Amelogenesis imperfecta, hypoplastic type - Dr Sanjana Ravindra
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Transcript of Amelogenesis imperfecta, hypoplastic type - Dr Sanjana Ravindra
GOODMORNIN
G
Dr Sanjana Ravindra
Post graduate Student
Oral Medicine and
Radiology
Amelogenesis Imperfecta, Hypoplastic Type
Associated with Some Dental Abnormalities:
A Case Report
Canger EM, Celenk P, Yenísey M, Odyakmaz SZ. Braz Dent J (2010) 21(2): 170-174.
JOURNAL CLUB: 3
Introduction
DEVELOPMENTAL
DISTURBANCES an abnormality where the
pathology starts in the
embryonic stage of human
life , before the formation
of the dentition
Orban’s Oral Histology and Embryology, 12th edition
Introduction
DEVELOPMENTAL TOOTH
ANOMALIES
SIZE
• Microdontia
• Macrodontia
NUMBER
• Anodontia
• Supernumerary
teeth
• Pre-deciduous
dentition
STRUCTURE
• AMELOGENESIS
IMPERFECTA
• Dentinogenesis
imperfecta
• Dentin dysplasia
• Regional
odontodysplasia
• Dentin
hypocalcification
SHAPE • Gemination
• Twinning
• Fusion
• Concrescence
• Talon cusp
• Dilaceration
• Dens in dente
• Dens evaginatus
• Enamel pearl
• Globodontia
• Mulberry molar
• Moon’s molar
• Hutchinson incisor
• Carabelli cusp
• Shovel shaped
incisor
encompasses a
complicated
group of conditions
that demonstrate
developmental
alterations in the
structure of the
enamel in the
absence
of a systemic
disorder.
AMELOGENESIS
IMPERFECTA
AMELOGENES
IS ?IMPERFECT
A
Hereditary
enamel
dysplasia
Hereditary
brown enamel
Hereditary
brown
opalescent
teeth
Shafer’s textbook of Oral Pathology. 6th ed. Elsevier;
2009
www.merriam-webster.comIntroduction
Case report
Canger EM, Celenk P, Yenísey M, Odyakmaz SZ. Amelogenesis Imperfecta, Hypoplastic
Type, Associated with Some Dental Abnormalities: A Case Report: Braz Dent J (2010)
21(2): 170-174.
Case reportB
IOD
ATA A 26-year-old
female
CH
IEF
CO
MP
LA
INT discolored teeth
ME
DIC
AL H
IST
OR
Y noncontributory.
FA
MIL
Y
HIS
TO
RY
None had
similar
problem
GINGIVA
Hyperemic and edematous gingiva.
No gingival enlargement
ORAL HYGIENE
Poor
Clinical crown length
Adequate
Case report
17 16 55 14 13 52 11 21 22 24 25 26
46 85 44 83 42 41 31 32 73 44 75 36
Clinically short
Yellow-brown coloured
Loss of contact
• CROWNS
Decreased –vertical dimension
Case report
Panoramic
view
Intraoral
periapical
radiographs
Periodontal therapy
Oral hygiene instructions, scaling, and root planning.
Prosthodontic rehabilitation
Full-mouth metal reinforced porcelain
fixed bridge restoration
Advised and motivated for maintenance of proper oral hygiene & Repeated follow ups
2 WEEKS -
NORMAL
GINGIVA
VERTICAL
DIMENSION
NORMAL
ESTHETIC OR
FUNCTIONAL
PROBLEMS
Case report
DISCUSSION
Introduction
Tooth enamel consists mainly of inorganic material (96%) and oraganic
substance and water(4%)
Physical properties and physiological function of enamel – directly
related to composition, orientation, disposition and morphology of
mineral components within tissue
During organogenesis, enamel transitions from soft to pliable tissue to
its final form- is devoid of protein
Final composition is reflection of unique molecular and cellular
activities that take place during its genesis
Deviation from this pattern lead – AMELOGENESIS IMPERFECTA
SYNONYMS
Hereditary enamel dysplasia
Hereditary brown enamel
Hereditary brown opalescent teeth
“AI encompasses a complicated group of conditions that demonstrate
developmental alterations in structure of the enamel in the absence of
a systemic disorder”
“AI represents a group of conditions, genomic in origin, which affect the
structure and clinical appearance of the enamel of all or nearly all the
teeth in a more or less equal manner, and which may be associated
with morphologic or biochemical changes elsewhere in the body”
Orphanet Journal of Rare Diseases 2007,
2:17
Definition
Historical background
Spokes in 1890,
described "brown
teeth" with a familial
history.
