‘ DEVELOPMENTAL
DISTURBANCES
OF TEETH AFFECTING
THE
STRUCTURE’’
Developmental
disturbances means an
abnormality where the
pathology starts in the
embryonic stage of
human life, before the
formation of the
dentition.
Developmental disturbances in the structure of the teeth,
The enamel of primary and secondary dentition may be
affected by a number of genetic or congenital conditions.
There may be effects due to local problems such as trauma
during birth or infection. The most notable change affecting
all teeth is the result of amelogenesis imperfecta which is
genetic and may be dominant or recessive. It is an
ectodermal disturbance and the anomalies can range from
pits in the teeth to failure of enamel development. It may
be associated with osteogenesis imperfecta. By contrast,
dentinogenesis imperfecta affects the mesodermal portion
of the odontogenic apparatus. The appearance of the teeth
is variable with the poorly supported enamel taking on a
opalescent tinge. The enamel is readily damaged. Both
amelogenesis and dentinogenesis imperfecta result in
rapid early tooth loss.
Structure Of Teeth:
1.Amelogenesis Imperfecta
2.Environmental Enamel
3.Hypoplasia
4.Dentinogenesis Imperfecta
5.Dentin Dysplasia
6.Regional Odontodysplasia
7.Dentin Hypocalcification
1]Amelogenisis Imperfecta:* Represents a group of hereditary defects of
enamel un associated with any other generalised
defects.
* It is an ectodermal disturbance classified in to
1) Hypo plastic
2) Hypo calcified
3) Hypo maturation
Clinically the crowns of the teeth may or may not
show discolouration if present varies depending on the
type of disorder, ranging from Yellow to dark brown‡
In
some cases enamel may be totally absent r it may have
chalky texture or even a cheesy consistency or be
relatively hard ‡Sometimes the enamel is smooth or it may
have numerous parallel vertical wrinkles or grooves‡It
may be chipped or show depressions in the base of
whichdentin may be exposed ‡
Contact points between
teeth are often open and occlusal surfaces and incisal
edges frequently abraded
ENVIRONMENTAL ENAMEL
The carbon and oxygen isotopic composition of the mineral phase of tooth enamel is
linked to diet and environment. Enamel is not remodelled once formed. Several studies of
intra-tooth isotopic variability in hypsodont mammal teeth have involved sequential
sampling of enamel in order to detect changes in diet and environment during tooth
formation. The possibility of exploring individual history opens the door to many
applications, particularly in palaeoenvironment and herd management reconstruction.
However, previous histological investigations have shown that enamel mineralization is a
progressive and discontinuous process. The goal of the present study is to determine if this
pattern significantly influences the time resolution of an intra-tooth sequential sampling.
Isotopic analyses (δ13C) were performed on tooth enamel from steers (Bos taurus) that had
changed from a C3 plant-based diet to a C4 plant-based diet with very different carbon
isotopic compositions. The change of diet was reflected in the mineral phase of enamel.
The pattern of intra-tooth isotopic variation suggests that completion of enamel
mineralization required six to seven months. Such a lag in enamel mineralization will
decrease the time resolution of enamel sequential sampling. The effects of prolonged
mineralization of enamel have to be considered when interpreting patterns of intra-tooth
isotopic variations.
2]Enamel Hypoplasia:It is defined as a incomplete or defective formation of the
organic matrix of teeth
• A number of different factors each capable of
producing injury tothe amiloblast may give rise to this
condition
• .Causes are:
• -Nutitional deficiency ( Vitamin A,D,C )
• -Examthematous diseases ( Measels,chicken
fox,scarlet fever )
• -Congenital syphilis
• -Hypocalcemia
• -Birth Injury,prematurity, RH Heamolytc disease
• -Local Infection or Trauma
• -Ingestion of chemical such as flouride
•
•
•
•
•
Radiographically:The most striking feature is the partial or
total precocious
* Obliteration of the pulp chamberand root
cannals by continued formation of the dentin.
Chemical and physical features:Chemical analysis shows that type-1 &2&3
‡
increased water content as much as above
while the inorganic content is less than that of
normal dentin
Dentin dysplasia(rootless teeth):-It is
‡
a raredisturbance of dentin formation
characterized ‡
By normal enamel but atypical
dentin formation withabnormal pulpal
morphology.‡
Transmitted as an autosomal
dominant charac.
Regionalodontoplasia
‡ hey exhibit either delay or total failure
T
in eruption.‡
Show a marked reduction
in radiodensity , so that the teethassume a
ghost appearance
Disturbances in the growth
of the teeth:1.Premature eruption
2.Eruption sequestrum
3.Delayed eruption
4.Impacted teeth
5. Ankylosed teeth
Hypoplasia results only if the injury occurs
during the time the teeth developing or more
specifically during the formative stage of enamel
development.Once the enamel is calcified no
such defects can be produced
E.H due to exanthmatous fever:Pitting varilog and this pits tend to
‡
strain.The clinical apearances of it
mau be very unsightly.
E.H due to congenitalsyphilis:
-Involves the maxillary and mandibular permanent incisors
and the first molars
-The anterior teeth affected are called HUTCHINSONS TEETH
and molars are referred to as mulberry molars ,moon¶s
molars, fournier,s molars.
-The anterior teeth will be screw driver shaped ,themesial and
distal surfaces of the crown tapering and converging towards
the cervical margin and it could be due the absence of cental
tubercle or calcification center.
-In the first molar crowns ,the enamel of the
occlusal surfaces and the occlusal third of the tooth appears
to be arranged in an agglomerate mass of the globules
rather than in well formed cusps.
.
E:H due to flouride
The iungestion of the flouride containing drinking water during the
‡
time of tooth formation may result in Mottled enamel.
‡ he permissible amount flouride ,for the clinical significance is at a
T
level below 0.9to1 ppm of flouride.‡
Above this level it causes the disturbances
.‡
Questionable changes appear in the enamel like white fleckingor
spotting of the enamel.
‡ ild changes manifested by white opaque areas involving more of
M
the tooth surface area.
‡ oderate or severe changes showing pitting &brownish staining of
M
the surface and even a corode appearance of the teeth
Mild fluorosis
A mild case of dental fluorosis
Dental fluorosis
A severe case of dental fluorosis, or"mottled
dental enamel."
3]Dentinogenesis imperfecta
Type-1,type-2,type-3. are present.
‡
I‡n type-1deciduous dentition is
more affected than the permanent
teeth.
I‡n type-2 both the dentitions are
equally affected.
I‡n the type-3both the dentitions
are affected.
The enamel may be lost early through fracturing
away especially on the incisal or occlusal surfaces of
the teeth presumbaly because of an abnorma
dentinoenamel junction.
The scalloping of the D.E.J not formed.
‡
‡ adiographically :-the most striking feature is
R
the partial or total precocious obliteration of the pulp
chambers and root cannals by continued formation of
dentin
Type I Dentinogenesis Imperfecta
Regional odontodysplasia
Regional odontodysplasia is a localized disorder of tissues of
dental origin resulting in characteristically bizarre clinical and
radiographic appearances. It most commonly affects the
maxillary anterior teeth of both the permanent and primary
dentitions. The authors present a worldwide bibliography of
reported cases and discuss the suggested theories regarding the
condition's etiology. Although the majority of cases of regional
odontodysplasia must be regarded as idiopathic, various
developmental anomalies may produce identical changes in the
teeth in one or more quadrants. A number of previously
reported cases are also reconsidered with regard to their
diagnosis and guidelines are suggested for the treatment of
patients affected by regional odontodysplasia.
THANK
YOU