Process during which the crown of a developing tooth moves from its place within the alveolar process to the occlusal plane

2. TOPIC OUTLINE
TOPIC OUTLINE

3. ERUPTION
ERUPTION
Process during which the crown of a
developing tooth moves from its place
within the alveolar process to the occlusal
plane
Process during which the crown of a
developing tooth moves from its place
within the alveolar process to the occlusal
plane

4. ERUPTION
ERUPTION
Actual movement of the tooth towards the
occlusal plane
Actual movement of the tooth towards the
occlusal plane
period of
period of
ACTIVE ERUPTION
ACTIVE ERUPTION
PASSIVE ERUPTION
PASSIVE ERUPTION
Gradual exposure of the crown and later of
the root by gradual recession of the gingiva
Gradual exposure of the crown and later of
the root by gradual recession of the gingiva

5. PHASES OF
ERUPTION
PHASES OF
ERUPTION
pre-eruptive
toothmovement
pre-eruptive
toothmovement
eruptivetooth
movement
eruptivetooth
movement
post-eruptive
toothmovement
post-eruptive
toothmovement
1.
1.
2.
2.
3.
3.

6. pre-eruptive
tooth movement
pre-eruptive
tooth movement
Change in position that a
tooth germ undergoes
during the bell stage
Bodily displacement of the
entire tooth germ
Occurs before the germ is
enclosed within its bony
crypt
Teeth are placed in position
within the jaw for eruptive
movement
Total bodily movement
of the tooth germ
Growth
Change in position that a
tooth germ undergoes
during the bell stage
Bodily displacement of the
entire tooth germ
Occurs before the germ is
enclosed within its bony
crypt
Teeth are placed in position
within the jaw for eruptive
movement
Total bodily movement
of the tooth germ
Growth

7. ERUPTIVE TOOTH
MOVEMENT
ERUPTIVE TOOTH
MOVEMENT
Made by a tooth to move from
its position within the bone of
the jaw to its functional
position in occlusion
It has two phases:
1
1.
.Phase of Prefunctional tooth
movement
2
2.
.Phase of Functional Tooth
movement
Made by a tooth to move from
its position within the bone of
the jaw to its functional
position in occlusion
It has two phases:
1.Phase of Prefunctional tooth
movement
2.Phase of Functional Tooth
movement

8. PRE-FUNCTIONAL
TOOTH MOVEMENT
PRE-FUNCTIONAL
TOOTH MOVEMENT
Occlusally directed eruption
that begins with root
formation and ends when the
tooth reaches the occlusal
plane and breaks through the
gingiva
Occlusally directed eruption
that begins with root
formation and ends when the
tooth reaches the occlusal
plane and breaks through the
gingiva

9. Three major events that occur:
1.Migration of the tooth towards oral
epithelium
CUSHION HAMMOCK LIGAMENT
Differentiation of dental sac into
strong bundles of fiber with spaces
in between containing mucoid fluid
Three major events that occur:
1.Migration of the tooth towards oral
epithelium
CUSHION HAMMOCK LIGAMENT
Differentiation of dental sac into
strong bundles of fiber with spaces
in between containing mucoid fluid
GUBERNACULAR CORD/DENTIS
Strands of fibrous tissue with
remnants of the dental
lamina
Connection between follicle
of successional teeth and
lamina propria of the oral
mucosa
GUBERNACULAR CANALS
Contains gubernacular cords
Holes in the jaws on the
lingual aspect of the
deciduous teeth
2. Emergence of the crown tip
into the oral cavity
3. First occlusal contact
GUBERNACULAR CORD/DENTIS
Strands of fibrous tissue with
remnants of the dental
lamina
Connection between follicle
of successional teeth and
lamina propria of the oral
mucosa
GUBERNACULAR CANALS
Contains gubernacular cords
Holes in the jaws on the
lingual aspect of the
deciduous teeth
2. Emergence of the crown tip
into the oral cavity
3. First occlusal contact

