2653. In normal occlusion , with which grooves / surface of the permanent mandibular first molar does the mesiobuccal cusp of the permanent maxillary first molar occlude______________? September 27, 2025 by Admin A. Distobuccal groove B. Mesial surface C. Mesiobuccal surface D. Transverse groove ✅ The correct answer is option C. Mesiobuccal surface.