Page 255 - My FlipBook

Pegs. 116. 117. A diagrammatic representation nf caries of the buccal surfaces, Fig-tirc 110, ami
of cross sections of the crowns, Figure 117, of the lower first and second bicuspids and first and
second molars, showing the location of caries and tendency to spread in a direction around the
crowns of the teeth, following the free margin of the gingiva?. In Figure 116, the dotted line repre-
sents the gingival line, or line of the attachment of the gum tissue to the teeth. The continuous
dark line represents the line of the free margin of the gingivic, which arches toward the occlusal
in passing between the teeth. The double line represents a saw cut dividing the crowns through the
decayed areas of the enamel. Figure 117 represents the decayed areas of enamel exposed by cutting
away the crowns. Tlie portions darkened represent the parts of the enamel most liable to caries,
while the areas left white at the niesio- and disto-buccal angles of the teeth represent areas that are
almost always immune to caries.