The document discusses the development of dentition and occlusion from the embryonic stage through adulthood. It describes the formation of the dental lamina and how it gives rise to the deciduous and permanent teeth. Key stages of tooth development are outlined, including the bud, cap and bell stages of the enamel organ as well as root formation and development of occlusion.

1. Development of
dentition & occlusion
• Dr. Nabil Al-Zubair

2. Dental development
Six-week-old embryo
• Dental development usually
begins in the 5th or 6th week
of prenatal life.
A-mandibular process
B-maxillary process
C-lateral nasal processes
D-medial nasal process
E-naso-optic furrows

3. • The embryonic Oral Cavity is lined by Str. squ epithelium known as the Oral Ectoderm

4. Around the 6th week of intra-uterine life
(1) The infero-lateral border of the maxillary arch
&
(2) The supero-lateral of the mandibular arch
show
Localized proliferation
ORAL ECTODERM
Resulting in the Horse-shoe shaped
formation band of tissue
DENTAL LAMINA

5. (1) The infero-lateral border of the
maxillary arch &
(2) The supero-lateral of the mandibular
arch show
Localized proliferation
ORAL ECTODERM
Resulting in the Horse-shoe shaped band of tissue
formation
DENTAL
LAMINA
Around the 6th week of intra-uterine life

6. DENTAL LAMINA: Two meanings
first refers
From this
Thickening in the ectoderm
A secondary dental lamina
Grows down into the mesenchyme
At intervals
Dental Organs
Along this deep lamina
(tooth buds) form

7. DENTAL LAMINA: Two meanings
As the dental organs are established
the original surface lamina reverts to oral lining ectoderm
(differentiating into gingival epithelium)
the secondary lamina starts to disintegrate
leaving
The first dental organ Successional lamina
for the second tooth bud

8. ‫المالءة‬
DENTAL LAMINA
Plays an important role in the development of the dentition LAMINA = Sheet
‫صفيحة رقيقة‬
Tongue Dental lamina Vestibular lamina

9. • Formation of the deciduous tooth
germs occurs on the labial aspect
of the dental lamina (DL).
• The free tip of DL proliferates into
the ectomesenchyme as the
successional lamina (SL)
providing the anlage ‫ البداءة‬for a
permanent tooth.
•Dental papilla (DP), dental follicle (DF).

10. All teeth originate from the dental lamina
DECIDUOUS TEETH are formed by
DIRECT proliferation of the dental
lamina
PERMANENT MOLARS develops as a result of its DISTAL proliferation
Permanent teeth that replace the deciduous teeth form a lingual extension

11. All teeth originate from
the dental lamina DENTAL LAMINA will grow back to
form germs for 3 permanent molars
BONE
DECIDUOUS TEETH
formed by
10 TOOTH GERM
DIRECT proliferation of the
20 Successional TOOTH
dental lamina GERM on lingual side of 10
PERMANENT MOLARS
develops as a result of its
DISTAL proliferation SYMPHYSEAL
CARTILAGE
Permanent teeth that replace the deciduous teeth
form a lingual extension

12. All teeth originate from the dental lamina
DECIDUOUS TEETH are formed by
DIRECT proliferation of the dental
lamina
PERMANENT MOLARS develops as a result of its DISTAL proliferation
Permanent teeth that replace the deciduous teeth form a lingual extension

13. Mitotic area TOOTH PRIMORDIUM/GERM
BUD
The ectoderm in certain areas of the dental lamina
proliferates & form knobs-like structures that grow into
the underlying mesenchyma
Oral Ectoderm
knobs-like structures
Mesenchyme

14. Each of this knobs represents a future deciduous tooth & is called ENAMEL ORGAN
ENAMEL ORGAN
DENTAL LAMINA
TOOTH GERM
• The enamel organ passes through
a number of stages ultimately
forming the teeth

15. • Based on the shape of the enamel
organ, the development of teeth
BUD
can be divided into three stages
CAP
• They are the bud, cap & bell stage
Outer dental epithelium
DENTAL LAMINA
Stellate reticulum
Stratum
intermedium
BELL
TOOTH GERM
Inner dental epithelium

