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Structural diseases in childhood
Abnormalities of tooth
structure
Defective enamel (dentin) formation may be caused by genetic or
environmental factors
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Dental enamel
• Dental enamel is a highly mineralized tissue with over 95% of its
volume occupied by unusually large, highly organized, hydroxyapatite
crystals.
Enamel
• Dental enamel, the most highly
mineralized structure in the
human body, is formed within a
unique, extracellular matrix
derived through the synthesis
and secretion of proteins by the
ameloblast cells.
Enamel
• Proteins in the enamel: ameloblastin, enamelin, tuftelin, amelogenin
etc..
• AMELX, ENAM, MMP20, KLK-4 etc genes provide instructions for
making protein that are essential for the normal development.
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Enamel formation
Dental enamel formation is divided into:
• pre-secretory,
• secretory,
• transition,
• maturation stages
Enamel
• The main structural proteins in forming enamel are amelogenin,
ameloblastin, and enamelin.
• During the secretory stage, enamel proteins are being secreted along
with proteases, creating a complex mixture of enamel matrix
constituents.
• During the transition stage there is an increase in proteolytic
activity, and in maturation stage the accumulated enamel proteins
nearly disappear from the matrix.
• Amelogenin: more than 90% of total enamel protein
• Ameloblastin: 5%
• Enamelin: 2% of total protein
Amelogenin
• Amelogenin is thought to form a scaffold for enamel crystallites and
to control their growth, but its exact functions are not fully known.
• At least 15 mutations
Ameloblastin (Amelin)
• Ameloblastin, also known as amelin, is expressed by the enamelproducing ameloblast cells
• the ameloblastin gene is located in chromosome 4
• ameloblastin is a key adhesion molecule for enamel formation and
suggest that ameloblastin plays an important role by binding to, and
maintaining the differentiated phenotype of secretory ameloblasts.
Enamelin
• Enamelin, the largest enamel extracellular matrix protein,
• It is produced by ameloblasts, initially during the secretory stage.
• At least 7 mutations
Metalloproteinase MMP20
PROTEINASES
• Different proteinases, serving different functions. These proteinases
are believed to regulate the enamel matrix protein processing that
ultimately defines the structure and composition of enamel. The
predominant proteinases are matrix metalloproteinase-20 in
secretory enamel matrix
• At least 2 mutations
3 level:
• Hypoplasia
• Hypocalcification
• hypomaturation
Amelogenesis imp.
Can have different inheritance pattern depending on the gene that is
altered.
ENAM – autosom. Dom (AD)
ENAM and MMP20 – autosom. Rec (AR)
AMELIX – X linked
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Classification (Witkop)
Amelogenesis imperfecta
• Represents a classic example of heritable enamel defect
• All teeth involved
• There are 14 subgroup classifications
• The prevalence varies from 1:700 to 1:14,000, according to the
populations studied
- Hypoplastic type- insufficient quantity of enamel is formed
- Hypocalcification type- quantity normal but the matrix is poorly calcified
- Hypomaturation type- low value of radiodensity and mineral content
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Amelogenesis imp.
• Amelogenesis imp. Classification based on the mode of inheritance :
autosomal dominant, autosomal recessive, X-linked or apparently
sporadic
• A. dominant – male and female are equally affected, both dentition
involved
amelogenin gene on the chromosome 4 has been shown to be
mutated
• A. recessive in isolated communities when the parents are close
relatives, first cousins..
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Diagnosis based on the phenotype
(appearance), and the mode of inheritance
TYPE I: HYPOPLASTIC AI
• All of the hypoplastic AI subtypes are characterized by the primary
feature of deficient amount of enamel formed. The decreased amount
of enamel varies in the different subtypes and can be characterized by
enamel that is pitted, has grooves or furrows, has large areas of missing
or very thin enamel surrounded by more normal enamel, or enamel that
is very thin over the entire tooth crown
• Crowns size varies from small to normal, small teeth may lack proximal
contacts, color varies from normal to opaque white – yellow brown
AI type I, hypoplastic X-linked
• Heterozygous females can pass on the mutant gene to children of either
sex with the risk of this being 50%. The condition affects males and
females in different ways.
• Males may have teeth which have only a thin layer of enamel of normal
color and translucency, or the enamel may be of normal thickness but
poorly mineralized with loss of translucency and/ or a yellow-brown
discoloration
AI type I, hypoplastic X-linked
• Females may have teeth with vertical ridges and grooves as a result
of hypoplasia of the enamel or have vertical bands of alternating
normal and discolored enamel.
