Aberrant root formation: review of root genesis and three case reports.

The mechanism of root formation and tooth eruption is a complex process which is not fully understood. Prior to a tooth emerging into the oral cavity, root genesis is initiated by derivatives of the enamel organ. The dental follicle mediates an eruption pathway allowing for movement of the developing tooth in a coronal direction. As the tooth moves towards the oral cavity, root formation occurs passively in the resulting space. Failure of the enamel organ and dental follicle to properly coordinate may result in complications in the eruption process. This clinical report presents 3 cases of isolated, unerupted teeth with dysmorphology of the roots. The process of root development and tooth eruption is also briefly reviewed.