The following radiograph shows:
Gemination
Geminated teeth are anomalies which arise from an attempt at the division of a single tooth germ by an invagination, with resultant incomplete formation of two teeth. The structure is usually one with two completely or incompletely separated crowns that have a single root and root canal. It is seen in deciduous as well as permanent dentition, and in some reported cases, appears to exhibit a hereditary tendency. It is not always possible to differentiate between gemination and a case in which there has been a fusion between a normal tooth and a supernumerary tooth.
Radiological signs
The tooth has a notched incisal margin with a confluent or partially joined pulp canal system.
Fusion in 22
Gemination in 22
Concrescence in 22
Dilaceration in 21