Maxillary 1st Premolar

Question 1

List the functions of premolars

Answer 1

-mastication
-assisting molars in grinding and canines in tearing
-maintain vertical dimensions of the face
-support corners of mouth and cheeks

Question 2

when do the mx 1st premolars calcify?

Answer 2

1.5 yrs

Question 3

when do the mx 1st premolars erupt?

Answer 3

10-11yrs

Question 4

when do the mx 1st premolars root complete?

Answer 4

12-13yrs.

Question 5

The facial view outline shape is…

Answer 5

pentagonal

Question 6

Compared to the canine, mx 1st premolars are…

Answer 6

-shorter
-narrower mesiodistally
-sharper mesial and distal marginal ridges

Question 7

Facial view height of contour

Answer 7

cervical 3rd

Question 8

Facial view mesial outline

Answer 8

-concave from the contact area to the cervical line
-prominent mesiocclusal angle

Question 9

Facial view distal outline

Answer 9

similar to mesial but no concavity

Question 10

mesial contact area

Answer 10

middle 3rd

Question 11

distal contact area

Answer 11

middle 3rd (but more cervical than mesial)

Question 12

crown surface

Answer 12

convex

Question 13

Facial View: the cusp tip is offset to the…

Answer 13

distal

Question 14

Mesial cusp ridge

Answer 14

longer and straighter
may have slight concavity
BEING LONGER IS UNIQUE TO MX 1st PM

Question 15

Distal cusp ridge

Answer 15

shorter and more convex

Question 16

Facial ridge

Answer 16

-extends from facial cusp to cervical line
-extremely well developed*
-result of middle facial lobe
-depressions on each side

Question 17

The crown tapers towards the…

Answer 17

lingual

Question 18

The lingual surface is…

Answer 18

smooth and convex
*NO lingual ridge

Question 19

Which cusp is shorter, lingual or buccal?

Answer 19

lingual by 1-1.3mm

Question 20

Lingual view: the cusp tip offsets to the…

Answer 20

mesial

Question 21

Which slope is short, the mesial lingual or the mesial facial

Answer 21

mesial lingual is shorter

Question 22

Lingual view height of contour

Answer 22

middle 3rd

Question 23

Lingual view mesial cusp ridge

Answer 23

shorter than the distal, small portion of buccal cusp can be seen from lingual view

Question 24

The proximal outline shape of the mx 1st premolar is…

Answer 24

trapezoidal

Question 25

Proximal view: the cusp tips are _____ over the root

Answer 25

centered; within the confines of the root*

Question 26

Proximal view: CEJ

Answer 26

cervical line less curved on distal compared to mesial

Question 27

Mesial marginal ridge groove

Answer 27

crosses well developed MMR and continued onto to root *not always present *special considerations when scaling

Question 28

Mesial developmental depression

Answer 28

on middle portion of cervical 3rd of crown, continues onto root across the CEJ, joining the developmental depression of the root *usually quite prominent

Question 29

Distal proximal view

Answer 29

-no grooves crossing the DMR -no developmental depression -more rounded and smooth

Question 30

What is the occlusal outline shape of the mx 1st premolar

Answer 30

hexagonal

Question 31

Occlusal view: the crown is wider on which surface, buccal or lingual

Answer 31

buccal

Question 32

Occlusal view: the crown is wider…

Answer 32

buccolingually than mesiodistally

Question 33

Occlusal view: distal proximal contact

Answer 33

facial to the mesial contact

Question 34

Occlusal view: mesial proximal contact

Answer 34

lingual to the distal contact

Question 35

Occlusal view: lingual vs facial cusp

Answer 35

lingual: more pointed facial: larger wider and longer

Question 36

Occlusal view: name the 4 cusp ridges

Answer 36

facial, lingual, distal, mesial

Question 37

Occlusal view: triangular ridges

Answer 37

runs from cusp tip to central groove *eventually join to form a transverse ridge

Question 38

Occlusal table

Answer 38

area bounded by the perimeter of the ridges

Question 39

Mesial marginal ridge

Answer 39

shorter than the DMR, located more occlusal than the DMR has MM groove running through it

Question 40

On the facial cusp, which cusp ridge is longer?

Answer 40

mesial facial is longer than distal facial

Question 41

Name the developmental grooves of the mx 1st premolar

Answer 41

sharp deep and V shaped -central -mesial marginal -mesiobuccal developmental -distobuccal development

Question 42

Name the 2 fossae

Answer 42

mesial triangular fossa distal triangular fossa

Question 43

Compared to the 2nd PM, there are _____ secondary/supplemental grooves

Answer 43

fewer

Question 44

Name the developmental pits

Answer 44

mesial- intersection of MB, ML, MM, and central grooves distal- intersection of DB, DL and central grooves

Question 45

The lingual surface of the root is ______ than the buccal

Answer 45

narrower

Question 46

mesial view of root

Answer 46

-deep depression -mesial marginal groove continues with mesial depression

Question 47

distal view of root

Answer 47

-convex or flat near cervical -not as deep depression as on mesial

Question 48

which type of root is more common, single or bifurcated?

Answer 48

bifurcated (1 buccal 1 lingual)

Question 49

what is the root trunk?

Answer 49

the area between cervical line and point of furcation

Question 50

number of pulp horns=

Answer 50

number of cusps

Question 51

Type I root

Answer 51

-single root w/ deep mesial groove -usually 2 root canals w/ 1 apical foramen -2 pulp horns

Question 52

Type II root

Answer 52

bifurcated- facial and lingual -bifurcation apical to the 1/2 -facial roots longer and larger -hardest to do root canal treatment

Question 53

Type III root

Answer 53

laminated (fused) roots- buccal and lingual joined

Question 54

Comparisons with anterior teeth

Answer 54

-greater faciolingual than mesiodistal -mesial and distal contact areas broader and closer to same level on the tooth -less mesial and distal curvature of cervical line -shorter crowns