Figure 4-33.Features of facial and lingual surfaces of a
straight, the cuspid has a definite point, or cusp. There
are two cutting edges, the mesioincisal and the
distoincisal. The distoincisal cutting edge is the longer
of the two. The developmental grooves that are so
prominent on the facial surface of the central incisor
are present here, extending two-thirds of the distance
from the tip of the cusp to the cervical line.
Lingual SurfaceThe lingual surface has the
same outline as the facial surface but is somewhat
smaller because the mesial and distal surfaces of the
crown converge toward the lingual surface.
lingual surface is concave, with very prominent mesial
and distal marginal ridges, and a lingual ridge, which
extends from the tip of the cusp toward the cervical
Figure 4-34.Surfaces of a mandibular cuspid.
line. There is often a cingulum in the cervical portion
of the lingual surface of the crown.
Root SurfaceThe root is single and is the
longest root in the arch. It is usually twice the length of
the crown. This is because the cuspid is designed for
seizing and holding food.
The mandibular cuspid (tooth #22 or #27) is
illustrated in figure 4-34. These teeth, like the
mandibular incisors, are smaller and more slender than
the opposing teeth in the maxillary arch.
Facial SurfaceThe facial surface of a
mandibular cuspid is much the same as that of a
maxillary cuspid, except that the distoincisal cutting
edge is almost twice the length of the mesial edge.
Lingual SurfaceThe lingual surface as a rule is
very smooth, and a cingulum is rarely present.
Root SurfaceThe single root is not so long as
that of the maxillary cuspid and is much flatter
MAXILLARY FIRST BICUSPID
The maxillary first bicuspid (tooth #5 or #12),
illustrated in figures 4-35 and 4-36, is the fourth tooth
from the midline. It is considered to be the typical
bicuspid. (The word bicuspid means having two
Figure 4-35.Surfaces of maxillary first bicuspid.