developmental disturbances of the teeth...macrodontia 12/7/2015 6 macrodontia (1) true generalized...
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DEVELOPMENTAL
DISTURBANCES OF THE TEETH
Dr. Ibtisam Briek SENUSSI
Oral pathology
19.11.2015
(1) Size
(2) Number and Eruption
(3) Shape/Form
(4) Defects of Enamel and Dentin
Developmental Disturbances
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Microdontia
Macrodontia
Size
Microdontia
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Microdontia
(1) True Generalized Microdontia
(2) Relative Generalized Microdontia
(3) Focal or Localized Microdontia
Size
All teeth are smaller than normal
Occur in some cases of pituitary dawrfism
Exceedingly rare
Teeth are well formed
(1) True Generalized Microdontia
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Normal or slightly smaller than normal teeth
Are present in jaws that are somewhat larger than
normal
(2) Relative Generalized Microdontia
Common condition
Affects most often maxillary lateral incisior + 3rd molar
These 2 teeth are most often congenitally missing
(3) Focal/Localized Microdontia
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Common forms of localized microdontia is that which
affects maxillary lateral incisor
Peg lateral
Instead of parallel or diverging mesial + distal surfaces
(3) Focal/Localized Microdontia
sides converge or taper together incisally
forms cone-shaped crown
root is frequently shorter than usual
Macrodontia
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Macrodontia
(1) True Generalized Macrodontia
(2) Relative Generalized Microdontia
(3) Focal or Localized Macrodontia
Size
All teeth are larger than normal
Associated with pituitary gigantism
Exceedingly rare
(1) True Generalized Macrodontia
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Normal or slightly larger than normal teeth in small
jaws
Results in crowding of teeth
Insufficient arch space
(2) Relative Generalized Macrodontia
Uncommon condition
Unknown etiology
Usually seen with mandibula3rd molars
(3) Focal/Localized Macrodontia
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(1) Size
(2) Number and Eruption
(3) Shape/Form
(4) Defects of Enamel and Dentin
Developmental Disturbances
Supernumerary
Anodontia
Impaction
Number and Eruption
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Supernumerary
Results from continued proliferation of permanent or
primary dental lamina to form third tooth germ
Teeth may have:
• normal morphology
• rudimentary
• miniature
Number and Eruption
Supernumerary
More often in permanent dentition than primary
dentition
More in the maxilla than in mandible
Number and Eruption
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Supernumerary
May be impacted erupted or impacted
Because of additional tooth bulk, it causes:
• Malposition of adjacent teeth
• Prevent their eruption
Number and Eruption
Supernumerary
Many are impacted
• Characteristically found in cleidocranial dysostosis
Number and Eruption
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Number and Eruption
Supernumerary
Mesiodens
Fourth molar
• Maxillary Paramolar
• Distomolar or Distodens
Mandibular Premolar
Maxillary lateral incisors
Number and Eruption
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Supernumerary
Mandibular central incisors
Maxillary Premolars
Number and Eruption
Most common supernumerary tooth
Tooth situated between maxillary central incisors
Singly , Paired , Erupted or impacted , Inverted
Mesiodens
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Small tooth
Cone-shaped crown
Short root
Mesiodens
Small + rudimentary
Situated bucally or lingually to one of the maxillary
molars
Interproximally between 1st + 2nd or 2nd + 3rd maxillary
molars
Para-molar
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Molar located distal to molar
Distomolar / Distodens
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
Fourth Molar
Distomolar
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Anodontia
lack of tooth development
absence of teeth
Number and Eruption
Anodontia
Complete Anodontia
Partial Anodontia
• Hypodontia
• Oligodontia
Pseudoanodontia
False Anodontia
Number and Eruption
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When all teeth are missing
Rare
Often associated with a syndrome known as hereditary
ectodermal dysplasia
Complete Anodontia
Lack of development of one or more teeth
Hypodontia
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Lack of development of six or more teeth
Oligodontia
When teeth are absent clinically because of impaction
or delayed eruption.
