Page 159 - My FlipBook
P. 159
; ;
THE REASON FOR THE SHEDDING OF THE TEETH. 143
Upper-Jaw ; and for this reason the Condyle of the Lower-Jaw
is nearly in the same line ; but afterwards, by the addition of
the Alveolar Process and Teeth, the line of the Gums-' in the
Upper-Jaw descends considerably below the articular cavity
and for that reason the Condyloid Process is then lengthened in
the same proportion.
In old people who have lost all their Teeth, the articulation
comes again into the same line with the Gums of the Upper-
Jaw ; but in the Lower-Jaw, the Condyles cannot be diminished
again for accommodating it to the Upper, so that it necessarily
projects beyond the Gums of the Upper-Jaw at the fore part.
When the mouth is shut, the projection of the Jaw at the chin,
fits the two Jaws to each other at that place where the Grinders
were situated, and where the strength of mastication lies ; for if
the chin was not further from the center of motion than the
Gums of the Upper-Jaw, at the fore part, the Jaws, in such
people as have lost all their Teeth, would meet in a point at the
fore part, like a pair of pinchers, and be at a considerable dis-
tance behind.
THE SEASON FOR THE SHEDDING OF THE TEETH.
As the shedding of the Teeth is a very singular process in
the animal oeconomy, many reasons have been asssigned for it
but these reasons have not carried along with them that
conviction which is desired. Authors have not fully considered
the appearances which naturally explain themselves ; nor have
they considered the advantages necessarily arising from the size
and construction of only such a number as the first set ; nor
have they considered fully the disadvantages that such size and
construction would have, if continued when it is necessary to
have a greater number, which is the case with the adult.
We shall consider these advantages in a child where the shed-
ding Teeth are all completely formed, which will be setting them
in the clearest point of light ; and also, the disadvantages that
THE REASON FOR THE SHEDDING OF THE TEETH. 143
Upper-Jaw ; and for this reason the Condyle of the Lower-Jaw
is nearly in the same line ; but afterwards, by the addition of
the Alveolar Process and Teeth, the line of the Gums-' in the
Upper-Jaw descends considerably below the articular cavity
and for that reason the Condyloid Process is then lengthened in
the same proportion.
In old people who have lost all their Teeth, the articulation
comes again into the same line with the Gums of the Upper-
Jaw ; but in the Lower-Jaw, the Condyles cannot be diminished
again for accommodating it to the Upper, so that it necessarily
projects beyond the Gums of the Upper-Jaw at the fore part.
When the mouth is shut, the projection of the Jaw at the chin,
fits the two Jaws to each other at that place where the Grinders
were situated, and where the strength of mastication lies ; for if
the chin was not further from the center of motion than the
Gums of the Upper-Jaw, at the fore part, the Jaws, in such
people as have lost all their Teeth, would meet in a point at the
fore part, like a pair of pinchers, and be at a considerable dis-
tance behind.
THE SEASON FOR THE SHEDDING OF THE TEETH.
As the shedding of the Teeth is a very singular process in
the animal oeconomy, many reasons have been asssigned for it
but these reasons have not carried along with them that
conviction which is desired. Authors have not fully considered
the appearances which naturally explain themselves ; nor have
they considered the advantages necessarily arising from the size
and construction of only such a number as the first set ; nor
have they considered fully the disadvantages that such size and
construction would have, if continued when it is necessary to
have a greater number, which is the case with the adult.
We shall consider these advantages in a child where the shed-
ding Teeth are all completely formed, which will be setting them
in the clearest point of light ; and also, the disadvantages that
