Permanent Posterior Teeth Flashcards
one or more major elevations on the masticatory
surface of canines and posterior teeth
Cusp
linear elevation on the masticatory surface of
posterior teeth
Ridge
sloping planes located between cusp
ridges on posterior teeth
Inclined cuspal planes
similar to fissure but not as deep a cleft
Groove
small pointed depression in enamel, usually at the
junction of two or more developmental grooves
Pit
deep cleft; developmental line usually found on the
occlusal or buccal surface, usually from the imperfect fusion
of dental lobes
Fissure
primary groove that marks the
junction among the lobes on
the lingual of anterior and
occlusal in posterior
Developmental Groove
the most prominent developmental groove on posterior teeth which usually travels mesiodistally
Central Groove
secondary groove that is
shallower, more irregular and
moves out from developmental
groove
Supplemental Groove
ridge that descends from each
cusp tip on posterior teeth
Cusp Ridge
rounded raised borders on
on the mesial and distal portion of the
lingual surface of anterior and the
occlusal table of posterior teeth
Marginal Ridge
cusp ridges that descend
from the cusp tip toward the central
portion of the occlusal table
Triangular Ridge
ridge formed by the joining of two triangular ridges crossing the occlusal table from labial to lingual; should be roughly parallel to the marginal ridges
Transverse ridge
ridge that crosses the occlusal
table of maxillary 1st and 2nd molars
only; at a diagonal angle to distal
marginal ridge
Oblique ridge
• Wide occlusal surface for chewing and grinding
• Central grooves are prominent grooves that traverse
mesiodistally
• Supplemental grooves, pits, fossa and ridges appear in varying
degree on the surface
• Occlusal appears wrinkled, increases the more posterior you
go
• Buccal and lingual view, crown appears trapezoidal (four sided)
• Contact area is much wider than anterior teeth
• Roots of molars are closer together as you go posterior.
• The more posterior a tooth, the more variation in anatomy. • CEJ is quite straight unlike the anterior teeth.
• More occlusal surface is visible from distal aspect!!!!!!
• Usually distal and lingual convergence.
General Characteristics of posterior dentition
For posterior teeth is more occlusal surface visible from the distal or mesial aspect
DISTAL
Usually posterior dentition will have mesial or distal lingual convergence
distal
Which of the following features is found only
on Maxillary 1st and 2nd molars?
Oblique ridge
• Older term is bicuspid
• Two or more cusps with one on buccal and one or two on
lingual (develop from 4-5 lobes, 3 facial and 1-2 lingual)
• Premolars are succedaneous • Shorter crown than anterior teeth
• Height of contour (crest of curvature) on buccal surface is in
the cervical 1/3, and lingually is the middle 1/3
• Usually have one root (except for maxillary first premolar) with
root concavities
General Characteristics for Premolars
• Maxillary premolars demonstrate mesial
inclination on lingual cusp
• Wider buccolingually than mesiodistally
General characteristics of Max. Premolars
Do maxillary premolars demonstrate inclination on a cusp
yes. mesial inclination on the lingual cusp
You are examining an extracted molar. It has
two roots, and 5 cusps. The roots are widely
spread, with the mesial root demonstrating a
deep concavity along the mesial surface.
Which molar are you examining?
Mandibular 1st
You are examining an extracted premolar. The
premolar in question is almost square in shape
when viewed from the occlusal plane, has two
cusps, and one root. There is no mesial root
groove and no mesiolingual groove on the
crown. The lingual cusp shows no mesial
inclination. Both cusps are in the occlusal
plane. Which premolar are you looking at?