16. Stages of Tooth Development
• Dental lamina
• Bud
• Cap
• Bell

17. BUD STAGE
Oral ectoderm
(1) Thickening in the ectoderm
Next step to
the (2) downgrowths
of dental lamina
Formation of a BUD
from the dental lamina

18. BUD STAGE
This is the initial stage of tooth formation
where
The enamel organ
resembles
A small bud
Enamel organ

19. BUD STAGE The surrounding mesenchymal cells
result in
Condensation in TWO areas Proliferate
1- Immediately below the enamel organ
Dental Papilla
2- Surrounds the tooth bud &
the dental papilla
Dental Sac

20. 1- Immediately below
the enamel organ
Dental Papilla
2- Surrounds the tooth bud &
the dental papilla
Dental Sac

21. A: ENAMEL ORGAN
•The cells of the dental papilla C: DENTAL SAC
form the
DENTIN & PULP
while the dental sac forms
CEMENTUM &
PERIODONTAL LIGAMENT
B: DENTAL PAPILLA

22. BUD STAGE
Usually 10 tooth buds are in each dental arch
give rise to
Future Primary teeth BONE
10 TOOTH GERM
 Tooth buds for 20 Successional TOOTH
GERM on lingual side of 10
Permanent Teeth form
b/w the 17th week of fetal
life through the age of 5. SYMPHYSEAL
CARTILAGE

23. DENTAL LAMINA Tooth Bud
Continue to proliferate
Resulting in
A CAP shaped
Enamel Organ

24. Continue to proliferate
Tooth Bud
Resulting in
A CAP shaped
Enamel Organ

25. CAP STAGE
• The tooth bud continues to proliferate
resulting in a cap shaped Enamel Organ
• This is characterized by a shallow
invagination on the under surface of the
bud

26. Cap Stage
This stage is also known as
Proliferation
(reproduction or multiplication)
in which
Cells of the tooth GROW
The tooth bud
Takes a hollowed caplike shape

27. The outer cells of the cap covering the Convexity are cuboidal & are called the
“OUTER ENAMEL EPITHELIUM”
The cells lining the Concavity of the cap
become tall columnar & are referred to as the
“INNER ENAMEL EPITHELIUM”

28. The central area of the enamel organ b/w the outer & inner enamel epithelium,
acquire more inter-cellular fluid & forms a cellular network called the
Stellate reticulum
Cap determines: position,
type, & size of tooth

29. Bell Stage
Due to uneven growth
ENAMEL ORGAN
(CAP)
BELL SHAPE
also known as Histodifferentiation
(the acquisition of tissue characteristics by
cell groups)

30. Bell Stage: DENTAL ORGAN: Cap,
becoming Bell stage
 The last period of growth is
 also known as
Histodifferentiation
(the acquisition of tissue
characteristics by cell
groups) or bell stage.

31. Bell stage
(5)
Dental papilla Odontoblasts
Outer dental epithelium Dentin
DENTAL LAMINA
(3) Stellate reticulum
(2)
Stratum intermedium
Stratum intermedium
TOOTH GERM
(1)
Inner dental epithelium
(4)
Ameloblasts Enamel

32. Bell stage
(5) Odontoblasts
Rich in capillary network dental papilla
Outer dental epithelium
(3) Stellate DENTAL LAMINA
reticulum
(2) Stratum
intermedium
TOOTH GERM
(1) Inner dental epithelium
Ameloblasts (4) Enamel P. fibres

33. TOOTH TISSUES: Sources
ENAMEL
DENTAL ORGAN DENTAL LAMINA
DENTINE
MESENCHYME
PULP
CEMENTUM
DENTAL PAPILLA
PDL
DENTAL SAC/FOLLICLE
ALVEOLAR BONE
A BONE

34. TOOTH TISSUES: Cell Sources
DENTAL LAMINA TOOTH
DENTAL ORGAN ENAMEL
Ameloblasts
DENTAL PAPILLA DENTINE
Odontoblasts
PULP
CT cells
DENTAL SAC/FOLLICLE CEMENTUM
Cementoblasts
PDL
Fibroblasts
ALVEOLAR BONE
A BONE
Osteoblasts & „clasts
Crest

