Premolars Flashcards
Premolars are also called
bicusbids
From the buccal view premolars are roughly ____ shaped. (true for all premolars)
pentagon
What is present from the tip of the buccal cusp down to cervical line?
Buccal ridges
Premolars usually have two cusps, which are …
one buccal and one lingual
Which premolar often has 2 lingual cusps?
mandibular second premolar
The buccal cusp tip is ____ to the midroot axis.
mesial
Exception: in which premolar is the cusp tip distal to the mesial axis?
maxillary first premolar
In premolars the mesial cusp ridge of the buccal cusp is ____ than the distal cusp ridge.
shorter
Exception: In which premolar is the mesial cusp ridge of the buccal cusp longer than the distal cusp ridge?
Maxillary first premolar
(True for all premolars) the mesial cusp ridge of the lingual cusp is ___ than the distal cusp ridge.
shorter
(True for all premolars) adjacent marginal ridges tend to be the same height and form _____.
occlusal embrasures
(True for all premolars) Triangular ridges from the buccal and lingual cusps meet slightly ___ to the midpoint of the occlusal surface.
lingual
(True for all premolars) The ____ triangular ridge is slightly larger.
Buccal
(True for all premolars) The ___ separates the two triangular ridges.
Central Groove
(True for all premolars) Mesial proximal contacts are near the junction of what two thirds?
Junction of the occlusal and middle thirds.
Distal proximal contacts are slightly more _____ in the middle third, than the mesial proximal contact.
cervical
Exception: on what premolar may the mesial contact be more cervical than the distal contact?
Mandibular first premolar
(True for all premolars) Proximal contacts are _____ to the center buccolingually.
buccal
Mesial marginal ridges are more _____ than distal marginal ridges.
occlusal
Exception: In which premolar may the distal marginal ridge be more occlusal than the medial marginal ridge?
Mandibular first premolar
(True for all premolars) Cusp ridges and marginal ridges for the boundary of what surface?
Occlusal surface
(True for all premolars) Cervical lines curve ____ on the buccal and lingual surfaces.
apically
(True for all premolars) Cervical lines curve ____ on the proximal surfaces.
occlusally
(True for all premolars) Mesial cervical line is ____ than the distal cervical line.
more convex
(True for all premolars) Apical third of roots bend ____ more often than _____.
distally more often than mesially
(True for all premolars) Lingual cusp is _____ than buccal cusp; more noticeable on first premolars.
shorter
Are the maxillary 1st & 2nd or the mandibular 1st & 2nd premolars more similar?
maxillary
Which maxillary premolar is larger?
maxillary first premolar
Which mandibular premolar is larger?
mandibular second premolar
On maxillary premolars lingual cusps are shorter BUT the the 2nd premolar cusps are almost …
equal in length
Mandibular premolars lingual cusps are relatively much shorter than buccal cusps, especially on the _____ premolar.
first
Both maxillary premolars have 1 prominent _____ cusp.
lingual
What premolar may have more than 1 lingual cusp?
mandibular second premolar
The medial cusp ridge of ____ is the shortest.
the lingual cusp
Lingual cusp tips are offset to the ____
mesial
____ premolar crowns are more in line with the root axis.
maxillary
____ premolars crowns tilt to the lingual.
Mandibular
Maxillary premolars crowns are wider ____
buccolingually
______ premolars crowns are about the same buccolingually as mesiodistally.
mandibular
Triangular ridges on _______ premolars have a steeper slope towards the central groove than any other tooth.
Maxillary
Buccal ridge is more prominent in _____
maxillary premolars
Buccal cusp tip is located more to the ____ in the maxillary first premolar. (only premolar with buccal cusp offset to the _____)
distal
Both buccal and lingual cusp tips are located slightly to the mesial on this premolar
Maxillary 2nd premolar
Mesial cusp ridge of the buccal cusp is longer than the distal cusp ridge; only tooth with a longer mesial cusp ridge than distal.
Maxillary 1st premolar
Mesial cusp ridge of buccal cusp is shorter than the distal cusp ridge.
Maxillary 2nd premolar
In what maxillary premolar is the crown wider and longer, and the buccal cusp more pointed?
maxillary 1st premolar
_____ cusp is rounded and blunt for both maxillary premolars.
lingual
____ cusp is pointed for both maxillary premolars
buccal
Maxillary 1st premolar almost always has what distinguishing trait?
mesial marginal ridge groove
The maxillary 1st premolar is the only premolar with ….
mesial crown concavity (development depression)
In which maxillary premolar is the central groove from mesial to distal pit 1/3 or less in length compared to the other?
Maxillary 2nd premolar
In which maxillary premolar is the mesial and distal pits closer to the marginal ridges; marginal ridges are thin?
maxillary 1st premolar
In which maxillary premolar are the marginal ridges relatively wide/thick M-D?
maxillary 2nd premolar
May have several supplemental grooves giving the occlusal surface a “wrinkled” look.
maxillary 2nd premolar
Occlusal outline is very angular on the buccal.
maxillary 1st premolar
Occlusal table is more rounded.
maxillary 2nd premolar
Buccal line angles are the sharpest in the entire mouth.
Maxillary 1st premolar
MAxillary 1st premolar crown has definite tape ( ______) to lingual.
convergence
Only premolar with divided (bifurcated) root and at least 2 canals
Maxillary 1st premolar
May have 2 cusps or 3 cusps.
mandibular 2nd premolar
On the mandibular 1st premolar, mesial half resembles canine, distal half resembles premolar; this is called?
transition form
When there are 3 cusps, there is no ____
transverse ridge
Premolar most likely to be congenitally missing?
Mandibular 2nd premolar
Buccal cusp tip is over center of the root.
Mandibular 1st premolar
Mandibular 2nd premolar, buccal cusp tip is slightly ____
mesial
Mandibular 1st premolar mesial contact may be more _____ than distal contact.
cervical
Mandibular 2nd premolar mesial contact is more _____ than distal (general rue for most teeth)
occlusal
Lingual cusp is very small and non-functional
Mandibular 1st premolar
Mandibular 2nd premolar lingual cusp is positioned to the ____ when there is 1 lingual cusp
mesial
Mesiolingual groove separates mesial marginal ridge from the lingual cusp; only tooth with a mesiolingual groove.
mandibular 1st premolar
Entire buccal profile is visible from the lingual.
mandibular 1st premolar
The mesial marginal ridge slopes servilely toward the lingual (45 degrees)
mandibular 1st premolar
Mesial marginal ridge is more horizontal
mandibular 2nd premolar
Central groove is offset to the lingual
true for both mandibular premolars