Abstract
Recent studies on prenatal innervation of the jaws have shown that three separate main innervation paths, constituting three bilateral neural developmental fields (incisor field, canine/premolar field, molar field) exist in each jaw. In this communication the sequences in which the fields are innervated are indicated. These correspond to the sequences of formation of teeth and jawbone. The normal pattern of tooth agenesis is closely related to the neural fields, as the region within a single field where innervation occurs last is always the area most often affected by tooth agenesis. The initial manifestations of juvenile periodontitis also appear at the sites within the different fields where innervation occurs last. It is suggested that the pubertal growth of the alveolar process does not occur in these regions due to deficient innervation, and that the infection in juvenile periodontitis might be secondary to this regional lack of bone apposition.