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.
The main body of a tooth consists of three
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.