Molars (complete) Flashcards
in the universal numbering system, what numbers are the molars
1,2,3 - 14, 15, 16 - 17, 18, 19 - 30, 31, 32
On the 1st and 2nd molars (maxillary and mandibular) how many cusps does each typically have?
Max 1st - 4 (5 if you have the cusp of carabelli)
Max 2nd - 4
Man 1st - 5
Man 2nd - 4
On the 1st and 2nd molars (maxillary and mandibular) how many lobes does each typically have
Max 1st - 4 (5 if you have the cusp of carabelli)
Max 2nd - 4 (or 3)
Man 1st - 5
Man 2nd - 4
what are the functions of molars
- Grinding mastication (grinding)
- Maintain of vertical dimension of face
- supports cheeks (esthetics)
- keep tongue confined in the arch
What happens to someones vertical dimension if they don’t have teeth
they have a decreased vertical dimension
in other words their chin can move a lot closer to their nose than normal
what are problems associated with loss of vertical dimension
muscle and joint pain
accelerated wear in TMJ cartilage and bone
less asthetics
In all molars, how does the mesiodistal dimension compare to the occlusocervical
the mesiodistal dimension is greater than the occlusocervical dimension
which type of teeth are the shortest occlusocervically
the Molars
How does the size of molars compare to all other teeth
they are generally larger than all other teeth (but they are the shortest)
on all molars, how do the distal cusps compare to the mesial cusps
distal cusps are shorter than the mesial cusps
(from a buccal, or lingual view) from mesial to distal, what is the taper like on all molars
all molars have a mesial to distal taper (because of the relative size of the mesial and distal cusps)
What is the taper like for the crowns of all molars from the occlusal view (buccal-lingually)
All molars have a buccal to lingual taper, (buccal is wider than lingual)
EXCEPT the maxillary first molar
What is the taper like for the crown of all molars from the occlusal view (mesial to distal)
All molars have a mesial to distal taper (mesial is wider than distal)
Which of the molars has a lingual to buccal taper, as opposed to the others that have a buccal to lingual taper
the 1st maxillary molar
Where is the buccal height of contour on molars
in the cervical third (all teeth)
Where is the lingual height of contour on molars
in the middle third (posterior teeth)
Where is the mesial contact located on molars
in the middle third (close to the middle/occlusal junction)
Where is the distal contact located on molars
in the middle third (slightly more cervical than the mesial contact)
how does the buccolingual dimension compare to the mesiodistal dimension in molars
Maxillary molars have a buccolingual dimension that is greater than the mesiodistal dimension
Mandibular molars have a mesiodistal dimension that is much greater than the buccolingual dimension
in maxillary molars, what happens to the distolingual cusp as you move from the 1st to the 3rd molar
the distolingual cusp gets smaller and smaller as you move from 1st to 2nd to 3rd maxillary molars
Which type of molars usually have 2 roots
all of the mandibular molars (not the maxillary)
What are the names of the three roots of maxillary molars
mesiobuccal root
distobuccal root
lingual (palatal) root
What happens to the roots of the molars as you move from 1st to 2nd to 3rd molars
they become closer together (sometimes they even fuse)
how many cusps does a mandibular 1st molar usually have
5
3 buccal cusps
2 lingual cusps
What are the names of the 5 cusps of mandibular 1st molars
distal distobuccal mesiobuccal mesiolingual distolingual
which teeth are shorter, the maxillary or the mandibular molars
mandibular
Which molars, Max or Man, have two roots
mandibular molars
what are the names of the two roots of mandibular molars
mesial and distal roots
When do the molars begin calcification
Max 1 - Birth Man 1 - Birth Max 2 - 3 years Man 2 - 3 years Max 3 - 9 years Man 3 - 9 years
When are the crowns of molars completed
Max 1 - 3 years Man 1 - 3 years Max 2 - 7.5 years Man 2 - 7.5 years Max 3 - 14 years Man 3 - 14 years
