mandibular Flashcards
_______ premolars are more similar to each other than ______ premolars
maxillary, mandibular
which premolars from the facial view have a common appearance?
maxillary and mandibular
which mandibular premolars are always larger in the same mouth?
second mandibular
compare the roots of mandibular premolars to canine roots
both premolar roots are shorter than the canine root
describe the facial cusp of a mandibular premolar.
describe the lingual cusps
single, well developed
lingual
- less developed
- 1st: single lingual cusp
- 2nd: 1 or 2 cusps, may develop from 4 or 5 lobes
which premolars show lingual convergence? lingual divergence?
lingual convergence:
- mandibular 1st
- 2 cusp mandibular 2nd
lingual divergence
- 3 cusp mandibular 2nd premolar
copare mandibular premolars to the mandibular anterior teeth
- FL vs. MD dimensions
- contact areas
- cervical line
mandibular premolars:
- FL > MD
- broader contact areas
- flatter cervical line
describe the mandibular first premolar, buccal view
- bilateral symmetry?
- shape of cusp
- mesial ridge vs distal
- vertical depressions
- nearly symmetrical bilaterally
- pointed cusp
- mesial ridge shorter than distal
- slight vertical deppresions
describe the buccal ridge on the mandibular first premolar
a ridge extending from the cervical third to the cups tips
describe the mandibular first premolar, lingual view
- occlusal table slants
- what is lingual cusp similar to?
- lingual cusp vs facial cusp
- occlusal table slants cervically
- lingual “cusp” similar to a cingulum
- lingual cusp shorter than facial
describe mandibular first premolar, lingual view
- shape of cusp
- mesiolingual groove
- root
- developmental depressions
- pointed and centered lingual cusp
- mesiolingual groove extends from the mesial fossa of the occlusal surface onto the mesiolingual surface
- root more narrow on the lingual
- mesial and developmental depressions are visible
describe the mandibular first premolar, proximal view
- position of facial cusp tip
- lingual cusp tip is _________ with lingual root ______
- facial height of contour is in _____
- lingual height of contour is in _____
- facial cusp tip is centered over root
- lingual cusp tip is IN LINE with lingual root OUTLINE
- cervical third
- lingual third
describe the mandibular first premolar, proximal view
- triangular ridges, facial and lingual
- angle of mesial marginal ridge
- distal marginal ridge
- mesiolingual groove
- long facial, short lingual triangular ridges
- mesial marginal ridge is at 45 degrees
- distal marginal ridge is nearly horizontal and more coronally positioned
- mesiolingual groove extends from the mesial fossa of the occlusal surface
describe the mandibular first premolar, occlusal view
- shape of outline
- shape of occlusal table
- triangular ridges
- what separates mesial and distal pits?
- diamond shaped occlusal outline
- triangular shaped occlusal table
- long facial, short lingual triangular ridges
- triangular ridges form transverse ridge which separates M and D pits
describe the mandibular first premolar, occlusal view
- describe the mesial groove
- shape of groove in distal fossa
- position of central groove
- mesial groove in the mesial fossa is continuous with mesiolingual groove
- comma shaped groove in distal fossa
- central groove is lingually positioned
why is the central groove lingually positioned?
due to the long triangular ridge of the buccal cusp
what type of cusps can be exhibited in a mandibular 2nd premolar
2 or 3 cusp
what tooth does the mandibular 2nd premolar have similar qualities with?
mandibular molar
compare the first and second premolar, buccal view
- cusp
- cusp ridges angulation
- mesial cusp ridge
- distal cusp ridge
- cusp tip
- distal cup notch more or less common
the second premolar:
- shorter buccal cusp
- cusp ridges show less angulation
- mesial cusp ridge is shorter than distal cusp
- cusp tip is more blunt
- distal cusp notch more common
compare the first and second mandibular premolars, lingual view
- lingual lobes
- amount of occlusal surface visible
the second premolar:
- lingual lobes are more developed
- less occlusal surface is visible
describe the types of lingual cusps on a mandibular second premolar for the 2 and 1 lingual cusp types
- total cusps, developed from how many lobes
two lingual cusps
- 3 total cusps
- developed from 5 lobes
1 lingual cusp
- 2 total cusps
- developed from 4 lobes
what is a distinguishing feature on a 3 cusp mandibular second premolar from the lingual view
3 cusp variety has a lingual groove between the 2 lingual cusps
compared to the facial cusp on the mandibular second premolar, compare these from the lingual view
- relative heights of mesiolingual cusps
- relative heights of distolingual cusps
- mesiolingual cusp tip is 1.5mm shorter than facial cusp
- distolingual cusp is about 2.0mm shorter than facial cusp
on the second mandibular premolar, which cusp is wider, the mesiolingual or distolingual?