Mandibular second premolar
Maxillary First Premolar
• From proximal view, two major cusps, one buccal and one lingual, both centered over root trunk • Buccal cusp about 1mm longer than lingual cusp (from lingual or proximal view, lingual cusp is smaller) • Mesial inclination on lingual cusp • Mesial marginal groove (not 100%), if it has a distal marginal groove, the mesial is still deeper • Mesial root groove (proximal root concavity)—depression actually begins just below the contact. What does this mean for us? • Only tooth in the permanent dentition with the mesiobuccal cusp slope that is longer than the distal • Usually has a bifurcated root at the apical third (one lingual, one buccal) • From distal proximal view, more occlusal surface is visible because distal marginal ridge is more cervically located
Only tooth in the permanent dentition with the mesiobuccal cusp slope that is longer than the distal
Maxillary first premolar
Does the maxillary first premolar always have a bifuracated root
no single root occurs 20 %
Does the maxillary first premolar have 2 pulp canals if it has one root
Yes always
which premolar has a mesial depression on root surface
maxillary first premolar
which maxillary premolar has even lingual and buccal cusps
maxillary second premolar
which premolar has a central groove does not cross the marginal ridge and has a wrinkled appearance
maxillary second premolar
• No depression on mesial or distal crown surfaces • Unlike the first premolar, the lingual cusp is closer to the same size as the buccal cusp • Central groove is shorter than first premolar with frequent supplemental grooves, but none that cross the marginal ridge, more wrinkled appearance • Lingual cusp offset to mesial • Occlusal view is more rounded/oval than first premolar
Max. Second Premolar
Doe the maxillary second premolar have one pulp cavity or two
one pulp cavity due to usually being single rooted
General Characteristics for mandibular premolars
• Mandibular premolars do not closely resemble each other like
maxillary premolars
• Distinct lingual inclination when viewed from the proximal
surface
• Almost equal distance mesiodistally and buccolingually (square)
• Lingual cusps are almost always smaller than buccal cusp • Single root with distal inclination
• Root concavities, more prominent and more frequent on mesial
surface
DO maxillary premolars or mandibular premolars have lingual inclination when veiwed from proximal surface
Mandibular premolars
Mandibular First Premolar
• Buccal cusp that is long and sharp and is the only functional cusp during occlusion, is usually slightly to mesial • Mesial cusp ridge is shorter than distal • Lingual cusp is small and non- functioning • Mesial fossa and distal fossa with associated pits are present (snake eyes) • Mesiolingual developmental groove • Buccal cusp is centered over the long axis of the tooth • Crown outline from buccal view is nearly symmetrical and resembles a canine • Distal marginal ridge more developed and unbroken • Buccal aspect of root is conical and tapered on the lingual aspect • Deep groove may be found on the distal aspect of root • Root may be bifurcated • Pulp cavity has two pulp horns and single pulp canal
Is the mandibular first premolars buccal cusp slightly to the mesial or distal
Mesial
which premolar has a non functional cusp
Mandibular first
The mandibular first premolar snake pits correlate with what anatomy
Mesial and distal fossa
Difference between the mandibular first premolar and maxillary first premolar groove that extends
Maxillary first premolar groove is a mesial marginal groove vs the mandibular first premolar has a mesial lingual developmental groove
Mandibular Second Premolar
• Occlusal view is almost square
• Crown is almost square with lingual inclination
• Mesial marginal ridge is almost at a 90 degree angle
to the long axis of the tooth
• Tricuspid-
– Mesiolingual cusp is wider and longer than
distolingual cusp – A lingual developmental groove is located
between cusps and located just distal to the
center of cusp and may extend to the lingual
surface (Y-shaped groove pattern)
• Bicuspid-
– Central groove most often is “U” shaped
– Less often a “H” shaped central groove
– Does not have a lingual groove or central pit like the tricuspid
• Proximal root concavities can be pronounced • Root apex may tip distally • Pulp cavity of tricuspids have three pulp horns, and
buccal cusp
two pulp horns in the bicuspids, and both are more pointed than the first premolar
• All cusps are functional!!!!!****
• Lingual cusp is slightly shorter (<2mm) than the
Which premolar is almost the most square from occlusal veiw
Mandibular second
– A lingual developmental groove is located
between cusps and located just distal to the
center of cusp and may extend to the lingual
surface (Y-shaped groove pattern)
What tooth is this located on and specifically is it a tricuspid or bicuspid
Tricuspid mandibular 2nd molar
Doe the bicuspid mandibular second premolar have a lingual groove or central pit like the tricuspid
NO
Which premolar are all cusps funcitonal BUT lingual cusp is slightly shorter by 2mm than buccal
Mandibular second premolar
You are examining an extracted premolar. The
premolar in question is almost square in shape
when viewed from the occlusal plane, has two
cusps, and one root. There is no mesial root
groove and no mesiolingual groove on the
crown. The lingual cusp shows no mesial
inclination. Both cusps are in the occlusal
plane. Which premolar are you looking at?
