Lecture 6 - Maxillary Premolars

Question 1

what are the numbers of the maxillary right first and second premolar

Answer 1

1st- #5
2nd - #4

Question 2

what are the numbers of the maxillary left first and second premolars

Answer 2

1st- #12
2nd- #13

Question 3

what are the 2 cusps on the maxillary premolars and describe each

Answer 3

lingual - functional cusp
buccal - non-functional cusp

Question 4

are premolars succedaneous teeth

Answer 4

yes they replace deciduous molar teeth

Question 5

what are the lobes of the maxillary first premolars

Answer 5

-3 buccal lobes ( mesial buccal, middle, and distobuccal)
- 1 lingual lobe - develops into the lingual cusp

Question 6

what does the buccal cusp develop from on maxillary first premolars

Answer 6

the middle buccal lobe

Question 7

what is the central developmental groove on maxillary first premolars

Answer 7

a demarcation between the lingual and buccal lobes

Question 8

describe the shape of the maxillary first premolar from the buccal view

Answer 8

roughly trapezoidal

Question 9

describe the buccal cusp arms (M vs D) of the maxillary first premolars

Answer 9

-mesial cusp arm is longer and straighter
- distal cusp arm is shorter and more curved

Question 10

where is the buccal height of contour of the maxillary first premolars

Answer 10

in the cervical third

Question 11

where is the mesial contact of the maxillary first premolars

Answer 11

middle 1/3rd

Question 12

describe the mesial outline from the facial view of the maxillary first premolars

Answer 12

mesial concavity below the contact

Question 13

where is the distal contact of the maxillary first premolar

Answer 13

middle 1/3rd, larger contact (broader) and more cervical

Question 14

describe the distal outline of the maxillary first premolar from the facial view

Answer 14

generally convex

Question 15

describe the lobes/ridges on the buccal view of the maxillary first premolars

Answer 15

-middle buccal lobe -> prominent buccal ridge and associated developmental depressions
- less developed mesial and distal lobes -> mesial and distal line angles

Question 16

which direction does the crown taper of the maxillary first premolars

Answer 16

lingually
- lingual is more narrow than buccal

Question 17

describe the lingual cusp of the maxillary first premolars

Answer 17

-smoothly convex
- 1 mm shorter than buccal cusp and more pointed

Question 18

where is the lingual cusp located of the maxillary first premolars

Answer 18

mesially

Question 19

describe the lingual cusp arms (M vs D) of the maxillary first premolars

Answer 19

mesiolingual cusp arm is shorter than the distolingual cusp arm

Question 20

what is the shape of the maxillary first premolar from the mesial view

Answer 20

trapezoidal

Question 21

what cusps are visible from the mesial view of the maxillary first premolars

Answer 21

both lingual and buccal

Question 22

where is the buccal height of contour of the maxillary first premolars

Answer 22

cervical 1/3

Question 23

where is the lingual height of contour of the maxillary first premolars

Answer 23

middle 1/3

Question 24

what depressions are visible from the mesial view of the maxillary first premolars

Answer 24

developmental depression on the cervical portion of the crown and the root

Question 25

where is the mesial contact area for the maxillary first premolar from the mesial view

Answer 25

middle 1/3 and offset buccally

Question 26

how many roots do maxillary first premolars have

Answer 26

- 50-60% have 2 roots (buccal and lingual) - 50% have 1 root

Question 27

how long is the root trunk of the maxillary first premolars

Answer 27

1/2-2/3 the length of the root

Question 28

what are the differences between the distal view and the mesial view of the maxillary first premolars

Answer 28

-distal view does not have concavity, developmental depreesion, or marginal ridge developmental groove - curvature of CEJ is less

Question 29

where is the distal contact area from the distal view of the maxillary first premolars

Answer 29

middle 1/3 -offset buccally -contact borader - located more cervical than mesial

Question 30

describe shape of the the maxillary first premolars from the occlusal view

Answer 30

hexagonal in outline

Question 31

which dimension is the maxillary first premolars larger in from occlusal view: BL or MD

Answer 31

BL > MD

Question 32

how many ridges make up each cusp on the maxillary first premolars

Answer 32

4 ridges each

Question 33

where is the buccal triangular ridge of the maxillary first premolars located from the occlusal view

Answer 33

from the central developmental groove to the middle cusp

Question 34

where is the lingual triangular ridge of the maxillary first premolars located from the occlusal view