35. Root Formation

36. Root formation
• Root development begins:
After the dentine & enamel formation
reaches the future cemento-enamel
junction
• The outer & inner enamel epithelium
join & form a sheath that helps in
molding the shape of the root
• This sheath is called the
“HERTWIG‟S EPITHELIAL ROOT
SHEATH “

37. Root Formation Cervical loop forms the epithelial
root sheath (of Hertwig)
Cervical loop
Dental papilla

38. Development of occlusion

39. Occlusion
• Occlusion is the relationship of the
mandibular and maxillary teeth
when closed or during excursive
movements of the mandible; when
the teeth of the mandibular arch
come into contact with the teeth of
the maxillary arch in any functional
relationship.

40. Periods of occlusal development

41. Occlusal development can be divided into
the following developmental periods:
1. Pre – dental period
2. The deciduous dentition period
3. The mixed dentition period
4. The permanent dentition period

43. Pre – dental period
 This is the period after birth
during which the neonate does not
have any teeth
 It usually lasts for 6 months after
birth

44. GUM PADS
• The alveolar processes at the time of
birth are known as gum pads
• The gum pads are:
(1) pink,
(2) firm &
(3) covered by a dense layer of fibrous
periosteum

45. GUM PADS
• They are HORSE-SHOE shaped
& develop in two parts:
(1) the labio-buccal portion &
(2) the lingual portion
• The two portions of the gum pads
are separated from each other by
a groove called the dental groove

46. GUM PADS Lateral sulcus
• The gum pads are divided into
TEN SEGMENTS by certain
grooves called
TRANSVERSE GROOVES
• Each of these segments consist of
one developing deciduous tooth
sac
• The gingival groove separates the
gum pads from the palate & floor
of the mouth
• The transverse groove b/w canine
& first deciduous molar segment is Transverse grooves
called the lateral sulcus

47. Lateral sulcus
• The lateral sulcus of the
mandibular arch is normally more
DISTAL to that of the maxillary arch
• The upper gum pad is both
(1) wider as well as
(2) longer than
the mandibular gum pad
Lateral sulcus

48. • Thus when the upper & lower gum
Complete overjet
pads are approximated, there is a
complete overjet all around
(1) Contact occurs b/w the upper &
lower gum pads in the first molar
region &
(2) A space exist b/w them in the
anterior region
• This infantile open bite is
Open bite
considered normal & it helps in
suckling

49. The status of dentition
• The neonate is without teeth for about
6 months of life
(1) At birth:
The gum pads are not sufficiently wide
to accommodate the developing
incisors which are crowded in their
crypts
(2) During the first year of life:
The gum pads grow rapidly permitting the
incisors to erupt in good alignment

50. The status of dentition
Very rarely teeth are found to have erupted at the birth time
• Such teeth that are present at the time of
birth are called NATAL TEETH
• Sometimes teeth erupt at an early age
• Teeth that are erupt during the first
month of age are called Neonatal teeth
• The natal & neonatal teeth are mostly
(1) LOCATED in the mandibular incisor
region &
(2) Show a familial tendency

51. The deciduous dentition period

52. Cause Aetiology
Pre – dental period (lasts for 6 (complete overjet)The upper
This is the period after
months after gum pad is both (1) wider as well as
birth during which the
birth) (2) longer than the mandibular gum
neonate does not have any
teeth  gum pads Ant. open bite
(divided into TEN Contact occurs b/w the upper
SEGMENTS) & lower gum pads in the first
molar region
 A space exist b/w them in the
anterior region
Deciduous dentition - Rarely endogenous
tongue thrust

53. Cause Aetiology
Deciduous dentition (lasts from 6 months 1. Spacing usually exists b/w the
deciduous teeth
The eruption begin at after birth to 6 yrs)
2. A normal feature of deciduous
about 6 months&  sequence of eruption dentition is a Flush Terminal
completed by 2 ½ - 3 ½ A–B–D–C–E Plane
years of age 3. A deep bite may occur in the
Initial Stages of development

