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
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
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
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
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
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
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
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
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
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
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
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
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
94. Dentinogenesis Imperfecta
Treatment:
prevent loss of enamel +
subsequent loss of dentin
through attrition
cast metal crowns on posterior
jacket crowns on anterior
teeth
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
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
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
111. Regional
Odontodysplasia
Radiographically:
marked reduction in
radiodensity
teeth assume a “ghost”
appearance
both enamel + dentin appear
very thin
pulp chamber is exceedingly
large
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)