Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Oral Anatomy > Morphology of Molars > Flashcards

Morphology of Molars Flashcards

1
Q

Universal # of maxillary right perm. molars

A

1 2 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Universal # of maxillary left perm. molars

A

14 15 16

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Universal # of mandibular right perm. molars

A

30 31 32

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Universal # of mandibular left perm. molars

A

17 18 19

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Maxillary and mandibular molar widths make up 51% (mandibular) and 44% (maxillary) of the quadrant

A

___ (mandibular) and ___ (maxillary) of the quadrant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

_____ are the only teeth with no tooth in proximal contact with the distal surface

A

Third molars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Functions of Molars

A

• Mastication (grinding)
• Maintenance of vertical dimension of face
• Maintenance of arch continuity for proper
alignment
• Support cheeks (esthetics)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Crown Size for All Molars

A

• Mesiodistal dimension is greater than occlusocervical (wider MD than tall OC)
• Have three to five cusps
• Larger crowns than other teeth but SHORTEST
occlusocervically
• Broader occlusal surfaces than other
teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Taper of molars

A
  • Buccal to lingual ( occlusal view )
  • Mesial to distal ( occlusal view )
  • Mesial to distal ( buccal view )
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Taper From Buccal to Lingual For All Molars

A

Crowns taper narrower from buccal to lingual
(EXCEPT maxillary first molar with large
distolingual cusp)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Taper to the Distal for All Molars

A

• From occlusal view, molar crowns taper narrower buccolingually from mesial to distal (are narrower buccolingually in distal third than in mesial third)

• All molar crowns taper
from mesial to distal
(distal cusps are
shorter than mesial
cusps)   M -> D
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

______ molar is the only molar wider buccal to lingual

A

maxillary first molar (large DL cusp)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Facial height of

contour for molars is in ______

A

cervical third (as on all teeth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Lingual height of

contour for molars is in _______

A 
middle third (as on all
posterior teeth)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Mesial contact for molars located

_________

A

near junction of middle/occlusal thirds

on all molars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Distal contact more
cervical near middle
third (on all molars)

A

more cervical; near middle

third (on all molars)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Crown Outline to Distinguish Maxillary From
Mandibular Molars:

Maxillary have occlusal ____ dimension greater: ____ shape

Mandibular have occlusal ___ dimension greater: ____ or ____ on firsts

A

Maxillary greater FL than MD
(wider faciolingually)

Maxillary: more square (rhomboid/parallelogram)

Mandibular greater MD than FL

Mandibular: Rectangular (pentagon on firsts)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mandibular molars are likely to have #___ large cusps, often a fifth cusp on __1st or 2nd

A

4 large cusps, often 5th on mandibular 1st molars (distal - think 19/30)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Maxillary molars are likely to have _#___ large cusps, plus a smaller distolingual cusp, and possible fifth cusp called ______

A

3 large cusps

cusp of Carabelli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

For maxillary and mandibular molars, each cusp is formed from how many lobes?

A

1 lobe (1:1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Mandibular crowns tilt
______ relative to root
axis

A

lingually

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

T/F Maxillary crowns are more
centered over the root
with a lingual tilt

A

F
Maxillary crowns are more
centered over the root
with NO lingual tilt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

T/F From buccal view, the
mandibular crowns tilt
slightly more mesially than
the maxillary

A 
F
From buccal view, the
mandibular crowns tilt
slightly more distally than
the maxillary 
(think 19 & 30 we've been drilling on, APPRECIATE that distal tilt)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

_____ have 3 roots

_____ have 2 roots

A

maxillary molars = 3 roots

mandibular molars = 2 roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

On maxillary molars, which root is the longest?
Which is shortest?
Is MB or DB root wider?

A

Maxillary
Lingual = longest
Distobuccal = shortest
Mesiobuccal = wider than DB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

On mandibular molars, which root is longer? Which is wider?

A

Mandibular
Mesial = longer and wider
Distal = shorter and narrower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

T/F Both mandibular molars are normally wider mesiodistally than occlusocervically (more so on firsts)

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Which mandibular molar is larger?

A

Mandibular first larger than second (think 30 vs. 31, 30 has that extra distal cusp)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Mandibular firsts most often have five

cusps, __ buccal and ___ lingual

A

3 buccal: MB > DB > Distal

2 lingual: mesiolingual longer than distolingual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Mandibular first molar has __ buccal groove(s)

A

First has two buccal grooves (mesiobuccal, distobuccal)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Mandibular second molar has ____

cusps, __ buccal and ___ lingual, with __ buccal groove(s)

A 
4 cusps:
2 buccal (MB-longer, DB) 
2 lingual (ML-longer, DL)

1 buccal groove

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

T/F All mandibular molars have proximal contact areas located more occlusal on the mesial surface (at junction of _____) than on the distal (near _______)

A

mesial: jxn middle and occlusal thirds
distal: near middle third

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

T/F Cervical line/ CEJ of mandibular molars is close to straight mesiodistally (rarely may dip into root bifurcation)

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Do mandibular first or second molars have more crown taper from the distal contact to the CEJ?

