development of tooth

DEVELOPMENT OF TOOTH
Topic : Five developmental disturbance of teeth
affecting the structure
Submitted by : Nafeesath shahana mahazi A.S
1. Amelogenesis imperfecta
• Amelogenesis imperfecta presents with abnormal
formation of the enamel or external layer of teeth.
Enamel is composed mostly of mineral, that is formed
and regulated by the proteins in it. Amelogenesis
imperfecta is due to the malfunction of the proteins in
the
enamel: ameloblastin, enamelin,tuftelin and amelogeni
n.
• People afflicted with amelogenesis imperfecta have
teeth with abnormal color: yellow, brown or grey. The
teeth have a higher risk for dental cavities and are
hypersensitive to temperature changes. This disorder
can afflict any number of teeth.
Amelogenesis imperfecta
2.Environmental Enamel Hypoplasia
• enamel hypoplasia,a defect in which the enamel of the
teeth is hard but thin and deficient in amount as a result of
defective enamel matrix formation with a shortage of the
cementing substance. It is characterized by lack of contact
between teeth, rapid breakdown of occlusal surfaces, and a
yellowish-brown stain that appears where the dentin is
exposed. The condition affects both primary and secondary
dentition. It is transmitted genetically or caused by
environmental factors such as vitamin A, C, or D deficiency;
fluorosis; rash-producing childhood diseases; congenital
syphilis; injury or trauma to the mouth; or administration of
tetracyclines during the second half of pregnancy or during
early tooth developmen
3.Dentinogenesis imperfecta
• Dentinogenesis imperfecta (hereditary Opalescent
Dentin) is a genetic disorder of tooth development.
This condition causes teeth to be discolored (most
often a blue-gray or yellow-brown color) and
translucent. Teeth are also weaker than normal,
making them prone to rapid wear, breakage, and loss.
These problems can affect both primary (baby) teeth
and permanent teeth. This condition is inherited in
an autosomal dominant pattern, which means one
copy of the altered gene in each cell is sufficient to
cause the disorder. Dentinogenesis imperfecta affects
an estimated 1 in 6,000 to 8,000 people.
4.Dentin dysplasia
• Dentin dysplasia is a genetic disorder of teeth, commonly
exhibiting an autosomal dominant inheritance. It is
characterized by presence of normal enamel but atypical
dentin with abnormal pulpal morphology. There are two
types. Type I is the radicular type, and type II is the coronal
type. In the radicular type, the roots of teeth are shorter
than normal and the pulp chamber may be nearly gone.
The pulp chamber is sometimes described as having a
"crescent shaped" appearance. In the coronal type, the
pulps are enlarged and are described as having a "thistle
tube" appearance, in permanent dentition. In the
deciduous dentition, coronal dentin dysplasia bears a
resemblance to Dentinogenesis Imperfecta type II.
Dentin dysplasia
5.Regional odontodysplasia
• Regional odontodysplasia or odontogenesis imperfecta is an
uncommon developmental abnormalityof teeth, usually localized to
a certain area of the mouth. The condition is nonhereditary. There
is no predilection for race, but females are more likely to get
regional odontodysplasia. The enamel, dentin, and pulp of teeth are
affected, to the extent that the affected teeth do not develop
properly. These teeth are very brittle. Onradiographs the teeth
appear more radiolucent than normal, so they are often described
as "ghost teeth".Most cases are considered idiopathic, but some
cases are associated with syndromes, growth abnormalities, neural
disorders, and vascular malformations. Permanent teeth usually
show effects of regional odontodysplasia if the deciduous tooth was
affected. Many of these teeth do not erupt with an increased risk
for caries and periapical inflammation.