Final answer:
The lobe on the lingual surface of a permanent incisor is correctly referred to as the cingulum.
Step-by-step explanation:
The lobe on the lingual surface of a permanent incisor is called a cingulum. The cingulum is a convex, raised area on the lingual surface of the incisal teeth, particularly the anterior teeth. It is not to be confused with the lingula, which is a small flap of bone located next to the mandibular foramen on the ramus, or the articular tubercle, a smooth ridge located anterior to the mandibular fossa.