When do the molars erupt
Max 1 - 6 years Man 1 - 6 years Max 2 - 12.5 years Man 2 - 12 years Max 3 - 19 years Man 3 - 19 years
When do the roots of molars become complete
Max 1 - 9 years Man 1 - 9 years Max 2 - 15 years Man 2 - 14.5 years Max 3 - 21.5 years Man 3 - 21.5 years
Where in the order of eruption for its arch do molars fall
1st is 1st
2nd is 7th
3rd is 8th
where in the overall order of eruption do the molars fall
Max 1 - 2nd Man 1 - 1st Max 2 - 14th Man 2 - 13th Max 3 - 16th Man 3 - 15th
from which view of the mandibular first molar can you see all of the cups
from the buccal view (because the lingual cusps are taller)
on the first max molar, how does the mesio and distobuccal cusps compare
the mesiobuccal cusp is wider
What kind of angle is formed on the mesiobuccal cusp (by the cusp ridges as the meet at the cusp tip) of maxillary first molars
it is an obtuse angle
what kind of angle is formed on the distobuccal cusp (by the cusp ridges as the meet at the cusp tip) of the maxillary first molars
it is an acute angle
What is the buccal groove like on the maxillary first molars
it runs parallel to the long axis of the distobuccal root
and it extends to a point near the center of the crown
What is the cervical line like on the maxillary first molar
very slightly curved
From the buccal view are all three roots on maxillary molars visible
yes
Do roots on maxillary molars converge apically? or do they diverge apically
they converge
in which direction are the roots of maxillary molars inclined toward
they are inclined toward the distal
Which ways do the three roots of maxillary molars typically curve
Mesiobuccal root curves distally at the middle third
Distobuccal root is straight or curves mesial at the middle third
Lingual/palatal root is straight
List the three roots of maxillary molars from longest to shortest
Lingual/palatal is longest
Mesiobuccal
Distobuccal is shortest
What is the root trunk?
the portion of the root from the cervical line to the point of furcation
What do you call the furcation, or the place where the root splits into multiple roots, on a maxillary molar
a trifurcation (because it splits into three roots, it is a bifurcation when it splits into two roots)
Is there a concave area on the buccal side of the root that extends from the trifurcation point to the cervical line on maxillary molars
yes. But on the buccal side it doesn’t extend up onto the crown, like it does on the lingual side
What are the lingual cusps like on maxillary first molars
the mesiolingual cusp is very wide, and the cusp ridges meet at an obtuse angle
the distolingual cusp is very rounded
at what angle does the mesiolingual mesial cusp ridge meet the mesial crown outline on the maxillary first molar
at a right angle
on which tooth do you often see carabellis cusp
the maxillary first molar
what is carabellis cusp
it is a little tiny cusp on the lingual aspect of the mesiolingual cusp
how do the cusp tips on carabellis cusp compare to the cusp tips on the mesiolingual cusp
they are parallel to them
Where is the lingual groove mesiodistally located
right in the middle of the lingual surface of the crown
the lingual groove of the maxillary first molar begins as an extension of _____. and often ends with a ______
the distal oblique ridge (groove?)
Pit
all three roots of the maxillary first molar are visible from three of the four views, which view aren’t all three visible from
They aren’t all three visible from the mesial view, because the mesiobuccal root is wider and taller than the distobuccal root
what does the apex of the palatal root line up with
the occlusal end of the lingual groove (where it is between the mesiolingual and distolingual cusps)
there is a shallow developmental depression on the lingual side of the maxillary first molar. It goes from where to where
it goes from the middle third of the lingual side of the of the lingual(palatal) root, and it crosses the cervical line onto the crown
From which proximal view is little or none of the occlusal surface visible on the maxillary 1st molars. and why?
