Developmental disorders of teeth

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

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

absent

• 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.