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9 Evaluation of the Third Molar Problem
Evaluation of the third m olar problem Daniei M. Laskin, DDS, MS, Chicago
A m o n g th e co m p lica tio n s w h ic h arise fro m un e ru p te d and im pacted th ird m olars are p e ric o ro n itis , p e rio d o n titis , p a th o lo g ic re so rp tio n , and cyst fo rm a tio n . The in d ic a tio n s f o r p ro p h y la c tic rem oval o f im pacted m olars and procedures fo r salvaging the m if th e y are needed f o r o rth o d o n tic reasons are discussed.
s u b j e c t , i t is n e c e s s a r y f i r s t t o u n d e r s t a n d t h e v a r i o u s c o m p lic a t io n s , o r t h o d o n t ic
and
o th e rs , th a t ca n b e
c a u s e d b y u n e r u p te d o r im p a c te d th ir d m o la r s .1
C o m p lic atio n s arising fro m m a n d ib u la r th ird m olars A lth o u g h b o t h th e o r th o d o n tis t a n d th e o r a l s u rg e o n a re c o n c e r n e d a b o u t th e u n e r u p t e d t h ir d m o l a r , th e ir
■ P e r ic o r o n itis :
v ie w p o in t s a re la r g e ly d ic t a te d b y th e t y p e o f p a t ie n t
e n c o u n te r e d p a th o lo g ic c o n d it io n in v o lv in g th e m a n
P e r i c o r o n i t i s is t h e m o s t c o m m o n l y
t h a t t h e y t r ë a t . T h e o r t h o d o n t i s t , d e a lin g p r in c ip a ll y
d ib u la r
w i t h y o u n g in d iv id u a ls , se es th e s e t e e t h m a i n ly d u r in g
t h e r e is a t e n d e n c y f o r t h e p r o c e s s t o r e c u r i n t e r m i t
th ir d
th e e r u p tiv e p h a s e , h e te n d s t o t h in k p r im a r ily a b o u t
te n tly
how
p o s s ib le . I n
th e y
c o u l d u l t i m a t e l y a f f e c t t h e r e s u l t s o f h is
w hen
m o la r.
O nce
c o m p le t io n
p e r ic o r o n it is
d e v e lo p s ,
o f n o r m a l e r u p t i o n is n o t
a d d it io n to th e e x tr e m e d is c o m fo r t th a t
t h e r a p y . T h e o r a l s u r g e o n , o n t h e o t h e r h a n d , u s u a lly
s u c h r e p e t i t i v e e p i s o d e s c a u s e , t h e y a ls o c a n r e s u l t i n
d e a ls
s u ffic ie n t b o n e
w ith
m a in ly
an
o ld e r
p a tie n t
p o p u la t io n
and
sees
t h e c o m p lic a t io n s c r e a t e d b y th e s e t e e t h . H e
a l l t o o f r e q u e n t l y is i n c l i n e d t o t h i n k o n l y i n t e r m s o f th e
im m é d ia te
re m e d y
fo r
such
c o n d itio n s
ra th e r
t h a n in te rm s o f th e ir p r e v e n tio n . T h e re b le m s
to
th e
t h ir d
m o la r
a lo n g
l in e s
com
th is
c o u ld
v ie w
u s u a l c a u s a t iv e
o r g a n is m s
o f p e r ic o
s t a p h y lo c o c c i, s t r e p to c o c c i, a n d V i n
s in c e
p r a c t i c a l s i g n i f i c a n c e is t h e f a c t t h a t r e c u r r e n t s t r e p t
o g y o f b o t h r h e u m a t ic fe v e r a n d g lo m e r u lo n e p h r itis .
fro m
o f
th e
o c o c c a l in fe c tio n s h a v e b e e n im p lic a t e d in th e e t io l
s p e c ia liz a tio n a n d th e n a p p r o a c h in g t h e m p o in ts
Am ong
r o n itis a re th e
of
p le t e ly
d iffe r e n t
second and
c e n t’ s b a c illi t h a t n o r m a lly in h a b it th e o r a l c a v ity . O f
is a d a n g ë r i n a r b i t r a r i l y d i v i d i n g t h e p r o
r e la te d
d e s tr u c tio n b e tw e e n th e
th ir d m o la r t o p r o d u c e a d e e p p e r io d o n ta l p o c k e t.
r e a d ily le a d to in a p p r o p r ia t e p a t ie n t m a n a g e m e n t. A s d e n tis ts
fir s t,
and
s p e c ia lis t s
second,
our
p r im a r y
■
P e r io d o n titis :
In fla m m a tio n
and
c o n s id e r a b le
c o n c e r n s h o u ld b e w i t h t o t a l o r a l h e a lt h . T h e r e f o r e ,
b o n e lo s s a ls o c a n o c c u r a s a r e s u l t o f c o n s t a n t f o o d
a t le a s t f r o m a d ia g n o s tic s t a n d p o in t , t h e r e m u s t b e a
im p a c t io n
com m on
and
in te r e s t
in
a ll a s p e c ts o f th e
th ir d
m o la r
p r o b le m . T o o r ie n t o u r t h in k in g p r o p e r ly a b o u t th is
824 ■ JADA, Vol. 82, April 1971
th e
b e tw e e n a d ja c e n t
a p a r tia lly second
e ru p te d
m o la r.
Such
th ir d
m o la r
p e r io d o n ta l
p o c k e t fo r m a t io n w e a k e n s th e s u p p o rt o f th e s e c o n d
F ig 1 ■ S e v e re d e s tr u c t io n o f in te r p r o x im a l b o n e a n d e x te n s iv e d e n ta l c a rie s a s s o c ia te d w it h a n im p a c te d m a n d ib u la r th ir d m o la r. F ig 2 ■ D e n tig e ro u s c y s t a ris in g fr o m a n u n e r u p t e d m a n d i m o la r , w h ic h m a y b e c o m e lo o s e ( F ig 1 ) . I n in s ta n c e s o f deep
p o c k e t f o r m a t io n , d e v it a liz a tio n
o f t h e se
b u la r
th ir d
m o la r.
Bone
re s o r p tio n
in v o lv in g
th e second
m o la r m a k e s r e te n tio n o f t h a t t o o t h d o u b t f u l.
c o n d m o la r b y a p ic a l e x te n s io n o f th e in fe c tio n m a y a ls o o c c u r . W h e n s e v e r e p e r i o d o n t i t i s h a s d e v e l o p e d , e v e n re m o v a l o f th e im p a c t e d t o o t h w ill n o t e lim in a te
■ C y s t f o r m a tio n :
th e p o c k e t.
o f ■ C a r ie s :
W hen
an
im p a c te d
th ir d
m o la r b e c o m e s
p a r tia lly e x p o s e d to th e o r a l e n v ir o n m e n t , its s u s c e p t i b i l i t y t o c a r ie s is i n c r e a s e d b e c a u s e o f t h e c o l l e c t i o n o f f o o d d e b r is a n d t h e d i f f ic u lt y in k e e p in g th e re g io n c le a n .
In
m ost
in s ta n c e s ,
th e
r e s to r a tio n
of
such
c a r i o u s l e s io n s is n o t o n l y i m p r a c t i c a l b u t a ls o o f t e n t e c h n i c a l l y i m p o s s i b l e . R e c u r r e n c e o f c a r ie s is a f r e quent
The
m a n d ib u la r
t h ir d
fin d in g .
