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Tooth Eruption
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.
Exfoliation: 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:
 
19 months = 12 teeth
 
23 months = 16 teeth
 
27 months =20 teeth
 
 
The primary teeth begin to erupt around 6 months of age, with eruption completed by 24 to 36 months.
 
The timing of typical primary eruption can be easily recalled using the 7+4 rule.
 
Eruption is usually symmetrical, with the lower teeth erupting before the upper teeth.
 
The primary teeth typically erupt in the following pattern: central incisors, lateral incisors, first molars, canines, second molars.
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