54. The deciduous dentition period
• The initiation of primary tooth
buds occurs during the first 6
weeks of intra-uterine life
• The primary teeth begin to erupt
at the age of about 6 months
• The eruption of all primary teeth is
completed by 2 ½ - 3 ½ years of
age when the second deciduous
molars come into occlusion

55. DECIDUOUS DENTITION
5 months in
utero 2 yrs
(± 6 mos.)
7 months in
utero
3 yrs
PRENATAL
(± 6 mos.)
Birth
6 mos. 4 years
(± 2 mos.) (± 9 mos.)
9 mos.
(± 2 mos.) 5 yrs
(± 9 mos.)
1 year
(± 3 mos.)
6 years
(± 9 mos.)
18 months
(± 3 mos.)
EARLY CHILDHOOD
INFANCY (Pre-school age)

56. Eruption age & sequence of deciduous dentition
• The mandibular central incisors are
the first teeth to erupt into the oral
cavity
• They erupt around 6-7 months of age

57. The sequence of eruption of the deciduous dentition is:
A–B–D–C–E
Central Incisors (6 – 8 mo) Usual Order of Appearance:
Lateral Incisors (6 – 10 mo)
Canines (16 – 20 mo)
First Molars (10 – 15 mo)
Second Molars (2 ½ - 3 ½ years )
Mandibular Teeth Usually Precede Maxillary in order of Appearance

58. The primary dentition is usually established by 3 years of age on eruption of
the second deciduous molars
B/w 3 – 6 years of age, the dental arch is relatively stable & very few changes
occurs
Central Incisors (6 – 8 mo)
Lateral Incisors (6 – 10 mo)
Canines (16 – 20 mo)
First Molars (10 – 15 mo)
Second Molars (2 ½ - 3 ½ years )

59. DECIDUOUS DENTITION
1. Spacing usually exists b/w
the deciduous teeth
2. A normal feature of deciduous dentition
is a Flush Terminal Plane
3. A deep bite may occur in the
Initial Stages of development

60. 1 Spacing in deciduous dentition
Spacing usually exists b/w the
deciduous teeth
• These spaces are called
Physiological spaces or
Developmental spaces

61. Spacing in deciduous dentition
Spacing
• The presence of spaces in
the PRIMARY DENTITION is
important for the normal
development of the
PERMANENT DENTITION

62. Spacing in deciduous dentition
No Spacing
• Absence of spaces in the
primary dentition is an
indication that crowding of
teeth may occur when the
LARGER permanent teeth
erupt

63. 2 Flush terminal plane
• The mesio – distal relation b/w the
DISTAL SURFACE of the lower &
upper Second Deciduous Molars
is called the terminal plane
• A normal feature of deciduous
dentition is a Flush Terminal Plane
where the distal surfaces of the upper
& lower second deciduous molars are
in the same vertical plane

64. 3 Deep bite
• A deep bite may occur in the Initial
Stages of development
• The deep bite is accentuated by
the fact that the deciduous
incisors are more upright than
their successors
• The lower incisal edges often
contact the cingulum area of the
maxillary incisors

65. Deep bite
This deep bite is later Reduced
due to the following factors:
a. Eruption of deciduous molars
b. Attrition of incisors
c. Forward movement of the
mandible due to growth

66. The mixed dentition period

67. A panoramic x-ray of a 7 year-old child. One can
notice the complex mix of the permanent and
the primary teeth at this stage.