The
sam e
fa c to rs
th a t
a ffe c t
o f th e a d ja c e n t s e c o n d m o l a r t o c a rie s ( F ig 1 ) .
d e n tig e r o u s
r e m a in th e y th e
c y s ts
(F ig
2 ).
Such
■ P a t h o lo g ic r e s o r p t io n :
P re s s u re
o f th e c ro w n o f
a n e r u p t i n g t h i r d m o l a r a g a in s t t h e r o o t s u r f a c e o f t h e m o la r
s o m e tim e s
re s o r p tio n
a n d u ltim a te
One
be
c a re fu l
can
re s u lt
d e v it a liz a tio n
n o t to
in
le s i o n s
o fte n
a s y m p to m a t ic f o r lo n g p e r io d s d u r in g w h ic h
u n d e rg o
c o n s id e r a b le
e n la r g e m e n t.
S o m e t im e s
c y s ts a re f ir s t d is c o v e r e d d u r in g a r o u t i n e r a d io -
g ra p h ic e x a m in a tio n . In
o th e r cases, th e y m a y u lt i
m a t e ly p r o d u c e i n t r a o r a l o r f a c ia l s w e llin g , o r c a u s e p a in b y c o m p r e s s io n o f th e i n f e r i o r a lv e o la r n e r v e o r as a r e s u l t o f s e c o n d a r y i n f e c t i o n .
■
A s s o c ia tio n
to m a s
w ith
B o th
n e o p la s m s :
a m e lo b la s
a n d c a r c i n o m a s a r is in g i n t h e w a l l s o f d e n t i
g e r o u s c y s ts in v o lv in g m a n d ib u la r t h ir d
m ust
is
th e
i m p a c t e d t h i r d m o l a r a ls o in c r e a s e t h e s u s c e p t i b i l i t y
second
m o la r
th e t o o t h m o s t f r e q u e n t ly in v o lv e d in th e f o r m a t io n
m o la rs h a v e
b e e n r e p o r t e d . 2 A l t h o u g h a n i n f r e q u e n t s e q u e l a , i t is c e r t a i n l y a m o s t s e r io u s o n e ( F i g 3 ) .
p a th o lo g ic
o f th e to o th .
c o n fu s e s u c h re s o rb e d
a re a s w it h th e s h a d o w s p r o d u c e d in th e ra d io g ra p h b y o v e rla p
o f
a n g u la tio n
th e
m o la r s
o f th e
X -ra y
due
to
im p r o p e r h o r iz o n ta l
cone o r because o f b u cco -
v e r s io n o r lin g u o v e r s io n o f th e im p a c t e d t o o t h . I d i o p a t h i c r e s o r p t i o n o f t h e i m p a c t e d t o o t h is a ls o s e e n o c c a s io n a lly . T h is s e e m s t o o c c u r m o s t o f t e n in te e th th a t d o n o t a p p e a r to h a v e a d ir e c t c o m m u n ic a tio n w ith
th e o r a l c a v it y . T h e p a t ie n t s a r e g e n e r a lly
e l d e r ly . P a in
m a y b e a s s o c ia te d w i t h
th e r e s o r p tiv e
p ro c e s s . B e c a u s e s u c h te e t h a re o f t e n a n k y lo s e d , th e s u r r o u n d i n g b o n e is v e r y d e n s e , a n d t h e p a t i e n t ’ s a g e m a k e s h i m a p o o r s u r g ic a l r is k , th e r e m o v a l o f th e s e te e t h c a n b e a fo r m id a b le p r o c e d u r e .
F ig 3 ■ A m e lo b la s t o m a m a n d ib u la r th ir d m o la r.
a s s o c ia te d
w it h
an
u n e ru p te d
Laskin: EVALUATION OF THIRD MOLAR PROBLEM ■ 825
■ Id io p a t h ic p a in :
P a in in th e re g io n o f a n im p a c t e d
n o r m a lly ,
but
th is
d r ift
is
due
to
th e
fo rc e
of
m a n d ib u la r t h ir d m o la r o r p a in r e fe r r e d to o t h e r p a rts
o c c lu s io n o n t h e m e s ia lly in c lin e d t e e t h r a t h e r t h a n t o
o f th e h e a d a n d n e c k m a y re s u lt f r o m
th e fo rc e o f e r u p tio n .
a num ber o f
T h e r e a r e s e v e ra l a lte r n a tiv e e x p la n a t io n s f o r th e
c o n d it io n s a lr e a d y m e n t io n e d , s u c h as p e r ic o r o n it is , c a r i e s , r o o t r e s o r p t i o n , p e r i o d o n t a l d is e a s e , a n d p e r i
a n t e r i o r c r o w d i n g . F i r s t , t h e r e is t h e i n c r e a s e d p l a s t i c
a p ic a l
ity
w ill
p a th o lo g y .
c o m p la in
r a d io g r a p h ic a lly o th e r
th a n
p a c te d
O c c a s io n a lly ,
o f such th e re
is
how ever
a lth o u g h
no
a p a tie n t
c lin ic a lly a n d
a p p a re n t
a b n o r m a lit y
o f th e
a lv e o la r b o n e
a n d p e r i o d o n t a l lig a m e n ts
w h ic h a c c o m p a n ie s th e h o r m o n a l c h a n g e s o f a d o le s cence
o c c u r r in g
a t a b o u t th e
sam e
tim e
th e
th ir d
p re s e n c e o f a d e e p ly e m b e d d e d im
m o l a r is a t t e m p t i n g t o e r u p t . 7 S i n c e t h e m a n d i b u l a r
w i t h n o o b v io u s o r a l c o m m u n i c a t i o n .
in c is o r s a r e l o c a t e d in a r e la t iv e ly p r e c a r io u s p o s it io n
th e
to o th
p a in
D e s p it e t h e la c k o f a n a d e q u a t e e x p la n a t io n , t h e f a c t
in
r e m a in s
t h e t o n g u e a n d l i p , a n y in c r e a s e i n t h e l a b i l i t y o f t h e
th a t
som e
p a tie n ts
a re
r e lie v e d
of
th e ir
th e a lv e o la r r id g e , b a la n c e d b e t w e e n th e fo r c e s o f
p e r io d o n tiu m
s y m p to m s a f t e r r e m o v a l o f th e s e te e t h .
te e th .
g r a p h ic
m o l a r is f o u n d
e x a m in a tio n
of
a
c r o w d in g
of
d u r in g r o u tin e r a d io -
in s t a n c e s
in
c lin ic a lly
“ e d e n tu lo u s ”
re m o v e d
c o m p r e s s io n o f t h e m u c o s a b e t w e e n t h e
m e n t .8
of
th e
c o n g e n ita lly
m a n d i b l e . U n l e s s i t is c o m p l e t e l y c o v e r e d w i t h b o n e , c ro w n an d
c o u ld r e a d ily re s u lt in s h if tin g o f th e
fa v o r
O c c a s io n a lly , a n
■ R e t e n t io n in “ e d e n t u lo u s ” r id g e : im p a c t e d t h ir d
In
t h is
concept
in c i s o r s
can b e
is
th e
fa c t
o b s e rv e d
th a t
even
in
w h ic h th e m a n d ib u la r th ir d
m o la rs a re
m is s i n g
have
been
o f o r th o d o n tic
tre a t
p r io r
to
or
in
w h ic h
c o m p le t io n
th e y
c a n c a u s e p a i n . P r e s s u r e n e c r o s is o f t h e
O th e r fa c to r s t h a t m a y o c c a s io n a lly c o n tr ib u t e to
o v e r l y i n g g i n g i v a m a y a ls o p r o v i d e a p a t h w a y f o r t h e
th e c r o w d in g a re r e s tr ic tio n o f fo r w a r d g r o w th o f th e
d e v e lo p m e n t
th e d e n tu r e
p a tie n ts ,
lo w e r a r c h b y a d e e p o v e r b ite in th e u p p e r , a n d th e
r e m o v a l o f th e s e te e t h c a n b e e x t r e m e ly d i f f ic u lt , a n d
n a t u r a l t e n d e n c y o f t h e l o w e r in c i s o r s t o u p r i g h t w i t h
t h e d a n g e r o f j a w f r a c t u r e is g r e a t e r t h a n n o r m a l .
a g e .9
o f
an
in fe c tio n .