Which contour is straighter? M or D

A

More crown taper from distal contact to CEJ on FIRSTS than seconds

Mesial contour is more straight than distal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

T/F Mandibular first and second molars have two roots: mesial (wider and shorter) and distal

A

M wider and longer > D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Root trunk shorter on mandibular first

or second?

A

First has shorter root trunk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

On mandibular firsts, the roots are more ___ toward the apex

A

Divergent - mandibular first

convergent - mandibular second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Crowns taper narrower from buccal to
lingual (more so on firsts) so proximal
surfaces are somewhat visible from the _______

A

lingual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Mesiolingual and distolingual cusps are

_____ than buccal cusp (mandibular molars)

A

Mesiolingual and distolingual cusps are longer than buccal cusp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

T/F Mesiolingual cusp is wider than distolingual cusp (mandibular molars)

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

T/F On mandibular molars, lingual groove, if onto lingual surface, is likely
to be carious

A

F

UNLIKELY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

T/F Roots narrower on buccal side than lingual side for mandibular molars

A

F

Roots narrower on lingual side than buccal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Mandibular molars:

Buccal height of contour is in the
____ third

Lingual height of contour is in ____ third

A

Buccal: cervical third
Lingual: middle third (as on all molars)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

T/F Buccal cervical ridge running mesiodistally and more prominent in mesial half (seen occlusally) of mandibular second molar

A

True

45
Q

On mandibular molars, are lingual or buccal cusps more pointed and longer (handheld)

A

lingual cusps are longer and more pointed than buccal

46
Q

With mandibular molars, you cannot see the occlusal from the mesial view, but from the distal view, you can see more of occlusal surface. This is due to:

A

taper shorter toward distal

-distal tilt of mandibular molars

47
Q

CEJ of mandibular molars when comparing proximal views

A

CEJ slopes occlusally from buccal to lingual (buccal more cervical, lingual more occlusal)

Very slightly curved

48
Q

Distal marginal ridge is more ___ than

mesial marginal ridge (similar to proximal contacts)

A

distal more cervical than mesial

49
Q

Mesial root is broader faciolingually
and longer than distal root, so cannot
see distal root from __ view

A

mesial view: can’t see distal, M is wider FL

50
Q

Mesial root of mandibular molar has ___ surface depression, but ___ is deeper.

Smaller distal root has mesial surface
depression but distal surface is _____

A

mesial, distal is deeper

distal is variable

51
Q

If mandibular molar is viewed along root axis, more ____ surface is visible than
_____ due to lingual tipping of
the crown relative to the root

A

facial > lingual

52
Q 
Outline Shape and Taper of Mandibular
Second Molars (occlusal)
A

Mandibular second molar is RECTANGULAR
(MD > BL)
• Tapers narrower from mesial to distal and from buccal to lingual
• Buccal cervical ridge prominent on mesial

53
Q

Outline Shape and Taper of Mandibular First

Molars (occlusal)

A

Mandibular first is more prominent in middle of buccal (over distobuccal cusp) and very small distal cusp, making outline more
PENTAGON shaped
• Tapers narrower from
buccal to lingual
• Distal third narrower buccolingually than mesial third

54
Q

___ triangular ridges form two transverse

ridges on mandibular molars

A

four

MB + ML = mesial transverse ridge
DB + DL = distal transverse ridge

*Distal cusp triangular ridge is separate

55
Q

First and second mandibular molars have ____ fossae

A

3 fossae
– Central (largest)
– Mesial triangular
– Distal triangular (very small)

56
Q

Mandibular second molar groove pattern is _______, where ___ and ____ grooves join and cross the central groove

Which groove is caries prone?

A

Mandibular second molar groove pattern is
“+” shaped where BUCCAL and LINGUAL grooves join and cross the central groove
• Buccal groove with buccal pit is caries
prone

57
Q

Mandibular first molar groove pattern is _______, where ___ and ____ grooves join and cross the central groove

Which groove separates distobuccal and distal cusps?

A

More “zig-zag” central groove from mesial to
distal fossa

MESIOBUCCAL and LINGUAL grooves join central groove near central fossa

Distobuccal groove

58
Q

T/F Mesial and distal contact areas normally slightly buccal to the central groove on mandibular molars, so lingual embrasure greater than buccal embrasure

A

True

59
Q

Which term refers to possible extra lingual cusp on mandibular molars?

Which term refers to extra cusp on distal marginal ridge of first molar?

