1. DEVELOPMENTA
L
DISTURBANCES
OF THE TEETH
Prepared by:
Dr. Rea Corpuz

2. Developmental
Disturbances
 (1) Size
 (2) Number and Eruption
 (3) Shape/Form
 (4) Defects of Enamel and Dentin

3. Size
 Microdontia
 Macrodontia

4. Size
 Microdontia
 (1) True Generalized
Microdontia
 (2) Relative Generalized
Microdontia
 (3) Focal or Localized
Microdontia

5. (1) True Generalized
Microdontia
 all teeth are smaller than
normal
 occur in some cases of
pituitary dawrfism
 exceedingly rare
 teeth are well formed

6. (2) Relative Generalized
Microdontia
 normal or slightly smaller than
normal teeth
 are present in jaws that are
somewhat larger than normal

7. (3) Focal/Localized
Microdontia
 common condition
 affects most often maxillary
lateral incisior + 3rd molar
 these 2 teeth are most often
congenitally missing

8. (3) Focal/Localized
Microdontia
 common forms of localized
microdontia is that which
affects maxillary lateral
incisior
 peg lateral
 instead of parallel or
diverging mesial + distal
surfaces

9. (3) Focal/Localized
Microdontia
 sides converge or taper
together incisally
 forms cone-shaped crown
 root is frequently shorter
than usual

10. Size
 Microdontia
 Macrodontia

11. Size
 Macrodontia
 (1) True Generalized
Macrodontia
 (2) Relative Generalized
Macrodontia
 (3) Focal or Localized
Macrodontia

12. (1) True Generalized
Macrodontia
 all teeth are larger than
normal
 associated with
pituitary gigantism
 exceedingly rare

13. (2) Relative Generalized
Macrodontia
 normal or slightly larger than
normal teeth in small jaws
 results in crowding of teeth
 insufficient arch space

14. (3) Focal/Localized
Macrodontia
 uncommon condition
 unknown etiology
 usually seen with
mandibular 3rd molars

15. Developmental
Disturbances
 (1) Size
 (2) Number and Eruption
 (3) Shape/Form
 (4) Defects of Enamel and Dentin

16. Number and Eruption
 Supernumerary
 Anodontia
 Impaction

17. Number and Eruption
 Supernumerary
 results from continued
proliferation of permanent
or primary dental lamina
to form third tooth germ
 teeth may have:
• normal morphology
• rudimentary
• miniature

18. Number and Eruption
 Supernumerary
 more often in permanent
dentition than primary
dentition
 more in the maxilla than in
mandible

19. Number and Eruption
 Supernumerary
 may be impacted erupted
or impacted
 because of additional tooth
bulk, it causes:
• malposition of adjacent
teeth
• prevent their eruption

20. Number and Eruption
 Supernumerary
 many are impacted
• characteristically found
in cleidocranial dysostosis

21. Number and Eruption
 Supernumerary
 Mesiodens
 Fourth molar
•Maxillary Paramolar
• Distomolar or Distodens
 Mandibular Premolar
 Maxillary lateral incisors

22. Number and Eruption
 Supernumerary
 Mandibular central incisors
 Maxillary Premolars

23. Mesiodens
 most common
supernumerary tooth
 tooth situated between
maxillary central incisors
 singly
 paired
 erupted or impacted


24. Mesiodens
 small tooth
 cone-shaped crown
 short root

25. Fourth Molar
 2nd most common
 situated distal to 3rd molar
 small rudimentary tooth,
but may be of normal size
 mandibular 4th molar also is
seen occasionally, but less
common than maxillary molar

26. Paramolar
 small + rudimentary
 situated bucally or lingually
to one of the maxillary
molars
 interproximally between 1st
+ 2nd or 2nd + 3rd maxillary
molars

27. Distomolar/Distodens
 molar located distal to molar

28. Number and Eruption
 Supernumerary
 Anodontia
 Impaction

29. Number and Eruption
 Anodontia
 lack of tooth development
 absence of teeth

30. Number and Eruption
 Anodontia
 Complete Anodontia
 Partial Anodontia
• Hypodontia
• Oligodontia
 Pseudoanodontia
 False Anodontia

31. Complete Anodontia
 when all teeth are missing
 rare
 often associated with a
syndrome known as hereditary
ectodermal dysplasia