10. c) Process of eruption decreases
because it is supposed by
occlusal contact.
d) Gradual working of tooth
tissues is compensated by
continuous vertical eruption and
mesial drift.
e) Appositional growth of
cementum is continuous along the
root.
c) Process of eruption decreases
because it is supposed by
occlusal contact.
d) Gradual working of tooth
tissues is compensated by
continuous vertical eruption and
mesial drift.
e) Appositional growth of
cementum is continuous along the
root.
FUNCTIONAL
TOOTH MOVEMENT
FUNCTIONAL
TOOTH MOVEMENT
All changes in position that a
functioning tooth undergoes
during its intra-oral existence.
a) As teeth meet the
antagonist there are forces
applied that stimulate the
bone formation and
strengthening of the
periodontal ligament.
b) There is continuous vertical
eruption or movement of teeth
in the oral cavity. The
movement is mesially and
occlusally.
All changes in position that a
functioning tooth undergoes
during its intra-oral existence.
a) As teeth meet the
antagonist there are forces
applied that stimulate the
bone formation and
strengthening of the
periodontal ligament.
b) There is continuous vertical
eruption or movement of teeth
in the oral cavity. The
movement is mesially and
occlusally.

11. FOUR POSSIBLE MECHANISMS OF ERUPTIVE TOOTH
MOVEMENT ARE CURRENTLY FAVORED,
thoughtheyarenotnecessarilymutuallyexclusive:
1. ROOT FORMATION, in which
the growing root is
accommodated by occlusal
movement of the crown.
2. HYDROSTATIC PRESSURE,
whereby local increases in tissue
fluid pressure in periapical
tissues push the tooth occlusally.
3. BONE REMODELLING,
selective deposition and
resorption of bone around the
tooth.
4. PERIODONTAL LIGAMENT, a
pulling of the tooth into occlusion
by the cells or fibers (or both) of
the periodontal ligament.
1. ROOT FORMATION, in which
the growing root is
accommodated by occlusal
movement of the crown.
2. HYDROSTATIC PRESSURE,
whereby local increases in tissue
fluid pressure in periapical
tissues push the tooth occlusally.
3. BONE REMODELLING,
selective deposition and
resorption of bone around the
tooth.
4. PERIODONTAL LIGAMENT, a
pulling of the tooth into occlusion
by the cells or fibers (or both) of
the periodontal ligament.

12. post-eruptive
tooth MOVEMENT
post-eruptive
tooth MOVEMENT
ACCOMODATION
FOR
GROWTH
ACCOMODATION
FOR
GROWTH
COMPENSATION
FOROCCLUSAL
WEAR
COMPENSATION
FOROCCLUSAL
WEAR
ACCOMODATIONFOR
INTERPROXIMALWEAR
ACCOMODATIONFOR
INTERPROXIMALWEAR
Are those made by the tooth after it has reached its functional
position in the occlusal plane.
They may be divided into 3 categories:
Are those made by the tooth after it has reached its functional
position in the occlusal plane.
They may be divided into 3 categories:

13. ACCOMODATION
FOR
GROWTH
ACCOMODATION
FOR
GROWTH
Posteruptive tooth movements
accommodating jaw growth occur mainly
between ages 14 and 18, completing by the
end of the 2nd decade.
These movements involve bone formation
at the alveolar crest and socket floor to
match jaw height increase.
Tooth apices shift 2–3 mm away from the
inferior dental canal, with changes
occurring earlier in girls due to earlier
condylar growth spurts.
Posteruptive tooth movements
accommodating jaw growth occur mainly
between ages 14 and 18, completing by the
end of the 2nd decade.
These movements involve bone formation
at the alveolar crest and socket floor to
match jaw height increase.
Tooth apices shift 2–3 mm away from the
inferior dental canal, with changes
occurring earlier in girls due to earlier
condylar growth spurts.
COMPENSATION
FOROCCLUSAL
WEAR
COMPENSATION
FOROCCLUSAL
WEAR
Axial tooth movement that
compensates for occlusal wear
is driven by the same
mechanism as tooth eruption,
primarily involving the
periodontal ligament (PDL).
While cementum deposition at
the apex is often cited, it occurs
after the tooth has moved,
reinforcing the key role of the
PDL in initiating movement.
Axial tooth movement that
compensates for occlusal wear
is driven by the same
mechanism as tooth eruption,
primarily involving the
periodontal ligament (PDL).
While cementum deposition at
the apex is often cited, it occurs
after the tooth has moved,
reinforcing the key role of the
PDL in initiating movement.

