STRUCTURE OF A TOOTH
teeth Hard, bone-like projections set in
the jaws and surrounded by the gums.
The teeth are used for
to form speech, and give shape to the
face. At the centre of each tooth is the
pulp, which contains blood vessels and
nerves and is surrounded by hard den-
tine. The part of the tooth above the
gum, the crown, is covered by enamel,
the hardest substance in the body.
The roots of the tooth, which fit into the
cementum. Humans have 32
, which erupt after the
are lost. These teeth comprise
chisel-shaped, biting incisors; sharp,
pointed canines; grinding premolars;
and larger grinding molars.
teeth, care of See
teething The period when a baby cuts
his or her
). While teething, a baby may be
irritable, fretful, clingy, have difficulty
sleeping, and may cry more than usual.
Symptoms may be relieved by the use
of painkilling gels that are rubbed on
the gums, or liquid preparations.
telangiectasia An increase in the size
of small blood vessels beneath the sur-
face of an area of skin, causing redness
and a “broken veins” appearance. It is
most common on the nose and cheeks.
There may be no obvious cause, or the
condition may be due to many years of
excessive alcohol consumption,
overexposure to sunlight, or a connective
tissue disease such as
Telangiectasia is not a cause for con-
cern, but the veins can be removed in
some cases by electrodesiccation (elec-
trical destruction of the upper layers of
the skin). (See also
is used to treat
and also as a
drug of abuse.
temperature The degree of hotness of a
body or substance. In the human body,
the temperature must be maintained at
around 37°C for optimum functioning.
Body temperature is maintained by the
, which monitors blood
temperature and activates mechanisms
to compensate for changes. When body
by muscle activity, and constriction of
blood vessels in the skin minimizes
heat loss. When the body temperature
results in cooling, and
dilation of blood vessels in the skin
increases heat loss.
temperature method See
tion, natural methods of
temporal A medical term meaning of or
near the temples or a temple.
temporal arteritis An uncommon dis-
ease of older people in which the walls of
the arteries in the scalp over the temples
become inflamed. Other arteries in the
body may also be affected. The cause is
unknown, but the condition is often
Symptoms may include severe headache
or both sides, scalp tenderness, a
low fever, and poor appetite. In about
half of the cases, the arteries supplying
the eyes are affected, which may cause
sudden blindness if left untreated.
Diagnosis of temporal arteritis is made
) and, in
some cases, by a
of the temporal
artery. Treatment involves the use of a
. If this is not suc-
given. The disease usually clears up