Page 259 - My FlipBook

The position of erosion is most commonly the buccal or
labial surfaces of the teeth. I hardly know whether to say it
appears oftenest upon the incisors or upon the bicuspids and
molars. Sometimes, however, it will begin upon the proximate
surfaces, and a few cases have been observed upon the lingual
surfaces. When it has begun upon a surface of a tooth there
is no inclination to spread to other surfaces, i. e., if it has be-
gun upon a labial surface there is no disposition to begin upon
a proximate surface or a lingual surface, but it will be con-
fined to labial surfaces ; but it will spread to other labial sur-
faces in the neighborhood. For instance, if it begins upon a
central incisor, which is not an uncommon place of beginning,
it is likely to spread to the other central incisor and to the
lateral incisors and cuspids, spreading from before backward.
If it begins upon a first molar it is liable to spread to the second
and third molars and to the bicuspids, and in most of these
cases it will be bilateral, though occasionally we find it unilat-
eral, not beginning upon the opposite side at all. It may also
spread apparently from the upper to the lower, or vice versa,
but continuing upon the labial or buccal surfaces, not spread-
ing to other surfaces of the teeth. If it begins on proximate
surfaces, proximate surfaces only will be affected. But it
wiir spread from tooth to tooth.
The forms presented by erosion are as various as the
cases. The most common form, however, we may describe as
a dish-shaped excavation, affecting the central incisors first,
and spreading to the teeth at either side of the tooth first at-
tacked ; hardly ever exactly bilateral, being more upon one
side of the mouth than the other, usually, and eating away the
labial surfaces. It usually begins in the gingival third of the
surface, or about the junction of the gingival and middle
thirds ; forming a little facet first upon the enamel, then eating
away more and more, and finally passing to the dentin, going
on without any distinction whatever between dentin and
enamel and increasing the size of these facets until the whole
of the labial surface has been removed ; not touching the
proximate surfaces, not touching the lingual surfaces, not
touching the incisal, except as it is approached from labial.
Now, here are two casts, one just beginning and the other
among the worst of the cases that I have seen with the teeth
standing. One of these cases was presented here in the in-

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