14. Interproximal wear occurs at contact points between teeth and can
exceed 7 mm in the mandible. This is compensated by mesial
(approximal) drift, where teeth gradually shift toward the midline.
Mesial drift and an understanding of its probable causes are
important to the practice of orthodontics, since the maintenance
of tooth position after the treatment depends on the extent of such
drift. The forces bringing about mesial drift are multifactorial and
include:
An anterior component of occlusal force.
Soft tissue pressure
Contraction of the transseptal ligament between teeth.
Interproximal wear occurs at contact points between teeth and can
exceed 7 mm in the mandible. This is compensated by mesial
(approximal) drift, where teeth gradually shift toward the midline.
Mesial drift and an understanding of its probable causes are
important to the practice of orthodontics, since the maintenance
of tooth position after the treatment depends on the extent of such
drift. The forces bringing about mesial drift are multifactorial and
include:
An anterior component of occlusal force.
Soft tissue pressure
Contraction of the transseptal ligament between teeth.
ACCOMODATIONFOR
INTERPROXIMALWEAR
ACCOMODATIONFOR
INTERPROXIMALWEAR

15. 1
1.
. Growth of Root. The proliferating root impinges on a fixed base,
causing force to the developing not, directing it occlusally.
2
2.
. Pressure from vascular beds in pulp and periapical tissues during
construction of pulp.
3
3.
. Apposition and resorption of bone.
4
4.
. Periodontal ligament traction.
5
5.
. Pressure from muscular action.
6
6.
. Control of endocrine glands.
7
7.
. Effect of nutrition.
8
8.
. Inherent tendency of teeth to erupt.
1. Growth of Root. The proliferating root impinges on a fixed base,
causing force to the developing not, directing it occlusally.
2. Pressure from vascular beds in pulp and periapical tissues during
construction of pulp.
3. Apposition and resorption of bone.
4. Periodontal ligament traction.
5. Pressure from muscular action.
6. Control of endocrine glands.
7. Effect of nutrition.
8. Inherent tendency of teeth to erupt.
CAUSES
CAUSES

16. CAUSES
CAUSES
SEQUENCE
SEQUENCE
AND
CHRONOLOGY
CHRONOLOGY
The timing of development and eruption of primary and
permanent teeth is determined by overall body growth and how
the jaws relate to the facial bones.
While the primary teeth are forming, erupting, and working, the
permanent teeth are also beginning to develop.
The timing of development and eruption of primary and
permanent teeth is determined by overall body growth and how
the jaws relate to the facial bones.
While the primary teeth are forming, erupting, and working, the
permanent teeth are also beginning to develop.
OF TOOTH ERUPTION

17. SEQUENCE
SEQUENCE
AND
CHRONOLOGY
CHRONOLOGY
OF TOOTH ERUPTION
A primary tooth takes
about 2 to 4 years to
fully form—from the
early tooth germ stage
to the completion of the
root apex.
For about 4 years (from
2.5 to 6.5 years old), the
primary teeth alone
handle chewing.
A primary tooth takes
about 2 to 4 years to
fully form—from the
early tooth germ stage
to the completion of the
root apex.
For about 4 years (from
2.5 to 6.5 years old), the
primary teeth alone
handle chewing.
A permanent tooth takes about 12
years to develop fully from the
tooth germ to apex formation.
The replacement of primary teeth
is usually completed between 10
and 13 years of age.
The order and timing of tooth
development and eruption follow
the growth of the jaws.
A permanent tooth takes about 12
years to develop fully from the
tooth germ to apex formation.
The replacement of primary teeth
is usually completed between 10
and 13 years of age.
The order and timing of tooth
development and eruption follow
the growth of the jaws.

