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70
SECTION I.
OF THE FORMATION OF THE TEMPORARY SET OF TEETH.*
When the foetus has advanced so far in the organization
of its different parts, as to take some determinate form or
; we may perceive a considerable progress in the pre-
figure
paratory steps for the formation of the teeth.
As soon as the ossific deposit commences in the cartila-
ginous part of the embryo, both jaws are filled with small
membranous, and, in the anterior parts, we may perceive
the rudiments of the alveolar processes.
In a foetus of about four months, the jaw bones are dis-
tinctly formed ; but at this time they only consist of thin
grooved bones, having a cavity, extending through their
whole length, f In the under jaw, anteriorly, this cavity is
narrower and deeper ; but, posteriorly, it becomes wider and
more shallow. At this time, if the membranous parts be re-
moved, small processes of bone may be perceived, shooting
across from each side, which as the fcetus increases in
growth, gradually acquire more distinctness, and at length
form separate sockets for the teeth.
During the fcetal state, and also for some months after
birth, the blood vessels and nerves belonging to the teeth,
run along at the bottom of this cavity, immediately below the
pulps of the teeth ; but afterwards, a distinct canal is form-
ed, through which the principal vessels and nerves pass
separate filaments being sent off to the several teeth.
* Fox, 1st to 5th page, first part,
i The description of what takes place in one jaw, will completely ex-
hibit what concerns the formation of the teeth in both, therefore in order
to avoid confusion, I shall refer to the under jaw only.
70
SECTION I.
OF THE FORMATION OF THE TEMPORARY SET OF TEETH.*
When the foetus has advanced so far in the organization
of its different parts, as to take some determinate form or
; we may perceive a considerable progress in the pre-
figure
paratory steps for the formation of the teeth.
As soon as the ossific deposit commences in the cartila-
ginous part of the embryo, both jaws are filled with small
membranous, and, in the anterior parts, we may perceive
the rudiments of the alveolar processes.
In a foetus of about four months, the jaw bones are dis-
tinctly formed ; but at this time they only consist of thin
grooved bones, having a cavity, extending through their
whole length, f In the under jaw, anteriorly, this cavity is
narrower and deeper ; but, posteriorly, it becomes wider and
more shallow. At this time, if the membranous parts be re-
moved, small processes of bone may be perceived, shooting
across from each side, which as the fcetus increases in
growth, gradually acquire more distinctness, and at length
form separate sockets for the teeth.
During the fcetal state, and also for some months after
birth, the blood vessels and nerves belonging to the teeth,
run along at the bottom of this cavity, immediately below the
pulps of the teeth ; but afterwards, a distinct canal is form-
ed, through which the principal vessels and nerves pass
separate filaments being sent off to the several teeth.
* Fox, 1st to 5th page, first part,
i The description of what takes place in one jaw, will completely ex-
hibit what concerns the formation of the teeth in both, therefore in order
to avoid confusion, I shall refer to the under jaw only.
