Mandibular 1st Premolar Flashcards
calcify
2yrs
erupt
10-12yrs
root complete
12-13yrs
The lingual cusp is….
afunctional (due to how small it is)
Facial view: outline shape
pentagonal
Facial view: the crown tapers…
lingually
Facial view: height of contour
cervical 3rd
Facial view: which cusp ridge is shorter?
mesial
Facial view: mesial and distal contact areas
junction of occlusal and middle 3rds
*mesial contact slightly more cervical
Facial view: facial cusp
-slightly toward mesial (due to longer distal ridge)
-more rounded than canine
Facial view: facial ridge
prominent w/ mesiobuccal and distobuccal developmental depressions
Lingual view: lingual cusp
smaller, afunctional
offset to mesial
*can see facial cusp from this view
*narrower than facial view
Lingual view: height of contour
middle 3rd
Lingual view: mesiolingual developmental groove
*identifying feature
-separates MMR from lingual cusp
-originates from mesial pit
Proximal view: outline shape
rhomboidal
*lingually inclined
Mesial view: buccal and lingual cusp tip
buccal: in line w/ root bisector
lingual: lingual to the root bisector
Distal view: CEJ curvature
less on the distal
Distal view: DMR
more developed than the MMR
MMR vs DMR
MMR is more cervical than the DMR
Occlusal view: occlusal table shape
triangular (due to small lingual cusp)
Occlusal view: transverse ridge
only premolar w/ transverse ridge not crossing occlusal development groove
*larger and longer buccal triangular ridge than lingual
Occlusal view: MMR
shorter than DMR
45 degree angle slope
resembles canine
Occlusal view: DMR
longer more prominent
more horizontal
not as great slope towards lingual
Occlusal view: fossae
mesial pit and distal pit
Occlusal view: grooves
-central
-mesiobuccal
-mesiolingual developmental
-distobuccal
-distolingual
-distal marginal
Describe the root
single, straight, narrower on lingual, distal curvature, mesial and distal depressions, *shorter than 2nd PM
How many canals and pulp horns
1 canal, 2 horns
If 2 roots are present, which pulp horn is more dominant?
buccal pulp horn
*longitudinal groove separates roots on proximal when 2 are present