2. What is dentinogenesis
Introduction to dentinogenesis
Classification
Etiology
Clinical features
Radiographic features
Histopathologic features
Treatment
imperfecta
3.
Dentinogenesis is the formation of dentin, which
starts before amelogenesis.
Dentin is formed by odontoblast cells.
Dentinogenesis takes place in two phases:
1. formation of organic collagen matrix
2. deposition of hydroxyapetite crystals
4.
Is an inherited disorder of dentin
formation
Autosomal dominant condition
Affects deciduous and permanent teeth
5. SHIELDS CLASSIFICATION
1. TYPE - I
2. TYPE - II
3. TYPE- III
1.
REVISED CLASSIFICATION
DENTINOGENESIS IMPERFECTA 1
DENTINOGENESIS IMPERFECTA 2
WITKOP CLASSIFICATION
1. DENTINOGENESIS IMPERFECTA
2. HEREDITARY OPALASCENT DENTIN
3. BRANDYWINE ISOLATE
6.
TYPE I: Occurs in patients affected with
osteogenesis imperfecta
TYPE II : Is not associated with osteogenesis
imperfecta
TYPE III: “Brandywine type” rare condition,
seen in racial isolate of Maryland, exhibits
multiple pulp exposures and periapical lesions
in deciduous dentition.
7. DENTINOGENESIS IMPERFECTA 1
Without osteogenesis imperfecta
Corresponds to type II of shields classification
DENTINOGENESIS IMPERFECTA 2
Corresponds to type III of shields classification
THERE IS NO SUBSTITUTE IN THE PRESENT
CLASSIFICATION FOR THE CATEGORY
DESIGNATED AS TYPE I IN THE SHIELDS
CLASSIFICATION
9.
MUTATION IN THE DENTIN SIALO PHOSPHO
PROTEIN (DSPP) gene ENCODING DENTIN
PHOSPHOPROTEIN AND DENTIN SIALOPROTEIN
10.
Clearly distinct from osteogenesis imperfecta with
opalescent teeth & affects only the teeth
No increased frequency of bone fracture is seen
Frequency: 1 in 6000-8000
12.
Some researchers say it is a separate mutation from DGI 1
Shield et al 1973 stated that markedly enlarged pulp chambers
and pulp exposures occurs in deciduous teeth do not occur in
DGI 1
Witkop 1975 suggested both are same
Recent studies suggests both are result of mutation in two tightly
linked genes
MacDougall et al 1999 stated DGI 2 differ from DGI 1 by the
presence of multiple pulp exposures normal non mineralized pulp
chambers ,and general appearance of shell teeth
13.
Affects males and females equally
Teeth are blue gray or amber brown and opalescent
Few days after eruption teeth may achieve a normal
color, following which they become translucent
14.
Finally become gray or brown with bluish reflection from
enamel
Enamel may split readily from dentin when subjected to
occlusal stress
Severe attrition of teeth
Obliterated pulp chamber
Sauk et al (1976)increase in glycosaminoglycans in edta
soluble dentin in teeth from patients with this disorder as
compared to controls and less gag in edta insoluble residue
15.
Teeth are not sensitive
Dentin is soft and easily penetrable but not caries prone
because of structural change in dentin
In some case there may be hypomineralised area on
the enamel
16.
Bulb shaped or bell shaped crowns of teeth with
constricted cervical areas
Roots - thin and spiked
Obliteration of coronal and radicular pulp chamber
depending on age
Cementum, alveolar bone and PDL appears normal
Type 2large pulp chambers with thin shell of dentin
and enamel “shell teeth”
17.
18.
Enamelnormal
Mantle dentin (narrow zone of dentin below
enamel)normal
Remaining dentin severely dysplastic with
vast areas of amorphous matrix with globular or
interglobular foci of mineralization
Reduced number of dentinal tubules
19.
Tubules distorted, irregular in shape, widely spaced
,larger in size
Absence of odontoblastic processes and presence of
degenerating cellular debris instead
Large area of atubular dentin
Pulp chamber and root canal obliterated by abnormal
dentin deposition
DEJ smooth or flattened instead of scalloped
(responsible for early chipping of enamel)
20. Increased
water content (60 % than
normal)
Decreased mineral content
Density, x-ray absorption and hardness
are low
Micro hardness near to cementum
21. AIMED AT PREVENTING LOSS OF ENAMEL AND
DENTIN THROUGH ATTRITION
Mild –moderate cases (no enamel loss or rapid
wear of teeth)
1. Routine restorative techniques Eg:amalgam,
composite
2. Bonding of veneers for esthetics as they mask
opalescence of anterior teeth
3. Bleaching to an extend lightens the color
22. Severe cases: (significant enamel loss and rapid
wear)
1. Full coverage crown restoration
2. Primary teeth
stainless steel in posteriors
stainless steel with open face
anterior teeth
3. Permanent
composite for
teeth porcelain fused metal crowns
23.
24.
25. Shafer’s
text book of oral pathology (6 th
edition)
Oral
and maxillofacial pathology-Neville
(3rd edition)
Teeth are not sensitive even if most of the surface enamel is lost as dentinal tubules are haphazardly arranged and most of them are devoid of odontoblastic processes
little scope for microorganism entry due to obliterated dentinal tubules