Molars Flashcards
What is the shape of the occlusal surface of an upper first molar
Diamond shaped
What is the largest cusp on the upper first molar
The mesio-palatal cusp
What is the smallest cusp on the upper first molar
The distal-palatal cusp
What is the longest diagonal on the occlusal surface of the upper first molar
It goes from the media-buccal to the disco-palatal cusp
What is an oblique ridge
A strong ridge of enamel on the occlusal surface of a tooth
What is present on each side of the oblique ridge on the upper first molar
A fissure
What are the fissures on the upper first molar connected by and what does this look like
They are connected with another shallow fissure which hives rise to an H shaped pattern
Where does the distal fissure on the upper first molar run
Parallel to the oblique ridge and continues to the palatal surface
What does the mesial fissure on the upper first molar look like
It has a right-angled bend and one arm runs towards the mesial surface (but not on it) while the other goes to the buccal surface
What is a tubercle of caramel I and where is it found
It is an extra cusp and it is found on the palatal-surface of the mesio-palatal cusp on the upper first molar
How many roots does an upper first molar have and where are they
3 roots - 2 buccal and 1 palatal diverging from a common root stalk
What is significant about the disto-palatal cusp on the upper second molar
It is greatly reduced and may be absent altogether which makes the shape of the crown more triangular
What is the shape of the upper second molar crown
Triangular/heart-shaped
What can be said about the roots of the upper second molars
They are much less divergent and the palatal root is often partially fused with either of the buccal roots
What is the crown of the upper third molar like and how many cusps does it have
Smallest of them all and usually only 3 cusps (no disto-palatal)
What are the roots of the upper third molar like
Usually fused together into one common bulky root with grooves where the usual fractions would be
What is the smallest cusp on the lower first molar
The distal cusp
How many cusps does the lower first molar have
5 - 3 buccal and 2 lingual
Where does the transverse fissure on the lower first molar run
From the buccal surface to the lingual surface
What causes the formation of a pit in the centre of the lower first molar crown
The deepening of the transverse fissure
What does the media-distal fissure do when it reaches the distal cusp
It bifurcated to pass onto each side of the distal cusp
How many roots does the lower first molar have
2 - one mesial and one distal
Both compressed Mexico-distally and may show distal curvature
What is the mesial root of the lower first molar like
Curved, grooved and broader than the distal root making the distal root invisible from the mesial aspect
Which tooth has a buccal surface which is at increased risk of caries
Lower 6
What is the difference between the mesial and distal roots of the lower 7
Mesial root is broader than the distal but the distal is longer
Compare the occlusal surface of the lower 7 compared to the lower 6
The lower 7 is more symmetrical and smaller than the lower 6
How many cusps does a lower second molar have
4
What is the shape of the occlusal surface of a lower 7
Square shaped
What is the fissure pattern on a lower second molar
+ shaped
What is the largest cusp on the lower 7
Mexico-buccal
What are the highest cusps on the lower 7
Lingual cusps
What are the roots of the lower second molar like
Less divergent and may be fused
What is the crown of the lower third molar like
It is variable in size as it can have 3-5 cusps
What are the roots of the third molar like
Often fused together
When making dentures where should the mediocre-palatal and disto-palatal cusps sit in occlusion
Mexico-palatal cusps should be on the occlusal plane and buccal cusps should be raised from the plane
What shape are the proximal surfaces of the lower first molar
Convex with the distal much rounder because of the distal cusp
Is the buccal or lingual surface of the lower first molar largest
The buccal surface
