Premolars Flashcards
What is the palatal surface of the upper 4 like compared to the buccal surface
Slightly lower and much narrower
What is the distal surface of the upper 4 like
Convex
What is the mesial surface of the upper 4 like
Convex in the occlusal half and concave in the cervical half
What is a canine fossa
The con cavity on the mesial surface of the upper 4
It contacts the distal surface of the upper canine
What are distinguishing features of the upper first premolar
Well-defined groove in the enamel of the mesial marginal ridge
This groove is in alignment with the developmental depression on the mesial surface of the root and is continuous with the central groove of the occlusal surface
What does the occlusal surface of the upper 4 appear like
Roughly oval, buccal cusp is wider and higher than lingual cusp,
Has a marked mesial displacement of the lingual cusp
What are the two cusps on the upper 4 separated by
A sharp fissure running mesio-distally which does not reach the distal marginal ridge but often extends across the mesial marginal ridge onto the mesial surface
What marginal ridge is more cervical on the upper 4
Distal
How many roots does the the upper 4 have
2 roots - one buccal and open lingual
What is the buccal surface of the upper 5 like in comparison to the upper 4
Smaller
Why are the 2 cusps of the upper 5 the same height
The reduction in size of the buccal cusp
What is the mesial surface of the upper 5 like
No development depression and is convex
What marginal ridge is more cervical on the upper 5
Distal
What separates the cusps on the upper 5
A sharp fissure running mediocre-distally which does not reach the marginal ridges
What is the occlusal surface of the upper 5 like compared to the upper 4
More symmetrical with only slight mesial displacement of the lingual cusp
What is the buccal surface of the lower 4 like
Inclined strongly lingually so that its tip lies almost above the centre of the tooth
What is the lingual surface of the lower 4 like
Slightly narrower and much longer than the buccal surface
What is the occlusal surface on the lower 4 like
Almost round, canine-like, greater difference in buccal and lingual cusps height and has a small groove running from the mesial pit onto the mesio-lingual surface
What is the crown of the lower 5 like
Much larger than that of the first
What is the occlusal surface of the lower 5 like
The lingual cusp is much larger than that os the first and is displaced mesially
How many cusps does the lower 5 have
Possibly 2 but the mesial is larger
Which is the bigger fossa on the lower 5
Distal
What marginal ridge is more cervical on the lower 4
Mesial
What marginal ridge is more cervical on the lower 5
Distal
What does unilateral mean
Affecting only one side
What does bilateral mean
Affecting both sides
What does ipsilateral mean
Belonging to or occurring on the same side of the body
What does contralateral mean
Occurs on the opposite side of the body
What is significant about the lingual cusp of the upper 4
It has marked mesial displacement
