Premolars (complete) Flashcards
When are the eruption dates of the 4 kinds of premolars
Maxillary 1st - 10 years
Maxillary 2nd - 10.5 years
Mandibular 1st - 11 Years
Mandibular 2nd - 11.5 years
What are the universal numbers of the maxillary 1st premolars
5,12
What are the universal numbers of the maxillary 2nd premolars
4,13
What are the universal numbers of the mandibular 1st premolars
21,28
What are the universal numbers of the mandibular 2nd premolars
20,29
When do the 4 premolar types begin calcification
all of them at 2 years
When do the crowns of the 4 premolar types become completed
Maxillary 1st - 5.5 years
Maxillary 2nd - 6.5 years
Mandibular 1st - 5.5 years
Mandibular 2nd - 6.5 years
When do the roots of the 4 premolar types become completed
Maxillary 1st - 12.5 years
Maxillary 2nd - 13 years
Mandibular 1st - 12.5 years
Mandibular 2nd - 13 years
What is the eruption pattern of the primary teeth
- Central incisors
- lateral incisors
- 4 First molars
- Canines
- 4 second molars
What is the eruption pattern of mandibular permanent teeth (according to the palmer numbering system)
(6-1) –> 2 –> 3 –> 4 –> 5 –> 7 –> 8
(6-1) –> 2 –> 4 –> 3 –> 5 –> 7 –> 8
What is the eruption pattern of maxillary permanent teeth (according to the palmer numbering system)
6 –> 1 –> 2 –> 4 –> 3 –> 5 –> 7 –> 8
6 –> 1 –> 2 –> 4 –> 5 –> 3 –> 7 –> 8
Which permanent teeth begin calcification at birth
1st molars
how does the faciolingual aspect compare to the mesiodistal aspect of ALL premolars
The faciolingual aspect of ALL PREMOLARS is greater than the mesiodistal aspect
How does the size proximal contacts of premolars compare to the size of proximal contacts anterior teeth
they have broader contact areas than the anterior teeth
How does the cervical line of the premolars compare to the cervical lines of anterior teeth
the cervical line is much flatter on the premolars than the anterior teeth
What is the shape of the premolars from the facial view, not including cusp tips?
trapezoidal
For all 4 of the different types of premolars, what are the relative length of buccal cusp ridges (are mesial cusp ridges or distal cusp ridges longer)
Maxillary 1st - MESIAL CUSP RIDGE IS LONGER
Maxillary 2nd - distal cusp ridge is longer
Mandibular 1st - distal cusp ridge is longer
Mandibular 2nd - distal cusp ridge is longer
Which premolar has a mesial cusp ridge of the buccal cusp that is longer than the distal cusp ridge of the buccal cusp
The maxillary first premolar
Where is the buccal cusp tip of the maxillary first premolar located relative to the long axis of the root
it is located slightly to the distal. (this is because it has a longer mesial cusp ridge than its distal cusp ridge)
What is the only permanent tooth with the mesial cusp ridge being longer than the distal cusp ridge
the maxillary 1st premolar
What are the buccal cusp tips like on the 4 different premolars
Maxillary 1st - relatively pointed
Maxillary 2nd - less pointed/more rounded
Mandibular 1st - relatively pointed
Mandibular 2nd - less angulation/less pointed
Which of the 4 premolars is relatively symmetrical from the buccal view
mandibular first premolar
What are the developmental depressions and buccal ridges like on the 4 types of premolars
Maxillary 1st - prominent and noticeable
Maxillary 2nd - less defined
Mandibular 1st - not as prominent and noticeable as the max 1st but more than the others
Mandibular 2nd - less defined
Where are the mesial and distal proximal contacts located on the 4 types of premolars
Maxillary 1st - Both in the middle third, mesial is more cervical
Maxillary 2nd - both in the middle third, both at the same height
Mandibular 1st - both in middle third
Mandibular 2nd - both in the middle third
Which of the 4 premolar types has a concavity when looking at it from the facial view on the mesial outline of the crown between the medial contact area and the cervical line
the maxillary 1st
What other tooth besides the maxillary first premolar has a concavity on the mesial side, near its cervical line
maxillary canines
Which of the 4 types of premolars usually has a bifurcated root
the maxillary 1st
Which root of the maxillary 1st premolar is usually wider
the facial root
Which of the 4 premolars has an occlusal table that slants vertically
the mandibular first
How do the lingual and buccal cusps of the 4 types of premolars compare to each other (lingual and buccal cusps of the same tooth)
Maxillary 1st - lingual is shorter and more narrow, and THE CUSP TIPS ARE ON OPPOSITE SIDES of the root
Maxillary 2nd - lingual is slightly SMALLER, but CLOSE TO THE SAME SIZE, and they are aligned on the long axis so the cusp ridges are parallel
Mandibular 1st - lingual cusp is MUCH shorter, and both are aligned on the long axis of the tooth
Mandibular 2nd - can have one or two lingual cusps. will be shorter and smaller than the buccal cusps
which of the 4 premolar types can have two lingual cusps instead of just one lingual cusp
the mandibular 2nd
how to the two lingual cusps of the mandibular 2nd premolar compare to each other
the mesiolingual cusp is taller and wider than the distolingual cusp
Which of the 4 types of premolars has a lingual cusp that is almost like a cingulum
the mandibular 1st
Which of the 4 types of premolars from the proximal views have cusp tips that are located within the confines of the root trunk