68. The mixed dentition period
• The mixed dentition period
begins at approximately 6
years of age with the eruption
of the first permanent molars
• During the mixed dentition
period, the deciduous teeth
along with some permanent
teeth are present in the oral
cavity

69. The mixed dentition period
The mixed dentition period can be classified into three phases:
1. First transitional period
2. Inter-transitional period
3. Second transitional period

70. First transitional period
• The first transitional period is
characterized by :
(1) the emergence of the first permanent
molars &
(2) the exchange of the deciduous
incisors with the permanent incisors

71. Emergence of the first permanent molars:
• The mandibular first molar is the first permanent tooth to erupt at around 6 years
of age

72. Emergence of the first permanent molars:
• The (1) location & (2) relationship of the first permanent molars depends much
upon the DISTAL SURFACE relationship b/w the lower & upper second
deciduous molars

73. Emergence of the first permanent molars:
• The first permanent molars are Guided into the dental arch by distal surface
of the second deciduous molars
• The mesio-distal relation b/w the Distal Surfaces of the upper & lower
second deciduous molars can be of three types

74. THE THREE TYPES OF TERMINAL PLANES
FLUSH PLANE MESIAL STEP DISTAL STEP
TYPE TYPE TYPE

75. A. Flush terminal plane:
• The distal surface of the upper & • This is a normal feature of the
lower second deciduous molars deciduous dentition
are in VERTICAL PLANE • Thus the erupting first
• This type of relationship is called permanent molars may also be
flush or vertical terminal plane
in a flush or end on Class I
molar relationship

76. Flush
Class I molar
• For such transition
the lower molar has to move
forward by about 3 – 5 mm
relative to the upper molar

77. Flush
Class I molar
• This occurs by
(1) utilization of the physiological spaces & leeway
space in the lower arch &
(2) by differential forward growth of the mandible

78. Flush
• The shift in lower molar can
occur in two ways
Class I relation
• They are designated as the
Late shift
Early shift
Shift: Refers to mandibular permanent
molar moving mesially

79. Early shift:
• Occurs during the early mixed Primate space
dentition period
• The ERUPTIVE FORCE of the
first permanent molar is sufficient
to push the deciduous first &
second molars forward in the arch
to close the PRIMATE SPACE
• Since this occur early in the mixed
dentition period it is called early
shift

80. • Many children lack the primate space
lack the primate
Late shift
space & thus
the erupting permanent molars
unable to move forward to
establish Class I relationship
• In this cases, when the deciduous
second molar exfoliate the
permanent first molars
DRIFT MESIALLY
utilizing
Leeway space
the leeway space
This occurs in the late mixed dentition period & is thus called late shift

81. Late Mesial Shift (cont.)
Molar moves into
FTP this space... Class I

82. Late Mesial Shift (cont.)

83. B. Mesial step terminal plane
• In this type of relationship the
Distal Surface of the lower
second deciduous molar is more
Mesial than that of the upper
• Thus the permanent molars erupt
directly into Angle’s Class I
occlusion

84. B. Mesial step terminal plane
• This type of mesial step terminal
plane most commonly occurs due
to
EARLY FORWARD GROWTH OF THE
MANDIBLE
• If the differential growth of the
mandible in a forward direction
persist, it can lead to an Angle‟s
Class III molar relation
• If the forward mandibular growth is
minimal, it can establish a Class I
molar relationship

85. B. Mesial step terminal plane
• This type of mesial step terminal
plane most commonly occurs due
to
EARLY FORWARD GROWTH OF THE
MANDIBLE
• If the differential growth of the
mandible in a forward direction
persist, it can lead to an Angle‟s
Class III molar relation

86. C. Distal step terminal plane
• This is characterized by the Distal
Surface of the lower second
deciduous molar being more
DISTAL to that of the upper
• Thus the erupting permanent
molars maybe in Angle‟s Class II
occlusion

87. C. Distal step terminal plane
• This is characterized by the Distal
Surface of the lower second
deciduous molar being more
DISTAL to that of the upper
• Thus the erupting permanent
molars maybe in Angle‟s Class II
occlusion

88. Primary Permanent
Distal Step Class II
Flush Terminal End-End
Plane
Class I
Mesial Step
Minimal Growth Differential
Class III
Forward Growth of Mandible
Shift of Teeth

89. First transitional period
• The first transitional period is
characterized by :
(1) the emergence of the first permanent
molars &
(2) the exchange of the deciduous
incisors with the permanent incisors