In 1907 Turner described
some cases of
hereditary hypoplasia of
teeth in five generations
of same family
Weinmann & associates in 1945 –
introduced term “AMELOGENESIS
IMPERFECTA” – it is an ectodermal
disturbance, mesodermal components
are normal
ETIOLOGY
Dental enamel is a highly mineralised tissue
Derived through the synthesis and secretion of proteins
Formation of this highly organised and unusual structure is controlled in
ameloblasts through interaction of a number of organic matrix molecules
Development of normal enamel occurs in three stages
1. Formative stage – deposition of organic matrix – Hypoplastic AI
2. Calcification stage – matrix is mineralized –Hypocalcified AI
3. Maturation stage – crystallites enlarge and mature –
Hypomaturative AI
ETIOLOGY
Genes and phenotypes
Proteins/ enzymes
forming enamel
Type of AI Inheritance
1 Amelogenin Diffuse smooth
hypoplastic &
hypomaturation
X linked
2 Ameloblastin Hypocalcified AD
3 Enamelin Hypoplastic AD, AR
4 Tuftelin hypoplastic AD,AR
5 Kallikrein Hypomaturation AR
6 Matrix metalloproteinase Pigmented
hypomaturation
AR
Modes of Mendelian Inheritance Associated with AI
https://www.google.co.in/search?q+phenotype
CLASSIFICATION
Sekar B, Dominic Augustine, Murali S.
Amelogenesis Imperfecta - A Case Report with
Genetic Transmission. IJDA, 2(4), October-
December, 2010 395.
Hypoplastic
Hypocalcified
By Weinnman et al (1945)
BASED ON CLINICAL, MICRORADIOGRAPHIC
AND HISTOPATHOLOGICAL FINDINGS BY
Darling (1956)
Hypoplastic
Group 1 – gen pitting
Group 2- vertical grooves
Group 3- gen hypoplasia
Hypocalcified
Type 4A- chalky, yellow, brown enamel
Type 4B- marked enamel discolouration 7 softness with post
eruptive loss of enamel
Type 5- gen/ localized discolouration and chipping of enamel
By Witkop
(1957)
Hypoplastic
Hypocalcification
Hypomaturation Pigmented
hypomaturation
Local hypoplasia
By Schulze
(1970)
Type 1 hypoplastic Specific features , inheritance
1A Hypoplastic, pitted AD
1B Hypoplastic, local AD
1C Hypoplastic, local AR
1D Hypoplastic, smooth AD
1E Hypoplastic, smooth x-linked D
1F Hypoplastic, rough AD
Typw 2 hypomaturation
2A hypomaturation
2B hypomaturation
2C Snow capped teeth, x linked
2D AD
Type 3 hypocalcification
3A AD
3B AR
Type 4 Hypomaturation- hypoplastic with taurodontismType 4A Hypomaturation- hypoplastic with
taurodontism AD
Type 4B Hypoplastic- hypomaturation with taurodontism AD
Neville BW, Douglass DD, Allen CM, Bouquot JE. Abnormalities of teeth. In: Oral and Maxillofacial Pathology. 2nd ed.. Pennsylvania:Elsevier;2004. 89
Prevalence range from 1 in 718 to 1 in 14,000, depending on the
population studied.
Hypoplastic AI represents 60 – 73% of all cases,
Hypomaturation AI represents 20 – 40%, and
Hypocalcification AI represents 7%
Prevalence
Clinical features
Hypoplastic type
Gen. pitted
Localized pitted
Diffuse smooth
Diffuse rough
ADLocalized pitted
Enamel Agenesis
AR
Males
Females
X-linked
Hypoplastic type – autosomal dominant
GENERALIZED PITTED
• Thin enamel
• Open contact
• Pinpoint to pinhead pits
• Newly erupted teeth: hard with normal yellow-white colour
• Staining of teeth-exposure to oral environment- black appearance
LOCALIZED PITTED
• Linear depression/ large area of hypoplasia
• Prominent on buccal surface
DIFFUSE SMOOTH
• Thin, glossy with smooth surface
• ¼ to 1/8 of normal thickness
• Yellow color –opaque to translucent brown
• Delayed eruption with alveolar resorption
DIFFUSE ROUGH
Hard with rough granular surface
White to yellowish white
Thicker enamel at cervical areas
https://www.google.co.in/search?q=amelogenesis+hypoplastic
Localized pitted
Severe form of AD
Enamel agenesis
Yellow colour like normal dentition
Surface is rough & granular-ground glass
Complete lack of enamel formation
Multiple missing teeth
https://www.google.co.in/search?q=amelogenesis+hypoplastic
Hypoplastic type – autosomal recessive
Males
– Thin, hard, glossy
– Like crown preparations, open bite
– Opaque white to brown
Females
– Alternating vertical bands of normal and
abnormal enamel
https://www.google.co.in/search?q=amelogenesis+hypoplastic
Hypoplastic type – x-linked dominant
Hypoplastic amelogenesis
imperfecta, gen pitted pattern .