the maxillary first
Which of the 4 types of premolars from the proximal views have a lingual cusp tip that is in line with the lingual root outline, and have a buccal cusp tip that is centered over the root
the mandibular 1st
Which of the 4 types of premolars from the proximal views have a buccal cusp tip that is facial to the long axis of the root
the mandibular 2nd
where are the cusp tips of the 4 types of premolars in comparison to their roots from the proximal view
Maxillary 1st - both the lingual and buccal cusp tips are within the confines of the root trunk
Maxillary 2nd - both the lingual and the buccal cusp tips are near being lined up with the lingual and buccal surfaces of the root
Mandibular 1st - the buccal cusp tip is centered over the root, and the lingual cusp tip is in line with the lingual surface of the root
Mandibular 2nd - the buccal cusp tip is facial to the long axis of the root, and the lingual cusp tip appears to be lingual to the lingual surface of the root
Where are the buccal and lingual heights of contour of the 4 types of premolars
All of the buccal heights of contour are in the cervical 1/3
All of the lingual heights of contour are in the middle 1/3
Which of the 4 types of premolars have the steepest triangular ridges
the maxillary 1st
Which of the 4 types of premolars has the mesiolingual groove
The mandibular 1st
From where to where does the mesiolingual groove on the madibular 1st premolar run
from the mesial fossa onto the mesiolingual surface of the crown
What are the slopes of the mesial marginal ridges like on each of the 4 premolar types
Maxillary 1st - almost perpendicular to the long axis of tooth
Maxillary 2nd - nearly horizontal
Mandibular 1st - 45 degrees
Mandibular 2nd - perpendicular, but higher than mandibular 1st
Which of the 4 types of premolars has the mesial marginal developmental groove
the maxillary 1st
From where to where does the mesial marginal developmental groove run on the maxillary 1st premolar
it crosses the marginal ridge and runs into the mesial developmental depression
Which of the 4 premolar types have a relatively deep developmental groove on the mesial side of the root that even crosses the cervical line onto the crown
the maxillary 1st premolar
What are the distal marginal ridges like on the 4 types of premolars
Maxillary 1st - nearly horizontal and it is more cervical than the mesial marginal ridge, and it has no groove running through it
Maxillary 2nd - horizontal, similar to the mesial marginal ridge
Mandibular 1st - nearly horizontal and more coronal than the mesial marginal ridge
Mandibular 2nd - more cervical than the mesial marginal ridge
On the first maxillary premolar where is the mesial proximal contact in relation to the mesial marginal groove
it is facial to the mesial marginal groove
on the first maxillary premolar where is the distal proximal contact in relation to the faciolingual long axis bisector
it is also facial
how do the mesial and distal proximal contacts compare on the maxillary 1st premolar
the distal proximal contact is positioned more occlusally, and is wider (it contacts wider teeth)
How can you tell the difference between the mesial and distal surfaces of the maxillary 1st premolar if you only look at the root
the mesial will have a profound developmental groove, and the distal will not have one that is very profound
How can you tell the difference between the ligual and buccal sides of the premolars if you only look at the root
the root on the lingual side will be thinner than the side of the root on the buccal side
What are the shapes of the occlusal tables of each of the 4 types of premolars
Maxillary 1st - hexagonal (sides aren’t equal sizes)
Maxillary 2nd - Rectangular
Mandibular 1st - triangular
Mandibular 2nd - not specified
What are the shapes of the crown outlines of each of the 4 types of premolars
Maxillary 1st - Not specified
Maxillary 2nd - Oval
Mandibular 1st - Diamond
Mandibular 2nd - Square (3 cusp), cirlce (2 cusp)
What is the approximate angle formed by the mesial cusp ridge of the buccal cusp and the mesial marginal ridge of the maxillary 1st premolar
nearly 90 degrees
What is the approximate angle formed by the distal cusp ridge of the buccal cusp and the distal marginal ridge of the maxillary first premolar
It is an acute angle (less than the angle on the mesial side)
Which of the 4 types of premolars have transverse ridges
Only the mandibular first premolar
occasionally the mandibular 2nd with two cusps can form one as well
How do the lengths of the triangular ridges of the mandibular first premolar compare
the facial triangular ridge is much longer than the lingual triangular ridge
Which of the 4 types of premolars has three distinct facial lobes and 2 depressions
the maxillary first premolar
Which of the 4 types of premolars have prominent “shoulder like” mesiofacial, and distofacial line angles
the maxillary first premolar
What are the mesial and distal crown contours like on the 4 types of premolars
they are all pretty convex, with the exception of the MESIAL crown contour of the Maxillary first premolar. This is shaped like a “3”
Which of the 4 types of premolars have a mesial crown contour that is in the shape of a “3”
the maxillary first premolar
the premolars of which arch tend to be more likely to have pits instead of fossa