Mandibular second premolar
General Characteristics of Molars
• Eruption of the third molars usually marks the end of growth
for the jawbones
• First molar is the largest • Nonsuccedaneous
• 3 or more cusps with at least 2 on the buccal
• Developmental pits are located on the occlusal and lingual
on maxillary molars and occlusal and buccal of mandibular
molars
• Multi-rooted: Maxillary: palatal largest, mesial second, distal third
largest
• Two roots on mandibular with mesial being larger
• Furcations are areas between two or more root branches before they
divide from the root trunk
originates from the crown
• Root concavity-is just apical to CEJ on the root trunk—NOT THE
FURCATION!
– Bifurcation on mandibular from buccal or lingual – Trifurcation on maxillary with mesial, distal, and buccal
• Root trunk-portion of the toot of multi-rooted teeth where the root
• Just slightly wider buccolingually than mesiodistally, opposite
from mandibular (square)
• Oblique ridge-ridge that runs from distobuccal cusp to distal
cusp ridge of mesiolingual cusp (never present on mandibular
molars) Two cusp ridges
• Oblique groove right next to oblique ridge on ML cusp!!!!
• Transverse ridge that runs from ML cusp to MB cusp
• Largest crown in permanent dentition
• Least variable in form
• 4-5 developmental lobes, may have a cusp of Carabelli on ML
cusp
• Buccal groove extends cervically ½ way to CEJ
and parallel to long axis of the tooth
• Mesiolingual cusp is largest
• From mesial view, only the mesiolingual and
mesiobuccal cusps are visible
• Mesial marginal groove crosses midway
through the mesial marginal ridge
• Central pit divides the central groove into
mesial and distal grooves
• Lingual root is largest and strongest and
extends outside the crown outline with
banana curve toward the buccal
• Lingual root has concavity
• All furcations usually begin near the junction
of cervical and middle third of the root
• Pulp cavity: one horn for each cusp
• Each root has one canal, but mesiobuccal root
sometimes has two
• Only tooth to be wider on the lingual surface
than buccal
Maxillary first molar
Eruption of which molar marks the end of growth for the jawbones
Third molars
Maxillary roots size in order
Largest is palatal
second is mesial
third is distal
Mandibular root: which is bigger
mesial being larger
Oblique ridge : Is it present on mandbular or maxilllary molars
MAxillary
Are 1 or 2 cusp ridges found on the ML cusp of maxillary first molars
2 cusp ridges
Which tooth is the largest crown in the permanent dentition and may have a cusp of carabelli on ML cusp
Maxillary first molar
Which cusp is the largest on the maxillary first molar
Mesial lingual cusp where that cusp of carabeli can be found
Mesial marginal groove crosses midway through the mesial marginal ridge
Maxillary first molar
Lingual root is largest and strongest and
extends outside the crown outline with
banana curve toward the buccal
Maxillary first Molar
Maxillary Second Molar
• Mesiolingual cusp much larger than less developed distolingual cusp, lingual groove is towards the distal (more than 1st) • Usually 4 cusps, but 3 cusp version is possible (no distolingual cusp) • No cusp of Carabelli • Buccal cusps unequal in size—distal smaller • Less prominent oblique ridge than maxillary first molar • Still has oblique groove • More supplemental grooves than maxillary first molar • 3 roots are smaller, closer together and more parallel than first molar • Roots may have distal tip • Mesiolingual cusp is still the largest • Distolingual cusp is typically not in occlusion—not part of occlusal table • Roots can be fused • Pulp cavity has three canals and each cusp has a pulp horn • Same width buccolingually as mesiodistally giving crown a rhomboidal (4 parallel sides, most common) or heart shape
Is the mesiolingual cusp the largest on the maxillary second molar or first or both
both
Which cusp on the maxillary second molar is not in occulsion
