Premolars Morphology - maxillary Flashcards
What is the main role of the premolars?
grinding
What side of the pre-molar is this?
the buccal aspect
trapezoidal
How many cusps does a premolar have?
2 cusps
bicuspid
What premolar is an exception to the bicuspid rule?
the 35 and 45 (second premolar)
the second premolar in the mandibular arch
How would you describe the lower second premolars?
tricuspid
1 large on the buccal and 2 smaller lingual
What does the CEJ look like on posterior teeth?
almost straight
When does the 14/24 erupt?
10-11
Are the premolars bigger or smaller than the primary molars they replace?
generally smaller
How many cusps does the 14 and 24 have?
2 cusps
pretty much equal in length
Name the features of the maxillary first premolar (24/14) - buccal
Buccal ridge (red)
Developmental depressions (blue)
Distal cusp slope (black)
Mesial cusp slope (brown)
Cusp tip (star)
Perikymata (arrows)
Name the features of the maxillary premolar (14/24) - palatal
Palatal ridge (blue)
Palatal cusp tip (red)
Mesial ridge (black)
What is the defining factor of the maxillary first premolar? (buccal)
the mesial cusp ridge is longer than the distal on the buccal
What is the defining feature of the maxillary first premolar (palatal)?
the mesial cusp ridge is slightly shorter than distal
Does the upper 4 have a bifurcation?
yes
What tooth is this and what are the defining features?
upper 4
Mesial marginal depression (grey).
CP just cervical to the junction of the occlusal and middle 1/3rd (red).
just before the bifurcation is the canine fossa
Where is the contact point on the upper 4?
just cervical to the junction of the occlusal and middle third
What side of the upper 4 is shown her?
distal
What does the distal aspect of the upper 4 not have that the mesial does?
does not have the deep developmental depression
What is the fossa called in the mesial upper 4?
canine fossa
Describe the occlusal features shown in this tooth, what tooth is it?
upper 4
Central groove
-Distal and mesial marginal grooves
Mesial and distal marginal grooves
Triangular grooves also.
How would you distinguish the upper 4s form upper 5s?
14/24 are very angled and bicuspid
long angled walls
the 5s are more rounded and not as pointy
How would you distinguish the left and right maxillary 4s?
The CEJ is more occlusally located on the mesial surface
The canine fossa is on the mesial aspect of the tooth
The mesial marginal depression
the roots will swing slightly distally
When do the maxillary 5s erupt?
10-12
What tooth is this?
upper 5
rounded buccal cusp
