The order of eruption of the 20 primary and 32 permanent teeth is fairly predictable, although the timing can range considerably among children.
Primary Teeth
The primary teeth begin to erupt around 6 months of age and eruption is completed by 24 to 36 months. Girls’ teeth usually erupt slightly earlier than boys. Delays in tooth eruption can be familial, but delays of more than 12 months merit further dental evaluation.
Eruption is usually symmetrical (lower teeth usually before upper) in the following pattern for the primary teeth: central incisors, lateral incisors, first molars, canines, second molars.
Falling out of the teeth.
Exfoliation often follows a similar pattern.
A helpful mnemonic to remember the timing of primary eruption is the
7+4 rule. At 7 months of age, children should have their first teeth; at 11 months (4 months later), they should have 4 teeth. At 15 months of age
(4 months later), they should have 8 teeth, and so on. This pattern continues as follows:
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19 months = 12 teeth |
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23 months = 16 teeth |
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27 months =20 teeth |
