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22 Natural History of the Teeth,
" For some time during the formation of the teeth, the alveoli
grow much faster than the teeth themselves, which are con-
sequently but loosely contained within them. At the time of
birth, the alveolar processes have increased so much, that they
almost enclose or cover the teeth ; thus a firm support is given
to the gums, and the infant is enabled to make considerable
pressure in sucking, &c. without injury to the process which
is going on underneath.
" The ossification of the teeth begins to take place very early
:
it is first visible upon the tips of the incisores. In a foetus of
about five or six months, ossification has commenced upon the
pulps of the incisores and cuspidati, and on the points of the
molures, this gradually advances and extends itselfj over the
pulp, down to the neck of the tooth, from the cutting edges or
highest points, where it had first commenced.
"At the time of birth, the bodies of ten teeth are distinctly
formed in each jaw; these are the teeth designed to serve dur-
ing the years of childhood, and are commonly called the tem-
porary, shedding, or milk teeth.
"Alter birth, as the ossification goes on, the teeth become
too long to be contained within the alveolar cavity, they there-
fore begin to make pressure upou those parts which cover
them; this produces the process of absorption, which proceeds
with the enlargement of the tooth, first removing the mem-
branes which enveloped the teeth, aud afterwards the thick
gum which covered them, this gradually becoming thinner
and thinner, till at length the teeth are suffered to pass through.
" The following is the order in which the teeth of a child
generally appear.—The first teeth are the central incisores of
the under jaw, one generally coming a few days before the
other ; then, in the course of a month, the two central incisores
of the upper jaw. These are succeeded in a few week6 by the
lateral incisores of the under jaw, and then soon after by the
lateral incisores of the upper jaw. The cuspidati are generally
slower in completing their growth than the molares; they are
placed deeper in the jaw, and therefore are preceeded by the
first molares. The small molares of the under jaw usually