As human beings, we are born without any teeth. Our first tooth erupts around 6 months of life. What if human beings are made to have no teeth at all? There would be a lot of things that we would not able to do. This section of the web site looks at teeth, what they are, and how they grow.

Tooth Structure

The main body of a tooth consists of three parts:

1. Enamel – This is the outer part, which is hard, inert, and rich in minerals. The highly mineralized covering enables this part of the tooth to withstand the many acid, enzymatic attacks and mastication forces of the mandibular muscles.

2. Dentin – This part supports the enamel. It is less mineralized but more resilient than the enamel. The dentin forms the bulk of the tooth and is the one responsible in helping the enamel bear with the masticatory forces.
3. Pulp – This part is a chamber that is covered and enclosed by the dentin. The pulp is made up of soft tissue. Although the hard dentin and soft pulp are anatomically different from each other, they should be considered as one. It is because the pulp itself forms, nourishes, protects, and produces new dentin when it is needed and required.

Teeth are attached to the bones of the jaws by connective tissues. These connective tissues are made up of cementum, periodontal tissues and the alveolar bone that provide flexibility to the teeth especially in mastication.

How Teeth Develop

The ectomesenchyme is an embryonic connective tissue that is covered by one to two layers of thick epitheliums. These are the cells that lines that newly formed primitive mouth. Development of teeth starts when the embryonic epithelial and the neural crest that arises from mesenchymal cells starts to interact with each other.

Later, a continuous band of thick epitehelium forms around this primitive mouth in which would become the jaws after about 37 days.

From each of these epithelium bands, the dental and vestibular lamina is quickly formed. Sites of the future teeth inside the dental lamina, which has every series of epithelial outgrowths into the mesenchyme are formed. After this, tooth development proceeds in three stages. These are the bud, cap, and bell.

Bio Signaling In Tooth Development

It has been made known that to be involved at different stages of tooth development, reciprocal epithelial-mesenchymal signaling is essential. The initiation of tooth germs requires a series of development signals—epithelial cell differentiation found in the tooth buds requires mesenchymal signals and the signals between epithelial and mesenchymal cells are also required for differentiation of ameloblasts and odontoblasts at later stages.