Pseudo - Anodontia
When teeth have been exfoliated or extracted
False Anodontia
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Impaction
most often affects the mandibular 3rd molars +
maxillary canines
less commonly:
• premolars
• mandibular canines
• second molar
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
tooth germ
Number and Eruption
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Impaction
Ankylosis
Number and Eruption
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
Ankylosis
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(1) Size
(2) Number and Eruption
(3) Shape/Form
(4) Defects of Enamel and Dentin
Developmental Disturbances
Crown
Root
Shape and Form
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Crown
Fusion
Gemination
Taurodontism
Talon’s Cusp
Leong’s Cusp
Shape and Form
Crown
Dens Invaginatus
Peg-shaped Lateral
Hutchinson Incisor
Mulberry Molar
Shape and Form
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Root
Concresence
Enamel Pearl
Dilaceration
Flexion
Ankylosis
Shape and Form
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
Fusion
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Fusion
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
Gemination
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Variation in tooth form:
Elongated crowns
Apically displaced furcations
• Resulting in pulp chambers that have apical
occlusal height
Taurodontism
May be seen as isolated
incident in families
Associated with syndromes
such as
Down syndrome
Taurodontism
little clinical significance
No treatment is required
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Talon’s Cusp
Leung’s Premolar
Dens Evaginatus
Well-delineated additional
cusp
Located on the surface of
an anterior tooth
Extends at least half the
distance from CEJ to
incisal edge
Talon’s Cusp
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Developmental condition
Clinically as an accessory cusp or a globule
Located on occlusal surface between buccal + lingual
cusps of premolars
Unilaterally or bilaterally
Leung’s Cusp
Deep surface invagination of crown or root that is
lined by enamel
2 forms:
Coronal
Radicular
Dens Invaginatus (Dens in Dente)
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Depth varies from slight enlargement of cingulum
to a deep in-folding that extends to apex
Historically, it has been classified into 3 major
types:
Type I
Type II
Type III
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
Dens Invaginatus (Dens in Dente)
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Type III
• Extends through the root
• Perforates in the apical or lateral
radicular area without any
immediate communication with
pulp
Dens Invaginatus (Dens in Dente)
Undersized lateral incisor
Smaller than normal
Occurs when permanent lateral incisors do not fully
develop
Peg-Shaped Lateral
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Characteristic of congenital
syphilis
Lateral incisors are peg-shaped
or screwdriver-shaped
Widely spaced
Notched at the end
With a crescent-shaped
deformity
Hutchinson’s Incisor
Notches on their biting surfaces
Named after Sir Jonathan Hutchinson
English surgeon + pathologist who 1st described it
Hutchinson’s Incisor
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Dental condition usually associated with congenital
syphilis
Characterized by multiple rounded rudimentary enamel
cusps on permanent 1st molars
Mulberry Molar
Dwarfed molars with cusps covered with globular enamel
growths
Giving the appearance of a mulberry
Mulberry Molar
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Root
Concresence
Enamel Pearl
Dilaceration
Flexion
Ankylosis
Shape and Form
2 fully formed teeth
Joined along the root surfaces
by cementum
Noted more frequently in
posterior and maxillary regions
Concrescence
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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
Concrescence
Diagnosis can frequently be established by routine
graphic 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
Concrescence
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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
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
Enamel Pearls
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May cause stagnation at gingival margin but, if they
contain pulp, this will be exposed when pearl is removed
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.
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
Dilaceration
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Movement of crown or of the crown and part of root
from remaining developing root may result in sharp
angulation after tooth completes development
Dilaceration
Hereditary factors are believed to be involved in small
number of cases
Eruption generally continues without problems
Dilaceration
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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
Flexion
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
Ankylosis
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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
Ankylosis
THANKS
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NATAL TEETH
These are extra teeth that are present at birth.
Cause:
A developmental disturbance creating intracellular
activity during the first stage of tooth development (bud
stage) can result in the development of extra teeth.
The most common natal teeth are lower incisors.
19.11.15
Treatment:
These teeth are defective and their removal is
generally recommended, particularly if mobility poses
a threat of aspiration. These teeth also make feeding
difficult.
Natal Teeth 19.11.15
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NEONATAL TEETH
These are primary teeth that erupt prematurely
(during the first few weeks of life).
Cause:
Premature tooth eruption.
19.11.15
Treatment These teeth are usually normal primary teeth and should be
retained. An x-ray will be taken if possible to confirm that
these are not extra teeth.
Neonatal Teeth
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• Accessory roots are most commonly seen in mandibular
canines, premolars and molars ( especially third molar).
• Very rare in maxillary anterior teeth & mandibular
incisors.
• Discovered in routine radiographic examination .
• This condition important in extraction of teeth and RCT.
