Page 186 - My FlipBook

lies. This must be mouth to mouth studies that you will ;
make among your patients in the future.
There are certain conditions that seem to influence these
hereditary pecuh'arities in a very marked degree. It is noted
most, perhaps, in those famihes that come from Europe and
settle in America. In very many of these where the parents
were immune, or very nearly immune, to caries, we find them
presenting us with children who are very susceptible to caries.
There has been some change brought about by the change of
climate or the conditions under which they live. The reverse
of this I have noted in a few cases where families have come
from Europe, the parents having suffered greatly from caries
and their children will be almost entirely immune. But gen-
erally it has been the other way. Another thing that is
sometimes prominent—in the cities you will find parents who
have come from the country who did not suffer much from
caries, and had come to the period of immunity, but present
children here in the city who sufifer greatly from caries. A
change in the mode of life seems to have influenced the
hereditary factor. These kinds of changes are quite frequent.
The predisposition to caries is much stronger in youth
indeed, caries of the teeth is a disease of youth rather than
of adult age. We have a whole list of diseases that are
peculiar to children. As the person arrives at adult age the
predisposition to these diseases passes away, immunity comes.
It is so with caries of the teeth, only not in quite so marked a
degree. There are, perhaps, something over two-thirds of the
people of this community, or the communities with which I
have been most intimately acquainted, in whom immunity to
decay of the teeth will become practically perfect by the time
they are thirty years old, provided the ravages of decay are
controlled and they maintain the full use of their teeth. This
has been my experience. And you will find in your after
practice that the great bulk of fillings you are called upon to
make in people over thirty years old are refillings, or fiUings
of little bits of cavities, dark in color, that have progressed so
slowly that they have not been noticed by the patient until
late in life, comparatively. Now these two characters of fill-
ings comprise the great bulk of fillings that you will have to
make in persons over thirty years of age. The new cavities,
the progressive decays, are nearly all to be treated in persons

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