speech
They help attain good nutrition (missing or decayed teeth make it difficult to chew causing children to reject foods)
They help give a healthy start to the permanent teeth (decay and infection in baby teeth can cause dark spots on the permanent teeth developing beneath it)

Permanent Teeth

As seen in this chart, permanent teeth begin to come in around the age of 6. In some children, the first permanent molars are the first to emerge; in others, the incisors are the first to emerge. By the age of 13, most of the 28 permanent teeth will be in place. One to four wisdom teeth, or third molars, emerge between the ages of 17 and 21, bringing the total number of permanent teeth up to 32.

Adult teeth start to form under the baby teeth. After the baby teeth are shed, the adult teeth will erupt through the gums.

An OPG x-ray showing the permanent teeth developing in the jaws beneath the primary teeth

Most children have a stage when they have a mix of primary and permanent teeth. During this time the smile can look uneven, with some big teeth, some small teeth and maybe even some missing teeth. Try not to worry! Things often even out once all the permanent teeth are through and your dentist will be watching for potential problems at each of your child’s regular check-ups.