• Supernumerary Roots
Shape and Form 19.11.15
(1) Size
(2) Number and Eruption
(3) Shape/Form
(4) Defects of Enamel and Dentin
Developmental
Disturbances
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also known as:
Hereditary Enamel Dysplasia
Hereditary Brown Enamel
Hereditary Brow Opalescent
Teeth
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
Amelogenesis
Imperfecta
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affects both dentition
deciduous
permanent
classified based on pattern of
inheritance:
hypoplasia
hypomaturation
hypocalcified
Amelogenesis
Imperfecta
No treatment except for
improvement of cosmetic
appearance
Amelogenesis
Imperfecta
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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
Hypoplastic
Amelogenesis Imperfecta
reduced enamel thickness
abnormal contour
absent interproximal
contact points
Radiographically:
enamel reduced in bulk
shows thin layer over occlusal
+ interproximal surfaces
Hypoplastic
Amelogenesis Imperfecta
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dentin + pulp chambers
appear normal
no treatment is necessary
Hypoplastic
Amelogenesis Imperfecta
enamel is normal in form on
eruption but:
opaque
white to brownish-yellow
softer than normal
tends to chip from
underlying
dentin
Hypomaturation
Amelogenesis Imperfecta
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Radiographically:
affected enamel exhibits
radiodensity similar to
dentin
Hypomaturation
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
Hypocalcified
Amelogenesis Imperfecta
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with years of function:
coronal enamel is removed
except for cervical portion
that is occasionally calcified
better
Radiographically:
density of enamel + dentin are
similar
Hypocalcified
Amelogenesis Imperfecta
also known as “Hereditary
Opalascent Dentin”
due to clinical discoloration
of teeth
mutation in the dentin
sialophosphoprotein
affects both primary + permanent
dentition
Dentinogenesis Imperfecta
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have blue to brown
discoloration
with distinctive translucence
enamel frequently separates
easily from underlying defective
dentin
Dentinogenesis Imperfecta
Radiographically:
bulbous crowns
cervical constriction
thin roots
early obliteration of roots
canals + pulp chambers
Dentinogenesis Imperfecta
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Treatment:
prevent loss of enamel +
subsequent loss of dentin
through attrition
cast metal crowns on posterior
jacket crowns on anterior
teeth
Dentinogenesis Imperfecta
Classification:
Type I
Type II
Type III
Dentinogenesis Imperfecta
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occurs in families with
Osteogenesis Imperfecta
primary teeth are more severely
affected than permanent teeth
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
Type I Dentinogenesis
Imperfecta
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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
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
Type II Dentinogenesis
Imperfecta
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“Bradwine type”
racial isolate in Maryland
multiple pulp exposures in
deciduous not seen in type
I or II
periapical radiolucencies
Type III Dentinogenesis
Imperfecta
enamel appears normal
large size of pulp chamber
is due not to resorption but
rather to insufficient + defective
dentin formation
Type III Dentinogenesis
Imperfecta
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also known as “Rootless Teeth”
rare disturbance of dentin
formation
normal enamel
atypical dentin formation
abnormal pulpal morphology
hereditary disease
Dentin Dysplasia
Classification:
Type I (Radicular Type)
Type II (Coronal Type)
Dentin Dysplasia
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both dentitions are of
normal color
periapical lesion
premature tooth loss may occur
because of short roots or
periapical inflammatory lesions
Type I (Radicular Type)
Radiographically:
roots are extremely short
pulps almost completely
obliterated
periapical radiolucencies:
• granulomas
• cysts
• chronic abscesses
Type I (Radicular Type)
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color of primary dentition
is opalescent
permanent dentition is normal
coronal pulps are usually large
(thistle tube appearance)
filled with globules of abnormal
dentin
Type II (Coronal Type)
Radiographically:
(Deciduous)
roots are extremely short
pulps almost completely
obliterated
(Permanent)
abnormally large pulp
chambers in coronal portion of
tooth
Type II (Coronal Type)
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also known as:
Odontogenic Dysplasia
Odontogenesis Imperfecta
Ghost Teeth
Regional
Odontodysplasia
one or several teeth in a
localized area are affected
maxillary teeth are involved
more frequently than
mandibular area
etiology is unknown
Regional
Odontodysplasia
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teeth affected may exhibit
a delay or total failure in
eruption
shape is altered, irregular
in appearance
Regional
Odontodysplasia
Radiographically:
marked reduction in
radiodensity
teeth assume a “ghost”
appearance
both enamel + dentin appear
very thin
pulp chamber is exceedingly
large
Regional
Odontodysplasia
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Treatment:
poor cosmetic appearance
of teeth
extraction with restoration
by prosthetic appliance
Regional
Odontodysplasia
normal thickness enamel
extremely thin dentin
enlarged pulps
thin dentin may involve
entire tooth or be isolated
to the root
most frequently in deciduous
Shell Tooth
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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)