upper right premolar numbers
4 and 5
upper left premolar numbers
12 and 13
lower left premolar numbers
20 and 21
lower right premolar numbers
28 and 29
functions of premolars
- mastication
- maintaining vertical dimension of face
- assist canines to cut and shear food
- support cheeks and corners of mouth
Most premolars have _______(one buccal and one lingual) but sometimes there are ____ (one buccal and two lingual)
two cusps; three cusps
premolars develop from ___ facial lobes and from one or two ____ lobes corresponding to one or two ____ cusps
three; lingual; lingual
the CEJ is ____ on premolars, compared to anterior teeth
less curved
roots taper narrower ____ and ____
apically; lingually
premolars have two or three ____ versus _____
occlusal cusps; incisal edge
marginal ridges are more ____, except mesial marginal ridge of mandibular first premolar
horizontal
crowns of premolars are ____ compared to anterior teeth
shorter
height of contour on premolars
- in cervical third on facial (not too close to CEJ except mandibular first premolar)
- in middle third on lingual
proximal contact areas more ____ and broader
cervical
All Premolars From Buccal View: have ___ outline of crown (like canine)
pentagon
All Premolars From Buccal View: contact areas are ____; the distal contact is more ___ than the mesial (except mandibular first premolar)
convex; cervical
All Premolars From Buccal View: ____ cusp ridge is shorter than the ____ (except on the maxillary first premolar)
mesial; distal
All Premolars From Lingual View: crown outline narrows toward ____ so some ____ surfaces are visible (except some three cusp type mandibular second premolars with two lingual cusps, seen best on occlusal view)
lingual; proximal
All Premolars From Lingual View: ____ cusp longer than ____ cusp
buccal; lingual
All Premolars From Lingual View: ___ cusp off center to the ____, except on the mandibular first premolar
lingual; mesial
All Premolars From Proximal Views: ____ marginal ridges are more ____ than ____, except on mandibular first premolar
mesial; occlusal; distal
All Premolars From Occlusal View: they are wider ____ than _____
faciolingually; mesiodistally
All Premolars From Occlusal View: occlusal table bound by ____ and _____
marginal ridges; cusp ridges
All Premolars From Occlusal View: proximal contacts are located ____ to the _____; ____ embrasure spaces are larger
buccal; buccolingual midline; lingual
All Premolars From Occlusal View: _____ join to form ____ ridges (except on three cusp type mandibular second premolars)
triangular ridges; transverse
All Premolars From Occlusal View: a groove extends from ____ to ____ (except on some mandibular first premolars)
mesial fossa; distal fossa
Arch Traits That Differentiate Maxillary From Mandibular Premolars: mandibular premolars have more noticeable _____ than maxillary
lingual crown tilt
Arch Traits That Differentiate Maxillary From Mandibular Premolars: mandibular premolars have less prominent ____
buccal ridge
all premolars are larger _____ than _____
buccolingually; mesiodistally
BUT, the mandibular premolar is closer to ____ (buccolingual slightly greater than mesiodistal)
square
maxillary premolar is ______ (buccolingual is obviously greater than mesiodistal)
rectangular
Relative Size of Maxillary Premolar Crowns From the Buccal View: maxillary first premolar is ____ than the second
larger
Relative Size of Maxillary Premolar Crowns From the Buccal View: there is more convergence from proximal contact to the cervical on the ____ than the ____
first; second
Location of Contacts for Maxillary Premolars From the Buccal View: mesial contact is ____, distal contact is _____ (for both types)
junction of occlusal and middle third; middle third
Location of Buccal Cusp Tip of Maxillary Premolars From the Buccal View: on the maxillary second, the ___ cusp ridge is shorter than the ____ (cusp tip is ____ or ____)
mesial; distal; mesial; centered
Location of Buccal Cusp Tip of Maxillary Premolars From the Buccal View: the maxillary first premolar has _____ longer than the _____ (this is unique); the cusp tip is ____
mesial cusp ridge; distal; distal
Shape of the Buccal Cusp of Maxillary Premolars From the Buccal View: the cusp is sharper on ____ than _____
