Page 233 - My FlipBook

OF TIIE IRREGULARITY OF THE TEETH. 217
directed, of bringing them even again. This principle, is
the power which many parts (especially bones) have of
moving out of the way of mechanical pressure.
The irregularity of the Teeth is at first owing to me-
chanical pressure ; for one Tooth getting the start of
another, and fixing firmly in its place, becomes a resistance
to the young, loose, forming Tooth, and gives it an oblique
direction. The same principle takes place in a completely
formed Tooth, whenever a pressure is made upon it. Pro-
bably a Tooth might by slow degrees be moved to any part of
the mouth, for I have seen the cuspidati pressed into the
place of the incisores. However it is observed, that the
Teeth are easier moved backwards than forwards, and when
moved back that they are permanent, but often, when
moved forwards, that they are very apt to recede.
The best time for moving the Teeth is in youth, while
the jaws have an adapting disposition ; for, after a certain
time, they do not so readily suit themselves to the irregu-
larity of the Teeth. This we see plainly to be the case,
when we compare the loss of a Tooth at the age of fifteen
years, and at that of thirty or forty. In the first case we
find, that the two neighbouring Teeth approach one another,
in every part alike, till they are close : but in the second,
the distance in the jaw, between the two neighbouring Teeth,
remains the same, while the bodies will in a small degree
incline to one another for want of lateral support.
And this circumstance of the bodies of the Teeth yielding,to
pressure upon their base, shows that, even in the adult, they
might be brought nearer to one another by art properly applied.
As the operation of moving the Teeth is by lateral pressure
upon their bodies, these bodies must first have passed through
the gum sufficiently for a hold to be taken.
The best time seems to be, when the two grinders of the
child have been shed; for at this time a natural alteration
is taking place in that part of the jaw.
The means of making this pressure I shall only slightly