Note the numerous pinpoint pits
scattered across the surface of
the teeth. The enamel between
the pits is of
normal thickness. hardness. and
coloration.
Hypoplastic amelogenesis
imperfecta, autosomal dominant
smooth pattern.
Small. yellowish teeth exhibiting
hard, glossy enamel with open
contact Points and anterior
open bite.
Neville BW, Douglass DD, Allen CM, Bouquot JE. Abnormalities of teeth. In: Oral and Maxillofacial Pathology. 2nd ed.. Pennsylvania:Elsevier;2004. 89-
Autosomal dominant
Autosomal recessive
Hypocalcific type
Thickness of enamel
Normal- hypoplasia( middle 3rd of labial surface)
Consistency of enamel
Soft – lost after eruption- scrapped with instrument
Colour of enamel
Newly erupted teeth- dull lustreless opaque, white, honey coloured or yellowish orange or brown
Significance :
Exposed dentin-
hypersensitive
anterior opn
bite
Rapid calculus
formation
Hypocalcified type – aD & AR
Neville BW, Douglass DD, Allen CM, Bouquot JE. Abnormalities of teeth. In: Oral and Maxillofacial Pathology. 2nd ed.. Pennsylvania:Elsevier;2004. 89-
Dentition exhibiting diffuse
yellow-brown discoloration .
Note numerous teeth with loss
of coronal enamel except for
the cervical portion.
Hypocalcified type – aD & AR
Extensive loss of coronal
enamel and the similar
density of enamel
and dentin.
Neville BW, Douglass DD, Allen CM, Bouquot JE. Abnormalities of teeth. In: Oral and Maxillofacial Pathology. 2nd ed.. Pennsylvania:Elsevier;2004. 89-
Autosomal dominant X linked recessive Autosomal recessive
Hypomaturative type
Commonly in males
Both in primary and permanent dentition
Primary teeth: ground glass opaque white appearance
Permanent teeth :mottled yellow white, may be darkened with absorption of stains
Tight contact point
Enamel approaches normal thickness.
Point of explorer can be forced into enamel
Hypomaturative type – autosomal dominant
Both in primary and permanent dentition
Enamel has milky to shiny, agar brown deeply stained on
contact with exogenous agents
Normal thickness. Chips away around
restoration
Forms large amount of calculus which
may contain pigment forming agents
Teeth may resorb within alveolus
https://www.google.co.in/search?q=amelogenesis+hypomaturative
Hypomaturative type – autosomal recessive
Snow capped
Zone of white opaque enamel on incisal
and
occlusal surface (1/4 to 1/3 of the surface)
Looks like fluorosis
Anteriors, premolars/molars
Both dentitions
https://www.google.co.in/search?q=snow+capped
Hypomaturative type – x linked recessive
Predominant defect – enamel hypomaturation
Enamel appears – mottled yellow-white to yellow brown
Pits are seen frequently on buccal surface of teeth
Radiographically – enamel appears similar to dentin
Large pulp chambers may be seen in single rooted teeth in
addition to varying degrees of taurodontism
Hypomaturation- hypoplastic with taurodontism – Autosomal dominant
https://www.google.co.in/search?q=amelogenesis+hypomatu+tauro
Predominant defect – enamel hypoplasia in which enamel is thin
but also hypomature
Radiographically-
Similar to hypomaturation-hypoplastic variant, except decrease
in thickness of enamel
https://www.google.co.in/search?q=amelogenesis+hypomatu+tauro
Hypoplastic - hypomaturation with taurodontism – Autosomal dominant
Radiographic features
Squarish type of crown being devoid of the normal mesial and distal contours
Normal enamel cap is missing and in its place a thin and opaque layer of enamel
Low or absent cusps, with serrations of varying sharpness
Lack of contrast between enamel and dentin
Obliteration of pulp chamber
Loss of contour Enamel Pulp chamber
https://www.google.co.in/search?q=amelogenesis+tauro
