development of dentition-dentistry undergraduate

development of dentition

1. DEVELOPMENT OF THE
DENTITION

2. THE DECIDUOUS DENTITION

Resorption of the roots begins :
« for incisors at 4

* for molars at about 6 and

* for canines at 7 years of age.

Also, if a permanent tooth is missing, the
primary predecesser usually undergoes
root resorption, but in the later time.

3. THE DECIDUOUS DENTITION

Resorption of the roots begins :
« for incisors at 4

* for molars at about 6 and

* for canines at 7 years of age.

Also, if a permanent tooth is missing, the
primary predecesser usually undergoes
root resorption, but in the later time.

4. THE DECIDUOUS DENTITION

Resorption of the roots begins :
« for incisors at 4

* for molars at about 6 and

* for canines at 7 years of age.

Also, if a permanent tooth is missing, the
primary predecesser usually undergoes
root resorption, but in the later time.

5. THE DECIDUOUS DENTITION

Resorption of the roots begins :
« for incisors at 4

* for molars at about 6 and

* for canines at 7 years of age.

Also, if a permanent tooth is missing, the
primary predecesser usually undergoes
root resorption, but in the later time.

6. THE DECIDUOUS DENTITION

Resorption of the roots begins :
« for incisors at 4

* for molars at about 6 and

* for canines at 7 years of age.

Also, if a permanent tooth is missing, the
primary predecesser usually undergoes
root resorption, but in the later time.

7. THE DECIDUOUS DENTITION

Resorption of the roots begins :
« for incisors at 4

* for molars at about 6 and

* for canines at 7 years of age.

Also, if a permanent tooth is missing, the
primary predecesser usually undergoes
root resorption, but in the later time.

8. THE DECIDUOUS DENTITION

Resorption of the roots begins :
« for incisors at 4

* for molars at about 6 and

* for canines at 7 years of age.

Also, if a permanent tooth is missing, the
primary predecesser usually undergoes
root resorption, but in the later time.

9. THE DECIDUOUS DENTITION

Resorption of the roots begins :
« for incisors at 4

* for molars at about 6 and

* for canines at 7 years of age.

Also, if a permanent tooth is missing, the
primary predecesser usually undergoes
root resorption, but in the later time.

10. THE DECIDUOUS DENTITION

Resorption of the roots begins :
« for incisors at 4

* for molars at about 6 and

* for canines at 7 years of age.

Also, if a permanent tooth is missing, the
primary predecesser usually undergoes
root resorption, but in the later time.

11. THE DECIDUOUS DENTITION

Resorption of the roots begins :
« for incisors at 4

* for molars at about 6 and

* for canines at 7 years of age.

Also, if a permanent tooth is missing, the
primary predecesser usually undergoes
root resorption, but in the later time.

12. THE MIXED DENTITION

« At the time of eruption
2/3 of the root is
generally formed.
Thereafter, 1,5 -3
years are needed to
complete root length
and even longer to
close the root apices
to the mature size.

13. THE MIXED DENTITION

« At the time of eruption
2/3 of the root is
generally formed.
Thereafter, 1,5 -3
years are needed to
complete root length
and even longer to
close the root apices
to the mature size.

14. THE MIXED DENTITION

« At the time of eruption
2/3 of the root is
generally formed.
Thereafter, 1,5 -3
years are needed to
complete root length
and even longer to
close the root apices
to the mature size.

15. THE MIXED DENTITION

« At the time of eruption
2/3 of the root is
generally formed.
Thereafter, 1,5 -3
years are needed to
complete root length
and even longer to
close the root apices
to the mature size.

16. REPLACEMENT OF THE TEETH

The eruption can be divided into periods:

1. The first period means a replacement of
incisors, after which a break (usually 2
years) follows.

2. Atthe age of 10-12 years the second
period is performed. So the canines and
premolars erupt.

17. ERUPTION OF THE FIRST
PERMANENT MOLARS

« if there is enough space, the maxilla and mandible are
large, the right relationship of the first molars can be

achieved

« the bad situation is,
if the lower second
deciduous molar is
too wide in relation
to upper or there is
a class II relationship
and the positive
step is present.