90. The exchange of incisors:
• During the first transitional period:
The deciduous incisors are replaced by
the permanent incisors
• The mandibular central incisors are
usually the first to erupt
• The permanent incisors are
considerably larger than the
deciduous teeth they replace

91. The exchange of incisors:
• This difference b/w the amount of
space needed for the
accommodation of the incisors &
amount of space available for this
is called “INCISAL LIABILITY”
7 mm in the maxillary arch
5 mm in the mandibular arch

92. Overcoming Incisal Liability
The incisal liability is overcome by
the following factors:
A. Utilization of interdental
spaces seen in primary
dentition
B. Increase in the inter – canine
width
C. Change in incisor
inclination

93. Overcoming Incisal Liability
A. Utilization of interdental spaces seen in primary dentition:
• The physiologic or the
developmental spaces that
exists in the primary dentition
are utilized to partly account
for the incisal liability

94. Overcoming Incisal Liability
A. Utilization of interdental spaces seen in primary dentition:
• The Permanent Incisors
are much more
easily accommodated in
normal alignment in cases exhibiting
Adequate Inter-dental Spaces
than in an arch that has
No space

95. Primary dentition, baby teeth, with
normal spaces between the teeth

96. Overcoming Incisal Liability
B. Increase in the inter – canine width:
– WIDTH GROWTH
creates more room
for the permanent incisors
(1) Mandibular intercanine growth
occurs mostly during permanent
incisor eruption
(2) Maxillary intercanine growth
occurs during incisor eruption,
and continues

97. Overcoming Incisal Liability
C. Change in incisor inclination:
• One of the differences b/w
deciduous & permanent incisors is
their inclination
• The primary incisors are
more upright
than the permanent incisors

98. Overcoming Incisal Liability
C. Change in incisor inclination:s
• Since the Permanent Incisors
erupt more labially inclined
they tend to increase
the Dental Arch Perimeter
• This is another factor that
helps in accommodating
the larger Permanent Incisors

99. The mixed dentition period
The mixed dentition period can be classified into three phases:
1. First transitional period
2. Inter-transitional period
3. Second transitional period

100. Inter – transitional period
• In this period the maxillary &
mandibular arches consist of Sets
of deciduous & permanent teeth
6edc21 12cde6
6edc21 12cde6
• B/w the permanent incisors & the first
permanent molars are the deciduous
molars & canines
• This phase during the mixed dentition
period is relatively stable & no
change occurs

101. The mixed dentition period
The mixed dentition period can be classified into three phases:
1. First transitional period
2. Inter-transitional period
3. Second transitional period

102. Cause Aetiology
The mixed  deciduous The first transitional period is characterized by :
dentition period teeth along with (1) the emergence of the first permanent molars
some permanent Flush transition to Class I molar
The eruption begin
teeth are present in (2) the exchange of the deciduous incisors with
approximately at 6
years of age with the the oral cavity the permanent incisors “INCISAL LIABILITY”
eruption of the first Classified into Inter – transitional period
permanent molars
three phases: ( First , Relatively stable & no change occurs
Inter-transitional ,
The second transitional period
Second) transitional
period Replacement of the deciduous molars & canines
by the premolars & permanent cuspids
respectively

103. The second transitional period
• The second transitional period is
• The surplus is called leeway
characterized by
space of Nance
the replacement of the deciduous
molars & canines by the
premolars & permanent cuspids
respectively
• The combined mesio-distal width
of the permanent canines &
premolars is usually less than that
of the deciduous canines & molars

104. The leeway spaces
Maxillary arch
1.8mm (0.9 mm on each side of the arch)
Mandibular arch
• The amount of leeway space is
greater in the mandibular arch
3.4mm (1.7 mm on each side of the arch)
than in the maxillary arch

105. The leeway spaces
Maxillary
c-d-e minus 3-4-5 is
0.9 mm per side
Mandibular
c-d-e minus 3-4-5 is
1.7 mm per side

106. The ugly duckling stage:
• Sometimes a Transient or Self Correcting malocclusion is seen in
the MAXILLARY INCISOR REGION b/w 8 – 9 years of age
This is a particular situation seen during the Eruption of the permanent canines