Answer 34

from the central developmental groove to the lingual cusp

Question 35

what is the difference between the buccal and lingual triangular ridges from the occlusal view of the maxillary first premolars

Answer 35

lingual less prominent and angled not straight

Question 36

what is a triangular ridge

Answer 36

prominent elevation, triangular in cross-section, which extends from the tip of a cusp towards the central portion of the occlusal surface of a tooth

Question 37

what ridges are visible from the maxillary first premolars occlusal view

Answer 37

- mesial and distal marginal ridges

Question 38

what grooves are visible from the maxillary first premolars occlusal view

Answer 38

-central developmental groove - mesial marginal ridge developmental groove - mesiobuccal and distobuccal supplemental groove

Question 39

what pits and fossa are visible from the maxillary first premolars occlusal view

Answer 39

mesial and distal developmental pits mesial and distal triangular fossa

Question 40

what does the root from the buccal (MD) aspect of the maxillary first premolar resemble

Answer 40

the root of the canine

Question 41

describe the root of the maxillary first premolar in cross section

Answer 41

broad BL, narrow MD - kidney shaped - mesial developmental depression

Question 42

how many pulp horns and pulp canals are there in the maxillary first premolar

Answer 42

2 pulp horns and 2 pulp canals ( buccal is larger canal)

Question 43

what is a distinct feature to help identify the maxillary first premolar

Answer 43

the mesial marginal ridge developmental groove on the occlusal surface

Question 44

what are the main differences between the maxillary first premolar and the maxillary second premolar

Answer 44

- smaller - more rounded - single rooted - more shape variations

Question 45

what are the differences from the buccal view from the maxillary first premolar and the maxillary second premolar

Answer 45

- MB and DB line angles are less prominent - buccal cusp ridge not as obvious - buccal developmental depressions not as developed

Question 46

compare the MB cusp arm to DB cusp arm of the maxillary second premolar from the buccal view

Answer 46

MB cusp arm is shorter than the DB cusp arm

Question 47

what is the difference between the lingual view of the maxillary first premolar and the maxillary second premolar

Answer 47

lingual cusp is longer in the second premolar so less visibility of the buccal cusp lingually

Question 48

describe the buccal and lingual cusps of the maxillary second premolar from the mesial view

Answer 48

buccal and lingual cusps are approximately equal in size but shorter compared to first premolar

Question 49

where is the mesial contact from the mesial view of the maxillary second premolar

Answer 49

middle 1/3 and slightly offset buccally

Question 50

describe the mesial view of the maxillary second premolar

Answer 50

no mesial marginal ridge developmental groove no mesial developmental depression single tapered root

Question 51

where is the distal contact from the distal view of the maxillary second premolar

Answer 51

middle 1/3 and offset to the buccal

Question 52

what shape is the maxillary second premolar from the occlusal view

Answer 52

rounded or oval

Question 53

describe the MB and DB line angles of the maxillary second premolar from the occlusal view

Answer 53

more rounded

Question 54

describe the central developmental groove of the maxillary second premolar from the occlusal view

Answer 54

central developmental groove is shorter therefore, mesial and distal marginal ridges are wider

Question 55

describe the supplemental grooves of the maxillary second premolar from the occlusal view

Answer 55

numerous supplemental grooves - wrinkled appearance

Question 56

describe the root of the second premolar

Answer 56

-single tapered root 50% have two canals - root length the same as first premolar broad BL, narrow MD - no developmental depression - oval shaped in cross section

Question 57

how many pulp horns and canals do the maxillary second premolar have

Answer 57

two pulp horns and 50% have two canals

Question 58

where is the mesial height of contour of the maxillary second premolar

Answer 58

middle third

Question 59

where is the distal height of contour of the maxillary second premolar

Answer 59

middle third

Question 60

where is the buccal height of contour of the maxillary second premolar

Answer 60

cervical third

Question 61

where is the lingual height of contour of the maxillary second premolar

Answer 61

middle third

Question 62

when does the maxillary first premolar erupt

Answer 62

10-11 years

Question 63

when does the maxillary second premolar

Answer 63

11-12 years

Question 64

describe the cervico- occlusal length of the maxillary first premolar crown vs the maxillary second premolar crown

Answer 64

same length

Question 65

describe the MD diameter of crown of the maxillary first premolar crown vs the maxillary second premolar crown

Answer 65

same

Question 66

describe the root length of the maxillary first premolar vs the maxillary second premolar

Answer 66

same