it describes tooth development and anomalies associated with tooth bud development along with other developmental stages of tooth development and some important terminologies.

1. 1 Presentation title 20XX

2. Chronology of
Tooth
Development
PRESENTED BY
DR. SIMRAN SHIVHARE
DEPARTMENT OF PAEDIATRIC AND PREVENTIVE
DENTISTRY
07/04/2023

3. CONTENT
S
INTRODUCTION
DEVELOPMENT OF TEETH
ROOT FORMATION
ERUPTION OF PRIMARY AND
PERMANENT TEETH
ANOMALIES ASSOCIATED
WITH STAGES OF TOOTH
BUD DEVELOPMENT
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4. Introduction
The purpose of knowing tooth development is to
know the course of normal development, clinical
features of dentition and the most common
developmental disturbances.
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5. • Tooth formation occurs in
the 6th week of IUL with
the formation of primary
epithelial band.
• At 7th week
Lingual process-------dental
lamina
Buccal process-------
vestibular lamina.
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DEVELOPMENT OF TEETH

6. The deciduous teeth are directly formed by the
proliferation of the lamina.
The accessional teeth permanent molars develop
as a result of its distal proliferation.
Succedaneous teeth develop from a lingual
extension of the lamina.
Fate of dental lamina-5 years
Remnants of dental lamina- Epithelial cell rests of
Serres
DENTAL LAMINA

7.  The ectoderm in certain areas
of the dental lamina proliferates
and forms knob like structures
that grow into the underlying
mesenchyme.
Each of these knobs represent
a deciduous tooth and is called
the enamel organ.
ENAMEL ORGAN
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8. Based on the shape of the Enamel Organ the
development of teeth is divided into 3 stages:-
BUD STAGE CAP STAGE BELL STAGE
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9. This is the initial stage of tooth
development where the enamel
organ resembles a small bud.
Occurs during the 7th week of
prenatal development.
The enamel organ consists of
peripherally located low columnar
cells and centrally located
polyhedral cells
BUD STAGE
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10. The tooth bud continues to proliferate resulting in a
cap shaped enamel organ.
During 9th and 10th week of prenatal development.
The outer cells of the cap covering the convexity
are cuboidal – the outer enamel epithelium.
The cells lining the concavity of the cap→ tall
columnar – the inner enamel epithelium.
The polygonal cells between the outer and the inner
epithelium forms a cellular network – the stellate
reticulum.
The ectomesenchymal condensation i.e:-dental
papilla and dental sac are pronounced during this
stage.
CAP STAGE
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11. Due to the continued uneven growth of the
enamel organ it acquires a bell shape
A few layers of flat squamous cells between
the inner enamel epithelium and the stellate
reticulum – stratum intermedium.
As the enamel formation starts the stratum
intermedium collapses to a narrow zone
reducing the distance between the outer and
the inner epithelium.
BELL STAGE
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12. Inner enamel epithelium → ameloblasts ( tall
columnar cells ) → enamel.
Dental papilla → odontoblast (cuboidal cells
then later columnar) → dentin.
Outer enamel epithelium→ low cuboidal cells
→ capillary network.
Dental sac → circular arrangement of fibers
→ periodontal ligament.
The junction between inner enamel epithelium
and odontoblast → dentinoenamel junction.
LATE BELL STAGE
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13. ROOT FORMATION
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14. • The development of roots begin after
enamel & dentin formation has reached the
future cementoenamel junction
• The enamel organ plays an important role in
root development by forming HERS, which
models the shape of the root
• HERS consists of outer & inner enamel
epithelium only
• As the first layer of the dentin has been laid
down, the epithelial root sheath loses its
structural continuity and gets in close relation
to the surface of the root
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15. •Its remnants persists as an epithelial network of
strands or clumps near the external surface of the
root
• These epithelial remnants are found in the
periodontal ligament of erupted teeth and are called
as rests of malassez.
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16. • Prior to the beginning of root formation,
the root sheath forms the epithelial
diaphragm
The outer & the inner enamel epithelium
bend at the future cementoenamel
junction into a horizontal plane,
narrowing the wide cervical opening
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17. • Connective tissue of the dental sac surrounding
the root sheath proliferates & invades the
continuous double epithelial layer dividing it into
network of epithelial strands
In the last stages of the root development, the
proliferation of the epithelium in the diaphragm lags
behind that of the pulpal connective tissue
• The wide apical foramen is reduced first to the
width of the diaphragmatic opening itself & later is
further narrowed by opposition of dentin &
cementum to the apex of the root
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18. Differential growth of the epithelial
diaphragm in the multirooted teeth
causes the division of root trunk into 2 or
3 roots
• Before division of the root trunk occurs,
free ends of the horizontal epithelial flaps
grow towards each other & fuse
• The single cervical opening is divided
into 2 or 3 openings
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19. On the pulpal surface of the dividing
epithelial bridges, dentin formation starts
• On the periphery of each opening, root
development follows in the same way as
described for single rooted teeth
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20. Clinical significance of dental follicle
1. Dental follicle stem cells and tissue engineering.
Dental follicle stem cells(DFSC) are a cell source for mesenchymal stem cells. DFSCs can be
isolated and grown under defined tissue culture conditions and recent characterization of these
cells have increased their potential for use in tissue engineering applications, periodontal and
bone regeneration and also the DF stem cells can differentiate into adipocytes and neurons.
• Differentiation of Stem Cells in the Dental Follicle J Dent Res. 2008
August ; 87(8): 767–771.
• Dental follicle stem cells and tissue engineering-review Journal of oral sciences 2010; 52(4)
541-55
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21. Central role in eruption
• In a study by Marks & Cahill,1980 the influence of the dental follicle on tooth
eruption was examined by studying eruption following selective removal of the
dental follicle. This was done by surgical removal of the tooth crown and
dental follicle, carefully stripping the adherent follicle from the crown and
replacing only the crown in its crypt which didn’t resulted in tooth eruption. The
area usually occupied by the dental follicle was filled with an irregular, dense
connective tissue histologically distinct from the follicle. These data indicate
that tooth eruption does not take place in the absence of the dental follicle.
• Tooth eruption: evidence for the central role of the dental follicle Journal of
Oral Pathology 1980:9: 189- 20
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22. Remnants of Dental Lamina : cell rests of Serres
These could in future form many Odontogenic cysts
1.OKC
2.Cyst of dental Lamina
3.Gingival cyst of newborn
4.Lateral periodontal cyst
5.Glandular odontogenic cyst
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23. ERUPTION OF PRIMARY
TEETH
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25. NATAL AND NEONATAL
TEETH
• Very rarely teeth are present at birth
called as natal teeth.
• If they erupt during the 1st 30 days
then they are called as neonatal
teeth.
• Mostly located in the mandibular
incisor region.
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NEONATAL LINE
It is a type of accentuated incremental line that separates the
enamel which is formed before and after birth . It is usually
associated with the disturbance in the enamel formation produced at
birth , due to abrupt change in nutrition and environment.
Seen in all deciduous teeth and permanent first molars.