In
e ld e r ly
F in a lly ,
a c tu a lly ■ In v o lv e m e n t
in
u n e ru p te d
im p a c te d
or
a
The
fra c tu re :
th ir d
p re s e n c e
m o la r
o f an
m ay
in
som e
tre a te d
re p re s e n t
a
p a tie n ts ,
r e la p s e
fro m
c r o w d in g a
p h y s io
lo g ic a lly u n t e n a b le t o o t h p o s itio n in g .
c o n s id e r a b ly
w e a k e n s th e p o s te r io r a s p e c t o f th e m a n d ib le . T h u s , a f t e r f a c i a l t r a u m a , t h i s is t h e m o s t c o m m o n s ite o f b o n e fra c tu re .
■ C r o w d in g o f d e n t it io n : im p a c te d
R e m o v a l o f u n e ru p te d o r
t h i r d m o l a r s is o f t e n
r e c o m m e n d e d in p a
C o m p lic atio n s arising fro m m a x illa ry th ird m olars The th ir d
c o m p lic a t io n s m o la rs
a re
a r is in g q u ite
fro m
s im ila r
im p a c te d m a x illa r y to
th o s e
fro m
th e
tie n t s d u r in g o r a f t e r o r t h o d o n t ic t r e a t m e n t b e c a u s e
m a n d ib u la r
it has b ee n
c la im e d t h a t th e s e t e e t h s o m e tim e s c a n
p e r ic o r o n it is , p e r i o d o n t i t is , c a rie s , p a t h o lo g ic r e s o r p
p r o d u c e a n a n t e r io r f o r c e t h a t w i l l c a u s e s e p a r a tio n in
t i o n , c y s t s , n e o p la s m s , a n d i d i o p a t h i c p a i n , o r t h e y
th e
c o n ta c t p o in ts a n d
te e th .
They
to o
can
be
in v o lv e d
w ith
s u b s e q u e n t c r o w d in g o f th e
m a n d i b u l a r i n c i s o r s . 3-5 I n a r e c e n t s u r v e y o f o v e r 6 0 0 r a n d o m ly
s e le c t e d
o r th o d o n tis ts
g e o n s , a p p r o x im a te ly to
t h is i d e a . 6
d e v e lo p s
65%
U n d o u b te d ly th e
d u r in g
th e
and
700
o r a l s u r
o f e a c h g r o u p s u b s c r ib e d
e r u p tio n
c o n d it io n g e n e r a lly p e r io d
of
th e
th ir d
m o la r . W h e t h e r th e t w o e v e n ts a re r e la te d , h o w e v e r , r e m a in s u n p r o v e n . I f a n a n t e r io r f o r c e w e r e p r o je c t e d fro m a
th e im p r o p e r ly e r u p tin g m o la r , it w o u ld re q u ire
c o r re s p o n d in g
te e th
in
o rd e r
fo rw a rd to
be
s h if t o f a ll th e
tr a n s m itte d
to
p o s te r io r
th e
in c i s o r s .
M o r e o v e r , th e m o s t lik e ly p la c e f o r s u c h d is r u p tio n o f to o th
c o n ta c t
to
occur
w o u ld
c a n in e r e g i o n . T h e f a c t t h a t t h e
seem
to
be
in
th e
r e la tio n s h ip o f th e
u p p e r a n d lo w e r p o s te r io r t e e t h d o e s n o t c h a n g e a n d th e
c r o w d in g
d is p u te
th e
u s u a lly
a ffe c ts
th e
in c is o r s , te n d s
r o le o f th e e r u p tin g t h ir d
to
m o la r in th e
e t io lo g y o f th is p ro c e s s . A n a n t e r io r d r i f t d o e s o c c u r
826 ■ JADA, Vol. 82, April 1971
F ig 4 ■ Im p a c t e d
m a x illa r y
th ir d
m o la r
s o r p tio n o f th e d is ta l r o o t o f th e s e c o n d m o la r.
p r o d u c in g
re
m ay
rid g e s ( F ig 4 ) . T h e
a b le t h a t e r u p tin g o r im p a c t e d m a x i l la r y t h ir d m o la r s
i n c i d e n c e o f s u c h s e q u e l a e , h o w e v e r , is le s s t h a n w i t h
be
fo u n d
in
“ e d e n tu lo u s ”
in d u c e c r o w d in g o f th e d e n t it io n . I n f a c t , w h ile th e y
th e lo w e r t h ir d m o la r s .
fr e q u e n tly
A s w i t h t h e m a n d i b u l a r t h i r d m o l a r s , i t is i m p r o b -
a re
fo u n d
in
a
m e s io a n g u la r
p o s itio n ,
c o m p a r a b l e s h i f t i n g o f t h e i n c i s o r s is s e l d o m , i f e v e r , s e e n in t h e m a x i lla . S in c e t h e s a m e m e c h a n is m t h a t w as p ro p o s e d
fo r
th e
e t io lo g y
o f c r o w d in g
in
th e
m a n d i b l e s h o u ld a p p l y h e r e , t h i s s e e m s t o b e f u r t h e r e v id e n c e
a g a in s t t h e
r o le
o f im p a c te d
t e e t h in th e
p r o d u c t i o n o f o r t h o d o n t i c r e la p s e .
In d ic atio n s fo r re te n tio n o f u n eru p ted th ird m olars I t is e v i d e n t f r o m
th e p r e c e d in g d is c u s s io n t h a t e v e n
i f o n e d is c o u n ts a n y r e la tio n s h ip b e t w e e n e r u p t io n o f th e th ir d a re
m o la r a n d c r o w d in g o f t h e in c is o r s , th e r e
s till n u m e r o u s o t h e r c o m p lic a t io n s t h a t c a n b e
caused b y
th e s e
a g re e m e n t.
