Page 423 - My FlipBook

419

behind the central incisores and the temporary cuspidati ; or
they grow up with one corner turned forwards, and the other
pointing backwards. In either of these cases the temporary
cuspidati must be removed to give room.
The four permanent incisores take up nearly the whole of
the space of the temporary incisores and cuspidati. The
permanent cuspidati are large teeth, and when they have not
sufficient room they occasion very great irregularity. Some-
times they come through on the inside, but most commonly
they cut the gum on the outside, and project very much out
of the circular line from the temporary incisores to the tem-
porary molares. In this case, the necessity of the removal
of the first temporary molares is obvious.
It is not very common that the bicuspides of the lower jaw
are irregular, because the temporary molares are generally
removed before they appear ; but when this is not the case,
they always come through the gums on the inside, pointing
towards the tongue, in which case the temporary molares
must be removed, that the bicuspides may rise into their pro-
per situations.*
In the upper jaw, the permanent central incisores some-
times pass through the gums behind the temporary ones ;
when this happens, the four temporary incisores must be ex-
tracted, and frequent pressure by the thumb should be ap-
plied to the new teeth, in order to bring them forward as
soon as possible, and prevent one of the cases of irregularity
most difficult to be remedied.
When the temporary central incisores have come out, the
space is generally too narrow for the permanent ones, and
hence they are pressed into some shape of distortion. Their
edges do not assume the regular curve, but stand obliquely,

Fig. 6.