A

tuberculum intermedium

tuberculum sextum

60
Q

List the following in order from tallest to shortest cusp height/length for mandibular molars:

A. mesiobuccal 
B. distal
C. mesiolingual
D. distobuccal
E. distolingual
A

Tallest

  1. C, E mesiolingual =distolingual (ML slightly taller)
  2. A mesiobuccal
  3. D distobuccal
  4. B distal

Shortest

61
Q

List the following in order from largest to smallest cusp size/bulk for mandibular molars:

A. mesiobuccal 
B. distal
C. mesiolingual
D. distobuccal
E. distolingual
A

Largest

  1. C mesiolingual
  2. A mesiobuccal
  3. E distolingual
  4. D distobuccal
  5. B distal

Smallest

62
Q

T/F For maxillary molars, both cusp length and size can be ordered largest to smallest as:

  1. Mesiolingual (largest, tallest)
  2. Mesiobuccal
  3. Distobuccal
  4. Distolingual (smallest, shortest)
A

True

63
Q

T/F Maxillary first molar is largest maxillary tooth

A

True

64
Q

Which maxillary molar is wider mesiodistally?

A

Maxillary first wider MD

65
Q

Maxillary molars have __ buccal cusps and ___ lingual cusps

A

Two buccal cusps:
-mesiobuccal (wider and longer) and
distobuccal

Two lingual cusps:
-mesiolingual (longest of the two) and
distolingual (shortest, can not be seen from buccal view)

66
Q

On maxillary molars, _____ separates the mesiobuccal and distobuccal cusps, ____ caries prone

A

buccal groove

is not caries prone

67
Q

Maxillary molars all have mesial contact at _________ and distal contact _________

A

mesial: junction of occlusal and middle thirds
distal: near middle third, more cervical

68
Q

From buccal view, maxillary molar has 3 roots with ____ as the longest, showing behind & between the mesiobuccal and distobuccal roots. ____ is longer and wider than ____, with ____ as the shortest

A 
lingual = longest
mesiobuccal = longer and wider than distobuccal

db=shortest

69
Q

The root trunk of which maxillary molar is shorter?

A

first maxillary trunk shorter than second maxillary root trunk

70
Q

Maxillary first have roots more (divergent/convergent), maxillary second have roots more (divergent/convergent)

A

first: roots more divergent
second: roots more convergent

71
Q

When viewed from the lingual, little or no proximal surface shows on maxillary first molar due to ____ lingual surface, ____ distolingual cusp. More proximal shows on second with _____ distolingual
cusp.

A

wider lingual surface
larger distolingual cusp

smaller or missing distolingual cusp = more proximal showing on second

72
Q

_____ molar has largest and longest mesiolingual cusp (often with cusp of Carabelli or groove 70%) and somewhat smaller distolingual cusp

A

maxillary first molar has largest and longest ML cusp

73
Q

Second molar also has longest and largest

_______ cusp compared to much smaller (or missing) ______ cusp

A

mesiolingual

distolingual

74
Q

T/F On maxillary molars, lingual grooves and pits are not caries prone

A

FALSE

on maxillary molars, lingual grooves and pits are prone to caries

75
Q

Longest lingual root often has ______ on lingual surface (on first molar)

A

longitudinal depression

76
Q

Are the distobuccal and mesiobuccal roots closer together on the maxillary first or maxillary second molars?

A

maxillary second molars

77
Q

T/F The faciolingual dimension of maxillary molars is greater than the occlusocervical dimension

A

True FL > OC

78
Q

T/F From the mesial view, only 3 cusps (but not Carabelli) are visible since distal cusps are shorter on maxillary molars.

A

FALSE

only 2 cusps (AND cusp of Carabelli) are visible since distal cusps are shorter

79
Q

From the distal view, you can visibly see ____ cusps on maxillary molars because mesial cusps are ____ than distal

A

from distal: 4 cusps visible

mesial cusps are LONGER than distal cusps

80
Q

For maxillary molars, the buccal height of
contour is in the cervical third (like all teeth), and the lingual height of contour is in the middle third (like all posterior teeth), or even ______ if big cusp of
Carabelli

A

more occlusal if big cusp of Carabelli

81
Q

From distal view, some of facial and lingual surfaces of maxillary molars may be visible due to crown tapering narrower toward ____

A

distal

82
Q

Mesial marginal ridge is ______ than

distal, so more occlusal surface is visible from distal view

A

mesial marginal ridge MORE OCCLUSAL than distal

83
Q

Tubercles and marginal ridge grooves are more common on ______ and on ___ marginal ridges than ____

A

more common on FIRST than second

more common on MESIAL ridges than distal

84
Q

Which root is known as the banana root?