T h is
th e re
is
te e th
ever a need
m o la r .1 O n e m e d ic a l
w h ic h
to
th e re
q u e s tio n
r e ta in
an
is c o m p l e t e
as to
to
a v o id
s u rg e ry ,
o f s u b s e q u e n tly
w h e th e r
u n e ru p te d
in d ic a t io n , o t h e r th a n w h e n
re a s o n s
lik e lih o o d
on
r a is e s t h e
is
lo s in g t h e
th ir d
th e r e a re
i f th e re
is a
s e c o n d m o la r
b e c a u s e o f a l a r g e r e s t o r a t i o n , p e r i o d o n t a l d is e a s e , o r e x te n s iv e te n tio n
c a r ie s . A n o t h e r p o s s ib le i n d i c a t i o n is
in
o r th o d o n tic
p a tie n ts
in
fo r re
w hom
fo u r
p r e m o la r s h a v e a lr e a d y b e e n e x t r a c t e d a n d r e m o v a l o f th e
th ir d
m o la rs w o u ld
re d u c e
th e
d e n titio n
by
a
t o t a l o f e i g h t t e e t h . F i n a l l y , t h e r e m a y b e i n s t a n c e s in w h ic h
th e
o r th o d o n tis t
m ay
need
th e s e
te e th
fo r
a n c h o ra g e . I n th o s e p a t ie n ts in w h o m r e t e n t io n o f th e t h ir d
m o l a r s is d e s i r a b l e , b u t t h e i r p o s i t i o n d o e s n o t
p e r m it n o r m a l e r u p tio n in to th e d e n ta l a r c h , th e o r a l s u r g e o n s o m e tim e s m a y b e h e lp f u l in c o r r e c tin g th e s itu a tio n
by
r e p o s i t i o n i n g o f t h e t e e t h 1 0 ,1 1 ( F i g 5 ) .
P ro p h y la ctic rem oval o f th ird m olars A lth o u g h
an im p a c te d
t h ir d m o la r o c c a s io n a lly m a y
r e m a in a s y m p to m a t ic th r o u g h o u t a p e r s o n ’ s lif e t im e , c lin ic a l e x p e r ie n c e h a s s h o w n t h a t m o s t o f th e s e te e t h u l t i m a t e l y g iv e r is e t o s o m e d i f f i c u l t y . M o r e o v e r , t h e d a m a g e p r o d u c e d b y s u c h c o m p l i c a t i o n s f r e q u e n t l y is n o t r e v e r s i b le e v e n a f t e r t h e t o o t h h a s b e e n e x t r a c t e d . On
th is
b a s is ,
w ith
th e
fe w
m e n t io n e d , i t s e e m s lo g ic a l t o F ig 5 ■ S u rg ic a l re p o s itio n in g o f im p a c te d m a n d ib u la r th ir d m o la r.
A : P r e o p e r a tiv e ra d io g ra p h . B : T o o t h
im m e d ia te ly
a f t e r r e p o s itio n in g . C : R a d io g r a p h ta k e n th r e e y e a rs a f te r s u rg e ry .
N o te
r e c o n to u r in g
of
th e
in te r p r o x im a l
bone,
c o m p le t io n o f th e r o o t, a n d r e fo r m a tio n o f th e la m in a d u ra .
e x c e p t io n s
p r e v io u s ly
r e c o m m e n d th e p r o
p h y l a c t i c r e m o v a l o f a l l t h i r d m o l a r s a s s o o n a s i t is e v id e n t
th a t
n o r m a lly .
th e y
T h is
can
a re
not
in
g e n e r a lly
a be
to
e ru p t
d e te r m in e d
p o s it io n
r a d io -
g r a p h ic a lly w h e n th e p a tie n ts a re b e tw e e n 1 6 a n d 1 7
Laskin: EVALUATION OF THIRD MOLAR PROBLEM ■ 827
y e a rs o f a g e , a t w h ic h tim e th e m a jo r g r o w th o f th e ja w s h a s b e e n c o m p le t e d . R e m o v a l o f t h e t e e t h a t th is a g e , w h e n t h e r e u s u a l l y is n o p a t h o l o g i c i n v o l v e m e n t , is a m u c h
le s s c o m p l i c a t e d
p ro c e d u re
th a n
s im ila r
s u r g e r y in a n o l d e r p e r s o n .
9 . B jo r k , A . T h e fa c e in p r o file . L u n d , B e rlin g s k a B o k t r y c k e r ie t , 1 9 4 7 , p 6 4 , 1 2 6 , 1 7 2 . 1 0 . L a s k in , D . M ., a n d P e s k in , S. S u rg ic a l a id s in o r t h o d o n tic s . D e n t C lin N A , J u ly 1 9 6 8 , p 5 0 9 . 1 1 . P e s k in , S ., a n d G rä b e r , T . M . S u rg ic a l re p o s itio n in g o f te e t h . J A D A 8 0 : 1 3 2 0 J u n e 1 9 7 0 .
T h e o r t h o d o n t i s t is i n a k e y p o s i t i o n t o j u d g e t h e id e a l t im e o f t h ir d m o la r r e m o v a l in h is p a t ie n ts a n d to
a d v is e t h e m a c c o r d i n g l y . T h e o r a l s u r g e o n , w h e n
ever
p o s s ib le ,
m ust
a ls o
e m p h a s iz e
p r e v e n tio n
of
c o m p lic a t io n s r a t h e r t h a n t h e i r c u r e . I n t h is m a n n e r , b o th
g ro u p s
w ill
th e n
be
m a k in g
an
even
g re a te r
c o n t r ib u t io n t o t o t a l o r a l h e a lt h .
1. L a s k in , D .M . In d ic a tio n s a n d c o n tr a in d ic a tio n s f o r re m o v a l o f im p a c te d t h ir d m o la rs . D e n t C lin N A 1 3 : 9 1 9 O c t 1969. 2 . T h o m a , K . H ., a n d G o ld m a n , H .M . O ra l p a t h o lo g y , ed 5 . S t. L o u is , C . V . M o s b y C o ., 1 9 6 0 , p . 7 8 3 - 7 8 4 . 3 . D e w e y , M . T h e th ir d m o la rs in r e la tio n to m a lo c c lu s io n . I n t J O r t h o d o n t 3 : 5 2 9 S e p t 1 9 1 7 . 4 . R o u n d s , C . E. P rin c ip le s a n d te c h n iq u e o f e x o d o n t ia , e d 2 . S t . L o u is , C . V . M o s b y C o ., 1 9 6 2 , p 2 7 9 . 5 . W a ld r o n , R . Q u e s tio n o f th e in flu e n c e o f e r u p tin g o r im p a c te d th ir d m o la rs o n th e o c c lu s io n o f tr e a te d a n d u n t r e a te d cases. A m e r J O r t h o d o n t 2 3 : 2 2 1 M a r c h 1 9 3 7 . 6 . L a s k in , D . M . U n p u b lis h e d d a ta . 7 . E n g e l, M . B ., a n d o th e rs . A th e o r y o f c o n n e c tiv e tiss u e b e h a v io r: its im p lic a tio n s in p e r io d o n ta l disease. A n n N Y A c a d S c i, 8 5 : 3 9 9 M a r c h 9 , 1 9 6 0 . 8 . S e lm e r -O ls e n , R . T h e n o r m a l m o v e m e n t o f th e m a n d i b u la r te e t h a n d th e c r o w d in g o f th e in c is o rs as a re s u lt o f g r o w th a n d f u n c t io n . D e n t R e c 5 7 : 4 6 5 S e p t 1 9 3 7 .
828 a JADA, Vol. 82, April 1971
D o c t o r L a s k in is p ro fe s s o r a n d a s s o c ia te h e a d o f th e d e p a r t m e n t o f o ra l a n d m a x illo f a c ia l s u rg e ry , C o lle g e o f D e n t is tr y , U n iv e r s ity o f Illin o is a t th e M e d ic a l C e n t e r , P O B o x 6 9 9 8 , C h ic a g o , 6 0 6 8 0 .
