<P> Accessory canals are pathways from the radicular pulp, extending laterally through the dentin to the periodontal tissue seen especially in the apical third of the root . Accessory canals are also called lateral canals, because they are usually located on the lateral surface of the roots of the teeth . </P> <P> The pulp has a background similar to that of dentin, because both are derived from the dental papilla of the tooth germ . During odontogenesis, when the dentin forms around the dental papilla, the innermost tissue is considered pulp . </P> <P> The central region of the coronal and radicular pulp contains large nerve trunks and blood vessels . </P> <P> This area is lined peripherally by a specialized odontogenic area which has four layers (from innermost to outermost): </P>

Where is the nerve located in a tooth