Amelogenesis imperfecta AD
• Autosomal dominant AI typically affects one or more individuals in each
generation of a family
• The phenotype in AI - AD may be predominantly or exclusively
hypoplastic, manifested by thin enamel and spacing between the teeth,
roughness, irregular or randomly pitted enamel.
Autosomal recessive AI
• This may more often occurs in certain ethnic and cultural groups where
intermarriage within the family is more common.
• Enamel pitting with an anterior open bite
Type II. hypomaturation AI
• Commonly associated with an open bite and creamy to yellow-brown
roughly surfaced teeth that may be tender and sore.
• The enamel is generally normal in thickness but is unusually brittle.
• Can be autosomal dominant, autosomal recessive, or X-linked.
Type III. hypocalcified AI
• Open bite and creamy to yellow-brown rough enamel-surfaced teeth
that may be tender and sore.
• The enamel is soft and may be lost soon after eruption leaving the
crown composed only of dentin. The enamel has a cheesy consistency
and can be scraped from the dentin
• Large masses of supragingival calculus become deposited on the teeth
AI – IV Type
• A variant with taurodontism.
• The sheath of Hertwig, that maps the shape of the roots of teeth, is
a derivative of the enamel organ and is also responsible for
differentiation of the inner dental epithelial cells to ameloblasts
producing enamel proteins
• smaller than normal teeth, the color of which may range from white
to yellow-brown, and teeth that appear to be mottled or spotted. The
enamel is thinner than normal with areas that are clearly less dense
(hypomineralized) and pitted. Genetically these characteristics are
transmitted as autosomal dominant traits.
Environmental enamel hypoplasia
Environmentaly induced enamel hypoplasia can result from systemic or local causes.
Factors: (mother side)
nutrition defiences
fever producing disorders
severe infections (rubeole,
syphilis)
asthma
endocrine disturbances
drugs
radiation
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Environmental enamel hypoplasia
Factors: (child side)
neorologic defects (cerebral palsy)
asthma
irradiation
drugs (chemotherpy, steroid, antibiotics,
endocrine diseases
imundefficiency
systemic diseases
LOCAL: trauma, caries,
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tetracyclin, fluorid etc.
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Chronological line
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Defective enamel formation
• Will exhibit either hypoplasia or hypocalcification
and hypomaturation.
• The neonatal line is manifest in all teeth, but
unless there is severe hypoxia or fetal distress
the disturbance will not be clinically evident
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Linea neonatalis
We must decide whether it is
• Caries incipiens – macula
cretosa (White spot) or a
structural disease
What helps:
•
•
•
•
anamnesis
Oral hygiene
Family anamnesis
Dietary information
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Hypoplasia or early childhood caries?
Turner tooth
Structural disease follows chronology
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Chrological line
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hypolasia
Fewer induced hypoplasia
Chemotherapy induced hypoplasia
and short roots
Fluorosis
• Depends on the age. It is critical in 2-3 years , when the fluoride is
more than 1 ppm (part per million )
• Be careful! Tooth paste, drinks, tea etc
• Dose dependent
Fluorosis
Tetracycline
• Since their introduction in 1947, tetracyclines have been used in the
treatment of various infections
• Doxycycline is a semi-synthetic, lipophilic and potent tetracycline
congener
• causing enamel hypoplasia and irreversible staining of decidious teeth,
staining of the permanent adult dentition
• results from the formation of insoluble tetracycline-calcium
orthophosphate complexes which are deposited in dentine and enamel
and darken upon exposure to light
• Calcification of permanent teeth begins around 4-6 months of life and is
largely complete by 5-6 years. But do not give it before 8-9 years of life!
• Vital bleaching with H2O2 and composite/porcelain veneers/crowns
remain as the best possible therapeutic approaches
Congetital syphilis
Moon’s (mulberry) molars
Hutchinson’s incisors
Celiac disease(gluten intolerance)
The enamel pitted, grooved or missing
Late eruption and frequent aphtosis,
ulcerations
Vitamin D deficiency
Non-Hodgkin lymphoma
Molar hypoplasia or hypomineralization (MH)
• Only the molars are involved
MIH –molar incisal hypomineralization or
hypoplasia
• Not only the first molars but! the incisors as well
• Different severity, opacity or loss of the whole enamel
• FDI 1992 Modified defect of dental enamel (DDE)
depends on the severity:
mild enamel < 30% affected
moderate – 31-50%
severe – 50% or more
signs
• Discoloration, opacity, enamel loss
• hypersensitivity
• Inability to anesthetize
• Rapid caries progression
Causes:
• Pre- and postnatal diseases Low birth weight
• Antibiotics –Amoxicillin!
