Mandibular Central Incisors

Question 1

For mandibular central incisors, what is the usual age of eruption?

Answer 1

4-6 years, First tooth to erupt

Question 2

The mandibular central incisors are the closest teeth to being mesial-distal symmetrical, however, if one edge is more curved than the other, which edge is it?

Answer 2

Mesial

Question 3

What is the smallest permanent tooth?

Answer 3

Mandibular central incisor

Question 4

For mandibular central incisors, what is the crown shape from the facial and lingual views?

Answer 4

Trapezoid

Question 5

For mandibular central incisors, what is the shapes of the distal and mesial outlines?

Answer 5

Due to it’s distal mesial bilateral symmetry both outlines are slightly convex with sharp MI & DI angles

Question 6

For mandibular central incisors, what are the mesial and distal heights of contour (occlusogingival contact locations)?

Answer 6

Agains these are the same mesial and distally, Incisal 1/3 for both.

Question 7

For mandibular central incisors, the contact points are nearly identical. This is unique to maxillary central incisors. For every other tooth what is the general rule about mesial vs. distal contact points?

Answer 7

The distal contact is always lower than the mesial contact.

Question 8

For mandibular central incisors, what are some differences in root shape compared to maxillary central incisors?

Answer 8

Mandibular central incisor roots are conical but more narrow and shorter. The root terminates in a pointed apex as opposed to a rounded apex of the maxillary. May be a slight distal curvature at the root apex.

Question 9

For mandibular central incisors, how many root chambers are present and what are their shape in cross section?

Answer 9

Mandibular central incisor roots generally have 1 pulp chamber but have 2 about 40% of the time. The pulp chamber is oval in shape (this differs from the triangular pulp chamber of the maxillary incisors)

Question 10

For mandibular central incisors, describe the 3 main structures that make up the lingual face?

Answer 10

The lingual fossa, cingulum and mesial and distal marginal ridges are all less pronounced in the mandibular cen. Inc. than Max. Cen. Inc.

Question 11

For mandibular central incisors, what is the crown shape from the mesial or distal views?

Answer 11

Wedge shaped

Question 12

For mandibular central incisors, what are the facial and lingual contour shapes and heights of contour?

Answer 12

Facial: Slightly convex in cervical 1/3 and flat in middle and incisal 1/3s. Height of contour is in cervical 1/3
Lingual: Convex cervical 1/3 (cingulum). Concave middle and incisal 1/3s (lingual fossa). Height of contour is in the cervical 1/3.

Question 13

For mandibular central incisors, where is the contact point buccolingually?

Answer 13

Centered on both the mesial and distal sides

Question 14

For mandibular central incisors, how do the mesial and distal CEJ curves compare?

Answer 14

The mesial CEJ curves incisally more than the distal CEJ

Question 15

For mandibular central incisors, what is the crown shape from the incisal view?

Answer 15

Triangle or diamond. If triangular the cingulum makes up the pointed region. However, both facial and lingual outlines are convex, round.

Question 16

For mandibular central incisors, how many lobes are there?

Answer 16

4 lobes. 3 facial and 1 lingual (cingulum)