19. PRIMARY TEETH (IN
ORDER OF ERUPTION)
BEGINNING
CALCIFICATION
CROWN COMPLETED
POSTNATALLY (MO)
APPEARANCE IN THE
ORAL CAVITY
(ERUPTION TIME) (MO)
ROOT COMPLETED
TIME (YR)
LOWER CENTRAL
INCISOR
3–4 2–3 6 1–2
LOWER LATERAL
INCISOR
3–4 2 7 ½ 1–2
UPPER CENTRAL
INCISOR
4 2–3 9 2
UPPER LATERAL
INCISOR
4 3 7 1–2
UPPER FIRST MOLAR 4 6 14 2–3
LOWER FIRST MOLAR 4 6 12 2–3
UPPER CANINE 4–5 9 18 3
LOWER CANINE 4–5 9 16 3
LOWER SECOND MOLAR 5 10 20 3
UPPER SECOND MOLAR 5 11 24 3

20. PERMANENT TEETH (IN
ERUPTION SEQUENCE)
BEGINNING
CALCIFICATION
CROWN COMPLETED
(YR)
APPEARANCE IN ORAL
CAVITY (ERUPTION
TIME) (YR)
LOWER FIRST MOLAR BIRTH 3–4 6–7
UPPER FIRST MOLAR BIRTH 4–5 6–7
LOWER CENTRAL INCISOR 3–4 MO 4 6–7
UPPER CENTRAL INCISOR 3–4 MO 5 7–8
LOWER LATERAL INCISOR 3–4 MO 4–5 7–8
UPPER LATERAL INCISOR 10–12 MO 4–5 8–9
LOWER CANINE 4–5 MO 5–6 9–10

21. PERMANENT TEETH (IN
ERUPTION SEQUENCE)
BEGINNING
CALCIFICATION
CROWN COMPLETED
(YR)
APPEARANCE IN ORAL
CAVITY (ERUPTION
TIME) (YR)
UPPER CANINE 4–5 MO 6–7 11–12
FIRST PREMOLAR
(UPPER & LOWER)
1–2 YR
5–6 (LOWER), 6–7
(UPPER)
10–11 (LOWER), 10–11
(UPPER)
SECOND PREMOLAR
(UPPER & LOWER)
2–3 YR 7–8
10–12 (LOWER), 10–12
(UPPER)
LOWER SECOND MOLAR 2–3 YR 7–8 11–13
UPPER SECOND MOLAR 2–3 YR 7–8 12–13
LOWER THIRD MOLAR 8–10 YR 12–16 17–21
UPPER THIRD MOLAR 7–9 YR 12–16 17–21

22. SHEDDING
SHEDDING
OR EXFOLIATION
OR EXFOLIATION
Physiological elimination
of deciduous teeth prior to
their replacement by
permanent teeth
Humans are considered
diphyodont
Physiological elimination
of deciduous teeth prior to
their replacement by
permanent teeth
Humans are considered
diphyodont
DIPHYODONT
possess 2 detentitions,
primary and permanent
set
DIPHYODONT
possess 2 detentitions,
primary and permanent
set

23. teeth in the
teeth in the
Smaller and fewer
Conform with the small
jaws of the infant
Primary dentition
function for a brief
period from 2 to 8 yrs of
age
Smaller and fewer
Conform with the small
jaws of the infant
Primary dentition
function for a brief
period from 2 to 8 yrs of
age
primary dentition
primary dentition