• Prolonged breast feeding(dioxin)
• Otitis media, pneumonia
• Asthma
• Urinary tract infections
• Measles
Az amoxicillin and fluoride!!
According to Van Amerongen
• The MIH severer than MH
• The primary etiological factors of MH : 48% delivery problems, 67%
respiratory infections
• MIH : antibiotics, and/or other medicaments, otitis, long lasting fewer,
early childhood infective diseases
Weerheijm classification:
• Opacity –
• PEB - post eruptive enamel breakdown
• Atypical restorations
• Extractions due to MIH
Treatment
• Risk assessment
• Early diagnosis
• Remineralization (MI Paste)
• Prevention (fissure sealing, fluoride, sensitive toothpaste)
• Restoration (GIC???)
• Crowns
Dentin hypoplasia
The condition causes the teeth to be discolored ( blue-gray, yellowbrown color) The teeth are also weaker, prone to rapid wear,
breakage and loss
Type I is in connection with osteogenesis imperfecta-bone are brittle
and easily broken
Type II and III with or without other inherited disorders
Type II – hearing loss
Type III – Brandywine type
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Dentinogenesis imperfecta
• Mutation of the DSPP gene can cause type II and III. Type I occurs as
part of the osteogenesis imperfecta, which caused by mutation
several other genes.
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Dentinogenesis imperfecta
•
•
•
•
Both in primary and permanent
In primary severe
inherited
Same as in amelogenesis
imperfecta:
• hypoplasia
• hypocalcification
• hypomaturation
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• Teeth are weaker than normal, making them prone to rapid wear,
breakage, and loss
• Radiographically, the teeth have bulbous crowns with constricted
short roots. Initially, pulp chambers may be abnormally wide and
resemble “shell teeth
• The presence of an atubular area in the dentin with reduced
mineralization and a reduced number of odontoblasts are consistent
findings.
• Pulpal inclusions and much interglobular dentin are also frequent.
• Attrition may cause pulpal involvement with dental abscesses,
• The short, constricted roots might break under load, thus
necessitating extraction.
• The severe attrition may result in a rapid decrease in the occlusal
height.
• 1. Maintain dental health and preserve vitality, form, and size of the
dentition.
• 2. Provide the patient with an esthetic appearance at an early age, in
order to prevent psychological problems.
• 3. Provide the patient with a functional dentition.
• 4. Prevent loss of vertical dimension.
• 5. Maintain arch length.
• 6. Avoid interfering with the eruption of the remaining permanent
teeth.
• 7. Allow normal growth of the facial bones and temporomandibular
joint (TMJ).
• 8. Establish a rapport with the patient and the patient’s family early
in the treatment
• In the early primary dentition, soon after eruption it is generally
necessary to protect the primary molars with stainless steel crowns.
• In the restorative treatment of pediatric patients, glass ionomer with
fluoride-releasing and chemically attaching materials are
recommended for occlussally non-stressed areas
• Polycarbonate crowns may offer an alternative for the restoration of
the anterior primary teeth.
• An acrylic overlay denture, resting over the remnants of crowns and
roots of the primary dentition, also has been used successfully.
• Dentinogenesis imperfecta estimated prevalence
1: 6,000 - 8,000.
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Dentinogenesis
Imperfecta
Osteogenesis imperfecta
Dentin Dysplasia
• Dentin Dysplasia (DD), a rare anomaly is an autosomal dominant
hereditary disturbance in dentin formation affecting either the
primary or both the dentitions in approximately one patient in every
100,000
Dentin Dysplasia
• Type I DD is characterized by crowns appearing normal or might be
slightly amber colored with no or only rudimentary root
development, aberrant growth of dentin in the pulp chamber leading
to reduced pulp space in permanent teeth and incomplete or total
obliteration of the pulp chambers, and periapical radiolucent areas or
cysts which might result in premature loss of tooth
Dentin Dysplasia
• DD type II is characterized by yellow, brown, grey amber, translucent
primary teeth with complete pulpal obliteration. The permanent
teeth have a normal appearance or might be slightly amber colored.
Roots are normal in size and shape with a ‘thistle tube’ shaped pulp
chamber with pulp stones. Obliteration of pulp chamber does not
occur before eruption
Regional odontodysplasia
• rare, severe developmental anomaly affecting the formation of the
teeth.
• affects the structures derived from epithelial and mesenchymal
components of the teeth, which include enamel, dentin, pulp, and
the dental follicle.
• The roots are short with open apices and the pulp appears much
larger than normal with little definition or contrast within the tooth
structures.