Figure 4-36.Features of an occlusal surface of maxillary first
cusps.) Sometimes bicuspids are called premolars
because they are just in front of the molar teeth.
Facial SurfaceThe facial surface is somewhat
similar to the facial surface of the cuspid. However,
the tip of the facial cusp is located in the center of the
biting edge, which is called the occlusal edge or
From the cusp tip to the cervical
margin, there is a slight ridge, called the facial ridge,
similar to the facial ridge found in cuspid teeth.
Lingual SurfaceThe lingual surface is
narrower and shorter than the facial surface, and is
smoothly convex in all directions. The cusp tip is in the
middle of the occlusal edge.
Root SurfaceThe root is quite flat on the mesial
and distal surfaces. In about 50 percent of maxillary
first bicuspids, the root is divided in the apical third,
and when it so divided, the tips of the facial and lingual
roots are slender and finely tapered.
Occlusal SurfaceThe occlusal surface (fig.
4-36) has a facial cusp and a lingual cusp. There are
mesial and distal marginal ridges. Two fossae are on
the occlusal surface-the mesial and distal fossae.
MAXILLARY SECOND BICUSPID
The maxillary second bicuspid (tooth #4 or #13),
illustrated in figure 4-37, resembles the first bicuspid
very closely, but is smaller in dimensions. The cusps
are not as sharp as the maxillary first bicuspid and have
only one root.
MANDIBULAR FIRST BICUSPID
The mandibular first bicuspid (tooth #21 or #28),
illustrated in figure 4-38, is the fourth tooth from the
midline. It is the smallest of the four bicuspids. The
term bell-crowned is used to describe its appearance.
The mandibular first bicuspid has many characteristics
of a cuspid.
Occlusal SurfaceA large facial cusp, which is
long and well defined, and a small nonfunctional
lingual cusp are present on the mandibular first
Root SurfaceThe root of the mandibular first
bicuspid is usually single, but on occasion can be
bifurcated (two roots).
The mandibular second bicuspid (tooth #20 or
#29), illustrated in figure 4-39, is the fifth tooth from
Figure 4-37.Surfaces of maxillary second bicuspid.