from the mesial view you can’t see the occlusal surface, or at least not much of it. This is because the mesial cusps are taller than the distal cusps, and the mesial marginal ridge is taller than the distal marginal ridge
how does the mesial marginal ridge on the maxillary first molar compare the distal marginal ridge on the maxillary first molar
the mesial marginal ridge is taller
from the mesial view, what outline helps you see the fifth (carabellis) cusp
the lingual outline, you will see an indentation 2mm cervical to the cusp tip
why is the mesiobuccal root wider than the distobuccal root
because the mesiobuccal root often has a second canal space
what is the second canal space in the mesiobuccal root called
MB2 (mesiobuccal #2)
how does the mesial root trunk compare to the buccal root trunk
it is shorter on the mesial aspect
what is the depression on the mesial surface of the maxillary first molar like
it goes from the trifurcation point up across the CEJ onto the crown
from the mesial view, what does the mesiobuccal root look like
it takes up almost two thirds of the width of the tooth,
it has a depression that runs its entire length.
Its root tip lines up with the mesiobuccal cusp tip
on the maxillary first molar which root is the longest
the lingual (palatal)
What is the shape of the lingual (palatal) root on the maxillary first molar from the mesial view
it is banana shaped (lingual outline is convex, the buccal outline is concave)
From the distal view of the maxillary first molar, can you see the occlusal surface
yes, because the distal marginal ridge is shorter than the mesial marginal ridge
from the distal view of the maxillary first molar, can you see the buccal surface of the crown
yes, because the tooth is wider buccolingually on the mesial side of the tooth than on the lingual side.
What does the cervical line on the distal side of the maxillary first molar look like
it is nearly straight
from the distal view of the maxillary first molar, how many roots can you see
all three of them (because the mesiobuccal is wider and taller)
Where is the distal contact of the maxillary first molar located
it is centered, both cervicocclusally and buccolingually
what does the root depression on the distobuccal root like on the maxillary first molar
it is on most of the root and extends over the CEJ onto the crown
What is the shape of the occlusal surface of the 1st maxillary molar
Rhomboid
Which angles of the rhomboid are acute for the maxillary first molar
the mesiobuccal and distolingual
Which angle of the rhomboid are obtuse for the maxillary first molar
the mesiolingual and distobuccal
list the 5 cusps of the maxillary first molar from largest to smallest
mesiolingual mesiobuccal distobuccal distolingual cusp of carabelli
Which cusps of the maxillary first molar make up the primary cusp triangle (or trigon)
mesiolingual
mesiobuccal
distobuccal
which two teeth can have a lingual to buccal taper
the maxillary first molar
the mandibular 2nd premolar (3 cusp type)
What makes up an oblique ridge
the disal cusp ridge of the mesiolingual cusp and the triangular ridge of the distobuccal cusp. of maxillary molars
how does the height of the oblique ridge compare to the height of the marginal ridges of maxillary molars
they are all on the same level
On which teeth can you have an oblique ridge
the maxillary molars only
when restoring a cavity on the occlusal surface of the maxillary molars, what structure that isn’t a cusp do we really try to preserve
the oblique ridge
What are the major fossa of the maxillary first molar
central and distal fossa
where is the distal fossa of the maxillary first molar
the fossa just distal to the oblique ridge
what are the minor fossa of the maxillary first molar
the mesial and distal triangular fossa (down from the mesial and distal marginal ridges)
What are the seven grooves of the maxillary first molar
- central groove
- buccal groove
- buccal groove of the central fossa
- transverse groove of the oblique ridge
- distal occlusal groove (oblique)
- lingual groove
- fifth cusp groove
What are mulberry molars
caused by congenital syphilis
short molars covered with rounded enamel growths
what is taurodontism
enlarged root trunks
Which cusps of maxillary molars are the functional cusps
the lingual cusps
which cusps of the maxillary molars are the non functional cusps
the buccal cusps
Where are the points of occlusion for the maxillary first molar
centric cusps = mesiolingual and distolingual
centric stops = Central fossa and mesial marginal ridge
What are the universal numbers for maxillary second molars
2 and 15
how does the occlusocervical dimension of maxillary second molars compare to that of maxillary first molars
maxillary second molars are shorter
How do the roots of maxillary second molars compare to the roots of the maxillary first molars
they are about the same length, but the maxillary second molars’ roots usually are more distally inclined and they are less diverged (closer together)
Which has a longer root trunk, the maxillary first molar or the maxillary second molar
the maxillary second molar
how does the mesial root depression on the maxillary second molar compare to the mesial root depression of the maxillary first molar
it is confined to the root surface and doesn’t extend onto the crown like the mesial root depression on the maxillary first molar does
how does the occlusal size of the maxillary second molar compare to the occlusal size of the maxillary first molar
they are about the same size buccolingually, but the maxillary second molar is smaller mesiodistally than the maxillary first molar
how does the number of cusps compare between the maxillary first and second molars
the second molar will only have four, where as the maxillary first can have 5
how does the supplemental anatomy of the maxillary second molar compare to the supplemental anatomy of the maxillary first molar
the maxillary second molar has more supplemental anatomy
What are the two shapes that can be used to describe the occlusal surface of the maxillary second molar
rhomboid or heart shaped
what determines whether the shape of the occlusal surface of the maxillary second molar is rhomboid or heart shaped
the size of the distolingual cusp.