18. ERUPTION OF THE FIRST
PERMANENT MOLARS

« if there is enough space, the maxilla and mandible are
large, the right relationship of the first molars can be

achieved

« the bad situation is,
if the lower second
deciduous molar is
too wide in relation
to upper or there is
a class II relationship
and the positive
step is present.

19. ERUPTION OF THE FIRST
PERMANENT MOLARS

« if there is enough space, the maxilla and mandible are
large, the right relationship of the first molars can be

achieved

« the bad situation is,
if the lower second
deciduous molar is
too wide in relation
to upper or there is
a class II relationship
and the positive
step is present.

20. ERUPTION OF THE FIRST
PERMANENT MOLARS

« if there is enough space, the maxilla and mandible are
large, the right relationship of the first molars can be

achieved

« the bad situation is,
if the lower second
deciduous molar is
too wide in relation
to upper or there is
a class II relationship
and the positive
step is present.

21. ERUPTION OF THE FIRST
PERMANENT MOLARS

« if there is enough space, the maxilla and mandible are
large, the right relationship of the first molars can be

achieved

« the bad situation is,
if the lower second
deciduous molar is
too wide in relation
to upper or there is
a class II relationship
and the positive
step is present.

22. ERUPTION OF THE FIRST
PERMANENT MOLARS

« if there is enough space, the maxilla and mandible are
large, the right relationship of the first molars can be

achieved

« the bad situation is,
if the lower second
deciduous molar is
too wide in relation
to upper or there is
a class II relationship
and the positive
step is present.

23. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

24. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

25. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

26. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

27. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

28. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

29. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

30. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

31. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

32. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

33. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

34. REPLACEMENT OF INCISORS
AA |

The lower incisors erupt before the uppers. It
causes the accelerated growth of mandible and
the “2th physiological reduction of overbite”.

36. THE SECOND PERIOD OF
REPLACEMENT

The order of eruption in mandible is: the canine, the first and
then the second premolar. The canine cannot drift distaly and
the space for it (because it is wider than its predecessor) is
made by accelerated growth of mandible. This is the cause of
the “3th physiological reduction of overbite”. The order of
eruption in maxilla is: the first premolar, the second premolar
and then the canine.

37. THE SECOND PERIOD OF
REPLACEMENT

The order of eruption in mandible is: the canine, the first and
then the second premolar. The canine cannot drift distaly and
the space for it (because it is wider than its predecessor) is
made by accelerated growth of mandible. This is the cause of
the “3th physiological reduction of overbite”. The order of
eruption in maxilla is: the first premolar, the second premolar
and then the canine.

38. THE SECOND PERIOD OF
REPLACEMENT

The order of eruption in mandible is: the canine, the first and
then the second premolar. The canine cannot drift distaly and
the space for it (because it is wider than its predecessor) is
made by accelerated growth of mandible. This is the cause of
the “3th physiological reduction of overbite”. The order of
eruption in maxilla is: the first premolar, the second premolar
and then the canine.

39. ERUPTION OF THE MOLARS

« The upper permanent molars develop in the maxillary tuberosity
with their occlusal surfaces facing distally and bucally. Posterior
growth in maxillary length is necessary to allow them to rotate
forwards and downwards into the line of the arch.

» The mandibular molars develop under the anterior border of the
ascending ramus of the mandible. Growth in the mandibular
lenght is necessary if the tooth is to have room to erupt.

45. = e >
to k

49. PERMANENT DENTITION

The upper arch is shaped like an elipse and that of lower like a parabole.

The mandibular teeth are set one inclined plane in advance of the maxillar
teeth. This is because the mandibular central incisor is smaller mesiodistally
than the maxillary central incisor. Thus every tooth occlude with two
antagonists except the lower central incisors and the upper third
molars.

The maxillary teeth are half a cusp to the buccal of the mandibular teeth.

Angle stated that the mesiobuccal cusp of the upper first molar occludes
with the intercuspal ses of the lower first molar. That relationship of
the first permanent molars is known as a key of occlusion.

The upper permanent canine falls into the embrasure between the
lower permanent canine and first premolar.

The lower incisor edges occlude with the cingulum plateau of the upper
incisors. Provided that the incisor inclinations are average this gives a
normal overbite of about one-third of the height of the lower incisor
crowns and an overjet of about 2 mm.