Some people in whom the disease is
indefinitely and seem to be cured.
A type of
relationship between the upper and
lower teeth) in w hich some or all of
the lower front teeth overlap the upper
front teeth. A molar crossbite, in w hich
the upper and lower back teeth overlap,
can also occur.
A type of
(squint) in w hich
one of the eyes turns inwards relative
to the other, or in w hich both eyes turn
inwards towards each other.
A procedure to
bility between the blood of a person
who requires a
that of a
Red blood cells from
one person are combined with
clear fluid that separates from
blood when it clots) from the other.
Clumping of red blood cells indicates
the presence of
the blood is not compatible.
young children, in w hich narrowing
and inflammation of the airways causes
(a grunting noise
during breathing), and a barking cough.
Croup may be caused by a viral or
bacterial infection affecting the
Most cases are due
to a viral infection and are generally
mild. Other causes include
spasm due to insufficient
levels in the blood, and inhalation
H um idifying the air
ease breathing. In some cases,
administered through a
and oxygen, may be pre-
scribed. If the infection is bacterial, it
is treated w ith
An autosomal dominant
that causes facial deformities. Affected
people have these features: eyes that
spaced widely apart; a
; an abnor-
mally tall skull; a large, beaked nose;
w hich makes the lower jaw look as if it
The name for the top of the head. The
word is also used of the visible part of a
tooth. (See also
crown, dental; crowning
An artificial replacement for the crown
of a decayed, discoloured, or broken
A crown made from porcelain is
usually used on front teeth, but back
teeth need the greater strength of a
crown made from gold or porcelain
fused to metal.
A crown may be fitted by filing the
tooth to form a peg and cementing
the crown over the top of it. For a badly
decayed or weakened tooth, it may be
necessary to remove the natural crown,
the artificial crown on to a post that is
cemented in the root canal. For details
on how crowns are fitted, see the illus-
trated box below.
A routine measurement of the length of
a newborn baby, taken from the
of the head to the heels.
The popular name given to the phase in
the second stage of labour (see
when the baby’s head first appears
at the mother’s vaginal opening.
HOW CROWNS ARE FITTED
The tooth is filed down to form a peg over which the replacement is fitted. An
impression of the peg and the natural tooth is taken and a replica is made.
Using this replica as a model, the artificial crown is constructed.
to metal crown
A cracked or broken tooth,
or one that has been
heavily filled, can be replaced
by a crown.
The damaged area ofthe
tooth is removed and the
remaining part is shaped to
receive the crown.
The artificial crown, a
hollow shell, is fitted over
the shaped tooth and then
cemented in place.
If the natural tooth is badly decayed
or has been weakened, its crown is
removed and a post crown is fitted.
R o o t c a n a l
. T o o t h r o o t
D a m a g e d
t o o t h
This tooth is
that a retaining
peg cannot be
R o o t c a n a l f i l l e d
T o o t h t r im m e d
G o ld
p o s t
in r o o t
c a n a l
C r o w n
A gold post is
cemented into the
root canal and the
crown is then cemented
over the post.