Orofacial Anatomy Chapter 15 Molars (Maxillary)

How many permanent molars are there?

12 (6 upper and 6 lower)

What is the primary function of the molars?

To grind or crush food

Where do the first permanent molars erupt?

Distal to the primary second molars

What are usually the first permanent teeth to erupt?

The permanent first molars (6 year molars)

Which teeth usually erupt first? mandibular or maxillary?

mandibular

When do the mandibular and maxillary first molars usually erupt?

6-7 years of age (enamel complete at 4 years)

T/F Molars are nonsuccedaneous teeth.

True; they do not replace any primary teeth

Generally, how many lobes are the first molars formed from?

5 lobes

Which are the most highly developed and largest molars?

maxillary and mandibular first molars

Which are most likely to have a minor and supplementary cusp in addition to major cusps?

first molars

T/F The maxillary first molars have only three major cusps, one minor cusp, and sometimes one supplementary cusp.

True

Which tooth is most likely to have a cusp of Carabelli?

Maxillary first molar

Where is the cusp of Carabelli located? ****

on lingual of mesiolingal cusp

T/F All molars (first second and third) have three well-developed major cusps and one minor cusp.

True

The minor (smallest) cusp of molars is located where?

distolingually

The largest cusp of molars is located where?

mesiolingual

T/F Cusps usually get smaller as you move more posteriorly.

True

The four functional cusps of maxillary molars are located where?

2 buccal/facial and 2 lingual (sometimes a 5th supplementary cusp called the cusp of Carabelli can be found on the lingual of the mesiolingal cusp)

T/F From the buccal view of the maxillary first molars four cusps can usually be seen.

True; the distolingual cusps are sharper and longer and can thus be seen from the facial view.

T/F from the lingual view of a maxillary first molar the lingual cusps alone can be seen.

True

T/F The distolingual cusp of the maxillary first molar is the most likely to be missing giving it a heart shape.

True

T/F The distobuccal cusp of the maxillary first molar is usually sharper and longer than the mesiobuccal cusp although it is smaller.

True

The maxillary first molar has how many roots?

3; 2 buccal and one lingual

From a lingual view of a maxillary first molar, which cusp is the largest?

The mesiolingual cusp; the mesiolingual cusp is the largest and longest on the maxillary first molar.

Which functional cusp on the maxillary first molar is the shortest and smallest?

The distolingual cusp

T/F the cusp of Carabelli is really a tubercle.

True

Why does the mesiobuccal root of a maxillary first molar block the distobuccal root from a mesial view?

Because it is wider; the distobuccal root is more narrow than the mesiobuccal root

Which root on a maxillary first molar is the largest?

The lingual root.

Where is the height of contour on the facial and lingual of a maxillary first molar?

facial/buccal cervical third

lingual middle third

T/F The cusp of carabelli can not be seen from a distal view of the maxillary first molar.

True; it can be seen from a mesial view or lingual view

Where does the oblique ridge of a maxillary first molar run from? ****

From mesiolingual cusp to distobuccal cusp.

After the mesiolingual cusp on the maxillary first molar, which cusp is the next largest?

mesiofacial, although it is not as long as the distal cusp

What groove separates the cusp of Carabelli from the mesiolingual cusp?

the mesiolingual groove

T/F the distolingual cusp is progressively smaller on the maxillary second and third molars.

True

T/F on the maxillary first molar all three roots can be seen form the lingual aspect

True

T/F a maxillary first molar from the occlusal view is rhomboidal.

True

T/F roots get closer together as you go further back in the mouth.

True

Oblique ridge

a transverse ridge that is unique to maxillary molars. It runs from the mesiolingual cusp to the distobuccal cusp.

When do the maxillary and mandibular second molars usually erupt?

11-13 years of age (often called 12 year molars) (evidence of calcification at 3 years and enamel completed at 7-8 years)

T/F The maxillary second molars show more supplemental grooves and pits than the maxillary first molars.

True; third molars show even more than the first two

Which of the maxillary molars has a more prominent oblique ridge?

maxillary first molars

What is the occlusal shape of second molars?

Less rhomboidal and more heart shaped

Which of the molars are often congenitally missing?

Third molars

T/F the second maxillary molar has a cusp of Carabelli.

False; only the first maxillary molars have a cusp of Carabelli

How many roots on a maxillary second molar?

3 roots; (2 buccal 1 lingual); lingual root is the largest

Which cusp on the maxillary second molar is the smallest?

The distolingual cusp is the smallest

On the distal view of a maxillary second molar, how many cusps can be seen? How many roots?

All four cusps can be seen from the distal view since distal cusps are smaller; all three roots can be seen as well (on the mesial view the mesial root blocks out the distal root so only two roots can be seen)

Where is the buccal and lingual height of contour on the maxillary second molar?

buccal cervical 1/3rd

lingual middle 1/3rd

How many cusps on the maxillary second molar?

4 cusps; if the distolingual cusp is missing it makes a more heart shape

T/F the mesiobuccal root of the maxillary first molar has two canals within one root.