mesiolingual cusp is wider on the second mandibular premolar
describe the second mandibular premolar
- position of buccal cusp tip to long axis of tooth
- buccal cusp is facial to long axis
-
compare 1st mandibular premolar to the 2nd
- mesial marginal ridge
- amount of occlusal surface seen
second mandibular premolar:
- mesial marginal ridge is at right angles
- shorter on second premolar
- less occlusal surface may be seen
compare first and second mandibular premolars
- distolingual cusp visibility
- mesiolingual developmental groove
- root length
- right surface…convex or concave, on which one?
- distolingual cusp not visible on 2nd
- no mesiolingual developmental groove on 2nd premolar
- longer root on 2nd
- 2nd root surface is slightly convex compared to 1st
describe the mandibular second premolar, occlusal view with 3 cusps
- shape it appears
- definition of triangular ridges
- presence of transverse ridge
- developmental grooves
- shape
- position of central pit
- fossae
- which is larger…mesiolingual or distolingual cusp
- appears square
- well formed triangular ridges
- NO TRANSVERSE RIDGE
- developmental grooves:
- Y shaped
- central pit slighty distal
- 3 fossae- mesial, central, distal
- mesiolingual cusp is larger/longer
does the 3 cusp mandibular 2nd premolar diverge or converge from buccal to lingual? the 2 cusp?
- 3 cusp may diverge from buccal to lingual
- 2 cusp may converge
describe the mandibular second premolar, occlusal view with 2 cusps
- shape it appears
- developmental grooves
- types of shapes
- fossae
- position of lingual cusp
- appears round
- developmental grooves
- most often: crescent (U) shaped
- Possibly H shaped
- mesial and distal fossae
- may have mesial and distal pits
- lingual cusp directly opposite buccal cusp
list the percentages for number of canals for the mandibular first premolar. list the same for roots
- one canal
- two canal
- three canal
- one root
- two roots
- one canal: 74%
- two canals: 25%
- three canals: 1%
- one root: 95%
- two roots: 5%
list the percentages for number of canals for the mandibular second premolar. list the same for roots
- one canal
- two canal
- three canal
- one root
- two roots
- three roots
- one canal: 93%
- two canals: 7%
- three canals: 0.5%
- one root: 98.5%
- two roots: 1%
- three roots: 0.5%
which mandibular premolar has lobe depressions? a distal notch on the distal cusp ridge?
lobe depressions: 1st premolar
distal notch: 2nd premolar
which mandibular premolar has a occlusal surface taper? which direction does it taper?
1st premolar, tapers to lingual
compare the MMR angles of the 1st and 2nd mandibular premolars
- 1st: 45 degrees
- 2nd: nearly horizontal
which mandibular premolar has a mesiolingual groove?
first premolar
between the 1st and 2nd mandibular premolars, which has a DMR that is more occlusal than the MMR?
1st premolar
- in the 2nd, the DMR is more cervical than the MMR
between the 1st and 2nd mandibular premolars, which has a smaller occlusal surface
first premolar
how many cusps can there be on a first mandibular premolar? second?
- first: 2 cusps
- second: 2 or 3 cusps
which mandibular premolar does not have a transverse ridge?
3 cusp 2nd premolar
compare lingual cusps of the 1st and 2nd mandibular premolars
- 1st: single, cingulum like
- 2nd: 1 or 2 cusps
between the 1st and 2nd mandibular premolars, which cusp tip is more pointed?
1st premolar
2nd is more blunt
