'Double' teeth-a diagnostic conundrum.

A 'double' tooth is an uncommon dental developmental anomaly that can occur in the deciduous and/or permanent dentition. It is not always possible to differentiate clinically between fusion and gemination. Clinical and radiographic examination, as well as a histological assessment, can help to differentiate between fusion and gemination. A case of fusion in the deciduous dentition is presented to demonstrate the diagnostic differences but also, more importantly, to draw attention to the potential impact of 'double' teeth on the developing secondary dentition and its future management.