Distobuccal cusp of the mandibular first molar | AIPGDEE Preparations with Explanations

The distobuccal cusp of the mandibular first molar occludes with which maxillary tooth surfaces?

a The mesial marginal ridge of the second molar and distal marginal ridge of the first molar
b The central fossa of the first molar
c The mesial marginal ridge of the first molar and the distal marginal ridge of the second premolar
d The embrasure between the first and second molars

Ans. B. 

The distobuccal cusp of a mandibular molar is a holding (supporting) cusp. The general rule of occlusion of mandibular holding cusps is as follows: the holding cusps of the mandibular teeth occlude on the mesial marginal ridges of their maxillary counterparts, and the distal marginal ridges of the maxillary tooth mesial to their counterparts, EXCEPT distobuccal cusps of mandibular molars occlude with central fossae of their counterparts, the distal cusp of the mandibular first molar occludes with the distal triangular fossa of its counterpart, and the first premolar occludes only with the mesial marginal ridge of its counterpart (but not the canine). In this case, the maxillary counterpart is the maxillary first molar, and the cusp should occlude in the central fossa of this tooth.