Orofacial Anatomy Chapter 15 Molars (Mandibular)

When does the mandibular first molar erupt?

6-7 years old

What is usually the first tooth to erupt?

mandibular first molar

Which cusp of the mandibular first molar is the smallest?

distal cusp

How many roots do lower molars have?

2 (mesial and distal root)

How many cusps on a mandibular first molar?

5 cusps (3 buccal and 2 lingual) [mesiobuccal, distobuccal, distal, mesiolingual and distolingual] (4 major; 1 minor)

Which root of the mandibular first molar has 2 canals?

mesial root

Is the permanent mandibular first molar a succedaneous tooth?

no; it erupts behind the primary second molar and is therefore a non-succedaneous tooth.

T/F Mandibular molars are wider mesiodistally than buccolingually.

T

What are the universal codes of mandibular first molars?

right 30

left 19

How many cusps on the mandibular first molar are seen from the buccal view?

3 (mesiobuccal, distobuccal, and distal)

How many grooves on the mandibular first molar are seen from the buccal view?

2 (mesiobuccal and distobuccal)_

Which cusp on the mandibular first molar is the widest and which is the smallest?

widest mesiobuccal cusp

smallest distal cusp

T/F the mesiolingual and distolingual cusps on the mandibular first molar are about equal in size.

T

How many cusps on the mandibular first molar can be seen from the lingual view?

2 (mesiolingual & distolingual)

Which root on mandibular molars is widest?

mesial root (this is why only one root can be seen from the mesial view)

How many roots can be seen from a mesial view on mandibular first molars? How many can be seen from a distal view?

mesial 1 root

distal 2 roots

Which of the 5 mandibular first molar cusps is a minor cusp?

The distal cusp

How many of the mandibular first molar cusps are functional.

5; all of them are functional

Which mandibular molars are the smallest?

mandibular third molars

T/F The crowns of mandibular molars are shorter cervicoocclusally than those of the teeth anterior to them.

T; in all other dimensions though molars are larger

T/F The crowns of mandibular molars are wider mesiodistally than buccolingually.

T; maxillary molars are opposite (wider buccolingually)

T/F First molars show evidence of calcification at birth.

T

Which are the only mandibular molars that have 5 cusps.

Mandibular first molars

On the mandibular first molar, which of the 3 facial cusps is widest?

mesiobuccal

Does the mandibular first molar have a pit?

yes (it has a buccal pit)

When does the mandibular second molar erupt?

11-13 years of age (12 year molars)

Does the mandibular second molar have a distal cusp?

No; it has 4 cusps of equal size.

How many cusps on a mandibular second molar?

4; they are all equal in size (no fifth cusp present)

T/F When compared to the mandibular first molar, the mandibular second molar has roots that are shorter and closer together.

True

What are the universal codes for the mandibular second molars?

right 31

left 18

How many roots on the mandibular second molar?

2 (one mesial; one distal) [mesial root is wider than distal]

Which mandibular molar is divided into "hot cross buns"?

Mandibular second molar

When do the third molars erupt?

age 17-21

T/F The mandibular third molars, like the maxillary third molars, are unpredictable and irregular.

T

When the first and second molars of the mandibular arch are compared, which of the following is not true?

a. Only one groove is visible from the facial surface on a second molar.

b. The crown is larger both mesiodistally and faciolingually on a second molar.

c. Less lingual convergence is on a second molar.

d. both have two roots

b.

When the mandibular first and second molars are compared, in what way are the two different?

a. The first has more roots and root canals.

b. The second has more pulp horns.

c. The second does not have a distal cusp.

d. The first has a different height of contour.

c

The lingual height of contour on all mandibular molars:

a. measures 0.5 mm

b. measures more than 0.5 mm

c. measures less than 0.5 mm

d. varies considerably from the first to third molar.

b

An important factor concerning personal oral hygiene is that mandibular molars:

a. do not have an oblique ridge, which helps deflect the food onto the gums

b. are more difficult to clean because of their lingual contours

b

Which of the following is least true of the mandibular second molar?

a. It has four cusps of nearly equal size.

b. It has three root canals, with two in the mesial root.

c. It has five cusps

d. It has four developmental lobes

c

Which of the following is a list of correct names for the cusps of the mandibular first molar?

c. distal, distolingual, distofacial, mesiolingual, mesiofacial

The roots of a mandibular first molar are:

d. mesial and distal

When comparing all maxillary and mandibular molars, fused roots would most likely be found on which of the following?

c. third molars

What is a major difference between first and second molars, whether maxillary or mandibular?

b. first molars have five cusps and second molars have 4

Which of the following is true concerning maxillary and mandibular molars?

a. both have oblique ridges

b. only maxillary molars have oblique ridges

c. neither have oblique ridges

d. only mandibular molars have oblique ridges

b.

Two root canals are commonly found in:

a. the lingual root of maxillary first molars

b. the distal root of mandibular first molars

c. the mesial root of mandibular first molars

d. none of the above

c

Furcation refers to:

a. the absence of a particular characteristic of the root anatomy

b. the splitting of a root trunk into terminal roots

c. the division of root canals from the root trunk

d. none of the above

b

Name the smallest permanent mandibular molar cusp.

distal - usually found on the first molars

A buccal pit is found at the end of the :

a. buccal groove of a mandibular second molar

b. mesiobuccal developmental groove of a mandibular first molar

c. distobuccal developmental groove of a mandibular first molar

d. distobuccal groove of a mandibular second molar

e. a and b

f. a and d

e

Name the occlusal pits of mandibular first molars

a. mesial

b. distal

c. central

d. all of the above

d.

Which are the largest mandibular teeth?

Mandibular right first molar