Premolars Morphology - maxillary

Question 1

What is the main role of the premolars?

Answer 1

grinding

Question 2

What side of the pre-molar is this?

Answer 2

the buccal aspect

trapezoidal

Question 3

How many cusps does a premolar have?

Answer 3

2 cusps

bicuspid

Question 4

What premolar is an exception to the bicuspid rule?

Answer 4

the 35 and 45 (second premolar)

the second premolar in the mandibular arch

Question 5

How would you describe the lower second premolars?

Answer 5

tricuspid

1 large on the buccal and 2 smaller lingual

Question 6

What does the CEJ look like on posterior teeth?

Answer 6

almost straight

Question 7

When does the 14/24 erupt?

Answer 7

10-11

Question 7

Are the premolars bigger or smaller than the primary molars they replace?

Answer 7

generally smaller

Question 7

How many cusps does the 14 and 24 have?

Answer 7

2 cusps

pretty much equal in length

Question 8

Name the features of the maxillary first premolar (24/14) - buccal

Answer 8

Buccal ridge (red)
Developmental depressions (blue)
Distal cusp slope (black)
Mesial cusp slope (brown)
Cusp tip (star)
Perikymata (arrows)

Question 9

Name the features of the maxillary premolar (14/24) - palatal

Answer 9

Palatal ridge (blue)
Palatal cusp tip (red)
Mesial ridge (black)

Question 10

What is the defining factor of the maxillary first premolar? (buccal)

Answer 10

the mesial cusp ridge is longer than the distal on the buccal

Question 11

What is the defining feature of the maxillary first premolar (palatal)?

Answer 11

the mesial cusp ridge is slightly shorter than distal

Question 12

Does the upper 4 have a bifurcation?

Answer 12

yes

Question 13

What tooth is this and what are the defining features?

Answer 13

upper 4

Mesial marginal depression (grey).

CP just cervical to the junction of the occlusal and middle 1/3rd (red).

just before the bifurcation is the canine fossa

Question 14

Where is the contact point on the upper 4?

Answer 14

just cervical to the junction of the occlusal and middle third

Question 15

What side of the upper 4 is shown her?

Answer 15

distal

Question 16

What does the distal aspect of the upper 4 not have that the mesial does?

Answer 16

does not have the deep developmental depression

Question 17

What is the fossa called in the mesial upper 4?

Answer 17

canine fossa

Question 18

Describe the occlusal features shown in this tooth, what tooth is it?

Answer 18

upper 4

Central groove
-Distal and mesial marginal grooves

Mesial and distal marginal grooves

Triangular grooves also.

Question 19

How would you distinguish the upper 4s form upper 5s?

Answer 19

14/24 are very angled and bicuspid

long angled walls

the 5s are more rounded and not as pointy

Question 20

How would you distinguish the left and right maxillary 4s?

Answer 20

The CEJ is more occlusally located on the mesial surface

The canine fossa is on the mesial aspect of the tooth

The mesial marginal depression

the roots will swing slightly distally

Question 21

When do the maxillary 5s erupt?

Answer 21

10-12

Question 22

What tooth is this?

Answer 22

upper 5

rounded buccal cusp

Question 23

What tooth is this?

Answer 23

upper 5

Question 24

What are the differentiating features of the 15/25 and the 14/24 palatal surface?

Answer 24

The 15/25 palatal cusp tip is larger

more-molar-like

Question 25

Do the upper 5s have a mesial developmental depression?

Answer 25

no

Question 26

Where is the CP of the upper 5?

Answer 26

CP is just cervical to the junction of the occlusal and middle 1/3rd

Question 27

What is the upper 4 and upper 5?

Answer 27

left is upper 4

right is upper 5

Question 28

What appearance does the second maxillary premolar have?

Answer 28

wrinkled

for grinding

Question 29

Describe the occlusal features of the upper 5

Answer 29

Question 30

Does the upper 4 or 5 have more supplemental grooves?

Answer 30

upper 5

Question 31

How would you distinguish the upper left and right second premolars?

Answer 31

lingual cusp is larger, almost same size as the buccal cusp

lingual cusp of the 5 is slightly displace to the mesial