Definition: A single developing tooth germ attempts to divide but is incomplete resulting in an abnormally larger than normal tooth. The overall tooth count is still 16 for an arch. This is sometimes referred to as twinning.
Location: More common in primary teeth in the anterior but can occur anywhere (maxillary and mandibular teeth)
Shape: Tooth shape.
Internal: Radiopaque and radiolucent. Radiopacity of tooth structure (enamel and dentin). Radiolucency of soft tissue (pulp chamber and root canal space).
Number: May be single or multiple.
Mandibular third molar
(looks like two molars creating one massive molar)