Amelogenesis

Amelogenesis is the formation of enamel on teeth and begins when the crown is forming during the bell stage of tooth development after dentinogenesis, which is the formation of dentin. Although dentin must be present for enamel to be formed, ameloblasts must also be for dentinogenesis to continue. A message is sent from the newly differentiated odontoblasts to the inner enamel epithelium (IEE), causing the epithelial cells to further differentiate into active secretory ameloblasts. Dentinogenesis is in turn dependent on signals from the differentiating IEE in order for the process to continue. This prerequisite is an example of the biological concept known as reciprocal induction, in this instance between mesenchymal and epithelial cells.