Section II. MAXILLARY TEETH
4-10. MAXILLARY CENTRAL INCISOR
The maxillary central incisor (figure 4-20) is located adjacent to the midline
(median line) on the anterior portion of the maxillary dental arch. Its mesial surface
contacts the mesial surface of the maxillary central incisor of the opposite side. This
tooth has the greatest mesiodistal width of all anterior teeth. Like all anterior teeth, it
develops from four fused lobes. Three of these lobes making up the facial surface and
the fourth forming the cingulum on the lingual surface. Newly erupted incisor teeth have
three mamelons (scallops) on their incisal edges conforming to the three labial lobes;
these mamelons are usually worn away within a short period of time.
a. Facial Surface. The facial surface is broad, resembling a thumbnail in
outline. Its incisal two-thirds is relatively flat and broad while the gingival one-third is
more convex. The gingival margin is convex toward the root. The surface has two
shallow, longitudinal (axial) depressions, which are developmental grooves representing
fusion of the three facial lobes. The distoincisal angle is more rounded than the
Figure 4-20. Maxillary right central incisor.