A m o n g th e co m p lica tio n s w h ic h arise fro m un e ru p te d and im pacted th ird m olars are p e ric o ro n itis , p e rio d o n titis , p a th o lo g ic re so rp tio n , and cyst fo rm a tio n . The in d ic a tio n s f o r p ro p h y la c tic rem oval o f im pacted m olars and procedures fo r salvaging the m if th e y are needed f o r o rth o d o n tic reasons are discussed.
s u b j e c t , i t is n e c e s s a r y f i r s t t o u n d e r s t a n d t h e v a r i o u s c o m p lic a t io n s , o r t h o d o n t ic
and
o th e rs , th a t ca n b e
c a u s e d b y u n e r u p te d o r im p a c te d th ir d m o la r s .1
C o m p lic atio n s arising fro m m a n d ib u la r th ird m olars A lth o u g h b o t h th e o r th o d o n tis t a n d th e o r a l s u rg e o n a re c o n c e r n e d a b o u t th e u n e r u p t e d t h ir d m o l a r , th e ir
■ P e r ic o r o n itis :
v ie w p o in t s a re la r g e ly d ic t a te d b y th e t y p e o f p a t ie n t
e n c o u n te r e d p a th o lo g ic c o n d it io n in v o lv in g th e m a n
P e r i c o r o n i t i s is t h e m o s t c o m m o n l y
t h a t t h e y t r ë a t . T h e o r t h o d o n t i s t , d e a lin g p r in c ip a ll y
d ib u la r
w i t h y o u n g in d iv id u a ls , se es th e s e t e e t h m a i n ly d u r in g
t h e r e is a t e n d e n c y f o r t h e p r o c e s s t o r e c u r i n t e r m i t
th ir d
th e e r u p tiv e p h a s e , h e te n d s t o t h in k p r im a r ily a b o u t
te n tly
how
p o s s ib le . I n
th e y
c o u l d u l t i m a t e l y a f f e c t t h e r e s u l t s o f h is
w hen
m o la r.
O nce
c o m p le t io n
p e r ic o r o n it is
d e v e lo p s ,
o f n o r m a l e r u p t i o n is n o t
a d d it io n to th e e x tr e m e d is c o m fo r t th a t
t h e r a p y . T h e o r a l s u r g e o n , o n t h e o t h e r h a n d , u s u a lly
s u c h r e p e t i t i v e e p i s o d e s c a u s e , t h e y a ls o c a n r e s u l t i n
d e a ls
s u ffic ie n t b o n e
w ith
m a in ly
an
o ld e r
p a tie n t
p o p u la t io n
and
sees
t h e c o m p lic a t io n s c r e a t e d b y th e s e t e e t h . H e
a l l t o o f r e q u e n t l y is i n c l i n e d t o t h i n k o n l y i n t e r m s o f th e
im m é d ia te
re m e d y
fo r
such
c o n d itio n s
ra th e r
t h a n in te rm s o f th e ir p r e v e n tio n . T h e re b le m s
to
th e
t h ir d
m o la r
a lo n g
l in e s
com
th is
c o u ld
v ie w
u s u a l c a u s a t iv e
o r g a n is m s
o f p e r ic o
s t a p h y lo c o c c i, s t r e p to c o c c i, a n d V i n
s in c e
p r a c t i c a l s i g n i f i c a n c e is t h e f a c t t h a t r e c u r r e n t s t r e p t
o g y o f b o t h r h e u m a t ic fe v e r a n d g lo m e r u lo n e p h r itis .
fro m
o f
th e
o c o c c a l in fe c tio n s h a v e b e e n im p lic a t e d in th e e t io l
s p e c ia liz a tio n a n d th e n a p p r o a c h in g t h e m p o in ts
Am ong
r o n itis a re th e
of
p le t e ly
d iffe r e n t
second and
c e n t’ s b a c illi t h a t n o r m a lly in h a b it th e o r a l c a v ity . O f
is a d a n g ë r i n a r b i t r a r i l y d i v i d i n g t h e p r o
r e la te d
d e s tr u c tio n b e tw e e n th e
th ir d m o la r t o p r o d u c e a d e e p p e r io d o n ta l p o c k e t.
r e a d ily le a d to in a p p r o p r ia t e p a t ie n t m a n a g e m e n t. A s d e n tis ts
fir s t,
and
s p e c ia lis t s
second,
our
p r im a r y
■
P e r io d o n titis :
In fla m m a tio n
and
c o n s id e r a b le
c o n c e r n s h o u ld b e w i t h t o t a l o r a l h e a lt h . T h e r e f o r e ,
b o n e lo s s a ls o c a n o c c u r a s a r e s u l t o f c o n s t a n t f o o d
a t le a s t f r o m a d ia g n o s tic s t a n d p o in t , t h e r e m u s t b e a
im p a c t io n
com m on
and
in te r e s t
in
a ll a s p e c ts o f th e
th ir d
m o la r
p r o b le m . T o o r ie n t o u r t h in k in g p r o p e r ly a b o u t th is
824 ■ JADA, Vol. 82, April 1971
th e
b e tw e e n a d ja c e n t
a p a r tia lly second
e ru p te d
m o la r.
Such
th ir d
m o la r
p e r io d o n ta l
p o c k e t fo r m a t io n w e a k e n s th e s u p p o rt o f th e s e c o n d
F ig 1 ■ S e v e re d e s tr u c t io n o f in te r p r o x im a l b o n e a n d e x te n s iv e d e n ta l c a rie s a s s o c ia te d w it h a n im p a c te d m a n d ib u la r th ir d m o la r. F ig 2 ■ D e n tig e ro u s c y s t a ris in g fr o m a n u n e r u p t e d m a n d i m o la r , w h ic h m a y b e c o m e lo o s e ( F ig 1 ) . I n in s ta n c e s o f deep
p o c k e t f o r m a t io n , d e v it a liz a tio n
o f t h e se
b u la r
th ir d
m o la r.
Bone
re s o r p tio n
in v o lv in g
th e second
m o la r m a k e s r e te n tio n o f t h a t t o o t h d o u b t f u l.
c o n d m o la r b y a p ic a l e x te n s io n o f th e in fe c tio n m a y a ls o o c c u r . W h e n s e v e r e p e r i o d o n t i t i s h a s d e v e l o p e d , e v e n re m o v a l o f th e im p a c t e d t o o t h w ill n o t e lim in a te
■ C y s t f o r m a tio n :
th e p o c k e t.
o f ■ C a r ie s :
W hen
an
im p a c te d
th ir d
m o la r b e c o m e s
p a r tia lly e x p o s e d to th e o r a l e n v ir o n m e n t , its s u s c e p t i b i l i t y t o c a r ie s is i n c r e a s e d b e c a u s e o f t h e c o l l e c t i o n o f f o o d d e b r is a n d t h e d i f f ic u lt y in k e e p in g th e re g io n c le a n .
In
m ost
in s ta n c e s ,
th e
r e s to r a tio n
of
such
c a r i o u s l e s io n s is n o t o n l y i m p r a c t i c a l b u t a ls o o f t e n t e c h n i c a l l y i m p o s s i b l e . R e c u r r e n c e o f c a r ie s is a f r e quent
The
m a n d ib u la r
t h ir d
fin d in g .