32. Hypodontia
 lack of development of
one or more teeth

33. Oligodontia
 lack of development of
six or more teeth

34. Pseudoanodontia
 when teeth are absent
clinically because of
impaction or delayed
eruption

35. False Anodontia
 when teeth have been
exfoliated or extracted

36. Number and Eruption
 Supernumerary
 Anodontia
 Impaction

37. Number and Eruption
 Impaction
 most often affects the
mandibular 3rd molars +
maxillary canines
 less commonly:
• premolars
• mandibular canines
• second molars

38. Number and Eruption
 Impaction
 occurs due to obstruction
from crowding
 from some other physical
barrier
 occasionally, may be due
to an abnormal eruption
path, presumably because
of unusual orientation of

39. Number and Eruption
 Impaction
 Ankylosis

40. Ankylosis
 fusion of a tooth to surrounding
bone
 with focal loss of periodontal
ligament, bone + cementum
become inextricably mixed
 cause fusion of tooth to
alveolar bone

41. Developmental
Disturbances
 (1) Size
 (2) Number and Eruption
 (3) Shape/Form
 (4) Defects of Enamel and Dentin

42. Shape and Form
 Crown
 Root

43. Shape and Form
 Crown
 Fusion
 Gemination
 Taurodontism
 Talon’s Cusp
 Leong’s Cusp

44. Shape and Form
 Crown
 Dens Invaginatus
 Peg-shaped Lateral
 Hutchinson Incisor
 Mulberry Molar

45. Shape and Form
 Root
 Concresence
 Enamel Pearl
 Dilaceration
 Flexion
 Ankylosis

46. Fusion
 joining of 2 developing
tooth germs
 resulting in a single
large tooth structure
 may involve entire length
of teeth
 or may involve roots only,
in which case cementum +
dentin are SHARED

47. Fusion

48. Gemination
 fusion of 2 teeth from a
single enamel organ
 partial cleavage
 appearance of 2 crowns
that share same root canal
 trauma has been suggested
as possible cause, the cause is
still unknown

49. Taurodontism
 variation in tooth form:
 elongated crowns
 apically displaced furcations
• resulting in pulp
chambers that have
apical occlusal height

50. Taurodontism
 may bee seen as isolated
incident in families
 associated with syndromes
such as
 Down syndrome
 Klinefelter’s syndrome

51. Taurodontism
 little clinical significance
 No treatment is required

52. Dens Evaginatus
 Talon’s Cusp
 Leung’s Premolar

53. Talon’s Cusp
 well-delineated additional
cusp
 located on the surface of
an anterior tooth
 extends at least half the
distance from CEJ to
incisal edge

54. Leung’s Cusp
 developmental condition
 clinically as an accessory cusp
or a globule
 located on occlusal
surface between buccal +
lingual cusps of premolars
 unilaterally or bilaterally

55. Dens Invaginatus
(Dens in Dente)
 deep surface invagination
of crown or root that is lined
by enamel
 2 forms:
 coronal
 radicular

56. Dens Invaginatus
(Dens in Dente)
 depth varies from slight
enlargement of cingulum
to a deep infolding that
extends to apex
 historically, it has been
classified into 3 major types:
 Type I
 Type II
 Type III

57. Dens Invaginatus
(Dens in Dente)
 Type I
• confined to the crown
 Type II
• extends below cemento
enamel junction
• ends in a blind sac
• may or may not
communicate with
adjacent dental pulp

58. Dens Invaginatus
(Dens in Dente)
 Type III
• extends through the root
• perforates in the apical or
lateral radicular area
without any immediate
communication with pulp

59. Peg-Shaped
Lateral
 undersized lateral incisor
 smaller than normal
 occurs when permanent lateral
incisors do not fully develop

60. Peg-Shaped
Lateral

61. Hutchinson’s Incisor
 characteristic of congenital
syphilis
 lateral incisors are peg-shaped
or screwdriver-shaped
 widely spaced
 notched at the end
 with a crescent-shaped
deformity

62. Hutchinson’s Incisor
 notches on their biting
surfaces
 named after Sir Jonathan
Hutchinson
 English surgeon +
pathologist who 1st
described it

63. Mulberry Molar
 dental condition usually
associated with congenital
syphilis
 characterized by multiple
rounded rudimentary enamel
cusps on permanent 1st molars

64. Mulberry Molar
 dwarfed molars with cusps
covered with globular enamel
growths
 giving the appearance of a
mulberry

65. Shape and Form
 Root
 Concresence
 Enamel Pearl
 Dilaceration
 Flexion
 Ankylosis

66. Concrescence
 2 fully formed teeth
 joined along the root surfaces
by cementum
 noted more frequently in
posterior and maxillary regions

