MCQs on Morphology of Permanent Incisors and Canines

A patient examining a maxillary central incisor notes that the incisal ridge lies directly over the long axis of the root. From which aspect is this relationship best observed?

• A. Distal

• B. Incisal

• C. Labial

• D. Lingual

• E. Mesial

In the lingual view of the maxillary central incisor, a student observes a shallow concavity bordered by marginal ridges and a convexity near the cervical third. Which of the following terms best describes this concavity?

• Cingulum

• Fossa

• Groove

• Pit

• Ridge

A dental student compares the maxillary central and lateral incisors and notes that one has the most rounded distoincisal angle among all incisors. Which permanent incisor displays this feature?

• Mandibular central incisor

• Mandibular lateral incisor

• Maxillary central incisor

• Maxillary lateral incisor

• Maxillary canine

While identifying an anterior tooth, the examiner notes a symmetrical crown with both mesial and distal outlines appearing nearly identical, and a straight incisal edge at right angles to the long axis. Which permanent tooth best fits this description?

• Mandibular central incisor

• Mandibular lateral incisor

• Maxillary central incisor

• Maxillary lateral incisor

• Maxillary canine

During identification, a student notes a mandibular incisor whose incisal edge curves distolingually, giving the crown a twisted appearance on its root. Which feature distinguishes this tooth from its central counterpart?

• A. Distally displaced cingulum

• B. Equal proximal outlines

• C. Straight incisal edge

• D. Sharp mesioincisal and distoincisal angles

• E. Flat labial surface

A 9-year-old patient presents with a small, peg-shaped crown replacing a maxillary incisor. The root is normal in length, and radiographs show no additional pathology. Which tooth most likely exhibits this morphology?

• Maxillary central incisor

• Maxillary lateral incisor

• Mandibular central incisor

• Mandibular lateral incisor

• Maxillary canine

A clinician observes severe attrition of a patient’s anterior teeth. On the maxillary central incisor, the incisal edge now slopes lingually from labial to lingual when viewed proximally. Which explanation best accounts for this slope?

• Attrition converted the incisal ridge to an incisal edge

• Malposition rotated the tooth distally

• Overeruption produced a labial tilt

• Cingulum hypertrophy displaced the edge

• Incisal mamelons persisted into adulthood

A patient’s upper incisor shows a deep lingual pit with caries penetrating toward the pulp. The clinician suspects a developmental invagination (“dens in dente”). Which tooth is most commonly affected by this condition?

• Maxillary central incisor

• Maxillary lateral incisor

• Mandibular central incisor

• Mandibular lateral incisor

• Maxillary canine

During wax carving of a mandibular central incisor, a student positions the incisal edge directly over the root’s long axis. When articulating the model, the upper and lower incisors do not meet properly. To restore normal contact, how should the student modify the incisal edge?

• Move it lingually

• Move it labially

• Rotate it distally

• Tilt it mesially

• Raise it cervically

A 14-year-old patient reports delayed eruption of the maxillary canine. Radiographs reveal the crown positioned above the root of the lateral incisor, but labial cortical expansion is evident. Which clinical finding best explains the labial swelling in this case?

• A. Canine eminence prominence

• B. Distal root curvature

• C. Lingual displacement

• D. Mesial impaction

• E. Palatal eruption