Premolars Flashcards
How many cusps do most premolars have?
2, they are biscuspid.
One buccal cusp, one palatal cusp.
Describe the buccal surface of the max first premolar
Looks similar in shape to canine.
Mesial slope of buccal cusp is longer than distal.
Concave at marginal ridge and mesial and distal
Describe what the first premolar would look like if you were to look at it from its occlusal surface
You would see that the buccal cusp is wider and larger than the palatal cusp, which makes the occlusal surface an oval shape.
There is also a deep fissure that runs from mesial to distal and onto the mesial margin ridge. This is called the canine groove.
What will you find on the mesial surface of the maxillary first premolar?
the canine fossa.
This is where the mesial crown and root surface is slightly concave. This is at the cervical margin where the canine fits into.
Describe the roots of the maxillary first premolar.
Usually has 2 root/root canals- buccal and palatal.
Remember roots CAN fuse into one single root, but it will still have 2 canals.
Describe the buccal surface of the max second premolar
Mesial slope of buccal cusp is shorter than the distal. Crown is flattened mesiodistally.
How does the maxillary second premolar compare to the max first premolar?
They look similar.
The second premolar is smaller. The sides of the tooth are not concave, so the tooth is rounded. The cusps are also less acute in comparison to the first premolar.
The mesial slope of the buccal cusp is shorter than the distal in the second premolar - this is the opposite for the first premolar.
The second premolar also doesn’t have fossa, whereas, the first premolar does.
The second premolar also has one root, whereas the first premolar usually has 2.
How would you describe the palatal surface of the second max premolar?
The palatal cusp is narrower than the buccal cusp and the cusp tip is more mesial.
Describe the root(s) of the second max premolar
Single root.
Usually bends towards the distal.
No canine fossa.
Describe what the second premolar would look like if you were to look at it from its occlusal surface
Palatal cusp tip is mesial.
Fissure does not extend over mesial marginal ridge
Which premolar is the smallest?
The mandibular first premolar
Describe the buccal/buccal cusp of the first mandibular premolar
Crown is smaller than 2nd premolar.
Rounded crown.
Buccal cusp is large and convex.
Mesial slope is shorter on the buccal cusp than distal slope.
Tilts towards the lingual.
Describe the lingual cusp of the mandibular first premolar
Lingual cusp tip is mesial.
Lingual cusp is shorter than buccal cusp.
Lingual cusp is upright with an overhang over the root, which allows for the tongue.
Describe what the first mandibular premolar would look like if you were to look at it from its occlusal surface
Rounded square in shape.
Ridge joins buccal and lingual cusps. 2 occlusal fossae - distal and mesial, either side of the ridge. The distal fossa is larger than the mesial.
Which premolar sometimes have 3 cusps instead of 2?
Mandibular second premolar.
