Delayed eruption of the primary teeth may only require confirmation that all teeth are present. Alternative terminology for this condition is fusion, gemination, connation, schizodontia, and dichotomy. This may explain the relatively large size of this tooth. If it occurs in the primary teeth, it is more likely to occur in the permanent teeth. Technically, fusion is different from gemination.
Fusion is the joining of two teeth by the pulp tissue and the dentin.
The detin is the layer underneath the enamel. Enamel is the outer layer of tooth structure. This larger tooth may originate from two tooth germs. If two regular tooth germs fused, the number of teeth in the arch will be reduced by one. Gemination is the budding of a second tooth from one tooth germ.