Tooth Eruption/Development Stages

Everybody develops in different ways and at different times and teeth are no exception. Commonly people have two sets of teeth in their life, a set of 20 primary (baby) teeth that are then replaced by 32 permanent (adult) teeth.

Baby teeth also known as deciduous teeth are the first teeth that come through. Usually the baby teeth start to come through around 6-8months. There are 20 deciduous teeth in total. Deciduous teeth are generally lost between 6 and 13 years of age in a child.

There are 3 phases used to chart what stage a person is at in their tooth development: Primary, Mixed and Permanent dentition stages.

By the age of around 12 there will be 28 teeth in the mouth and by the age of 21 all of the permanent teeth have usually erupted, that’s 32 teeth!

Primary Dentition Stage

The Primary dentition stage starts from the first erupted tooth at around 6-8 months old until around 2-3 years of age, the process also known as “teething”. These teeth stay in the child’s mouth until they are around 6 years old.

Mixed dentition Stage

During the mixed dentition stage the first permanent tooth will erupt at around the age of 6, often called the ‘six year molars’. This starts the time where there is a “mixed” stage of permanent (adult) and deciduous (baby) teeth present. This stage lasts until the last baby tooth is lost at around 10-12 years old.

Permanent Dentition stage

The permanent dentition stage is when all baby teeth are lost, usually at around 10 to 12 years old where they will have 28 teeth. There will be a total of 32 teeth in the mouth at around the age of 21 when the last teeth, the third molars or also known as “wisdom teeth” come through.

Below is a Primary and Permanent eruption tooth chart

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