Teeth develop as epidermal appendages from reciprocal inductive interactions between the epithelium and the mesenchyme. The morphological and molecular mechanisms defining tooth formation are highly conserved and resemble the morphogenesis of other epithelial organs such as lung, hair or kidney. Indeed, tooth development presents a powerful system for the understanding of more general questions of organogenesis. In recent years, the mechanisms underlying tooth formation and disease have been elucidated by the identification of causative genes in human malformation syndromes, the generation of genetically manipulated mice, and tissue recombination experiments. In the future, it is conceivable that molecular findings may lead to a regrouping of tooth malformations in genetic terms. In this paper we present an overview covering molecular concepts of tooth development and malformation conditions based on orthodontic findings, taking into account recent molecular and developmental insights.
amelogenesis imperfecta, dentinogenesis imperfecta, supernumerary teeth, hypodontia, tooth development