True

Which maxillary molars vary more than any tooth in the mouth?

maxillary third molars

When do maxillary third molars erupt?

17-21 years old

How many cusps on a maxillary third molar?

3-5

Which cusp of maxillary molars is most often missing?

Distolingual

Which roots of maxillary molars are most likely to be fused together?

Third molar roots

Which tooth (maxillary first or second molar) shows more supplemental grooves and pits?

maxillary second molar

Which of the molars have a tendency to become impacted?

Third molars

Which of the three roots of the maxillary third molars are the largest and smallest?

largest lingual root

smallest distobuccal

What are the universal codes for maxillary first molars?

right 3

left 14

What are the universal codes for maxillary second molars?

right 2

left 15

What are the universal codes for maxillary third molars?

right 1

left 16

How many roots pulp horns cusps and developmental lobes in a maxillary first molar?

roots 3 (2 facial 1 lingual)

pulp horns 4

cusps 4 (5 including cusp of Carabelli)

developmental lobes 5

What is the location of the mesial and distal proximal contact areas in maxillary first molars?

middle third

What is the height of contour (facial and lingual) of maxillary first molars?

facial cervical third

lingual middle third

How many roots pulp horns cusps and developmental lobes in a maxillary second molar?

roots 3 (2 facial 1 lingual)

pulp horns 4

cusps 4

developmental lobes 4

What is the location of the proximal contact areas of the maxillary second molar?

mesial middle third

distal middle third

What is the height of contour (facial and lingual) of the maxillary second molars?

facial cervical third

lingual middle third

How many roots, pulp horns, cusps, and developmental lobes in maxillary third molars?

roots 1-4

pulp horns 1-4

cusps 3-5

developmental lobes 4

What is the location of the proximal contact areas in maxillary third molars?

mesial middle third

distal none (since its the last tooth in the arch)

Which cusp of a maxillary first molar has the widest mesiodistal measurement?

mesiolingual cusp

Which two cusps join to form the oblique ridge?

mesiolingual and distobuccal cusps

Which of the five cusps of a maxillary first molar is least developed.

fifth cusp (cusp of Carabelli)

Which of the four functional cusps is least developed?

distolingual cusp

On which cusp is the tubercle of Carabelli located?

mesiolingual cusp

Which cusps surround the central fossa?

mesiolingual, mesiobuccal, and distobuccal cusps

Are the terms mesiolingual groove and developmental groove of the cusp of Carabelli synonymous?

yes

Are the terms distolingual groove and distal oblique groove synonymous?

no

Are the terms mesiolingual triangular groove and mesiolingual groove synonymous?

no

If a mesial pit is present on a maxillary first molar, in which fossa is it located? Where it the distal pit found?

a. central fossa

b. distal fossa

c. mesial triangular fossa

d. distal triangular fossa

c

Which of the following is more likely to be present only on maxillary first molars?

a. oblique ridge

b. distolingual cusp

c. cusp of Carabelli

d. distobuccal root with its apex curved slightly mesially

c

Of the three roots of a maxillary molar, which is most likely to help differentiate the maxillary first, second, and third molars from each other?

mesiobuccal root because it can have two root canals

Which cusp is more likely to be smaller on a maxillary second molar than on a maxillary first molar?

a. distobuccal cusp

b. distolingual cusp

b

The roots of a maxillary second molar lie closer together than the roots of which tooth?

a. maxillary first molar

b. maxillary third molar

a

Which two cusp ridges make up the transverse oblique ridge?

the lingual cusp ridge of the distobuccal cusp and the distolingual cusp ridge of the mesiolingual cusp

Identify the tooth in figure 15-37.

maxillary first molar (most likely)

Maxillary molars usually have three root canals, but if four root canals are present, which maxillary molar is most likely to have four canals?

a. none of them

b. maxillary first molar

c. maxillary second molar

d. maxillary third molar

b. maxillary first molar

A 6-year old patient is given tetracycline antibiotics. If tetracycline can discolor teeth that are in their formation stages, which molars might be affected?

a. maxillary permanent first molars

b. first and second permanent molars

c. second and third permanent molars

d. only third molars

c

If a maxillary third molar has only three cusps, which three cusps are they most likely to be?

a. mesiobuccal

b. mesiolingual

c. distolingual

d. distobuccal

e. cusp of Carabelli

ab&d (the distolingual cusp is most likely to be missing and cusp of Carabelli is only present on maxillary first molars)

A tooth that is an obvious maxillary molar is found with four roots fused to each other, but is severely dilacerated at the apical third. Which molar is the tooth most likely to be?

a. first

b. second

c. third

d. first or second

c

Where are the locations of all proximal contact areas on maxillary molars (first second and third molars)

All proximal contact areas of maxillary molars (mesial and distal) are located in the middle third. The third molar, however, does not have a distal contact area since it is the last tooth in the arch. (The same is true for the proximal contact areas of the mandibular molars - middle third)