Human Dentition Or Teeth axiom February 26, 2015

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:

 

ToothErupt in the mouthShedding time
Upper Central Incisor8-12 Month6-7 years
Upper Lateral incisor9-13 months7-8 years
Upper canine16-22 months10-12 years
Upper first molar13-19 months9-11 years
Upper second molar25-33 months10-12 years
Lower Central incisor6-10 months6-7 years
Lower lateral incisor10-16 months7-8 years
Lower canine17-23 months9-12 years
Lower first molar14-18 months9-11 years
Lower second molar23-31 months10-12 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 toothEruption timeReplaced primary tooth
Upper Central incisor7-8 yearsPrimary central incisor
Upper Lateral incisor8-9 yearsPrimary lateral incisor
Upper canine11-12 yearsPrimary canine
Upper first premolar10-11 yearsPrimary first molar
Upper Second premolar10-12 yearsPrimary second molar
Upper first molar6-7 yearsDoesn’t replace any primary tooth
Upper second molar12-13 yearsDoesn’t replace any primary tooth
Upper third molar17-21 yearsDoesn’t replace any primary tooth
Lower Central incisor6-7 yearsPrimary central incisor
Lower lateral incisor7-8 yearsPrimary lateral incisor
Lower canine9-10 yearsPrimary canine
Lower first premolar10-12 yearsPrimary first molar
Lower second premolar11-12 yearsPrimary second molar
Lower first molar6-7 yearsDoesn’t replace any primary tooth
Lower second molar11-13 yearsDoesn’t replace any primary tooth
Lower third molar17-21 yearsDoesn’t replace any primary tooth

*** American Dental Association ***

Scroll to Top