Human Dentition or Teeth
Human has two sets of teeth. Primary (milky, baby or deciduous)teethform during the child’s formation in the womb. Permanent or adult teeth form after birth.
When do primary teeth appear in the mouth and how many they are?
Primary teeth appear in the mouth on average from 6 months till 2.5 years of age. They are 10 in each jaw, 5 on each side.
They are divided into 3 categories:
Incisor: 2 on each side
Canine: 1 on each side
Molar: 2 on each side
The primary teeth start to shed at 6 years of age.
Lower incisors are the first to shed and upper canines are the last ones.
When each primary tooth erupts and when they shed?
The table below shows you the time of eruption and shedding of each primary tooth in each jaw:
|Tooth||Erupt in the mouth||Shedding time|
|Upper Central Incisor||8-12 Month||6-7 years|
|Upper Lateral incisor||9-13 months||7-8 years|
|Upper canine||16-22 months||10-12 years|
|Upper first molar||13-19 months||9-11 years|
|Upper second molar||25-33 months||10-12 years|
|Lower Central incisor||6-10 months||6-7 years|
|Lower lateral incisor||10-16 months||7-8 years|
|Lower canine||17-23 months||9-12 years|
|Lower first molar||14-18 months||9-11 years|
|Lower second molar||23-31 months||10-12 years|
**** American Dental Association *****
What are permanent teeth and when they start to appear in the mouth?
As the name suggests these teeth don’t change after eruption and if lost will not be replaced naturally by other tooth.
They are 32 in number (including the wisdom teeth). Permanent teeth start to replace primary ones at around age 6 years. At the same time the first permanent molar will erupt behind the primary second molar.
Permanent teeth are divided into 4 categories:
Incisor: 2 on each side and replacing the 2 primary incisors
Canine: 1 on each side and will replace the primary canine
Premolar: 2 on each side and replace the primary molars
Molar: 3 on each side and do not replace any primary teeth
When each permanent tooth erupts in the mouth?
The table below shows each permanent tooth and its eruption time. As well which primary teeth they replace.
|Permanent tooth||Eruption time||Replaced primary tooth|
|Upper Central incisor||7-8 years||Primary central incisor|
|Upper Lateral incisor||8-9 years||Primary lateral incisor|
|Upper canine||11-12 years||Primary canine|
|Upper first premolar||10-11 years||Primary first molar|
|Upper Second premolar||10-12 years||Primary second molar|
|Upper first molar||6-7 years||Doesn’t replace any primary tooth|
|Upper second molar||12-13 years||Doesn’t replace any primary tooth|
|Upper third molar||17-21 years||Doesn’t replace any primary tooth|
|Lower Central incisor||6-7 years||Primary central incisor|
|Lower lateral incisor||7-8 years||Primary lateral incisor|
|Lower canine||9-10 years||Primary canine|
|Lower first premolar||10-12 years||Primary first molar|
|Lower second premolar||11-12 years||Primary second molar|
|Lower first molar||6-7 years||Doesn’t replace any primary tooth|
|Lower second molar||11-13 years||Doesn’t replace any primary tooth|
|Lower third molar||17-21 years||Doesn’t replace any primary tooth|
*** American Dental Association ***