Developmental disorders of teeth

=Numerical Dissorders=

Hyperdontia
=Dissorders of Size=

Macrodontia
=Dissorders of Shape=

Gemination
2 teeth from 1 tooth bud

Fusion
Union between 2 or more separate teeth.

Dens Invaginatus
Deep invagination of crown or root lined by enamel

Taurodontism
Enlargement of body and pulp chamber of multirooted tooth

Hypercementosis
Nonneoplastic deposition of excessive cement

Accessory roots

 * Supernumerary roots


 * Dilaceration (root bends)

=Dissorders of Structure=

Amelogenesis Imperfecta
It is a hereditary enamel defect. Autosomal dominant, recessive or x-linked patterns.

3 main types

 * Hypoplastic: decreased enamel matrix production.


 * Hypomineralised: hypocalcified or hypomaturation.


 * Mixed

Hypocalcified:enamel is dull opaque white or honey colour

Hypomaturation: similar to hypocalcified except no normal enamel is present at cervical regions.

Dentinogenesis Imperfecta
Teeth are opalescent and on transillumination appear bluish or brownish.

Early loss of enamel exposing underlying dentine.

Transmition is usually autosomal dominant.

Dentine Dysplasia
Autosomal dominant

absent
 * Type1: rootless teeth:crown colour is bluish or brownish short blunt roots, pulp chambersmall and root canals


 * Type2: coronal dentine dysplasia

=Eruption and exfoliation disorders=

Premature eruption
Endocrine abnormalities : e.g. increased growth hormone. In children with a high birth weight

Delayed eruption
associated with Down,Turner Syndrome, nutritional def. in children with a very low birth weight

Premature exfoliation
Apart from trauma it can be also due to hypophosphatasia.

Delayed exfoliation
In ectopic permanent successors.