a. Facial Surface. The facial surface is rectangular in shape and convex in
form. Its occlusal margin consists of the slopes of two similarly shaped cusps separated
by a facial groove. The facial groove is a continuation of a groove from the occlusal
surface which ends at the middle of the facial surface. The mesial cusp is slightly larger
than the distal cusp.
b. Lingual Surface. The lingual surface resembles the lingual surface of the
mandibular first molar. The lingual groove, which is a continuation of the lingual groove
of the occlusal surface, ends at the middle of this surface.
c. Mesial Surface. The mesial surface is similar in outline to the mesial surface
of the mandibular first molar but is more convex in all directions. The contact area is
located in the middle of the occlusal third.
d. Distal Surface. The distal surface is similar to the mesial surface but is
smaller in area and more convex. The contact area is located in the middle of the
e. Roots. The two roots of the mandibular second molar resemble those of the
mandibular first molar but are less divergent. The two roots present a distal inclination.
4-25. MANDIBULAR THIRD MOLAR
The mandibular third molar (figure 4-35) is commonly known as the "wisdom
tooth." It may appear in any of a wide range of forms, sizes, and shapes. Typically, it
resembles either the first or second mandibular molar (more often the latter). It is
smaller in its overall size. Abnormalities of eruption and occlusion of third molars