A

Lingual root of maxillary molars (esp. 1st)

85
Q

T/F Only two roots visible from mesial (since
distobuccal is shorter and narrower than
mesiobuccal)

A

True

86
Q

T/F Less spread of first molar roots compared to second

A

False, less spread on second

87
Q

_____ root has mesial and distal root depression; the _____ root is less likely to have depressions

A

MB root = mesial and distal depressions

DB root less likely to have depressions

88
Q

T/F First and second maxillary molars have buccolingual less than mesiodistal dimension

A

False, first and second maxillary molars are wider BL than MD

89
Q

Maxillary first molars often have a buccal half narrower mesiodistally than lingual half due to large ______

A

large distolingual cusp

90
Q

______ molars are rhomboid or almost square in occlusal outline, with sharp MB and DL angles and other angles more rounded

A

Maxillary first molars

91
Q

In ______, there is great variety. Because the distolingual cusp is often quite small, lingual half is narrower mesiodistally than buccal half. Distolingual cusp may be missing, making this molar a tricuspid.

A

maxillary second molars

92
Q

Do maxillary first or second molars have a more twisted rhomboid outline due to the prominent mesiobuccal cervical ridge?

A

Maxillary second molarsz

93
Q

Maxillary first molar has ___ cusps plus often Carabelli cusp (or depression) on _____ cusp

A

four

mesiolingual = carabelli or depression

94
Q

Maxillary second molar has ___
larger cusps, which form the ______, and one smaller or absent
(distolingual)

A

3 larger cusps MB DB ML (mesiobuccal, distobuccal, and mesiolingual) = Primary Cusp Triangle

95
Q

Name the 2 distinct components of maxillary molars

A

Trigon
Talon

Well-developed in 1st molar & undergoes
reduction in size in 2nd & 3rd molars

96
Q

Bears MB, ML & DB cusps (Tricuspate or

Primary cusp triangle)

A

Trigon

97
Q

Bears DL cusp & D MR Located DL to the

Tricuspate

A

Talon

98
Q

Cusp of Carabelli Present on __ of Maxillary First Molars; Varies Greatly in Size

A

70%

RARELY: carabelli found on second maxillary molars

99
Q

If 4 cusp type maxillary molar, what ridges exist?

A

Transverse ridge: from mesiolingual to
mesiobuccal cusp

Oblique ridge: from mesiolingual to distobuccal cusp

100
Q

If maxillary molar has four cusps, it has ___ fossae

A

4 cusps = 4 fossae

  1. Central (largest)
  2. Distal oblique (second largest, cigar shaped)
  3. Mesial triangular
  4. Distal triangular (minute)
101
Q

If three-cusp type maxillary molar: only

three fossae: ____, _____, and ______

A

mesial, central, and distal

102
Q

Grooves on Maxillary Molars (Four-cusp Type)

A
  • Central groove: from mesial to central fossa
  • Buccal groove: from central fossa
  • Distal oblique groove: from distal fossa
  • Lingual groove: continues from distal oblique (caries prone)
  • Transverse groove of oblique ridge (if present)
103
Q

Grooves on Maxillary Molars (Three-cusp Type)

A

If three cusped (heart shaped occlusal outline), grooves are:
– Buccal
– Central

(No distal oblique groove,
no lingual groove, and
no transverse groove of
oblique ridge)

104
Q

Mesial and distal contacts for maxillary molars are located ____ to buccolingual
center, with _____ more buccal, EXCEPT on the maxillary first molar where the ___ is centrally located

A

buccal to buccolingual center
mesial more buccal than distal
distal on 1st centrally located

105
Q

Match the following occlusal outlines to their molar:

  1. Rhomboid/square
  2. Pentagon
  3. Heart
  4. Rectangle
A. Mandibular first 
B. Mandibular second
C. Maxillary first 
D. Maxillary second 
E. Maxillary second, 3 cusp type
A
  1. Rhomboid/square = C or D (max 1st or second)
  2. Pentagon = A (mand first)
  3. Heart = E (max second 3 cusp; also max third)
  4. Rectangle = B (mand second)
106
Q

All Third Molars Traits (diff from 1st and 2nd molars)

A
  • often smaller (crowns and roots) than first or second molars
  • maxillary third molars are ONLY maxillary teeth to occlude with only one tooth (recall: mandibular central incisor as well)
  • more bulbous, smaller occlusal table
  • more wrinkled (accessory grooves/fissures)
  • morphology may resemble first, second, or heart shape
  • roots OFTEN FUSED, long trunk
  • roots thin, pointed; if bent, distally
107
Q

Size varies greatly but usually ___ molars are the shortest of permanent teeth (short crowns and short roots)

A

third molars

greatest variance of shape as well

108
Q

Because third molars are often so distal in location and may not fully erupt, they may be covered with a tissue flap called _____;
trauma and infection of this tissue may cause ______

A

operculum

trauma/infection can cause pericoronitis

Oral Anatomy (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions