Rock Island Argus., 1909-05-17
THE TEETH AS THEY GROW
The Way Nature Forms and Fixes
Them in the Gums.

Them in the Gums.
Familiar to everybody as are the
teeth, few persons, save those who
have dipped into their history viewed
from the scientific side, can form an
adequate idea regarding their true ma
ture. If the man in the street were
asked to construct 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 to
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 to natures way of making Il
tooth-in other words, to study its de-
velopment-to assure ourselves that
teeth are not bones at all, but struc-
lures Of q 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 is the birthplace of the
teeth. From the groove arise as many
little projections Of the gum as there
are to he teeth. Each projection we
call papilla.
Now, this little body contains Il plen-
tiful supply of blood vessels, destined
to bring to it the raw material-blocd
! out of which not teeth alone, but all
other organs. tissues and secretions,
are manufactured. The papilla. be-
sides. is composed of and particularly
invested with living cells of special
kind. These cells are TO be regarded
as the SWOrllmen 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 it, as
on mold. the hard material Of the
tooth is deposited. 1t is elaborated
into n substance which. under the
microscope. shows Il special structure
of its own, differing widely from that
which is represented in bone. The
great bulk of q tooth consists OF ivory
or dentine. rs 1t is also called. This
Is 4 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 n layer of diff
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
ance to 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 attrition.
Thus on the papilla, as on living
mold, the tooth is formed, its sub
stance coming to cover, as in an eu-
yelope, the little projection itself.
Long before the tooth, however, is
completed the groove in the gum has
become partitioned off into series of
sacS or compartments. The furrow
itself becomes converted into a tube
by the upward growth and union of
fits edges in the middle line. Then
succeeds division into sacs, in each of
which papilla is present and in each
Of which developing tooth is con.
tanned
! If the hard materials of the tooth be
found around the papilla we discover
thus that the tooth is hollow and not
solid structure, for the pulp inside
every tooth, substance richly sup
piled with nerves and blood vessels
really represents the papilla Of Tho
early stages. The tooths nourishmen
is thus duly provided for. since proc
esses of the pulp pass into the minut,
! tubules of the ivory and SO contribut,