Developmental disorders of teeth

From WikiLectures

Numerical Dissorders[edit | edit source]

Hypodontia[edit | edit source]

Oligodontia[edit | edit source]

Hyperdontia[edit | edit source]

Dissorders of Size[edit | edit source]

Microdontia[edit | edit source]

Macrodontia[edit | edit source]

Dissorders of Shape[edit | edit source]

Gemination[edit | edit source]

2 teeth from 1 tooth bud

Fusion[edit | edit source]

Union between 2 or more separate teeth.

Dens Invaginatus[edit | edit source]

Deep invagination of crown or root lined by enamel

Taurodontism[edit | edit source]

Enlargement of body and pulp chamber of multirooted tooth

Hypercementosis[edit | edit source]

Nonneoplastic deposition of excessive cement

Accessory roots[edit | edit source]

  • Supernumerary roots
  • Dilaceration (root bends)

Dissorders of Structure[edit | edit source]

Amelogenesis Imperfecta[edit | edit source]

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

3 main types[edit | edit source]

  • 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[edit | edit source]

Teeth are opalescent and on transillumination appear bluish or brownish.

Early loss of enamel exposing underlying dentine.

Transmition is usually autosomal dominant.

Dentine Dysplasia[edit | edit source]

Autosomal dominant

  • 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[edit | edit source]

Premature eruption[edit | edit source]

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

Delayed eruption[edit | edit source]

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

Premature exfoliation[edit | edit source]

Apart from trauma it can be also due to hypophosphatasia.

Delayed exfoliation[edit | edit source]

In ectopic permanent successors.