ORPHAN DRUGS
O
o rp h a n d ru g s
D r u g s t h a t h a v e b e e n d e v e l o p e d t o t r e a t
r a r e
c o n d i t i o n s
b u t
a r e
n o t
m a n u f a c -
t u r e d g e n e r a l l y .
o rp h e n a d rin e
A
m u s c l e - r e l a x a n t d r u g
u s e d t o t r e a t t h e
m o v e m e n t d i s o r d e r
P a r k i n s o n ’s d i s e a s e
.
S i d e
e f f e c t s o f o r p h e n a d r i n e i n c l u d e a
d r y m
o u t h a n d b l u r r e d v i s i o n .
O RT
T h e a b b r e v i a t i o n f o r
o r a l r e h y d r a t i o n t h e r -
a p y
.
( S e e a l s o
r e h y d r a t i o n t h e r a p y
.)
o rth o -
A p r e f i x m e a n i n g
n o r m a l , c o r r e c t , o r
s t r a i g h t , a s i n
o r t h o p a e d i c s
,
a b r a n c h o f
s u r g e r y c o n c e r n e d w i t h c o r r e c t i n g d i s -
o r d e r s o f t h e b o n e s a n d j o i n t s .
o rth o d o n tic a p p lia n c e s
F i x e d o r r e m o v a b l e d e v i c e s , c o m m o n l y
k n o w n a s b r a c e s , w o r n t o c o r r e c t
m a l -
o c c l u s i o n
( a n
a b n o r m a l
r e l a t i o n s h i p
b e t w e e n t h e u p p e r a n d l o w e r t e e t h ) o r
t o r e p o s i t i o n o v e r c r o w d e d o r
b u c k t e e t h
.
U s u a l l y
f i t t e d
d u r i n g
c h i l d h o o d
a n d
a d o l e s c e n c e , a b r a c e m o v e s t e e t h u s i n g
s u s t a i n e d g e n t l e p r e s s u r e .
A f i x e d a p p l i a n c e h a s b r a c k e t s a t t a c h -
e d t o t h e t e e t h t h r o u g h w h i c h a n a r c h
w i r e i s t h r e a d e d a n d t i g h t e n e d t o e x e r t
p r e s s u r e . T h e s e a r e u s u a l l y k e p t i n p l a c e
f o r
a b o u t
a y e a r ,
a f t e r
w h i c h
t i m e
a
r e t a i n e r p l a t e m a y b e n e e d e d t o
h o l d
t h e t e e t h i n p l a c e u n t i l t o o t h a n d j a w
g r o w t h h a s f i n i s h e d .
R e m o v a b l e a p p l i a n c e s , w h i c h c o n s i s t
o f a p l a s t i c p l a t e w i t h a t t a c h m e n t s t h a t
a n c h o r
o v e r
t h e
b a c k t e e t h ,
a r e
u s e d
w h e n o n l y o n e o r a f e w t e e t h n e e d c o r -
r e c t i n g . T h e y a p p l y f o r c e b y m e a n s o f
s p r i n g s , w i r e b o w s , s c r e w s ,
o r r u b b e r
b a n d s f i t t e d t o t h e p l a t e .
o rth o d o n tic s
A b r a n c h
o f
d e n t i s t r y
c o n c e r n e d w i t h
p r e v e n t i o n a n d t r e a t m e n t o f
m a l o c c l u s i o n
( a n a b n o r m a l r e l a t i o n s h i p b e t w e e n t h e
u p p e r a n d l o w e r t e e t h ) . T h e p r o c e d u r e s
a r e u s u a l l y p e r f o r m e d w h i l e t e e t h a r e
d e v e l o p i n g a n d r e l a t i v e l y m a n o e u v r a b l e
b u t c a n a l s o b e o f b e n e f i t i n a d u l t h o o d .
A n o r t h o d o n t i s t m a y f i r s t m a k e m
o d -
e l s o f t h e t e e t h
( s e e
i m p r e s s i o n , d e n t a l
)
a n d t a k e
X - r a y s
o f t h e h e a d a n d j a w s .
