- The document describes the development and eruption sequence of both primary (deciduous) and permanent teeth. - By age 2, all primary teeth have erupted but their roots are still forming, being complete by age 3. Primary teeth begin shedding at age 7 as permanent successors erupt. - Permanent first molars erupt around ages 6-7, followed by incisors and other molars, with most permanent teeth erupted by age 12 except the third molars.

2. College of DentistryCollege of Dentistry
Human Dentition IIHuman Dentition II
Deciduous and Permanent TeethDeciduous and Permanent Teeth
Dr. Hazem Al AjramiDr. Hazem Al Ajrami

4. From the previous table we can note that:From the previous table we can note that:
 Calcification of deciduous teeth begins beforeCalcification of deciduous teeth begins before
birth and only the 1birth and only the 1stst
permanent molars beginpermanent molars begin
calcification at birth.calcification at birth.
 Eruption means that the developing tooth willEruption means that the developing tooth will
move from the bony crypt to appear in the oralmove from the bony crypt to appear in the oral
cavity. This occurs for every tooth when itscavity. This occurs for every tooth when its
crown and cervical third of the root arecrown and cervical third of the root are
completed. While the tooth complete its eruptioncompleted. While the tooth complete its eruption
to reach the occlusal plane the remaining part ofto reach the occlusal plane the remaining part of
the root will be almost completed.the root will be almost completed.
 Sequence of eruption for the deciduous teethSequence of eruption for the deciduous teeth
occur as A > B > D > C > E (note thatoccur as A > B > D > C > E (note that
mandibular tooth precedes the maxillary one ofmandibular tooth precedes the maxillary one of
the same type).the same type).

6.  So by the age of 2 years all the deciduous teethSo by the age of 2 years all the deciduous teeth
almost erupted, but their roots are allalmost erupted, but their roots are all
completed by the age of 3 years.completed by the age of 3 years.
 Root formation of deciduous tooth = eruptionRoot formation of deciduous tooth = eruption
+ 1.+ 1.
 Shedding means resorption of deciduous rootShedding means resorption of deciduous root
by the pressure done by the eruptiveby the pressure done by the eruptive
movement of its successor till the deciduousmovement of its successor till the deciduous
tooth becomes weak, loose and exfoliated totooth becomes weak, loose and exfoliated to
be replaced by its successor.be replaced by its successor.

8.  Shedding of deciduous teeth begins at 7 yearsShedding of deciduous teeth begins at 7 years
for the central incisors and ends at 10 years forfor the central incisors and ends at 10 years for
second molars (note that shedding date =second molars (note that shedding date =
eruption date of successor).eruption date of successor).
 Beginning of root resorption of deciduousBeginning of root resorption of deciduous
teeth = shedding - 3 years (except lowerteeth = shedding - 3 years (except lower
canine - 1 year).canine - 1 year).
 Sequence of eruption for permanent teethSequence of eruption for permanent teeth
occur as:occur as:
In the mandible 6-1-2-3-4-5-7-8.In the mandible 6-1-2-3-4-5-7-8.
In the maxilla 6-1-2-4-3-5-7-8.In the maxilla 6-1-2-4-3-5-7-8.

10.  Root formation date for permanent teeth =Root formation date for permanent teeth =
eruption + 3 years.eruption + 3 years.
 Crown completed for permanent teeth =Crown completed for permanent teeth =
eruption - 3 years.eruption - 3 years.
 From 6 months to 6 years → pure deciduousFrom 6 months to 6 years → pure deciduous
dentition.dentition.
 From 6 years to 12 years → mixed dentition.From 6 years to 12 years → mixed dentition.
 From 12 years → pure permanent dentition.From 12 years → pure permanent dentition.

12. At early dates of development; x-rayAt early dates of development; x-ray
examination to the jaws can help to know theexamination to the jaws can help to know the
condition of the teeth before eruption. We willcondition of the teeth before eruption. We will
take the mandible as a model for description.take the mandible as a model for description.

14. Condition of teeth at birth:Condition of teeth at birth:
The newly born child has no erupted teeth, but x-The newly born child has no erupted teeth, but x-
ray examination will reveal the different amount ofray examination will reveal the different amount of
calcified teeth structures.calcified teeth structures.
The roof of the bony crypts are widely opened atThe roof of the bony crypts are widely opened at
birth so that these calcified parts may fall out of thebirth so that these calcified parts may fall out of the
dried specimen. Later on nearly after 15 days thedried specimen. Later on nearly after 15 days the
edges of the bony crypts have grown and formededges of the bony crypts have grown and formed
roofs, so that these calcified tooth parts will notroofs, so that these calcified tooth parts will not
drop out the dry specimen.drop out the dry specimen.