The
sam e
fa c to rs
th a t
a ffe c t
o f th e a d ja c e n t s e c o n d m o l a r t o c a rie s ( F ig 1 ) .
d e n tig e r o u s
r e m a in th e y th e
c y s ts
(F ig
2 ).
Such
■ P a t h o lo g ic r e s o r p t io n :
P re s s u re
o f th e c ro w n o f
a n e r u p t i n g t h i r d m o l a r a g a in s t t h e r o o t s u r f a c e o f t h e m o la r
s o m e tim e s
re s o r p tio n
a n d u ltim a te
One
be
c a re fu l
can
re s u lt
d e v it a liz a tio n
n o t to
in
le s i o n s
o fte n
a s y m p to m a t ic f o r lo n g p e r io d s d u r in g w h ic h
u n d e rg o
c o n s id e r a b le
e n la r g e m e n t.
S o m e t im e s
c y s ts a re f ir s t d is c o v e r e d d u r in g a r o u t i n e r a d io -
g ra p h ic e x a m in a tio n . In
o th e r cases, th e y m a y u lt i
m a t e ly p r o d u c e i n t r a o r a l o r f a c ia l s w e llin g , o r c a u s e p a in b y c o m p r e s s io n o f th e i n f e r i o r a lv e o la r n e r v e o r as a r e s u l t o f s e c o n d a r y i n f e c t i o n .
■
A s s o c ia tio n
to m a s
w ith
B o th
n e o p la s m s :
a m e lo b la s
a n d c a r c i n o m a s a r is in g i n t h e w a l l s o f d e n t i
g e r o u s c y s ts in v o lv in g m a n d ib u la r t h ir d
m ust
is
th e
i m p a c t e d t h i r d m o l a r a ls o in c r e a s e t h e s u s c e p t i b i l i t y
second
m o la r
th e t o o t h m o s t f r e q u e n t ly in v o lv e d in th e f o r m a t io n
m o la rs h a v e
b e e n r e p o r t e d . 2 A l t h o u g h a n i n f r e q u e n t s e q u e l a , i t is c e r t a i n l y a m o s t s e r io u s o n e ( F i g 3 ) .
p a th o lo g ic
o f th e to o th .
c o n fu s e s u c h re s o rb e d
a re a s w it h th e s h a d o w s p r o d u c e d in th e ra d io g ra p h b y o v e rla p
o f
a n g u la tio n
th e
m o la r s
o f th e
X -ra y
due
to
im p r o p e r h o r iz o n ta l
cone o r because o f b u cco -
v e r s io n o r lin g u o v e r s io n o f th e im p a c t e d t o o t h . I d i o p a t h i c r e s o r p t i o n o f t h e i m p a c t e d t o o t h is a ls o s e e n o c c a s io n a lly . T h is s e e m s t o o c c u r m o s t o f t e n in te e th th a t d o n o t a p p e a r to h a v e a d ir e c t c o m m u n ic a tio n w ith
th e o r a l c a v it y . T h e p a t ie n t s a r e g e n e r a lly
e l d e r ly . P a in
m a y b e a s s o c ia te d w i t h
th e r e s o r p tiv e
p ro c e s s . B e c a u s e s u c h te e t h a re o f t e n a n k y lo s e d , th e s u r r o u n d i n g b o n e is v e r y d e n s e , a n d t h e p a t i e n t ’ s a g e m a k e s h i m a p o o r s u r g ic a l r is k , th e r e m o v a l o f th e s e te e t h c a n b e a fo r m id a b le p r o c e d u r e .
F ig 3 ■ A m e lo b la s t o m a m a n d ib u la r th ir d m o la r.
a s s o c ia te d
w it h
an
u n e ru p te d
Laskin: EVALUATION OF THIRD MOLAR PROBLEM ■ 825
■ Id io p a t h ic p a in :
P a in in th e re g io n o f a n im p a c t e d
n o r m a lly ,
but
th is
d r ift
is
due
to
th e
fo rc e
of
m a n d ib u la r t h ir d m o la r o r p a in r e fe r r e d to o t h e r p a rts
o c c lu s io n o n t h e m e s ia lly in c lin e d t e e t h r a t h e r t h a n t o
o f th e h e a d a n d n e c k m a y re s u lt f r o m
th e fo rc e o f e r u p tio n .
a num ber o f
T h e r e a r e s e v e ra l a lte r n a tiv e e x p la n a t io n s f o r th e
c o n d it io n s a lr e a d y m e n t io n e d , s u c h as p e r ic o r o n it is , c a r i e s , r o o t r e s o r p t i o n , p e r i o d o n t a l d is e a s e , a n d p e r i
a n t e r i o r c r o w d i n g . F i r s t , t h e r e is t h e i n c r e a s e d p l a s t i c
a p ic a l
ity
w ill
p a th o lo g y .
c o m p la in
r a d io g r a p h ic a lly o th e r
th a n
p a c te d
O c c a s io n a lly ,
o f such th e re
is
how ever
a lth o u g h
no
a p a tie n t
c lin ic a lly a n d
a p p a re n t
a b n o r m a lit y
o f th e
a lv e o la r b o n e
a n d p e r i o d o n t a l lig a m e n ts
w h ic h a c c o m p a n ie s th e h o r m o n a l c h a n g e s o f a d o le s cence
o c c u r r in g
a t a b o u t th e
sam e
tim e
th e
th ir d
p re s e n c e o f a d e e p ly e m b e d d e d im
m o l a r is a t t e m p t i n g t o e r u p t . 7 S i n c e t h e m a n d i b u l a r
w i t h n o o b v io u s o r a l c o m m u n i c a t i o n .
in c is o r s a r e l o c a t e d in a r e la t iv e ly p r e c a r io u s p o s it io n
th e
to o th
p a in
D e s p it e t h e la c k o f a n a d e q u a t e e x p la n a t io n , t h e f a c t
in
r e m a in s
t h e t o n g u e a n d l i p , a n y in c r e a s e i n t h e l a b i l i t y o f t h e
th a t
som e
p a tie n ts
a re
r e lie v e d
of
th e ir
th e a lv e o la r r id g e , b a la n c e d b e t w e e n th e fo r c e s o f
p e r io d o n tiu m
s y m p to m s a f t e r r e m o v a l o f th e s e te e t h .
te e th .
g r a p h ic
m o l a r is f o u n d
e x a m in a tio n
of
a
c r o w d in g
of
d u r in g r o u tin e r a d io -
in s t a n c e s
in
c lin ic a lly
“ e d e n tu lo u s ”
re m o v e d
c o m p r e s s io n o f t h e m u c o s a b e t w e e n t h e
m e n t .8
of
th e
c o n g e n ita lly
m a n d i b l e . U n l e s s i t is c o m p l e t e l y c o v e r e d w i t h b o n e , c ro w n an d
c o u ld r e a d ily re s u lt in s h if tin g o f th e
fa v o r
O c c a s io n a lly , a n
■ R e t e n t io n in “ e d e n t u lo u s ” r id g e : im p a c t e d t h ir d
In
t h is
concept
in c i s o r s
can b e
is
th e
fa c t
o b s e rv e d
th a t
even
in
w h ic h th e m a n d ib u la r th ir d
m o la rs a re
m is s i n g
have
been
o f o r th o d o n tic
tre a t
p r io r
to
or
in
w h ic h
c o m p le t io n
th e y
c a n c a u s e p a i n . P r e s s u r e n e c r o s is o f t h e
O th e r fa c to r s t h a t m a y o c c a s io n a lly c o n tr ib u t e to
o v e r l y i n g g i n g i v a m a y a ls o p r o v i d e a p a t h w a y f o r t h e
th e c r o w d in g a re r e s tr ic tio n o f fo r w a r d g r o w th o f th e
d e v e lo p m e n t
th e d e n tu r e
p a tie n ts ,
lo w e r a r c h b y a d e e p o v e r b ite in th e u p p e r , a n d th e
r e m o v a l o f th e s e te e t h c a n b e e x t r e m e ly d i f f ic u lt , a n d
n a t u r a l t e n d e n c y o f t h e l o w e r in c i s o r s t o u p r i g h t w i t h
t h e d a n g e r o f j a w f r a c t u r e is g r e a t e r t h a n n o r m a l .
a g e .9
o f
an
in fe c tio n .