C e r t a i n t e e t h , o f t e n p r e m o l a r s , m a y b e
e x t r a c t e d t o m a k e r o o m f o r t h e r e m
a i n -
i n g
t e e t h .
P o o r l y
p o s i t i o n e d
t e e t h a r e
t h e n m o v e d b y g e n t l e p r e s s u r e e x e r t e d
b y
o r t h o d o n t i c a p p l i a n c e s
.
o rth o g n a th ic s u rg e ry
O p e r a t i o n s t o c o r r e c t d e f o r m i t i e s o f t h e
j a w a n d t h e s e v e r e
m a l o c c l u s i o n
( a b n o r -
m a l r e l a t i o n s h i p b e t w e e n t h e u p p e r a n d
l o w e r t e e t h ) t h a t i s a s s o c i a t e d w i t h t h e m .
O r t h o g n a t h i c
s u r g e r y
i s
p e r f o r m e d
u n d e r
g e n e r a l
a n a e s t h e s i a . A
j a w
t h a t
p r o j e c t s
t o o
f a r
c a n
b e
s h o r t e n e d
b y
r e m o v i n g a b l o c k o f b o n e f r o m
e a c h
s i d e
a n d
m a n o e u v r i n g
t h e
f r o n t
o f
t h e
j a w
b a c k w a r d s . A j a w
t h a t
i s
t o o
s h o r t c a n b e r e s h a p e d b y d i v i d i n g t h e
b o n e o n e a c h s i d e , s l i d i n g t h e f r o n t o f
t h e
j a w f o r w a r d s ,
a n d
i n s e r t i n g
b o n e
g r a f t s
( t a k e n
f r o m
e l s e w h e r e
i n
t h e
b o d y )
i n t o t h e g a p s . A f t e r r e p o s i t i o n -
i n g , t h e j a w b o n e s o f t e n r e q u i r e w i r i n g
t o g e t h e r
( s e e
w i r i n g o f t h e j a w s
)
u n t i l
t h e y h a v e h e a l e d .
o rth o m y x o v iru s
O n e o f a f a m i l y o f
v i r u s e s
t h a t i n c l u d e s
t h e m i c r o o r g a n i s m s r e s p o n s i b l e f o r r e s -
p i r a t o r y t r a c t d i s e a s e s , e s p e c i a l l y
i n f l u e n z a
.
HOW ORTHODONTIC APPLIANCES WORK
The tooth sockets are remarkably
responsive to sustained pressure against
the teeth. Orthodontic appliances, which
maybe fixed or removable, provide such
pressure. Even gentle pressure applied
in a particular direction will move teeth.
As theymove, bone is remodelled so
that the new position is stable.
Overcrowding
This is frequently
associated with
malocclusion (poor
alignment between upper
and lower teeth). Some
teeth have to be extracted
to make room for others to
be straightened.
FIXED APPLIANCES
Appearance of brackets and wires
Brackets are fixed appliances cemented to the
outer surface ofthe teeth; they have slots into
which arch wires can be fitted.
Repositioning a tooth
Bycareful design of the
arrangement ofwires and
spring, force can be exerted in
any direction to move a tooth
into the desired position.
1
Teeth are removed to create space and an
appliance made to correctthe alignment
ofthe remaining teeth and to close gaps
between them.
2
Once the teeth in the upper and lower jaws
are completely aligned, the appliance is
adjusted to tip or rotate the teeth in order to
achieve a good appearance and bite.
REMOVABLE APPLIANCES
Arrangement of wires over teeth
These are easier to keep clean than fixed
appliances and are less obtrusive, but they may
interfere with speech; their efficiency relies on
patients using them as directed. This type exerts
pressure to push the teeth atthe sides outwards.
Bow device
This simple wire spring
acts by exerting force to
straighten the tooth. Many
bow devices are more
___
complicated.
I
D ir e c t io n o f D u ll
A removable bow
One ofthe many forms of orthodontic wire
appliance, this bow device exerts pressure on
the teeth at the sides, which straightens and
moves them outwards.
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