16. Condition of teeth at birth:Condition of teeth at birth:
 Deciduous teeth:Deciduous teeth:
Half crown of A.Half crown of A.
Less than half of crown of B.Less than half of crown of B.
Tip of the cusp of C.Tip of the cusp of C.
Occlusal 1/3 (united cusps) of D.Occlusal 1/3 (united cusps) of D.
Cusp tips (separated cusps) of E.Cusp tips (separated cusps) of E.
 Permanent teeth:Permanent teeth:
The mesiolingual cusp of lower 6.The mesiolingual cusp of lower 6.

18. Condition of teeth at 6 months:Condition of teeth at 6 months:
 Deciduous teeth:Deciduous teeth:
The A starts to erupt in the oral cavity withThe A starts to erupt in the oral cavity with
1/3 of its root is formed.1/3 of its root is formed.
The crown and small portion of root of B isThe crown and small portion of root of B is
formed.formed.
Parts of the crowns of C, D, and E.Parts of the crowns of C, D, and E.

20.  Permanent teeth:Permanent teeth:
The incisal third of 1, 2.The incisal third of 1, 2.
Tip of the cusp of 3.Tip of the cusp of 3.
Separate cusps of the 6.Separate cusps of the 6.
(NB. The(NB. The 22 shows beginning of calcificationshows beginning of calcification
at 10 - 12 m.).at 10 - 12 m.).

21. Condition of the teeth at 3 years:Condition of the teeth at 3 years:
 Deciduous teeth:Deciduous teeth:
All deciduous teeth are erupted with fullyAll deciduous teeth are erupted with fully
formed roots (The upper and lower teeth are informed roots (The upper and lower teeth are in
occlusion).occlusion).
 Permanent teeth:Permanent teeth:
More than half of the crown of 1 & 2 are notMore than half of the crown of 1 & 2 are not
yet completed.yet completed.
Half the crown of 3 is formed.Half the crown of 3 is formed.

23.  Small parts of the crown of 4 & 5 are calcified.Small parts of the crown of 4 & 5 are calcified.
 Crown of the 6 is completed.Crown of the 6 is completed.
 Crown of the 7 begins to calcify so separateCrown of the 7 begins to calcify so separate
cusps are formed.cusps are formed.

24. Condition of the teeth at 6 years:Condition of the teeth at 6 years:
 Deciduous teeth:Deciduous teeth:
A may be shedded and replaced by 1.A may be shedded and replaced by 1.
B, C, D show different amount of rootB, C, D show different amount of root
resorption.resorption.
 Permanent teeth:Permanent teeth:
1 may be erupted and has 1/3 of its root is1 may be erupted and has 1/3 of its root is
formed.formed.
2 has less than 1/3 of its root is formed.2 has less than 1/3 of its root is formed.

26.  3, 4, 5 have their crowns may be completed.3, 4, 5 have their crowns may be completed.
 6 is erupted with 1/3 of its root is formed.6 is erupted with 1/3 of its root is formed.
 7 its crown is not yet completed.7 its crown is not yet completed.

27. Condition of teeth at 9 years:Condition of teeth at 9 years:
 Deciduous teeth:Deciduous teeth:
All the deciduous incisors are shedded.All the deciduous incisors are shedded.
While in molars most of their roots showWhile in molars most of their roots show
resorption (shedding of E at 10 y.).resorption (shedding of E at 10 y.).
 Permanent teeth:Permanent teeth:
1 is erupted and its root is completed.1 is erupted and its root is completed.
2 is erupted and most of its root is formed2 is erupted and most of its root is formed
but not yet completed.but not yet completed.

29.  3 may be erupted with 1/3 of its root is formed3 may be erupted with 1/3 of its root is formed
(it may be erupted at 12 y.).(it may be erupted at 12 y.).
 4, 5 not yet erupted and less than 1/3 of their4, 5 not yet erupted and less than 1/3 of their
roots are formed.roots are formed.
 6 is erupted and its root are completed.6 is erupted and its root are completed.
 7 shows crown completion and small part of7 shows crown completion and small part of
its roots is formed.its roots is formed.
 8 begins to be calcified (calcified separate8 begins to be calcified (calcified separate
cusps are shown).cusps are shown).

30. Condition of teeth at 12 years:Condition of teeth at 12 years:
 Deciduous teeth:Deciduous teeth:
All the deciduous teeth are shedded and if anyAll the deciduous teeth are shedded and if any
deciduous tooth remains after this age it isdeciduous tooth remains after this age it is
consider to be retained deciduous tooth.consider to be retained deciduous tooth.
 Permanent teeth:Permanent teeth:
All the permanent teeth are erupted except theAll the permanent teeth are erupted except the
8.8.
All the erupted permanent teeth haveAll the erupted permanent teeth have
completed roots except 7 which has 1/3 of itscompleted roots except 7 which has 1/3 of its
roots is formed.roots is formed.