maxillary first premolar; second
Buccal Ridge and Depression of Maxillary Premolars From the Buccal View: the buccal ridge is more prominent on the ____ than _____
maxillary first premolar; maxillary second
Root of Maxillary Premolars From the
Buccal View: maxillary ____ premolar is more likely to have two roots, whereas the ____ premolar has one root
first; second
Relative Cusp Size of Maxillary Premolars From the Lingual View: the ___ cusp is shorter than the ____; more so on the maxillary first than the maxillary second
lingual; buccal
Cusp Ridges of Maxillary Premolars From the Lingual View: the lingual cusp is relatively sharper on the _____ than on the _____
maxillary second premolar; first premolar
Lingual Cusp Position for Maxillary Premolars From the Lingual View: both maxillary first and second premolars have the lingual cusp tip positioned ____ to the midroot axis
mesial
Marginal Ridges of Maxillary Premolars From the Lingual View: the ____ marginal ridge is more ____ than _____ for both maxillary first and second premolars (best seen when comparing mesial and distal views)
distal; cervical; mesial
Roots of Maxillary Premolars From the
Lingual View: on the maxillary first premolar, the ___ root is shorter than the ____ root
lingual; buccal
Roots of Maxillary Premolars From the
Lingual View: the root crown ratio is 1.56 on the ____ and 1.82 on the ____
first maxillary premolar; second maxillary premolar
Crown Shape and Morphology of Maxillary Premolars From the Proximal Views: maxillary premolars have ____ outline
trapezoid
Crown Shape and Morphology of Maxillary Premolars From the Proximal Views: the _____ is the only premolar to have a crown depression (always on the mesial)
maxillary first premolar
Relative Cusp Height of Maxillary Premolars From the Proximal Views: the ____ cusp is shorter than the ____ cusp, more so on the maxillary first premolar than second premolar
lingual; buccal
Height (Crest) of Contour of Maxillary Premolars From the Proximal Views: the facial height of contour is in the ____ (like all teeth)
cervical
Height (Crest) of Contour of Maxillary Premolars From the Proximal Views: the lingual height of contour is in the _____ (like all posterior teeth)
middle
Distance Between Cusps on Maxillary Premolars From the Proximal Views: the distance between cusps is the same for both maxillary first and second premolars; both ___ and ____ cusp tips are located ____
buccal; lingual; over the root
Marginal Ridge Grooves of Maxillary Premolars From the Proximal Views: the marginal ridge groove is found most often on : ______ (not as common on all other maxillary premolars)
the mesial marginal ridge of maxillary first premolars
Cervical Lines of Maxillary Premolars When Comparing the Proximal Views: there is more CEJ curvature on ____ than ____ on both 1st and 2nd premolars (as on all premolars and anterior teeth)
mesial; distal
Roots and Root Depressions of Maxillary Premolars From the Proximal Views: _____ is the only premolar with the ____ more pronounced than the distal
maxillary first premolar; mesial root depression
the maxillary first premolar is the only premolar with ____ joining with the _____
mesial crown depression; deep root depression
_____ more pronounced on maxillary second premolar
distal root depression
Relative Size of Maxillary Premolars From the Occlusal View: _____ likely to be slightly larger than ____
maxillary first premolar; the second
Grooves and Fossae of Maxillary Premolars From the Occlusal View: the ____ of the maxillary first premolar is longer than on the second premolar
central groove
the maxillary second premolar has more ____ than the first
supplemental grooves
Both maxillary premolars have noticeably greater dimension _____ than _____ (by over 2 mm)
faciolingually; mesiodistally
Outline of Maxillary Premolars From the
Occlusal View: the ____ is more prominent on the maxillary first premolar than the second
buccal ridge
Outline of Maxillary Premolars From the
Occlusal View: the maxillary first premolar is more _____ than the second premolar
asymmetrical (hexagonal)
Contact Areas and Heights of Contour of Maxillary Premolars From the Occlusal View: contacts are ____ for both
