Overlying this cap structure is the ectomesenchyme, which is attached to the mesodermal tissue known as the dental papilla superiorly, and lies within the epithelial concavity.

It gives rise to the nervous system, sense organs, outer layer of the skin, teeth and the membrane lining the oral cavity (mouth).

[5]: 119 A section of the ectomesenchyme (a group of tissue made up of neurocrest cells which are present in the initial development of an embryo.

This forms the hard and soft tissues of the neck and skull),[6] condenses into a mass within the concavity of the cap of the enamel organ.

It includes the connective tissue and overlying keratinised membrane lining the oral cavity that surrounds the teeth, the periodontal ligament, cementum which provides a protective covering for the root surface and supporting alveolar bone.

During this stage of odontogenesis, the epithelial tooth germ forms a bell-shaped structure in the labio-lingual section and is characterised by the formation of the dental sac.

This differentiation occurs to supplement the development of the dental sac which is responsible for cementum, periodontal ligament and the alveolar process.

[10][full citation needed] The central cells of dental papilla form the primordium of the pulp during root development.

When all of the individual components of the tooth germ have become developed, the entire cell mass would have appeared to have migrated deeper into the underlying connective tissues.

This phenomenon, which will continue throughout the whole life of the teeth, is most possibly due to the cell mass moving towards a rich blood supply that can be found in the deeper parts of the mandible (lower jaw) and the maxilla (upper jaw) The probable need for a rich blood supply would seem to show that the cell mass will soon be highly productive in the formation of dental tissues.

In the dental papilla the number of blood vessels increase and the matrix deposition will begin once the maximum is reached during the bell stage.

Nerve-related signaling molecules, such as glial cell line-derived growth factor, neurotrophin and semaphorin are among the few which have been studied during the tooth development process.

Of which, the verve-related signaling molecules seems to show a trend that suggest an early implication of innervation of tooth development.

Understanding how odontoblast differentiate from ectomesenchymal cells allows comprehension and explanation of normal development and affects their recruitment when needed to start repairing the dentin.

[12] Growth factors in the cells of the inner enamel epithelium and expressions of signaling molecules bring about the differentiation of odontoblast through normal development of the dental papilla.