(2) Marginal ridge. Marginal ridges (see figure 4-12) are elevations of
enamel which form the mesial and distal margins of the occlusal surfaces of posterior
teeth (on a bicuspid or a molar). They also form the mesial and distal margins of the
lingual surface of anterior teeth (on an incisor or a cuspid).
Figure 4-12. Marginal ridges.
(3) Triangular ridge. This feature is a triangular-shaped ridge of enamel.
The triangular ridge (see figure 4-13) passes from the tip of a cusp to the central part of
the occlusal surface of a bicuspid or molar.
Figure 4-13. Triangular ridge.
(4) Transverse ridge. The transverse ridge is formed by the union of a facial
and a lingual triangular ridge on the occlusal surface of a posterior tooth.