near the junction of the buccal/middle thirds
mandibular premolars _____ more than maxillary premolars
vary in shape
_____ is the only premolar more likely to have 3 cusps (one buccal and two lingual: mesiolingual and distolingual)
mandibular second premolar
Relative Crown Shape and Size of Mandibular Premolars From the Buccal View: the _____ is longer than the ____
mandibular first premolar; second
Relative Crown Shape and Size of Mandibular Premolars From the Buccal View: both have rounded _____ (first wider than second)
shoulders
Relative Crown Shape and Size of Mandibular Premolars From the Buccal View: the ____ of the mandibular first premolar is sharper than the second
buccal cusp apex
Relative Crown Shape and Size of Mandibular Premolars From the Buccal View: cusp ridge notches are more common on the ____ of the first and the ____ of the second
mesial; distal
Morphology of Mandibular Premolars From the Buccal View: buccal developmental grooves on either side of buccal ridge (when present) are likely deeper on the ____ of the first premolar and on the ____ of the second premolar
mesial; distal
___ are shorter than ____
mesial cusp ridges; distal
Cervical Lines of Mandibular Premolars From the Buccal View: CEJ more curved on ____ than ____
mandibular first premolar; second
Contact Areas of Mandibular Premolars From the Buccal View: the mandibular first premolar is the only premolar (only adult tooth) where the mesial contact is ____ than the distal
more cervical
Contact Areas of Mandibular Premolars From the Buccal View: first premolar distal contact is in _____ and mesial contact is ____
occlusal third; at the junction of the occlusal and middle third
Roots of Mandibular Premolars From the
Buccal View: both types of mandibular premolar roots taper to ____ with ____ of apex more common
apex; distal bend
root to crown ratio on _____ is larger
mandibular second premolar
Crown Shape of Mandibular Premolars From the Lingual View: most mandibular premolars taper narrower toward _____ (EXCEPT 3 cusp type of mandibular second premolar where lingual half may be wider than buccal half)
lingual
Lingual Cusps of Mandibular Premolars From the Lingual View: lingual cusp of mandibular first premolar is ____ than the buccal, is ____ and is located ____
shorter; nonfunctional; mesial, center, or distal
Lingual Cusps of Mandibular Premolars From the Lingual View: the lingual cusp of the mandibular second premolar (with one lingual cusp) is slightly ___ than the buccal and is ___ to the midroot axis
mesial
Lingual Cusps of Mandibular Premolars From the Lingual View: when the mandibular 2nd premolar has two lingual cusps, the _____ cusp is normally wider and longer than the ____
mesiolingual; distolingual
Marginal Ridges of Mandibular Premolars From the Lingual View: the mandibular first premolar is the only premolar (only posterior tooth) to have its mesial marginal ridge more ____ than the distal
cervical; distal
Grooves on Mandibular Premolars From the Lingual View: only mandibular second premolar with two lingual cusps have a ____ separating them
lingual groove
Grooves on Mandibular Premolars From the Lingual View: most mandibular first premolars have a _____ separating the ____ from the _____
mesiolingual groove; mesial marginal ridge; mesial cusp ridge of the lingual cusp
Roots of Mandibular Premolars From the
Lingual View: roots taper ____ and to ____
lingual; apex
Crown Shape of Mandibular Premolars From the Proximal Views: crowns tip noticeably to the ____, more so on _____ than ____
mandibular first premolar; second
Crown Shape of Mandibular Premolars From the Proximal Views: outlines are ____
rhomboid
Crown Shape of Mandibular Premolars From the Proximal Views: lingual cusps are ___ than buccal, more so on first with nonfunctional lingual cusp
shorter
Marginal Ridges of Mandibular Premolars From the Proximal Views: the mesial marginal ridge of mandibular first premolar slopes at ____, nearly parallel to _____
45 degrees; buccal triangular ridge
Marginal Ridges of Mandibular Premolars From the Proximal Views: _____ is very short
lingual triangular ridge
