Tooth Eruption: What Happens When?

Tooth eruption is a process in tooth development in which the teeth erupt into the mouth and becomes visible. The arrival of a new tooth, or tooth eruption is a big event for most of us! As a baby, tooth eruption allows for introduction of new foods with more substance. Later on, many parents and kids look forward to a visit from the tooth fairy, and for their new “grown up” teeth to come in. It is an exciting time for parents and children alike and losing baby teeth is an important milestone in most kids and parents lives. It means they are growing up, getting bigger, and taking on more responsibility for themselves at home and school.

Tooth Eruption Facts

Humans have two sets of teeth, primary (or baby) teeth and then permanent teeth. These teeth develop in stages. The schedule is different but the development and tooth eruption of each of these sets of teeth is very much the same. Following are a few facts about tooth eruption: –Tooth eruption tends to happen in parallel. This means that the bottom molar tooth on your left side should erupt into your mouth at about the same time as the bottom molar tooth on the right side.

• -Primary tooth development begins during the 2nd trimester of a woman’s pregnancy. Primary teeth are place holders for permanent teeth. -Loss of primary teeth due to extraction or loss of space due to breakdown of baby teeth, makes a child susceptible to malocclusion and more likely to need orthodontic treatment.
• -The crown of a tooth is the first to begin forming. The roots continue to develop and lengthen even after the teeth have come through the gums.
• -There are 20 primary teeth. These are usually fully erupted by age 3, and remain until around 6 years of age when they begin to fall out to make room for your permanent teeth.
• -Adult teeth usually begin to erupt into the mouth between 6 and 12 years of age. Most adults have 32 permanent teeth. -Permanent teeth are larger and take longer to erupt than primary teeth.

Tooth Eruption – Types of Teeth

A person’s teeth will vary in size, shape, and their location. Each tooth in your mouth has a job to do and that is why it is shaped the way it is and where it is located. Tooth eruption follows a definite pattern.  

There are 5 types of teeth:

1) Incisors. Incisors are the eight teeth in the front of your mouth (four on top and four on bottom). These teeth are used to take bites of your food. Incisors are usually the first teeth to erupt. Primary incisors erupt at around 6 months of age.Permanent incisors should come in at  6 and 8 years of age.

2) Canines. We have four canines in our mouths. These are the next type of teeth to erupt. Canines are your sharpest teeth and are used for ripping and tearing food apart. Teeth eruption for primary canines usually occurs between 16 and 20 months of age, with the upper canines coming in just before  the lower canines. The order is reversed for permanent teeth. Lower canines erupt around age 9, with the uppers erupting at about 11-12 years of age.

3) Premolars. Primary molars are replaced by premolars. Premolars (also called bicuspids) are used for chewing and grinding of food. You have four premolars on each side of your mouth, two on the upper and two on the lower jaw. The first premolars appear around age 10 and the second premolars arrive about a year later. Premolars are generally the teeth that may need to be removed during orthodontic treatment to create space.

4) Molars. Primary molars (replaced by the permanent premolars) are also used for chewing and grinding food. Teeth eruption for these happens between 12 and 15 months of age. The first permanent molars erupt around 6 years of age while the second molars come in around 11-13 years old.

5) Third Molars. These are also referred to as “wisdom” teeth. These are the last teeth to erupt into the mouth and do not typically erupt until age 18-21 years of age. Some

people never develop third molars at all. These molars may cause crowding and need to be removed. Other times they develop in the jaw but never erupt into the mouth. When this happens it is referred to as impacted.

Tooth Eruption Issues

-Supernumerary teeth.  Extra teeth may form and make normal tooth eruption more difficult, delayed or impacted. This happens most often in the wisdom tooth area. Another type of extra tooth is called a mesiodens. This is an extra small tooth growing right between the two upper front teeth and needs to be removed surgically. There is also Gemination, or twinning of a tooth, wherein, a double tooth forms.

–Malformed  Teeth. Tooth eruption is not always perfect. Sometimes genetics, medications etc. can cause malformed teeth. Examples are peg laterals (very small lateral incisors), mulberry molars (a molar that has a raspberry like appearance), Fused teeth (two different teeth which form conjoined into one tooth such as a lateral and canine),  Dens in dente (a tooth growing completely inside of another tooth). If a tooth does not form in the primary dentition (for example a child never forms a front baby tooth), there will never be a permanent tooth to replace it. Also, tooth eruption in the lower arch in front can sometimes erupt behind the primary teeth.

This is quite normal but may necessitate the need of removal of the primary teeth to aid tooth eruption. If teeth are not erupting properly, have your dentist take an x ray. Sometimes there are developmental or genetic issues causing malformed teeth, extra teeth or lack of tooth development. It is important to monitor tooth eruption as it happens. The earlier these issues are detected, the better you can prepare for future treatment needs.