Primary Teeth

Primary teeth (baby teeth or deciduous teeth) are teeth that appear in the mouth of a child and stay there for some years before falling and leaving their place to permanent teeth. There are 20 deciduous teeth including eight incisors, four canines, and eight molars.

Primary Teeth

They begin to come out from the gums around the age of 6 to 7 months, normally starting with the two lower central incisors. The second primary molars emerge between 24 and 30 months. The set of deciduous teeth should therefore have completed full eruption around the age of 3 years and any delay of more than one year of this chronology is to be regarded as pathological.

Primary teeth have anatomical and physiological differences when compared to permanent teeth. The enamel is thinner and more translucent, making teeth look paler. The enamel is also less mineralized, whereas dental cavities and baby bottle tooth decay become more common. The pulp chamber is larger; therefore if an aggressive cavity is to form, dental abscesses arise more easily.

Eruption Pattern of Primary Teeth

Upper Teeth Eruption Time Age of Loss of Tooth
Central Incisor 8 to 12 months 6 to 7 years old
Lateral Incisor 9 to 13 months 7 to 8 years old
Cuspid 16 to 22 months 10 to 12 years old
First Molar 13 to 19 months 9 to 11 years old
Second Molar 25 to 33 months 10 to 12 years old
 
Lower Teeth Eruption Time Age of Loss of Tooth
Central Incisor 6 to 10 months 6 to 7 years old
Lateral Incisor 10 to 16 months 7 to 8 years old
Cuspid 17 to 23 months 9 to 12 years old
First Molar 14 to 18 months 9 to 11 years old
Second Molar 23 to 31 months 10 to 12 years old

Dental Classification

  Canine Incisor Molar Permanent Teeth Premolar Primary Teeth Tooth Eruption Wisdom Teeth

References

Naudin C., Grumbach N., Larousse Médical, 3ième édition, Paris, 2003.
Marcovitch H., Black's Medical Dictionary, 41st edition, London, 2005.
Leikin J. B., Lipsky M. S., Complete Medical Encyclopedia, First edition, New York, 2003.
Wikipedia, the free encyclopedia (www.wikipedia.org).
Last update: 9th of March 2008.