DEFINITION/OVERVIEW

Variation in tooth size
- Macrodontia: crown oversized, root normal
- Microdontia: crown normal shape, but small
- Peg tooth: small, cone-shaped tooth with a single cusp
Variation in tooth structure/shape
- Fusion: two separate tooth buds joined to form an entire single tooth or joined at the roots by cementum and dentin
- Gemination: developing tooth bud undergoes an incomplete split, resulting in two crowns with a common root canal
- Dilacerated: distorted or malformed tooth (crown or root); a general term that may be used for many different presentations
- Dens-in-dente (tooth within a tooth): external layers invaginate into internal structures with varying severity
- Shell teeth: crown present, but little to no root development
- Amelogenesis imperfecta: hereditary reduction in the amount of developed enamel matrix

ETIOLOGY/PATHOPHYSIOLOGY

Stress or stimulus (trauma) at time of development can alter tooth formation
- Infection, trauma to tooth buds, or traumatic extraction of deciduous teeth during permanent tooth formation can significantly alter the structure
Genetic or familial tendencies not known for most conditions
Dogs/cats

CLINICAL FEATURES

See “Definitions/Overview” section
Fusion: fused crown will be larger than a single tooth; there will be a reduced number of teeth (two counted as one)
Gemination tooth: actual number of teeth will be unaltered, but one tooth will be larger, with duplication of part of the crown (and possibly roots radiographically); “Siamese twin”
Dilacerated teeth
- Any variation in structure or form: extra root, curved root
- Each tooth must be evaluated for integrity of the pulp system, as any disruption in the continuity of the crown and roots may result in exposure of the pulp to the external environment (Fig. 18-1)

Figure 18-1 Extensive dilaceration at the palatal aspect of the right maxillary first molar. Pulpal exposure and compromise is likely.

Only gold members can continue reading. Log In or Register to continue

May 22, 2017 | Posted by admin in GENERAL | Comments Off