Page 221 - My FlipBook

Fia. 136. A photograph of the lingual surface of a cuspid with a broad open cavity. From
what remains of the surface of the tooth, it is seen that there is an unusually prominent lingual
groove on the left side of the picture, in the line of which a small dark pit appears. This indicates
that there were other and deeper pits in this surface in which decay in this unusual position started.
The case illustrates the fact that often decays in unusual positions have occurred because of some
imperfection which has furnished a place of lodgment, and the imperfection has been wholly destroyed
by the decay, leaving no sign explaining the cause.