Tooth morphogenesis: the role of the innervation during induction and pattern formation.

The hypothesis is discussed that the innervation of the early mandibular and maxillary processes influences the initiation and patterning of tooth germs. Silver staining of embryonic mouse tissue supports the notion that the innervation is present before tooth buds appear. Data from other experimental studies is discussed in support of this hypothesis. The importance of the early events of tooth morphogenesis in initiating and patterning the dentition is discussed in the context of tooth morphogenesis as a whole. The processes involved in odontogenesis are categorized as Phase I: Initiating events; Phase II: Histogenetic events; and Phase III: Cytodifferentiative events. The complications of the interrelationship of these three seemingly discrete segments of tooth development are discussed in the context of inductive tissue interaction.