Dental Which one of the following is found on the crown of permanent mandibular first molars but is not found on the crowns of mandibular second molars? A MB cusp. B Distobuccal groove. C Lingual groove. D DB cusp. 💡 Explanation Which one of the following is found on the crown of permanent mandibular first molars but is not found on the crowns of mandibular second molars? ✓ Correct Answer: B. Distobuccal groove.