The Marion daily mirror. (Marion, Ohio) 1892-1912, 1909-10-28
TEETH As THEY GROW
The Way Nature Forms and Fixes
Them In the Gums.
THEY ARE NOT MADE OF BONE
Teeth Are Really Skin Structures In
Respect to Their Mode Of Origin.
The Variety Of Form Which Adspts
Them For Varying Uses.

have dipped into their history viewed
from the scientific side, can form an
adequate idea regarding their true ma
ttre. IL the man IN the street were
asked TO construct n classified list OF
his bodily belongings he would almost
certainly place teeth In the section
which included the bones. There ap-
pears reason for his choice. Teeth are
hard and bonelike in structure. and
they are fixed in the jaws. These facts
would seem on the face OF things 10
Justify the inclusion OF the teeth in
| the list Of skeletal structures. This
view of the teeth, however. is readily
proved to be incorrect. We have only
/ to appeal 10 natures way OF making
touth--in other words. TO study its de.
velopment--to assure ourselves that
teeth are not bones at all, but struc.
lures OF very different kind.
The first indication Of tooth forma-
ton begins In very early life with the
formation OF a groove In the gum, or
mucous membrane lining the mouth
This furrow IL the birthplace Of the
teeth. From the groove arise as many
little projections of the gum as there
are TO be teeth. Each projection we
call a papllln.
Now, this little body contains n plen
tful supply OF blood vessels. destined
to bring to It the raw material blood
--out OF which not teeth alone, but all
other organs, tissues and secretions.
are manufactured. The papllln. be.
sides, Is composed OF and particularly
invested with living cells OF speciat
kind. These cells are to be regarded
as the worEmeR which fabricate the
tooth. The material specially required
! for tooth formation consists of com.
pounds OF lime associated with other
substances.
Around the papilla and upon 1t, as
on mold the hard material OF the
tooth is deposited. 1t is elaborated
into substance which, under the
microscope. shows special structure
Of its own, differing widely from that
which Is represented In bone. The
great bulk of tooth consists OF ivory
or dentine. as IL Is also called. This
is dense. hard substance which
shows texture composed OF an In.
finite variety Of microscopic tubules.
But at the crown Of the tooth es-
pecially we meet with a layer of DIFF.
ferent kind and of still harder coii-
sistence. This Is the enamel, which
ranks as the hardest substance In the
! body. Its position on the crown OF
the tooth bears n relation to the resist.
ancc 10 wear and tear the tooth Is In.
tended to exhibit, the softer ivory be.
ing thus protected from the obvious
results OF the process OF attrltion.
Thus on the papilla, as on living
mold, the tooth Is formed, its sub.
stance coming to cover, as In an en-
velope the little projection itself
Long before the tooth. however. If
completed the groove In the gum has
become partitioned off into q series OF
sacs or compartments. The furrow
itself becomes converted into tube
by the upward growth and union OF
its edges In the middle line. Then
succeeds division into sacs, in each OF
which a papi!la Is present and In each
Of which developing tooth Is con.
tained
If the hard materials Of the tooth be
found around the papilla we discover
thus that the tooth Is a hollow and not
solid structure. for the pulp inside
every tooth, a substance richly sup
piled with nerves and blood vessels.
really represents the papilla of the
early stages. The tooth's nourlshment
Is thus duly provided for. since proc,
esses of the pulp pass into the minute
tubules OF the ivory and SO contribute
to the maintenance Of the vitality OF
the organ.
When the tooth is completed within
Its sac, all that remains Is for 1t to ap.
pear In the jaw, In which provision
has been made for Its fxation. A
tooth 'cuts" the gum when through
upward pressure ON the sac 1t bursts
through Its investment and takes the
| place nature has mapped out for 1t In
the Recommendation Of the mouth.
Now, In all this history there Is no
hint given us OF any connection be.
tween bone formation and tooth devel-
| oDIutiit save iuuctu lOT luc COuHcCtlOli
between the two structures In the
jaw. The gum is the present tissue OF
the teeth, and the gum Is simply the
skin layer Of the body folded inward
at the mouth to form the lining mem.
brane of that cavity, while 1t is con.
tinued onward, with variat tons in its
organization, to form the lining of the
digestive tubes as well. Teeth are
therefore truly skin structures In re.
spect of their mode Of origin, which,
after all, is the surest and indeed the
only test Of the nature OF any living
tissue or part
BY all odds the very longest tooth In
the worh Is that Of the narwhal,
which grows into twisted ivory pole
often exceeding six feet In length
A. Wilson in Illustrated London News,