if it is large then it will be rhomboid shaped
if it is small then it will be heart shaped
name the four cusps of the maxillary second molar from smallest to largest
distolingual (smallest)
distobuccal
mesiobuccal
mesiolingual (largest)
on the maxillary second molar, which cusps make up the primary triangle (trigon)
mesiolingual
Mesiobuccal
distobuccal
On the maxillary second molar which cusps are the centric cusps (functional)
mesiolingual
distolingual
(same as the max. 1st molar)
on the maxillary second molar, where are the centric stops
the mesial marginal ridge (MMR)
the central fossa
(same as the max first molar)
what occludes with the MMR of the max first molar
mesiobuccal cusp of the mandibular first molar
what occludes with the central fosssa of the max first molar
distobuccal cusp of the mandibular first molar
what occludes with the MMR of the max second molar
the mesiobuccal cusp of the man 2nd molar
what occludes with the central fossa of the max second molar
distobuccal cusp of the mandibular 2nd molar
Which tooth is the most likely to never form
maxillary third molar
which of the maxillary molars is the most variable
the third molar
how does the size of the max third molar compare to the other max molars
smaller in all dimensions
which of the max molars has the most supplemental grooves
the third
what can be the shapes of the occlusal surface of the max third molar
heart or rhomboid
what are the cusps of the max third molar
mesiolingual
mesiobuccal
distobuccal
distolingual (small, sometimes even missing)
how do the roots of the max third molars compare to the roots of the other two max molars
shorter closer together (often fused) more distally inclined
is it common that the roots of the max third molar are long, and the crown is short
yes, that is common
how many canals does the max first molar usually have
it has four canals slightly more often than it has three
if there are only three roots in the max first molar, where does the common fourth canal form
in the mesiobuccal root
how many pulp horns does the max first molar have
4 (one per major cusp)
how many canals does the max second molar usually have
3 and 4 are about equally common
where does the common fourth canal of the max second molar usually form
the mesiobuccal root
what are the universal numbers of the man 1st molar
30 and 19
from what view can you see all five cusps of the man 1st molar. Why?