In
e ld e r ly
F in a lly ,
a c tu a lly ■ In v o lv e m e n t
in
u n e ru p te d
im p a c te d
or
a
The
fra c tu re :
th ir d
p re s e n c e
m o la r
o f an
m ay
in
som e
tre a te d
re p re s e n t
a
p a tie n ts ,
r e la p s e
fro m
c r o w d in g a
p h y s io
lo g ic a lly u n t e n a b le t o o t h p o s itio n in g .
c o n s id e r a b ly
w e a k e n s th e p o s te r io r a s p e c t o f th e m a n d ib le . T h u s , a f t e r f a c i a l t r a u m a , t h i s is t h e m o s t c o m m o n s ite o f b o n e fra c tu re .
■ C r o w d in g o f d e n t it io n : im p a c te d
R e m o v a l o f u n e ru p te d o r
t h i r d m o l a r s is o f t e n
r e c o m m e n d e d in p a
C o m p lic atio n s arising fro m m a x illa ry th ird m olars The th ir d
c o m p lic a t io n s m o la rs
a re
a r is in g q u ite
fro m
s im ila r
im p a c te d m a x illa r y to
th o s e
fro m
th e
tie n t s d u r in g o r a f t e r o r t h o d o n t ic t r e a t m e n t b e c a u s e
m a n d ib u la r
it has b ee n
c la im e d t h a t th e s e t e e t h s o m e tim e s c a n
p e r ic o r o n it is , p e r i o d o n t i t is , c a rie s , p a t h o lo g ic r e s o r p
p r o d u c e a n a n t e r io r f o r c e t h a t w i l l c a u s e s e p a r a tio n in
t i o n , c y s t s , n e o p la s m s , a n d i d i o p a t h i c p a i n , o r t h e y
th e
c o n ta c t p o in ts a n d
te e th .
They
to o
can
be
in v o lv e d
w ith
s u b s e q u e n t c r o w d in g o f th e
m a n d i b u l a r i n c i s o r s . 3-5 I n a r e c e n t s u r v e y o f o v e r 6 0 0 r a n d o m ly
s e le c t e d
o r th o d o n tis ts
g e o n s , a p p r o x im a te ly to
t h is i d e a . 6
d e v e lo p s
65%
U n d o u b te d ly th e
d u r in g
th e
and
700
o r a l s u r
o f e a c h g r o u p s u b s c r ib e d
e r u p tio n
c o n d it io n g e n e r a lly p e r io d
of
th e
th ir d
m o la r . W h e t h e r th e t w o e v e n ts a re r e la te d , h o w e v e r , r e m a in s u n p r o v e n . I f a n a n t e r io r f o r c e w e r e p r o je c t e d fro m a
th e im p r o p e r ly e r u p tin g m o la r , it w o u ld re q u ire
c o r re s p o n d in g
te e th
in
o rd e r
fo rw a rd to
be
s h if t o f a ll th e
tr a n s m itte d
to
p o s te r io r
th e
in c i s o r s .
M o r e o v e r , th e m o s t lik e ly p la c e f o r s u c h d is r u p tio n o f to o th
c o n ta c t
to
occur
w o u ld
c a n in e r e g i o n . T h e f a c t t h a t t h e
seem
to
be
in
th e
r e la tio n s h ip o f th e
u p p e r a n d lo w e r p o s te r io r t e e t h d o e s n o t c h a n g e a n d th e
c r o w d in g
d is p u te
th e
u s u a lly
a ffe c ts
th e
in c is o r s , te n d s
r o le o f th e e r u p tin g t h ir d
to
m o la r in th e
e t io lo g y o f th is p ro c e s s . A n a n t e r io r d r i f t d o e s o c c u r
826 ■ JADA, Vol. 82, April 1971
F ig 4 ■ Im p a c t e d
m a x illa r y
th ir d
m o la r
s o r p tio n o f th e d is ta l r o o t o f th e s e c o n d m o la r.
p r o d u c in g
re
m ay
rid g e s ( F ig 4 ) . T h e
a b le t h a t e r u p tin g o r im p a c t e d m a x i l la r y t h ir d m o la r s
i n c i d e n c e o f s u c h s e q u e l a e , h o w e v e r , is le s s t h a n w i t h
be
fo u n d
in
“ e d e n tu lo u s ”
in d u c e c r o w d in g o f th e d e n t it io n . I n f a c t , w h ile th e y
th e lo w e r t h ir d m o la r s .
fr e q u e n tly
A s w i t h t h e m a n d i b u l a r t h i r d m o l a r s , i t is i m p r o b -
a re
fo u n d
in
a
m e s io a n g u la r
p o s itio n ,
c o m p a r a b l e s h i f t i n g o f t h e i n c i s o r s is s e l d o m , i f e v e r , s e e n in t h e m a x i lla . S in c e t h e s a m e m e c h a n is m t h a t w as p ro p o s e d
fo r
th e
e t io lo g y
o f c r o w d in g
in
th e
m a n d i b l e s h o u ld a p p l y h e r e , t h i s s e e m s t o b e f u r t h e r e v id e n c e
a g a in s t t h e
r o le
o f im p a c te d
t e e t h in th e
p r o d u c t i o n o f o r t h o d o n t i c r e la p s e .
In d ic atio n s fo r re te n tio n o f u n eru p ted th ird m olars I t is e v i d e n t f r o m
th e p r e c e d in g d is c u s s io n t h a t e v e n
i f o n e d is c o u n ts a n y r e la tio n s h ip b e t w e e n e r u p t io n o f th e th ir d a re
m o la r a n d c r o w d in g o f t h e in c is o r s , th e r e
s till n u m e r o u s o t h e r c o m p lic a t io n s t h a t c a n b e
caused b y
th e s e
a g re e m e n t.