TYPE CLINICAL
APPEARANCE
ENAMEL
THICKNESS
HYPOPLASTIC
(TYPE I)
Crowns size : small to
normal, lack proxmal
contacts, color varies
from normal to opaque
white – yellow brown
Varies from thin and
smooth to normal
thickness with
grooves, furrows
and/or pits
HYPOMATURATIO
N
(TYPE II)
Varies from creamy
opaque to marked
yellow/brown, surface
of teeth soft and rough,
dental sensitivity and
open bite common
Normal thickness
with enamel that
often chips and
abrades easily
around restoration
HYPOCALCIFIE
D
(TYPE III)
Opaque white to
yellow-brown, soft
rough enamel surface,
dental sensitivity and
open bite common,
heavy calculus
formation common
Normal thickness
with enamel that
often chips and
abrades easily
HYPOMATURATIO
N/ HYPOPLASIA/
TAURODONTISM
(TYPE IV)
White/Yellow-
Brown mottled,
teeth can appear
small and lack
proximal contact
Reduced,
hypomineralized
areas and pits
RADIOGRAPHIC
APPEARANCE
INHERITANCE
Enamel has normal
to slightly reduced
contrast/ thin
Autosomal
dominant,
recessive, or X-
linked
Enamel has contrast
similar to or > than
dentin, unerupted
crowns have normal
morphology
Autosomal
dominant,
recessive, or X-
linked
Enamel has contrast
similar to or <
dentin, unerupted
crowns have normal
morphology
Autosomal
dominant, recessive
Enamel contrast
normal to slightly >
dentin, large pulp
chambers
Autosomal dominant
Neville BW, Douglass DD, Allen CM, Bouquot JE. Abnormalities of teeth. In: Oral and Maxillofacial Pathology. 2nd ed.. Pennsylvania:Elsevier;2004. 89-
Histopathological examination
Very thin enamel, voids within enamel & composed of laminations of
irregularly arranged enamel prisms
Enamel-dentin junction, show some exaggerated scalloping.
Areas of homogeneous aprismatic enamel or fused indistinct prisms, with
“a reduction in distance between enamel rod incremental lines”
https://www.google.co.in/search?q=amelogenesis+slides
Syndromes associated
Amelogenesi
s imperfect
with
taurodontism
Trichodentoo
sseous
syndrome
Tricho-dento-osseous syndrome. Dentition
exhibiting diffuse enamel hypop lasia and
hypomaturat ion. At birth, the patient
exhibit kinky "steel wool" hair texture
with time, the hair gets straightened.
Taurodontism of the first molar and the
enamel. which is thin and similar in density to
the dentin.
Neville BW, Douglass DD, Allen CM, Bouquot JE. Abnormalities of teeth. In: Oral and Maxillofacial Pathology. 2nd ed.. Pennsylvania:Elsevier;2004. 89-
Cone rod dystrophy
Kohlschutter-Tonz syndrome
Usher syndrome
Other syndromes
Non enamel anomalies seen
in Amelogenesis Imperfecta
Delayed tooth eruption
Congenitally missing
teeth
Anterior open bite
Taurodontism
Pulpal calcification
Root and crown
resorption
Hypercementosis
Root malformations
Malocclusion
Gingivitis
Diagnosis
Clinical diagnosis
Cheesy consistency of
enamel with loss of
enamel
Radiographic diagnosis
Missing enamel cap with
low or absent cusp
Differential diagnosis
Dental fluorosis Dentinogenesis imperfecta
Management
Cosmetic
improvement Desensitizing
agent
Prosthetic
rehabilitation
https://www.google.co.in/search?q=amelogenesis+treat+crowns
Reason for choosing this article
Developmental disorder presents with severe dental anomalies. Its important to diagnose the condition as early as possible to balance the decision for early intervention and long-term survival of therestorations. Also consider the social implications for these patients and intervene to relieve their suffering. Thus, this article is anattempt to improve the clinician’s knowledge about the clinical & radiographic diagnosis as well as intervention required for such a condition.
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