Distolingual cusp
Which molar is the same width buccolingually as mesiodistally
Maxillary second molar
rhomboidal or heart shaped
Even butt cheeks or cusps
Maxillary first molar
Uneven butt cheeks or cusps
Maxillary second molar
Maxillary Third Molar
• 3 roots are smaller, closer together and more parallel than first molar • Roots may have distal tip • Mesiolingual cusp is still the largest • Distolingual cusp is typically not in occlusion—not part of occlusal table • Roots can be fused • Pulp cavity has three canals and each cusp has a pulp horn • Same width buccolingually as mesiodistally giving crown a rhomboidal (4 parallel sides, most common) or heart shape • Trifurcated roots fused or very close together and much shorter • Roots tend to diverge to the distal • Roots shorter than maxillary first or second molars • Distobuccal root is smallest • Pulp has three pulp horns (corresponding with number or cusps) and one large canal
For third molars sometimes its just good to do what first
count the roots
What do third maxillary roots typically do
fused together or very close an short and curve toward distal
• Four to five cusps
• Two lingual cusps about the same size
• Wider mesiodistally than buccolingually,
opposite for maxillary
• Occlusal outline is rectangular
• Proximal view shows lingual inclination
• 2 roots: Mesial (larger) and distal roots
• Roots shows distal inclination
• Concavity on mesial aspect of mesial root
• Mesial roots may have 2 canals if there is
a mesial root groove
General Characteristics of Mandibular Molars
Are maxillary molars or mandibular molars wider MD than BL
Mandibular molars
Do maxillary or mandibular molars show proximal lingual inclination
mandibular molars
You are looking at a molar and you see a mesial concavity on root
mandibular molar
Mesial roots may have _ canals if there is a mesial root groove on a mandibular molar
2
Mandibular first molar
• Three facial cusps—looks like a paw • Two facial grooves • Distal cusp is smallest facial cusp • Rare, but may have sixth cusp • Mesiobuccal cusp is largest, widest and highest cusp on buccal portion • Mesiobuccal groove extends cervically but slightly mesial to the center and ends in buccal pit • Distobuccal groove extends cervically and 1 may end in a distal pit • Lingual inclination of buccal cusps • Roots widely separated and vertical (mesial and distal) • Mesial root is wider and stronger • Buccal furcation is 3mm from CEJ and 4mm on lingual • Pulp cavity has three canals (distal, mesiobuccal and mesiolingual) • Five pulp horns
On the mandibular first molar which cusp is the SMALLEST
Disto buccal cusp
Is there lingual inclination on the mandibular first molar
YES
Mandibular Second Molar
• Four cusps of fairly equal size from four
developmental lobes-grooves look like +
• Cross shaped occlusal groove pattern*****
• Crown has lingual inclination
• No groove to cross the mesial or distal
marginal ridges
• Less divergence of roots
• Root trunk in longer than first molar
• Pulp cavity has three pulp canals, two in
mesial root
• Four pulp horns
Which molar has four cusps fairly equally in size and has a + sign on occulsual table
Mandibular second
Between the mandibular first and second molar which has less diveragance of roots
Mandibular second
What does lingual inclination of molars let you decide
Mandibular molars have lingual divergence
You are examining an extracted molar. It has
two roots, and 5 cusps. The roots are widely
spread, with the mesial root demonstrating a
deep concavity along the mesial surface.
Which molar are you examining?
Mandibular first
• Has no standard form
• Usually has four developmental lobes • Crown tapers distally
• Occlusal seems wrinkled with irregular groove
patterns
• Numerous supplemental grooves and pits
• More occlusal anatomy is visible from distal aspect
• Roots often fused and curved distally
• Pulp cavity has four pulp horns and three or two
canals
Mandibular Third Molars