T h is
th e re
is
te e th
ever a need
m o la r .1 O n e m e d ic a l
w h ic h
to
th e re
q u e s tio n
r e ta in
an
is c o m p l e t e
as to
to
a v o id
s u rg e ry ,
o f s u b s e q u e n tly
w h e th e r
u n e ru p te d
in d ic a t io n , o t h e r th a n w h e n
re a s o n s
lik e lih o o d
on
r a is e s t h e
is
lo s in g t h e
th ir d
th e r e a re
i f th e re
is a
s e c o n d m o la r
b e c a u s e o f a l a r g e r e s t o r a t i o n , p e r i o d o n t a l d is e a s e , o r e x te n s iv e te n tio n
c a r ie s . A n o t h e r p o s s ib le i n d i c a t i o n is
in
o r th o d o n tic
p a tie n ts
in
fo r re
w hom
fo u r
p r e m o la r s h a v e a lr e a d y b e e n e x t r a c t e d a n d r e m o v a l o f th e
th ir d
m o la rs w o u ld
re d u c e
th e
d e n titio n
by
a
t o t a l o f e i g h t t e e t h . F i n a l l y , t h e r e m a y b e i n s t a n c e s in w h ic h
th e
o r th o d o n tis t
m ay
need
th e s e
te e th
fo r
a n c h o ra g e . I n th o s e p a t ie n ts in w h o m r e t e n t io n o f th e t h ir d
m o l a r s is d e s i r a b l e , b u t t h e i r p o s i t i o n d o e s n o t
p e r m it n o r m a l e r u p tio n in to th e d e n ta l a r c h , th e o r a l s u r g e o n s o m e tim e s m a y b e h e lp f u l in c o r r e c tin g th e s itu a tio n
by
r e p o s i t i o n i n g o f t h e t e e t h 1 0 ,1 1 ( F i g 5 ) .
P ro p h y la ctic rem oval o f th ird m olars A lth o u g h
an im p a c te d
t h ir d m o la r o c c a s io n a lly m a y
r e m a in a s y m p to m a t ic th r o u g h o u t a p e r s o n ’ s lif e t im e , c lin ic a l e x p e r ie n c e h a s s h o w n t h a t m o s t o f th e s e te e t h u l t i m a t e l y g iv e r is e t o s o m e d i f f i c u l t y . M o r e o v e r , t h e d a m a g e p r o d u c e d b y s u c h c o m p l i c a t i o n s f r e q u e n t l y is n o t r e v e r s i b le e v e n a f t e r t h e t o o t h h a s b e e n e x t r a c t e d . On
th is
b a s is ,
w ith
th e
fe w
m e n t io n e d , i t s e e m s lo g ic a l t o F ig 5 ■ S u rg ic a l re p o s itio n in g o f im p a c te d m a n d ib u la r th ir d m o la r.
A : P r e o p e r a tiv e ra d io g ra p h . B : T o o t h
im m e d ia te ly
a f t e r r e p o s itio n in g . C : R a d io g r a p h ta k e n th r e e y e a rs a f te r s u rg e ry .
N o te
r e c o n to u r in g
of
th e
in te r p r o x im a l
bone,
c o m p le t io n o f th e r o o t, a n d r e fo r m a tio n o f th e la m in a d u ra .
e x c e p t io n s
p r e v io u s ly
r e c o m m e n d th e p r o
p h y l a c t i c r e m o v a l o f a l l t h i r d m o l a r s a s s o o n a s i t is e v id e n t
th a t
n o r m a lly .
th e y
T h is
can
a re
not
in
g e n e r a lly
a be
to
e ru p t
d e te r m in e d
p o s it io n
r a d io -
g r a p h ic a lly w h e n th e p a tie n ts a re b e tw e e n 1 6 a n d 1 7
Laskin: EVALUATION OF THIRD MOLAR PROBLEM ■ 827
y e a rs o f a g e , a t w h ic h tim e th e m a jo r g r o w th o f th e ja w s h a s b e e n c o m p le t e d . R e m o v a l o f t h e t e e t h a t th is a g e , w h e n t h e r e u s u a l l y is n o p a t h o l o g i c i n v o l v e m e n t , is a m u c h
le s s c o m p l i c a t e d
p ro c e d u re
th a n
s im ila r
s u r g e r y in a n o l d e r p e r s o n .
9 . B jo r k , A . T h e fa c e in p r o file . L u n d , B e rlin g s k a B o k t r y c k e r ie t , 1 9 4 7 , p 6 4 , 1 2 6 , 1 7 2 . 1 0 . L a s k in , D . M ., a n d P e s k in , S. S u rg ic a l a id s in o r t h o d o n tic s . D e n t C lin N A , J u ly 1 9 6 8 , p 5 0 9 . 1 1 . P e s k in , S ., a n d G rä b e r , T . M . S u rg ic a l re p o s itio n in g o f te e t h . J A D A 8 0 : 1 3 2 0 J u n e 1 9 7 0 .
T h e o r t h o d o n t i s t is i n a k e y p o s i t i o n t o j u d g e t h e id e a l t im e o f t h ir d m o la r r e m o v a l in h is p a t ie n ts a n d to
a d v is e t h e m a c c o r d i n g l y . T h e o r a l s u r g e o n , w h e n
ever
p o s s ib le ,
m ust
a ls o
e m p h a s iz e
p r e v e n tio n
of
c o m p lic a t io n s r a t h e r t h a n t h e i r c u r e . I n t h is m a n n e r , b o th
g ro u p s
w ill
th e n
be
m a k in g
an
even
g re a te r
c o n t r ib u t io n t o t o t a l o r a l h e a lt h .
1. L a s k in , D .M . In d ic a tio n s a n d c o n tr a in d ic a tio n s f o r re m o v a l o f im p a c te d t h ir d m o la rs . D e n t C lin N A 1 3 : 9 1 9 O c t 1969. 2 . T h o m a , K . H ., a n d G o ld m a n , H .M . O ra l p a t h o lo g y , ed 5 . S t. L o u is , C . V . M o s b y C o ., 1 9 6 0 , p . 7 8 3 - 7 8 4 . 3 . D e w e y , M . T h e th ir d m o la rs in r e la tio n to m a lo c c lu s io n . I n t J O r t h o d o n t 3 : 5 2 9 S e p t 1 9 1 7 . 4 . R o u n d s , C . E. P rin c ip le s a n d te c h n iq u e o f e x o d o n t ia , e d 2 . S t . L o u is , C . V . M o s b y C o ., 1 9 6 2 , p 2 7 9 . 5 . W a ld r o n , R . Q u e s tio n o f th e in flu e n c e o f e r u p tin g o r im p a c te d th ir d m o la rs o n th e o c c lu s io n o f tr e a te d a n d u n t r e a te d cases. A m e r J O r t h o d o n t 2 3 : 2 2 1 M a r c h 1 9 3 7 . 6 . L a s k in , D . M . U n p u b lis h e d d a ta . 7 . E n g e l, M . B ., a n d o th e rs . A th e o r y o f c o n n e c tiv e tiss u e b e h a v io r: its im p lic a tio n s in p e r io d o n ta l disease. A n n N Y A c a d S c i, 8 5 : 3 9 9 M a r c h 9 , 1 9 6 0 . 8 . S e lm e r -O ls e n , R . T h e n o r m a l m o v e m e n t o f th e m a n d i b u la r te e t h a n d th e c r o w d in g o f th e in c is o rs as a re s u lt o f g r o w th a n d f u n c t io n . D e n t R e c 5 7 : 4 6 5 S e p t 1 9 3 7 .
828 a JADA, Vol. 82, April 1971
D o c t o r L a s k in is p ro fe s s o r a n d a s s o c ia te h e a d o f th e d e p a r t m e n t o f o ra l a n d m a x illo f a c ia l s u rg e ry , C o lle g e o f D e n t is tr y , U n iv e r s ity o f Illin o is a t th e M e d ic a l C e n t e r , P O B o x 6 9 9 8 , C h ic a g o , 6 0 6 8 0 .