The cusp of Carabelli: frequency, distribution, size and clinical significance in Nigeria.

In a population of 2,604 Nigerians, 454 (17.43%) showed the presence of the cusp of Carabelli in maxillary molars. Bilateralism in the upper first molars accounted for 70.71% of the total, while bilateralism involving the upper first and second molars simultaneously accounted for only 1.98% of the total. Unilateralism in the upper first molars accounted for 25.99%. There was no sexual dimorphism in its occurrence, but great variations were observed in the size of this structure. Its frequency of occurrence is compared with that of other population while its clinical significance is discussed.