Marginal Ridges of Mandibular Premolars From the Proximal Views: other posterior marginal ridges are more _____
horizontal
Marginal Ridges of Mandibular Premolars From the Proximal Views: occlusal plane in relation to midroot axis line ___ on 1st mandibular premolar
45 degrees
Marginal Ridge Grooves and Mesiolingual Grooves on Mandibular Premolars From the Proximal
Views: mesiolingual groove is often present on _____, not _____
mandibular first premolars; seconds
second premolars ____ have marginal ridge grooves
sometimes
Height (Crest) of Contour of Mandibular Premolars From the Proximal Views: the buccal height of contour is the _____ (near the CEJ on first premolar)
cervical third
Height (Crest) of Contour of Mandibular Premolars From the Proximal Views: the lingual height of contour is in ____, nearly to cusp tip in mandibular first premolar, and beyond root outline)
middle third
Cervical Lines of Mandibular Premolars From the Proximal Views: more CEJ curve on ____ than ___ surface (as on all premolars)
mesial; distal
Cervical Lines of Mandibular Premolars From the Proximal Views: ___ CEJ more ____ than ____ CEJ (as on all premolars)
lingual; occlusal; buccal
Roots of Mandibular Premolars From the
Proximal Views: roots taper to ____ (as they all do)
apex
Root Depressions of Mandibular Premolars From the Proximal Views: _____ has mesial and distal root depressions, deeper on ____
mandibular first premolar; distal
Root Depressions of Mandibular Premolars From the Proximal Views: mandibular second premolar likely to have ____ but none on ____
distal root depression; mesial
Outline Shape of Mandibular Premolars From the Occlusal View: the mandibular first premolar has more bulk in ___ half than ____ half
distal; mesial
Outline Shape of Mandibular Premolars From the Occlusal View: the ____ line angle is flat or pushed in on the mandibular first premolar
mesiolingual
the mandibular first premolar has a ____ occlusal outline
diamond shaped
the occlusal table on the mandibular first premolar is ____
triangular
Outline Shape of Mandibular Premolars From the Occlusal View: the mandibular second premolar has ____ outline (on 2 cusped type)
almost rounded
3 cusped type has more ___ outline ; may actually taper narrower from ___ to ____
square; lingual; buccal
occlusal tables are ____ on mandibular second premolars
square
Ridges, Fossae, and Grooves of Mandibular First Premolars From the Occlusal View: prominent ____ may separate ____ and ____ fossae (with no central groove)
transverse ridge; mesial; distal
Ridges, Fossae, and Grooves of Mandibular First Premolars From the Occlusal View: mesial and distal _____ fossae resemble ____
circular; “snake eyes”
Ridges, Fossae, and Grooves of Mandibular First Premolars From the Occlusal View: the ____ fossa is larger than the ____
distal; mesial
Ridges, Fossae, and Grooves of Mandibular First Premolars From the Occlusal View: _____ extends from _____
mesiolingual groove; mesial circular fossa
Ridges, Fossae, and Grooves of the Two-Cusp Mandibular Second Premolars From the Occlusal View: ____ connects mesial and distal fossae
central groove
Ridges, Fossae, and Grooves of the Two-Cusp Mandibular Second Premolars From the Occlusal View: groove pattern may be ___ or ___ shaped
H; U
Ridges, Fossae, and Grooves of the Two-Cusp Mandibular Second Premolars From the Occlusal View: ___ and ____ triangular ridges form ____
buccal; lingual; transverse ridge
Ridges, Fossae, and Grooves of the Three-Cusp Mandibular Second Premolar: there are ____ triangular ridges that do not connect, so there is no ____
three; transverse ridge
Ridges, Fossae, and Grooves of the Three-Cusp Mandibular Second Premolar: only premolar with a _____
central fossa
Ridges, Fossae, and Grooves of the Three-Cusp Mandibular Second Premolar: central groove may be called mesial and distal grooves, joining at _____
central fossa
Ridges, Fossae, and Grooves of the Three-Cusp Mandibular Second Premolar: lingual groove forms ____ pattern
Y
\_\_\_\_\_ are not common on mandibular premolars (although the mandibular first premolar often has a \_\_\_\_\_\_, which separates the mesial marginal ridge from mesial cusp ridge of lingual cusp)
marginal ridge grooves; mesiolingual groove