Page 33 - My FlipBook

ATROPHY. 29

of regular, because the former are impeded in their
eruption, and thus impaired. But this, to say the
least, is questionable; for it will be remembered
that the crowns of the teeth are formed and ossified
before they can be much affected by a crowded state;
and it is hardly probable that they could be materially
modified in their structure after this period. The
crowns of the teeth are rarely if ever deformed by a

crowded condition. The principal cause of the liability
of irregular teeth to decay, is the facility they furnish
for the lodgment of foreign substances about them,
and the difficulty they present to its removal. And,
again, in irregular teeth, parts are approximated that
nature did not intend should be brought together.
Irregularity impairs the speech, impedes the mastica-
tion, and often distorts the countenance and deforms

the features.

ATROPHY.

This affection is characterized by defective spots in
the enamel, white, chalk-like—which scarcely ever

penetrate the dentine. In these spots there is little
or nothing of that organic structure exhibited by well
formed enamel. They are in all cases quite small,
but vary greatly in number. They are often found
arranged in transverse rows across the tooth affected.