D) The maxillary first premolar has a smooth.flat mesial surface. 15. Which of the following statements is incorrect regarding the morphological differences between the maxillary first and second premolars? A) The maxillary first premolar typically has a more pronounced mesial groove than the second premolar. B) The maxillary second premolar usually has two roots, while the first premolar has only one root. C) The maxillary first premolar has a more prominent mesial concavity on the crown than the second premolar. D) The maxillary second premolar generally has a broader occlusal surface compared to the first premolar. 16. Which feature is common to both the mandibular first and second premolars? A) Both have two roots. B) Both have a prominent mesial groove. C) Both have a large, equal-sized buccal and lingual cusp. D) Both have a transverse ridge. 17. According to the FDI Numbering System, which of the following is tooth number 27? A) Left mandibular first molar B) Left maxillary second molar C) Left mandibular second premolar D) Left mandibular first premolar 18. Which feature distinguishes canine teeth from incisors? A) Canines have a straight incisal ridge like incisors. B) Canines have a well-formed pointed cusp instead of a straight ridge. C) Canines have two roots, unlike incisors. D) Canines are generally shorter than incisors. 19. Which of the following is a difference between maxillary and mandibular canines? A) Maxillary canines have a longer distal cusp slope than the mesial cusp slope. B) Mandibular canines have a more pronounced cingulum than maxillary canines. C) Maxillary canines have a less prominent labial ridge than mandibular canines. D) Mandibular canines are generally wider mesiodistally than maxillary canines. 20. Which of the following is true about the morphology of mandibular canines?