Page 27 - My FlipBook

DYSTROPHIES OF THE TEETH.
ILLUSTRATIONS: FIGURES 1-47.
THE condition resulting from imperfect, defective, or bad
formation of growth constitutes a dystrophy ; dys — imper-
fect, defective, bad ; trophy — growth, development. Therefore,
any dystrophy noted must have occurred during the growth of
the tissue. A tooth that is misshapen, off color, or otherwise
deformed during growth, is in the condition of dystrophy.
Acquired deformities, such as erosion, abrasion of the teeth in
chewing food, etc., after the teeth have formed, are excluded
from dystrophies.
The dystrophies of the teeth consist of imperfections in
development due to some disturbance of nutrition during the
time of formation or growth. In each class of cases some part
of the tissue is either imperfectly developed, or some particular
part has failed to develop, or has developed in an erratic man-
ner. Among these dystrophies, there are certain things common
to several, such as imperfection of the cementing substance
between the enamel rods. In others, the enamel may be want-
ing or may have an unusual arrangement, while in others defects
may be present in all of hard tissues of the teeth.
It is only recently that these conditions have received such
histological study as to make out the scheme of each, and sep-
arate them into special classes of deformity. The gross appear-
ance of some of the more frequent of these deformities of the
teeth has of course been well known for many years.
All of these deformities thus far seen may be grouped in
such a way that each one will be distinguished as a special
deformity, and those that are essentially alike may be grouped
together. Sections prepared for microscopic observation form
the basis of this classification.*
* These examinations have convinced me that the words atrophy and hypoplasia
are no longer desirable. These words have been applied to a specific deformity of
the teeth caused by malnutrition, and they have also been used almost continuously
in describing abnormal teeth of any and all classes. This they can not properly do,
and it seems actually necessary that other words be substituted. The continued use
of the word atrophy has become a bar to progress, and it will be noticed that I have
in this writing substituted the word dystrophy as applied to all forms of imperfect
development, and have used other terms as descriptive of the several dystrophies. I
have, as in previous editions of this work, used the word atrophy as applied to that
form of dystrophy caused by malnutrition, only because I am unable to find a satis-
factory word to replace it.