24. teeth in the
teeth in the
Larger and more
numerous
Accommodate the
larger jaws of the adult
Larger and more
numerous
Accommodate the
larger jaws of the adult
PERMANENT DENTITION
PERMANENT DENTITION

25. Mixed
dentition
period
Mixed
dentition
period
When both dentitions are present,
extend from 5 to 15 years of age
Only part of the primary tooth roots
are present since it undergo resorption
and only permanent root are present
In this way, nearly 50 teeth can be
present in the jaws during 4-year
period
When both dentitions are present,
extend from 5 to 15 years of age
Only part of the primary tooth roots
are present since it undergo resorption
and only permanent root are present
In this way, nearly 50 teeth can be
present in the jaws during 4-year
period
On the average of exchange
of teeth required:
On the average of exchange
of teeth required:
GIRLS: 3.6 years
BOYS: 4.6 years
GIRLS: 3.6 years
BOYS: 4.6 years
Both natural loss of the
deciduous teeth differ in:
Both natural loss of the
deciduous teeth differ in:
Boys than in girls (occurs earlier
in girls)
Maxillary than mandible
Boys than in girls (occurs earlier
in girls)
Maxillary than mandible

26. TOOTHLESS
TOOTHLESS
Interval averaging 1 month between
exfoliation of deciduous tooth and
eruption of the corresponding
succedaneous tooth
Interval averaging 1 month between
exfoliation of deciduous tooth and
eruption of the corresponding
succedaneous tooth

27. Cells that is directly involved during
shedding
Capable of resorbing all dental hard tissue
including enamel
They have a ruffled border and sealing
zone.
This is most commonly found on the
surface of roots where it reabsorbs
cementum and dentin
Cells that is directly involved during
shedding
Capable of resorbing all dental hard tissue
including enamel
They have a ruffled border and sealing
zone.
This is most commonly found on the
surface of roots where it reabsorbs
cementum and dentin
ODONTOCLAST
ODONTOCLAST

28. The dental pulp and PDL are associated with:
The dental pulp and PDL are associated with:
Little known about resorption of dental hard tissue
Less in know about resorption of soft tissues
This shows that the loss of Periodontal Ligament fibers is abrupt
Little known about resorption of dental hard tissue
Less in know about resorption of soft tissues
This shows that the loss of Periodontal Ligament fibers is abrupt
1
1.
.Fibroblasts accumulate intracellular collagen
2
2.
.Ligament fibroblasts exhibit morphologic features characteristic
of apoptotic cell death
1.Fibroblasts accumulate intracellular collagen
2.Ligament fibroblasts exhibit morphologic features characteristic
of apoptotic cell death
CELL DEATH assumes at least 2 forms:
CELL DEATH assumes at least 2 forms:

29. Shedding of primary teeth happens when eruption
and root growth of permanent teeth begin.
It is strictly coordinated chronologically –
meaning permanent teeth grow right on time to
push primary teeth out.
Shedding of primary teeth happens when eruption
and root growth of permanent teeth begin.
It is strictly coordinated chronologically –
meaning permanent teeth grow right on time to
push primary teeth out.

30. Is resorbed by osteoclasts and structurally identical
odontoclasts
Is resorbed by osteoclasts and structurally identical
odontoclasts
Is resorbed by fibroblasts and macrophages
Is resorbed by fibroblasts and macrophages

31. Resorption starts a few years before the
deciduous tooth falls out.
Begins immediately after completion of their root
formation.
Usually begins at the apical and lingual parts of
the root.
Resorption starts a few years before the
deciduous tooth falls out.
Begins immediately after completion of their root
formation.
Usually begins at the apical and lingual parts of
the root.
wherein;
wherein;
Starts between the roots of deciduous incisors and canines.
May also begin apical to the roots of the deciduous tooth.
Permanent molars push from underneath, while premolars
develop between the roots.
Starts between the roots of deciduous incisors and canines.
May also begin apical to the roots of the deciduous tooth.
Permanent molars push from underneath, while premolars
develop between the roots.

