Tooth fusion

Overview
The phenomenon of tooth fusion arises through union of two normally separated tooth germs, and depending upon the stage of development of the teeth at the time of union, it may be either complete or incomplete. On some occasions, two independent pulp chambers and root canals can be seen. However, fusion can also be the union of a normal tooth bud to a supernumerary tooth germ. In these cases, the number of teeth is also normal and differentiation from tooth gemination may be very difficult, if not impossible. In geminated teeth, division is usually incomplete and results in a large tooth crown that has a single root and a single canal. Both gemination and fusion are prevalent in primary dentition, with incisors being more affected.

Tooth gemination, in contrast to fusion, arises when two teeth develop from one tooth bud and, as a result, the patient has a larger tooth but a normal number.

Related abnormalities of the dentition

 * Amelogenesis imperfecta
 * Dentinogenesis imperfecta
 * Hyperdontia - More than the average number of teeth
 * Anodontia - Lack of tooth development