Which structure is not found on the occlusal surface of a mandibular molar?

The cingulum is a structure commonly associated with the facial surface of anterior teeth, primarily on the lingual aspect of incisors and canines. It is a rounded ridge found on the enamel of these teeth, serving as an anatomical feature that helps in the articulation and aesthetics of the anterior dentition.

In contrast, the occlusal surface of a mandibular molar is characterized by the presence of features such as fossa, grooves, and cusps. Fossa are depressions on the occlusal surface that help with the interdigitation of opposing teeth during chewing. Grooves are surface indentations that guide food during mastication and help in positioning the teeth. Cusps are pointed or rounded projections that play a critical role in the mechanical breakdown of food.

Since the cingulum does not have a role on the occlusal surface of a mandibular molar and is instead a feature of anterior teeth, it is the correct answer to this question.