32. Secondary incisors and canines move occlusally
and facially
Germs of premolars begin between the deciduous
molars and later move away occlusally (towards
the surface).
Tooth germ of the permanent tooth remains
behind the deciduous tooth.
Secondary incisors and canines move occlusally
and facially
Germs of premolars begin between the deciduous
molars and later move away occlusally (towards
the surface).
Tooth germ of the permanent tooth remains
behind the deciduous tooth.

33. Resorptive process is not continuous
Many nucleated odontoclasts appear along honeycomb-
like lacunae on the tooth surface, alternating with resting
phases
Resorptive process is not continuous
Many nucleated odontoclasts appear along honeycomb-
like lacunae on the tooth surface, alternating with resting
phases
Root is often resorbed on the opposite side and in
many other places at the same time:
Root is often resorbed on the opposite side and in
many other places at the same time:
RESTING
PHASE
RESTING
PHASE
RESTINGENDOF
RESORPTIVE
PHASE
RESTINGENDOF
RESORPTIVE
PHASE

34. The crown of the deciduous tooth gets wiggled
and removed.
The junctional epithelium grows between the
deciduous tooth and gum, helping the shedding.
The crown of the deciduous tooth gets wiggled
and removed.
The junctional epithelium grows between the
deciduous tooth and gum, helping the shedding.
RESTING
PHASE
RESTING
PHASE
RESTINGENDOF
RESORPTIVE
PHASE
RESTINGENDOF
RESORPTIVE
PHASE
No resorption happens
Pitted root surface becomes smooth again due to
reparative deposition of lamellated cellular
fibrillar cementum
New positions of PDL and Alveolar bone may be
temporarily rebuilt
No resorption happens
Pitted root surface becomes smooth again due to
reparative deposition of lamellated cellular
fibrillar cementum
New positions of PDL and Alveolar bone may be
temporarily rebuilt
NOTE:
NOTE: The Pulpal Tissue (inside the tooth) usually stays
normal and unaffected during resorption.
The Pulpal Tissue (inside the tooth) usually stays
normal and unaffected during resorption.

35. CLINICAL CONSIDERATIONS
CLINICAL CONSIDERATIONS
1
1.
. ANKYLOSIS
1. ANKYLOSIS
Lack of eruption may
be related to fusio of
roots to the bony
socket or to the crown
of a permanent tooth
Lack of eruption may
be related to fusio of
roots to the bony
socket or to the crown
of a permanent tooth
May be due to the
lack of development
of the permanent
successor
May be due to the
lack of development
of the permanent
successor
2. RETAINED
PRIMARY TEETH
2. RETAINED
PRIMARY TEETH

36. CLINICAL CONSIDERATIONS
CLINICAL CONSIDERATIONS
3. TEETHING
3. TEETHING
4. PREDOMINANTLY
MANDIBULAR
DECIDUOUS
CENTRAL INCISOR
4. PREDOMINANTLY
MANDIBULAR
DECIDUOUS
CENTRAL INCISOR
Teeth that appear in
mouth at birth or
neonatally (up to 30
days after birth)
Teeth that appear in
mouth at birth or
neonatally (up to 30
days after birth)
Eruption of the deciduous teeth is
frequently accompanied by pain and
fever
Eruption of the deciduous teeth is
frequently accompanied by pain and
fever
5. Delayed eruption of teeth is far more common and
may be caused by congenital, systemic, or local
factors (predominating )
5. Delayed eruption of teeth is far more common and
may be caused by congenital, systemic, or local
factors (predominating )
CLINICAL CONSIDERATIONS
CLINICAL CONSIDERATIONS

37. N O N o H E R R E r A T I G L A O B A E N A
N O N o H E R R E r A T I G L A O B A E N A