Figure 4-33. Mandibular right first molar.
a. Facial Surface. The facial surface is convex in all directions. A facial groove
and a distofacial groove are continuations of grooves from the occlusal surface which
end on the facial surface. Its occlusal margin is made up of six slopes (two slopes for
each of three facial cusps).
b. Lingual Surface. The lingual surface is smaller than the facial surface. Its
occlusal margin is formed by the four slopes of the two lingual cusps. A distinct lingual
groove is continuous from the occlusal surface ending in the middle third of this surface.
c. Mesial Surface. The mesial surface has the form of a lingually inclined
parallelogram. It is flat in appearance with its greatest convexity in the occlusal third.
The contact area is located at the junction of the middle and occlusal thirds.
d. Distal Surface. The distal surface is convex in all directions. It is smaller in
area than the mesial surface. The contact area is located at the junction of the middle
and occlusal thirds, slightly more to the lingual than is the contact area of the mesial