67. Concrescence
 often involves a 2nd molar
tooth in which its roots
closely approximate the
adjacent impacted 3rd molar
 may occur before or after the
teeth have erupted
 usually involves only 2 teeth

68. Concrescence
 diagnosis can frequently be
established by
roentgenographic examination
 often requires no therapy
unless union interferes with
eruption; then surgical
removal may be warranted
since with fused teeth,
extraction of one may result in
extraction of the other

69. Enamel Pearls
 droplets of ectopic enamel
 or so called enamel pearls
 may occasionally be found on
roots of teeth
 uncommon, minor
abnormalities,
which are formed on normal
teeth

70. Enamel Pearls
 occur most commonly in
bifurcation or trifurcation
of teeth
 may occur on single-rooted
premolar as well
 maxillary molars are
commonly affected than
mandibular molars

71. Enamel Pearls
 consist of only a nodule
of enamel attached to dentin
 may have a core of dentin
containing pulp horn
 may be detected on
radiographic examination

72. Enamel Pearls
 may cause stagnation at
gingival margin but, if they
contain pulp, this will
be exposed when pearl is
removed

73. Dilaceration
 angulation or a sharp
bend or curve in root
or crown of a formed tooth
 trauma to a developing
tooth can cause root to form
at an angle to normal
axis of tooth
 rare deformity

74. Dilaceration
 movement of crown or
of the crown and part of root
from remaining developing
root may result in sharp
angulation after tooth
completes development

75. Dilaceration
 hereditary factors are
believed to be involved
in small number of cases
 eruption generally continues
without problems

76. Flexion
 deviation or bend restricted
just to the root portion
 usually bend is less than 90
degrees
 may be a result of trauma to
the developing tooth

77. Ankylosis
 also known as
“submerged teeth”
 fusion of a tooth to surrounding
bone
 deciduous teeth most commonly
mandibular 2nd molars
 undergone variable
degree of root resorption

78. Ankylosis
 have become ankylosed
to bone
 this process prevents their
exfoliation + subsequent
replacement by permanent
teeth
 after adjacent permanent
teeth have erupted,
ankylosed tooth appears to
have submerged below level
of occlusion

79. Developmental
Disturbances
 (1) Size
 (2) Number and Eruption
 (3) Shape/Form
 (4) Defects of Enamel and Dentin

80. Amelogenesis
Imperfecta
 also known as:
 Hereditary Enamel
Dysplasia
 Hereditary Brown Enamel
 Hereditary Brow Opalescent
Teeth

81. Amelogenesis
Imperfecta
 group of conditions caused by
defects in the genes encoding
enamel matrix proteins
 genes that encode for enamel
proteins:
 amelogenin mutated in
 enamelin in patients
 others with this
condition

82. Amelogenesis
Imperfecta
 affects both dentition
 deciduous
 permanent
 classified based on pattern of
inheritance:
 hypoplasia
 hypomaturation
 hypocalcified

83. Amelogenesis
Imperfecta
 No treatment except for
improvement of cosmetic
appearance

84. Hypoplastic
Amelogenesis Imperfecta
 inadequate formation of matrix
 enamel is randomly:
 pitted
 grooved or very thin
 hard + translucent
 defects become stained but teeth
are not especially susceptible to
caries unless enamel is scanty
and easily damaged

85. Hypoplastic
Amelogenesis Imperfecta
 reduced enamel thickness
 abnormal contour
 absent interproximal
contact points
 Radiographically:
 enamel reduced in bulk
 shows thin layer over
occlusal
+ interproximal surfaces

86. Hypoplastic
Amelogenesis Imperfecta
 dentin + pulp chambers
appear normal
 no treatment is necessary

87. Hypomaturation
Amelogenesis Imperfecta
 enamel is normal in form on
eruption but:
 opaque
 white to brownish-yellow
 softer than normal
 tends to chip from
underlying
dentin

88. Hypomaturation
Amelogenesis Imperfecta
 Radiographically:
 affected enamel exhibits
radiodensity similar to
dentin

89. Hypocalcified
Amelogenesis Imperfecta
 enamel matrix is formed in
normal quantity
 poorly calcified
 when newly erupted:
 enamel is normal in thickness
 normal form
 but weak
 opaque or chalky in appearance

90. Hypocalcified
Amelogenesis Imperfecta
 with years of function:
 coronal enamel is removed
 except for cervical portion
that is occasionally calcified
better
 Radiographically:
 density of enamel + dentin are
similar

91. Dentinogenesis Imperfecta
 also known as “Hereditary
Opalascent Dentin”
 due to clinical discoloration
of teeth
 mutation in the dentin
sialophosphoprotein
 affects both primary + permanent
dentition