from the buccal, because the lingual (non-functional) cusps are taller than the buccal cusps
how do the buccal cusps compare to the lingual cusps of the man 1st molar
they are shorter and more rounded, the lingual cusps are taller and more pointed
how do the three buccal cusps of a man 1st molar compare
the mesiobuccal cusp is the widest and the least round
the distobuccal cusp is almost as wide but more rounded than the mesiobuccal cusp
the distal cusp is the most narrow and most pointed
how many developmental grooves are there on the buccal surface of mandibular 1st molars
2
what are the two developmental grooves on the buccal surface of the man 1st molar
the mesiobuccal groove
the distobuccal groove
which is longer, the mesiobuccal groove or the distobuccal groove of the man 1st molar
the distobuccal groove is longer
where does the mesiobuccal groove of man 1st molars begin and end
it begins between the mesiobuccal and distobuccal cusps and ends in the middle third of the crown in a depression or pit (buccal pit)
how is the pit of the mesiobuccal groove clinically significant
it often needs to be restored
where does the distobuccal groove of the man 1st molar begin and end
it begins between the distobuccal and distal cusps, and ends just distal to the cervical ridge
which of the two buccal grooves on the man 1st molar typically ends in the buccal pit
the mesiobuccal groove
what feature of the mandibular molars is similar to the buccal bulge of primary molars
the cervical ridge (it is a horizontal ridge at the gingival third of the buccal surface of the crown of the man 1st molar)
how does the root trunk of the mandibular 1st molar compare to the root trunk of the maxillary molars
it is shorter
is there a depression on the buccal surface of the root of mandibular 1st molars
yes, it begins deep at the bifurcation point, then becomes more shallow as it approaches the CEJ
Where are the two roots of the mandibular molars positioned
Mesiodistally or buccolingually
mesiodistally
how do the roots of the mandibular first molar usually compare to the roots of the other two mandibular molars
they are usually longer and more divergent on the man 1st molar than the other two
on the man 1st molar how do the mesial and distal roots compare to each other
the mesial root is a little longer, more curved than the distal root and less pointed
the distal root is usually shorter, less curved, and more pointed
How many cusps can you see from the lingual view of the man 1st molar
three
which cusps can you see from the lingual view of the man 1st molar
mesiolingual cusp
distolingual cusp
distobuccal cusp
how does the mesiolingual cusp compare to the distolingual cusp of the man 1st molar
the mesiolingual cusp is taller and wider than the distolingual cusp
how does the anatomical crown length of the lingual surface of the man 1st molar compare to the anatomical crown length of the buccal surface
they are the same size
how are the anatomical crown lengths of the buccal and lingual surfaces the same length if the lingual crowns are taller
the cervical line is more occlusally located on the lingual surface of the tooth than it is on the buccal surface
how does the root trunk of the lingual side of the man 1st molar compare to the root trunk of the buccal side
the root trunk on the lingual side is longer (because the cervical line is more occlusal)
how does the length of the roots on the lingual side compare to the length of the roots measured on the buccal side
the roots on the lingual side measure longer because of the more occlusal cervical line
what is the anatomical crown
the amount of tooth covered by enamel
what is the clinical crown
the amount of tooth exposed occlusal to the gingiva
what is the anatomical root
the area of the tooth covered with cementum
what is the clinical root
the amount of tooth embedded in the alveolar bone
where is the greatest curvature on the buccal side of the tooth from the mesial view
it is in the cervical third, That bump is the cervical ridge
how does the height of the crest of contour of the mandibular molars compare to the height of the crest of contour of maxillary molars
it is still in the cervical third, but it is more occlusal on the mandibular molars
from the mesial view of the mandibular 1st molar, how many cusps are visible
2, the mesiolingual and mesiobuccal
how many roots can you see on the man 1st molar from the mesial view
- because the mesial root is longer and broader than the distal root
does the mesial root of man 1st molars usually have a depression on it
yes, it usually has two, one on the mesial surface and one on the distal surface
How many canals does the mesial root of the man 1st molar usually have
2
which of the molars have a lingual tilt of their crown
the mandibular molars
do the mandibular molars have a lingual tilt of their crown
yes
when working on mandibular molars, should you hold your bur parallel to the long axis of the tooth
no, you should hold it to the long axis of the crown
on what surface of the tooth is the distal cusp of the man 1st molar
it is considered as being on both the distal and buccal surfaces (occlusal as well)
from the distal view of the man 1st molar, how many roots can you see
- because the distal root is shorter and thinner than the mesial root
does the distal root of the man 1st molar usually have longitudinal depressions. compare them to those on the mesial root
yes, but they aren’t as prominent as those on the mesial root
how many canals does the distal root of the man 1st molar usually have
1 (but it may have two)
this one will be wide buccolingually
what is the occlusal crown outline shape for man 1st molars
hexagonal
does the crown of the man 1st molar converge or diverge from the mesial to the distal
it converges from the mesial to the distal
how does the buccolingual dimension on the mesial end of the man 1st molar compare to the buccolingual dimension on the distal end
it is greater at the mesial end
does the occlusal crown surface of the man 1st molar converge or diverge from buccal to lingual
it converges from buccal to lingual
Name the 5 cusps from largest to smallest on the man 1st molar
mesiobuccal cusp
mesiolingual cusp = distolingual cusp
distobuccal cusp
distal cusp
How many developmental grooves are there on the man 1st molar. what are they named
4 central groove mesiobuccal groove distobuccal groove lingual groove
what are the different letters compared to the groove patterns of the man 1st molar
W, M, and Y
W and M demonstrate the wandering central groove
Y demonstrates the lingual groove and the mesio and distobuccal grooves
does the man 1st molar have a transverse ridge?
