<unk>  is a dental phenomenon that appears to be two teeth developed from one. There is one main crown with a cleft in it that, within the incisal third of the crown, looks like two teeth, though it is not two teeth. The number of the teeth in the arch will be normal.
Tooth gemination
Tooth fusion
Neural clique
Zona hatching
Labial fusion
Tooth regeneration
Sensory decussation
Vitreomacular adhesion