92. Dentinogenesis Imperfecta
 have blue to brown
discoloration
 with distinctive translucence
 enamel frequently separates
easily from underlying defective
dentin

93. Dentinogenesis Imperfecta
 Radiographically:
 bulbous crowns
 cervical constriction
 thin roots
 early obliteration of roots
canals + pulp chambers

94. Dentinogenesis Imperfecta
 Treatment:
 prevent loss of enamel +
subsequent loss of dentin
through attrition
 cast metal crowns on posterior
 jacket crowns on anterior
teeth

95. Dentinogenesis Imperfecta
 Classification:
 Type I
 Type II
 Type III

96. Type I Dentinogenesis
Imperfecta
 occurs in families with
Osteogenesis Imperfecta
 primary teeth are more severely
affected than permanent teeth

97. Type I Dentinogenesis
Imperfecta
 Radiographically:
 partial or total obliteration
of pulp chambers + root canals
 by continued formation
of dentin
 roots may be short + blunted
 cementum, periodontal
membrane + bone appear
normal

98. Type II Dentinogenesis
Imperfecta
 never occurs in association
with osteogenesis imperfecta
unless by chance
 most frequently referred to as
hereditary opalascent dentin
 only have dentin abnormalities
and no bone disease

99. Type II Dentinogenesis
Imperfecta
 Radiographically:
 partial or total obliteration
of pulp chambers + root canals
 by continued formation
of dentin
 roots may be short + blunted
 cementum, periodontal
membrane + bone appear
normal

100. Type III Dentinogenesis
Imperfecta
 “Bradwine type”
 racial isolate in Maryland
 multiple pulp exposures in
deciduous not seen in type
I or II
 periapical radiolucencies

101. Type III Dentinogenesis
Imperfecta
 enamel appears normal
 large size of pulp chamber
is due not to resorption but
rather to insufficient + defective
dentin formation

102. Dentin Dysplasia
 also known as “Rootless Teeth”
 rare disturbance of dentin
formation
 normal enamel
 atypical dentin formation
 abnormal pulpal morphology
 hereditary disease

103. Dentin Dysplasia
 Classification:
 Type I (Radicular Type)
 Type II (Coronal Type)

104. Type I (Radicular Type)
 both dentitions are of
normal color
 periapical lesion
 premature tooth loss may occur
because of short roots or
periapical inflammatory lesions

105. Type I (Radicular Type)
 Radiographically:
 roots are extremely short
 pulps almost completely
obliterated
 periapical radiolucencies:
• granulomas
• cysts
• chronic abscesses

106. Type II (Coronal Type)
 color of primary dentition
is opalescent
 permanent dentition is normal
 coronal pulps are usually large
(thistle tube appearance)
 filled with globules of abnormal
dentin

107. Type II (Coronal Type)
 Radiographically:
(Deciduous)
 roots are extremely short
 pulps almost completely
obliterated
(Permanent)
 abnormally large pulp
chambers in coronal portion of
tooth

108. Regional
Odontodysplasia
 also known as:
 Odontogenic Dysplasia
 Odontogenesis Imperfecta
 Ghost Teeth

109. Regional
Odontodysplasia
 one or several teeth in a
localized area are affected
 maxillary teeth are involved
more frequently than
mandibular area
 etiology is unknown

110. Regional
Odontodysplasia
 teeth affected may exhibit
a delay or total failure in
eruption
 shape is altered, irregular
in appearance

111. Regional
Odontodysplasia
 Radiographically:
 marked reduction in
radiodensity
 teeth assume a “ghost”
appearance
 both enamel + dentin appear
very thin
 pulp chamber is exceedingly
large

112. Regional
Odontodysplasia
 Treatment:
 poor cosmetic appearance
of teeth
 extraction with restoration
by prosthetic appliance

113. Shell Tooth
 normal thickness enamel
 extremely thin dentin
 enlarged pulps
 thin dentin may involve
entire tooth or be isolated
to the root
 most frequently in deciduous

114. References:
 Books
 Cawson, R.A: Cawson’s Essentials of Oral
Oral Pathology and Oral Medicine,
8th Edition
• (pages 24-36)
 Neville, et al: Oral and Maxillofacial Pathology
3rd Edition
• (pages 77-113)
 Regezi, Joseph et al: Oral Pathology, Clinical
Pathological Correlations
5th Edition
• (pages 361-373)
 Shafer, et al: A textbook of Oral Pathology,
3rd Edition
• (pages 37-69)