Deck 12: Incisors

Question 1

Which anatomical landmark could make an incisor more prone to dental caries?

A) Cingulum
B) Lingual pit
C) Mamelons
D) Prominent marginal ridges

Answer 1

B
Of the four selections, only the lingual pit is concave in nature; the remaining selections are primarily convex. Concavities provide ideal nurturing locale for plaque biofilms, primary etiologic factors of dental caries.

Question 2

Extracted mandibular central incisors are the easiest to identify as either right or left because they are located anteriorly and near the midline.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct, but the reason is NOT correct.
D) The statement is NOT correct, but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Answer 2

E
Mandibular central incisors are the most difficult to identify as either right or left because they are bilaterally symmetrical and difficult to differentiate. Their anterior location does not assist in right/left identification. An occasionally helpful feature is that the distofacial line angle is more rounded than the mesiofacial.

Question 3

Maxillary central incisors usually develop normally. Two anomalies that sometimes occur are a longer root or a shorter crown.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Answer 3

B
While the central incisors usually develop normally, two anomalies that sometimes occur are a shorter root and a longer crown. A third anomaly is gemination, where the tooth shows evidence of attempting to divide itself. An additional note, the maxillary central incisors are the largest and most prominent incisors.

Question 4

Mandibular lateral incisors are generally smaller than mandibular central incisors. Mandibular lateral incisors have greater facial curvature than the central incisors.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 5

Each of the following is true of the permanent central incisor EXCEPT one. Which one is the EXCEPTION?

A) Evidence of calcification occurs at three months.
B) This is the widest mesiodistally of any of the anterior teeth.
C) Root formation is completed by six years of age.
D) Gemination is an anomaly that sometimes occurs.
E) Development is usually normal.

Question 6

The eruption time for both the maxillary central incisor and mandibular lateral incisor is

A) 6 to 7 years
B) 7 to 8 years
C) 8 to 9 years
D) None of the above

Question 7

Which of the following are characteristic of one or both maxillary incisors (select all that apply)?

A) Slender roots
B) Linguoincisal attrition
C) Greater labiolingual than mesiodistal crown dimension
D) Most prominent teeth in the mouth

Question 8

All incisors have two marginal ridges, a cingulum, and a lingual fossa. The mandibular central incisor has the least distinct lingual anatomy.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 9

Which incisor is not derived from four primary lobes?

A) Maxillary central
B) Maxillary lateral
C) Mandibular central
D) Mandibular lateral
E) All of the above are derived from four lobes.

Question 10

Each of the following statements correctly describes maxillary lateral incisors EXCEPT one. Which is the EXCEPTION?

A) The incisal aspect can resemble that of a central incisor or a canine.
B) Incisally, they exhibit more convexity both labially and lingually than maxillary centrals.
C) Of all incisors, the maxillary laterals vary the least in form.
D) The mesial aspect of a maxillary lateral incisor is similar to that of a small central incisor.
E) Frequently maxillary lateral incisors are peg-shaped.

Question 11

Which of the following are characteristic of one or both mandibular incisors (select all that apply)?

A) All contact areas are in incisal third
B) Rounded distoincisal angle
C) Smooth, shallow lingual surface
D) Slender roots

Question 12

The mandibular lateral incisors are wider mesiodistally than the mandibular central incisors because the mesial developmental lobe of the laterals is larger than that of the centrals.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct, but the reason is NOT correct.
D) The statement is NOT correct, but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Question 13

The maxillary lateral incisor usually has a straight, thick, cylindrically shaped root. The root length of the maxillary lateral incisor is about 1.5 times the length of the crown.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 14

Which of the following are commonly found on roots of maxillary incisors?

A) Proximal grooves
B) Evidence of division
C) Bifurcation
D) Indentation
E) None of the above

Question 15

In an anterior crossbite, the maxillary central incisors would exhibit wear in which location?

A) Labioincisal edge
B) Linguloincisal edge
C) Cervical region
D) Apex

Question 16

Which incisor has a lingual pit?

A) Maxillary central
B) Maxillary lateral
C) Mandibular central
D) Mandibular lateral

Question 17

The mandibular central incisor occludes with both the maxillary central incisor and the maxillary lateral incisor. Similar to other anterior teeth, a mandibular incisor is derived from five lobes, three facial lobes and two lingual lobes.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 18

Each mamelon forms the incisal edge of one of the primary labial lobes of the incisors. With wear, the rounded incisal edge becomes flat and is then referred to the incisal ridge.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 19

The teeth most likely to be peg-shaped are the mandibular lateral incisors because the distal developmental lobe is large and located more lingually than its mesial lobe.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct, but the reason is NOT correct.
D) The statement is NOT correct, but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Question 20

When incisors first erupt the incisal ridge is smooth. After the teeth have been in function for several months, mamelons, which aid in mastication, develop on the incisal ridge.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 21

Proximal grooves are commonly found on the roots of the maxillary incisors.

Question 22

All incisors can erupt with mamelons.

Question 23

Gemination is an anomaly that most commonly occurs in mandibular incisors.

Question 24

Mandibular lateral incisors are distolingually inclined when viewed incisally.

Question 25

Mandibular incisors do not have marginal ridges.

Question 26

Maxillary lateral incisors vary in form more than any other teeth in the mouth.