107. The ugly duckling stage:
7 years old 9 years old 14 years old
• As the developing permanent canines erupt, they displace the roots
of the lateral incisors mesially
• This result in transmitting of the force on to the roots of the central
incisors which also get displaced mesially

108. The ugly duckling stage:
7 years old 9 years old 14 years old
• A resultant distal divergence of the crowns of the two central incisors
causes a midline spacing
• This situation has been described by Broadbent as the ugly duckling stage
as children tend to look ugly during this phase of development

109. The ugly duckling stage:
7 years old 9 years old 14 years old
• Parents are often apprehensive during this stage & consult the dentist
• This condition usually corrects by itself when the canines erupt & the
pressure is transferred from the roots to the coronal area of the incisors

110. The permanent dentition period

111. The permanent dentition period
• The permanent dentition forms
within the jaws soon after birth,
except the cusps of the first
permanent molars which form
before birth
• The permanent incisors
develop lingual or palatal to
the deciduous incisors & move
labially as they erupt

112. The permanent dentition period
• The premolars develop below the diverging roots of the deciduous molars
• The eruption sequence of the permanent dentition may exhibit variation

113. The permanent dentition period
• The frequently seen
sequences in the maxillary
arch are:
– 6 – 1 – 2 – 4 – 3 – 5 – 7 or
– 6–1–2–3–4–5–7
• In case of the mandibular arch
the sequence is
– 6 – 1 – 2 – 3 – 4 – 5 – 7 or
– 6–1–2–4–3–5–7

114. Time of Eruption (Years)
Tooth Maxilla Mandible
1 7-8 6-7
2 8-9 7-8
3 11-12 9-10
4 10-11 10-12
5 10-12 11-12
6 6-7 6-7
7 12-13 11-13
8 17-21 17-21

115. Chronology of Tooth Development
Permanent Dentition
Calcification Crown Eruption Root completed
begins completed
Tooth Max. Mand. Max. Mand. Max. Mand. Max. Mand.
Central 3 mo. 3 mo. 4 ½ yr. 3 ½ yr. 7 ¼ yr. 6 ¼ yr. 10 ½ yr. 9 ½ yr.
Lateral 11 mo. 3 mo. 5 ½ yr. 4 yr. 8 ¼ yr. 7 ½ yr. 11 yr. 10 yr.
Canine 4 mo. 4 mo. 6 yr. 5 ¾ yr. 11 ½ yr. 10 ½ yr. 13 ½ yr. 12 ¾ yr.
1st Pre 20 mo. 22 mo. 7 yr. 6 ¾ yr. 10 ¼ yr. 10 ½ yr. 13 ½ yr. 13 ½ yr.
Molar
2nd Pre 27 mo. 28 mo. 7 ¾ yr. 7 ½ yr. 11 yr. 11 ¼ yr. 14 ½ yr. 15 yr.
Molar
1st Molar 32 wk. 32 wk. 4 ¼ yr. 3 ¾ yr. 6 ¼ yr. 6 yr. 10 ½ yr. 10 ¾ yr.
in utero in utero
2nd Molar 27 mo. 27 mo. 7 ¾ yr. 7 ½ yr. 12 ½ yr. 12 yr. 15 ¾ yr. 16 yr.
3rd Molar 8 yr. 9 yr. 14 yr. 14 yr. 20 yr. 20 yr. 22 yr. 22 yr.

116. ?

117. SEQUENCES of DENTAL ERUPTION
Favorable sequence Unfavorable sequence

118. SEQUENCES of DENTAL ERUPTION
Favorable sequence
-345
-435
- (3 4) 5
- 3 (4 5)

119. SEQUENCES of DENTAL ERUPTION
Unfavorable sequence
- 543
-534
- 5 (3 4)
-453

120. SEQUENCES of DENTAL ERUPTION
Unfavorable sequence
SECOND MOLARS
erupting before
Second premolars
and/or
CANINES

121. 4. Favorable sequences of eruption.
5. Tooth size and jaw in harmony.

122. n

124. Thank you for listening!
Dr. Nabil Al-Zubair