no, although all cusps have a triangular ridge, none of them meet
How many major fossa does the man 1st molar have
1 (central fossa)
how many minor fossa does the man 1st molar have
2 (mesial and distal triangular fossa)
how many canals does the man 1st molar usually have
3 (2 in the mesial root)
what is the shape assigned to the two roots of the man 1st molar (when sliced transversely)
mesial = dumbell shaped (two canals, with two depressions) distal = oval shaped (one wide canal)
What are the universal numbers of the man 2nd molars
18 and 31
how does the crown of the man 2nd molar compare to the crown of the man 1st molar (size wise)
it is narrow mesiodistally and shorter occluscervically
From the buccal view how many cusps will you see on the man 2nd molar
all 4 cusps
how many cusps does the man 2nd molar have
4
why from the buccal view can you see the 4 cusps of the man 2nd molar
because the buccal (functional) cusps are shorter than the lingual cusps
how doe the buccal cusps of the man 2nd molar compare to the lingual cusps
they are shorter and more rounded
how many buccal grooves are there on the man 2nd molar? how does that compare to the man 1st molar
there is one on the man 2nd molar, there are 2 on the man 1st molar
does the single buccal groove of the man 2nd molar usually end in a pit
yes
how do the roots of the man 2nd molar copare to those of the man 1st molar
they are closer together, more parallel, and more distally inclined
how does the buccolingual width of the man 2ndmolars mesial root compare to that of the man 1st molars mesial root
it is more narrow buccolingually, and may have a curved tip
how does the occlusal size of the man 2nd molar crown compare to the occlusal size of the man 1st molar’s crown
it is smaller in all dimensions
what is the shape assigned to the mandibular 2nd molars occlusal surface
rectangular
does the man 2nd molars crown taper toward the distal (converge toward the distal)
yes, (even though it is said to be a rectangular shape)
what about the mandibular 2nd molar makes the tooth converge toward the distal
the mesiobuccal prominence on the mesiobuccal line angle
name the four cusps of the man 2nd molar from largest to smallest
they are all about the same size mesiolingual mesiobuccal distolingual distobuccal
what is the shape of the developmental grooves of the man 2nd molar
it is a + shape
What are the grooves of the man 2nd molar
central groove
buccal groove
lingual groove
which of the grooves on the man 2nd molar often ends in a pit
the buccal groove
how many pits does the man 2nd molar have
3
mesial (mesial end of central groove)
central (where buccal, lingual, and central grooves meet)
distal (distal end of central groove)
how many fossa does the man 2nd molar have
3
central
mesial triangular
distal triangular
does the man 2nd molar have a transverse ridge
yes, in fact it usually has two (one mesial, one distal)
how many canals does the man 2nd molar usually have
3
what are the universal numbers for the man 3rd molars
17 and 32
what is the crown of the man 3rd molar like
outline varies a lot
more rounded
resembles man 2nd molar, but can have 5 cusps
what are the roots of the man 3rd molar like
shorter than the other two man molar roots
often fused
often these teeth remain impacted and need to be surgically removed
