Mandibular 1st Premolars (Ye's Version) Flashcards
Mandibular Left 1st premolar tooth #?
21
Mandibular Right 1st premolar tooth #?
28
Mandibular 1st premolars: Chronological Events
First evidence of calcification:
Enamel completed (crown completion):
Eruption:
Root completion:
First evidence of calcification: 1.75-2 yrs
Enamel completed (crown completion): 5-6 yrs
Eruption: 10-12 yrs
Root completion: 12-13 yrs
Mandibular 1st premolars:
How many lobes?
4 lobes
Mandibular 1st premolars:
How many buccal vs lingual?
3 buccal vs 1 lingual
Mandibular 1st premolars:
What are the buccal lobes?
- MB
- Midbuccal
- DB
Mandibular 1st premolars:
What’s the lingual lobe?
The lingual lobe
Mandibular 1st premolars: General Characteristics
Have a well developed _______ cusp and small ________ cusp.
Well developed - Buccal cusp
Small - linugal cusp
Mandibular 1st premolars: General Characteristics
Resemble small _________
Canines
Mandibular 1st premolars: General Characteristics
Are they smaller or larger than maxillary 2nd premolars?
SMALLER (opposite is true for the maxillary arch)
Mandibular 1st premolars: General Characteristics
Are they succedaneous teeth? If so, what do they replace?
YES: replace mandibular 1st MOLARS
Mandibular 1st premolars: General Characteristics
How many roots do they have?
Single root
Mandibular 1st premolars: Buccal view
___________ in shape.
Trapezoidal
Mandibular 1st premolars: Buccal view
The __________ lobe is well-developed with a prominent bucal ridge and a buccal cusp that resembles the _______ ________ (tooth type and arch) but the cusp tip is MORE rounded.
Midbuccal lobe
Mandibular canine
Mandibular 1st premolars: Buccal view
The mesial slope (cusp arm) of the buccal cusp is (shorter/longer) than the distal slope.
Shorter
Mandibular 1st premolars: Buccal view
The buccal surface is more ________ (convex/concave) than in the maxillary premolars especially in the cervical 1/3. There are _________ _________ between lobes.
Convex; developmental depressions
Mandibular 1st premolars: Buccal view
The _________ outline is straight/slightly concave above the cervical line.
Mesial
Mandibular 1st premolars: Buccal view
The _________ outline is slightly concave above the cervical line.
Distal
Mandibular 1st premolars: Buccal view
The mesial and distal heights of contour (HOC) are located in the __________
Middle 1/3
Mandibular 1st premolars: Buccal view
The cervix is much (narrower/broader) ______ M-D than the crown width at the contact points
Narrower
Mandibular 1st premolars: Buccal view
The cervical line exhibits slight curvature (T/F)
True
Mandibular 1st premolars: Lingual view
Both the crown and the root taper markedly toward the lingual. Therefore the ________ and _______ surfaces are visible from the lingual.
Mesial and Distal
Mandibular 1st premolars: Lingual view
The __________ cusp is small, it resembles the _________ of a canine.
Lingual; cingulum
Mandibular 1st premolars: Lingual view
The occlusal surface slopes ____________ (buccally/lingually) in a cervical direction. Therefore, the occlusal surface is (not/is visible) from the lingual view?
Lingually; IS visible
Mandibular 1st premolars: Lingual view
There are concavities between the ________ line and the contact areas on the ________ portion of the mesial and distal surfaces.
Cervical line
Lingual portion
Mandibular 1st premolars: Lingual view
The mesial and distal outlines are _______ (convex/concave) from the CEJ to the contact areas.
Concave
Mandibular 1st premolars: Lingual view
There is a _____________________ which separates the mesial marginal ridge from the lingual cusp.
Mesiolingual developmental groove
Mandibular 1st premolars: Lingual view
The mesiolingual developmental groove is a demarcation between the ______ lobe and the ______ lobe.
Lingual lobe and MB lobe
Mandibular 1st premolars: Lingual view
The root tapers ________ (which direction?)
Lingually
Mandibular 1st premolars: Lingual view
The root appears very ________ when viewed from the lingual.
Narrow
Mandibular 1st premolars: Lingual view
The root tapers evenly from the cervix to a pointed apex. Often, ________________ or _____________ can be seen on the root mesially.
Developmental depressions or developmental grooves
Mandibular 1st premolars: Mesial view
___________ in outline
Rhomboidal