Teeth are NOT bone, but they are anchored to
the jaw bones.
Designed for the crushing of food - mechanical
digestion of food.
Image adapted from
https://en.wikipedia.org/wiki/Human_tooth
Molars - the biggest teeth, large flat ridged
surfaces to grind and chew food into smaller pieces that are easy to
swallow.
Pre-molars - have many ridges and their main
function is to chew and grind up food.
Canines ('fangs') - the strongest, but
smaller sharpest pointed front teeth are used for biting food - you
use them to bite into food first.
Incisors - flat sharper front teeth for
tearing food, and used in first biting action too. They also support
the lips.
The structure
of the human tooth
image adapted from
https://en.wikipedia.org/wiki/Human_tooth_development
The crown is the visible top part of your
tooth and the 'invisible' root extends down below the gum line and
helps anchor the tooth to the jaw bone.
Enamel coating - is the hardest and most
mineralised part of a tooth that covers and protects the tooth
crown.
Dentine - is the substance between the enamel
or cementum and is a mineralised tissue not as hard as enamel, so
susceptible to decay if the enamel is worn away.
Pulp - the central region of the tooth and
contains the blood vessels, nerves and softer tissues that delivers
nutrients and signals to and from the tooth.
Gums - tissue that covers the root of the
tooth.
Cementum - a specialized bone like substance
covering the root of a tooth and helps tether the root firmly to the
jaw bones.
Bone - the root
of the tooth is anchored to the jaw bone.
Blood vessels - bring nutrients
and oxygen to the teeth cells,
note the network of blood vessels and nerves right up to near the
dentine.
Nerves - the inner softer tissue of teeth
contain neurons which are part of the peripheral nervous system -
very effective in sending pain signals to the brain if the tooth is
infected, ouch!!!
Dental decay
and plaque
Your teeth get coated with bacteria and food.
The bacteria respiring sugars in the food producing acidic
molecules. The acids dissolve the enamel and dentine.
The bacteria and undigested food and saliva form
soft deposits called plaque which hardens with salts to form a
deposit called calculus. Both plaque and calculus act as food
reservoirs by absorbing sugars on which the bacteria can feed on.
Looking after
your teeth and gums.
Brush your teeth regularly, which clears out
residual food and bacteria so the acidic molecules are not formed in
the first place - prevention is better than cure (if possible!) at
the dentist.
It is not good to consume too many sugary foods or
drinks on which the acid producing bacteria can feed on.
Calcium ions are an important component of the
harder bone tissues, so your diet should include sources of calcium
like milk, cheese, yogurt, nuts and green leafy vegetables.
Although very rare, lack of vitamin C from fruit and
vegetables can lead to scurvy whose effect includes bleeding gums -
gum disease.
