Mesiodentes in twins: a case report and a review of the literature.

This report describes 7-year-old Afro-Caribbean monozygotic twin boys who both presented with bilateral unerupted mesiodentes palatal to the central incisors. There have been two previous similar reports. From this case and previous reports it was concluded that mesiodentes in monozygotic twins are likely to be concordant with respect to the number of supernumerary teeth. Unilateral mesiodens usually have been mirror imaged in each twin. Minor discordance between monozygotic twins is common with respect to the shape (conical, incisiform or tuberculate) and orientation (inverted or normal) of individual mesiodens within and between each twin.