Premolars - Maxillary vs. Mandibular Flashcards
The outline of the … premolars are rhomboid in shape (four sided with all opposite sides parallel), and the … premolars are trapezoidal (four-sided with only two opposite walls parallel”like a rectangle with one large side having a slant”) (proximal views).
The outline of the mandibular premolars are rhomboid in shape (four sided with all opposite sides parallel), and the maxillary premolars are trapezoidal (four-sided with only two opposite walls parallel”like a rectangle with one large side having a slant”) (proximal views).
… crowns tilt to the lingual, so mandibular lingual cusp tips may be lingual to the root (proximal views). … crowns do not tip noticeably.
Mandibular premolar crowns tilt to the lingual, so mandibular lingual cusp tips may be lingual to the root (proximal views). Maxillary crowns do not tip noticeably.
Although … cusps are shorter than … cusps for all premolars, the (arch & side) cusps are relatively much shorter than … cusps compared to (arch & side) cusps, which are closer to the same length. (… premolar cusps are almost equal in length) (proximal views).
Although lingual cusps are shorter than buccal cusps for all premolars, the mandibular lingual cusps are relatively much shorter than buccal cusps compared to maxillary lingual cusps, which are closer to the same length. (maxillary second premolar cusps are almost equal in length) (proximal views).
… premolars are more square or round from the occlusal view; … premolars are more rectangular or oblong (relatively wider …) (occlusal view).
Mandibular premolars are more square or round from the occlusal view; Maxillary premolars are more rectangular or oblong (relatively wider buccolingually) (occlusal view).
Mandibular Premolars crowns tilt toward the ___.
Lingual. Remember the facial cusp rests on the Marginal ridge of the maxillary premolars.
Maxillary Premolars Lingual and buccal tips are ~ _____.
vs.
Mandibular premolars lingual cusps are much ___ than the buccal tisps.
equal; shorter.
Maxillary Premolars occlusal shape is more ___ ( ____).
vs.
Mandibular Premolars occlusal shape is more ____.
rectangular (wider buccolingually); square.
Maxillary 1st and 2nd premolars are ___.
vs.
Mandibular premolars are ____.
similar; dissimilar.
Maxillary premolars ___ premolar is larger.
vs.
Mandibular premolar ___ premolar is larger.
1st; 2nd.
Maxillary premolar has ___ prominenet lingual cusp.
vs.
Mandibular premolar have ___ lingual cusps, that are ___ prominent.
1; more than 1, less prominent.
Cusp tip of this tooth is centered over the root.
Mandibular 1st Premolar
Mandibular 1st Premolar:
- Fa cusp tip centered with root tip.
- Me cusp slope shooter than Di cusp slope.
- Nearly bilaterally symmetrical.
- Cannot see Li aspect from buccal view.
- Non-functional Li cusp.
- Me and Di root con concavity.
- Entire occlusal surface visible from Li view.
- ML groove crosses MMR (distinguishing factor).
- Occlusal table slants 45° from long axis of tooth.
- Distal occlusal fossa distinguishes R/L.
- Bifurcated roots sometimes occur.
- Variable crown & root.
Occlusal View of Mandibular 1st Premolar reveals:
M pit
D pit
Central groov
Mand. 1st Premolar - Occlusal Anatomy:
^ Triangular Occlusal Table ^
M pit D pit Central groove ML groove MB groove DL groove DB groove MMR DMR
- Distinct M and D Triangular Fossa
- Transverse Ridge
- Somewhat flat ML line angle
- Distinct ML groove
Mand. 2nd Premolar - Occlusal Anatomy:
- Square Occlusal Table.
- 2 or 3 cusps
- Shorter Bu cusp than Mand. 1st Premolar.
- Larger Li cusp than Mand. 1st Premolar.
- Occ. table perpendicular to long axis of tooth.
- Fa root concavity.
- Fa & ML cusps are almost =
- Blunted Apex
- DMR more cervical.
- Y shaped groove pattern (2 cusp)
- H/U shaped groove patter (3 cusp) [listed by most common]
Li groove
HOC: Fa) Cervical 1/3
Bu) Middle
PCA: Me) Cervical to junction of occ. and Mid 1/3.
Di) Cervical to the junction of the Occ. and Mid. 1/3.
Cusps (largest to smallest):
ML —–> DL