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.
Followed with mandibular 3rd molars
In bone demineralization cases tooth mineralization is more reliable
Peak
growt
h
spurt

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34. ERUPTION OF
PERMANENT TEETH
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36. PRE EMERGENT
ERUPTION
• Eruptive movements begin soon after
the root begins to form.
• Two processes are necessary for pre
emergent eruption:-
1. There must be resorption of bone and
primary tooth roots overlying the
crown of the erupting tooth.
2. The eruptive mechanism itself must
move the tooth in the direction where
the path has been cleared.
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37. Theories of Eruption
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1.Bone Remodeling
Theory
2.Root End Theory
3.Hydrostatic Pressure
Theory
4.PDL Traction Theory
: most accepted

38. POST EMERGENT
ERUPTION
• Once the tooth erupts into the mouth it
approaches the occlusal level and is
subjected to the forces of mastication.
• The amount of tooth eruption after the
teeth have come into occlusion equals
the vertical growth of ramus in a patient
who is growing normally
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39. • The stage of relatively rapid eruption from the time a tooth first
penetrates the gingiva to the occlusal level is called the post
emergent spurt.
• This is followed by the phase of very slow eruption termed the
juvenile occlusal equilibrium.
• When the pubertal growth ends a final phase in tooth eruption
called the adult occlusal equilibrium .
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40. If the antagonist is lost at any
age a tooth can erupt more
rapidly demonstrating that the
eruption mechanism remains
active and capable of producing
significant tooth movement
even late in life.
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42. ANOMALIES
ASSOCIATED WITH
STAGES OF TOOTH BUD
DEVELOPMENT

43. Initiation stage
No dental lamina
No teeth
ANODONTIA
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Phase of deciduous tooth-5th
month in utero
Phase of permanent tooth-6th
month in utero
Phase of accessional tooth- 4th
month in utero to 4-5 years.

44. Proliferation Stage
>10 Enamel Organ
SUPERNUMERARY TEETH
<10 Enamel Organ HYPODONTIA
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45. Histodifferentiation and
Morphodifferentiation
Histodifferentiation
-Dentinogenesis Imperfecta
-Atypical dentin formation
Morphodifferentiation
Fusion/Macrodontia/Microdontia
-Hutchinson’s Incisors
-Dens in dente, Talon’s cusp, Twinning
-loss of cusp or roots
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DENTINOGENESIS
IMPERFECTA FUSION
MACRODONTIA HUTCHINSON’S
INCISOR
DENS IN DENTE
MICRODONTIA

47. Apposition stage
• Enamel hypoplasia
• Hypocalcification
• Intrinsic staining
• Concrescence
• Odontodysplasia
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48. Factors affecting development of dentition
Accelerating effect:
Hyperthyroidism
Hyperpituitarism
Turners syndrome
Decelerating effect:
Hypothyroidism
Hypopituitarism
Downs syndrome
Hypovitaminosis
Amelogenesis imperfecta
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Systemic Factors

49. • Aberrant tooth position
• Lack of space in the arch
• Early loss of predecessor
• Ectopic eruption
• Congenital absence of tooth
• Ankylosed tooth
• Retained deciduous teeth
• Supernumerary tooth
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Local Factors

50. OTHER ASSOCIATED
PROBLEMS

51. Cleidocranial Dysplasia
In children with cleidocranial
dysplasia not only the
resorption of primary teeth
and bone deficient but heavy
fibrous gingiva and multiple
supernumerary teeth also
impede normal eruption.
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52. ANKYLOSIS
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53. Retained Primary Teeth
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54. DILACERATION
• Dilaceration refers to an angulation or a
sharp bend or curve anywhere along the
root portion of a tooth
• Condition probably occurs subsequent to
trauma or any other defect of
development which alters the angulation
of the tooth germ during root formation
• Can easily be detected by radiographs
• Care should be taken during extraction
since these teeth are more prone to
fracture
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55. Congenitally Missing Teeth
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56. Turner's Hypoplasia
• Secondary to periapical inflammatory
disease of the overlying deciduous tooth
• Enamel defects vary from focal areas of
white, yellow or brown to extensive
hypoplasia involving the entire crown.
• Most frequently affects permanent
bicuspids- Traumatic injury to deciduous
teeth also causes Turner's teeth (45% of
children sustain injuries to primary teeth)
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58. Thank you