the mandibular premolars are more likely to have pits than the maxillary premolars
Which of the premolars have a comma shaped distal fossa
the mandibular first premolar
What is specific and unique about the central grooves of each of the 4 types of premolars
Maxillary 1st - the central groove extends over the mesial marginal ridge as the mesial marginal developmental groove
Maxillary 2nd - there are many supplemental grooves coming off of the central groove giving its occlusal surface a wrinkled look, also it has a short central groove
Mandibular 1st - the central groove is located lingual to the faciolingual crown bisector
Mandibular 2nd - the central groove can be Y, H, or U shaped
Which of the 4 types of premolars have a crown that appears to be bent or slanted lingually on the root
the mandibular first premolar
what is the clinical significance of the mandibular first premolar having an occlusal table that is so slanted
you need to drill perpendicular to the occlusal table, not to the tooth as a whole. if you don’t, then you will more easily drill far and risk hitting the pulp chamber
Which of the 4 types of premolars usually has one root and two pulp canals
the maxillary 2nd premolar
Which of the 4 types of premolars is most likely to have q distal notch on the distal cusp ridge of the buccal cusp
the mandibular 2nd premolar
How do the lingual lobes of the first and second mandibular premolars compare
the second mandibular premolar has a more developped lingual lobes, making a larger lingual cusp, leading to a less angled occlusal table
Which of the premolars is capable of having three cusps instead of two
the mandibular 2nd
When the mandibular 2nd premolar has 3 cusps, how many lobes did it develop from
5
on the maxillary 2nd premolar which of the cusp tips is more pointed? the buccal or the lingual
the buccal (because it is a non functional cusp, typically the functional cusps are less pointed)
How does the mesial developmental groove on the root compare between the 1st and 2nd maxillary premolars
the 2nd premolar doesn’t have as defined of a developmental groove, and it doesn’t extend onto the root of the tooth like the one on the 1st mandibular premolar does
Which of the 4 types of premolars can have a lingual groove
only the mandibular 2nd premolar (when it is the 3 cusp variety)
What are embrasures
the negative space that surrounds contact points
What are the different kinds of embrasures
buccal/facial
lingual/palatal
occlusal
cervical
on the 4 types of premolars what are the roots like
Maxillary 1st - bifurcated, distinct and large mesial developmental depression, slight distal developmental depression
Maxillary 2nd - good sized mesial and distal developmental depression, but it doesn’t cross onto the crown,
Mandibular 1st - mesial has better developmental depressions than the distal
Mandibular 2nd - neither side has a very distinct developmental depression
Which has the longer root, the 1st or 2nd mandibular premolar
the 2nd mandibular premolar
from the distal view how can you tell between the 1st and 2nd mandibular premolar
the 2nd mandibular premolar has its distal marginal ridge that is more cervical than the mesial marginal ridge, so you can see the occlusal surface of the tooth.
Which is larger, the 1st or second maxillary premolar
the 1st maxillary premolar is larger, the 2nd is smaller
Which of the 4 types of premolars have relatively wide marginal ridges
the maxillary 2nd premolar
Which of the 4 types of premolars have mesial and distal fossae that are nearer to the center of the tooth
the maxillary 2nd premolar
Which of the maxillary premolars have a kidney shape, and which have an oval shape when looking at a cross section of the root
the maxillary 1st premolar has a kidney shape, the maxillary 2nd has an oval shape
What is the most common root, and canal number for the 4 types of premolars
Maxillary 1st - 2 canals, 2 roots
Maxillary 2nd - 1 and 2 canals almost equally common, 1 root
Mandibular 1st - 1 canal, 1 root
Mandibular 2nd - 1 canal, 1 root
Which is more common, the 3 cusp type or the 2 cusp type of mandibular 2nd premolars
the 3 cusp type
what shapes are the crown outlines of the 3 and 2 cusp mandibular 2nd molars
3 cusp is square shaped
2 cusp is oval shape
which of the 3 and 2 cusp mandibular 2nd molars can form transverse ridges
the 2 cusp type
what are the three shapes possible for the developmental grooves of the mandibular 2nd premolars
Y shaped
H shaped
U shaped
When do you see the Y shaped developmental grooves on mandibular 2nd premolars
always when you have the three cusp style
When do you see the H and U shaped developmental grooves on the mandibular 2nd premolars
when it is the 2 cusp style
where is the central pit located on the 3 cusp type mandibular 2nd premolar
slightly distal
how many fossae do you have on the 3 and 2 cusp type mandibular 2nd premolars
3 cusp type = 3 fossae
2 cusp type = 2 fossae
Which way does the 2 cusp type mandibular 2nd premolar diverge
from lingual to buccal
which way can the 3 cusp type mandibular 2nd premolar diverge
from buccal to lingual
how do the 3 cusps of the mandibular 2nd premolar line up
they don’t quite line up, the buccal is just slightly distal to the mesiolingual cusp, and it is mesial to the distolingual cusp
how do the 2 cusps of the mandibular 2nd premolar line up
they line up directly opposite
