Mandibular Second Premolar Flashcards Preview

Dental Anatomy > Mandibular Second Premolar > Flashcards

Flashcards in Mandibular Second Premolar Deck (25)
Loading flashcards...
1
Q

For the mandibular second premolar, what is the expected age at eruption?

A

11-12 years

2
Q

For the mandibular second premolar, what are the tooth numbers in the universal numbering system?

A

20 & 29

3
Q

For the mandibular second premolar, what is the crown shape as seen from the facial or lingual view?

A

Trapezoid (M-D length longer at occlusal 1/3 than cervical 1/3) or pentagon (reflects the central facial cusp and M,D ridges).

4
Q

For the mandibular second premolar, is the O-C crown dimension longer or shorter than the M-D crown dimension?

A

Longer. The facial surface is taller than it is wide in the M-D direction.

5
Q

For the mandibular second premolar, describe the mesial and distal outlines as seen from the facial and lingual views.

A

Mesial outline: convex. The mesial cusp ridge is shorter than distal cusp ridge. Notches are often seen in mesial cusp ridge.
Distal outline: Convex. Distal cusp ridge longer. Notches common.

6
Q

For the mandibular second premolar, what are the heights of contour (occlusogingival contact points) of the mesial and distal faces?

A

Mesial: Middle 1/3 just below occlusal-middle junction
Distal: Middle 1/3; cervical to mesial height of contour.

7
Q

For the mandibular second premolar, how many developmental lobes are there? How many cusps are present on the occlusal surface?

A

Usually 5! Sometimes four. First time we have seen this. Usually 3 cusps (if 5 developmental lobes)

8
Q

For the mandibular second premolar, if, as usual, the occlusal surface has 3 cusps, which has a wider M-D dimension, the lingual or buccal ridge of tooth?

A

The lingual if 3 cusp. Buccal if two cusps.

9
Q

For the mandibular second premolar, are the mesial and distal marginal ridges parallel?

A

Yes.

10
Q

For the mandibular second premolar, what is the crown shape as seen from the occlusal view?

A

Depends on # of cusps:
3 cusps=square
2 cusps=round or oval (same as max 2nd premolar)

11
Q

For the mandibular second premolar, describe the facial and lingual outlines as seen from the occlusal view.

A

Facial outline: Convex; prominent middle lobe

Lingual outline: mostly convex; more square shaped than buccal side in 3 cusp tooth.

12
Q

For the mandibular second premolar, is there a transverse ridge present on the occlusal surface?

A

NOT when the tooth has 3 cusps. Three triangular ridges don’t meet to form a transverse ridge.

13
Q

For the mandibular second premolar, when 3 cusps are present how many fossa are present? what are they called? Which is largest?

A
  1. The Mesial, distal, and central fossa. Central fossa is largest.
14
Q

For the mandibular second premolar, what are the buccolingual contact locations?

A

Mesial: Buccal to B-L center
Distal: Just slightly buccal to B-L center or at B-L center. Distal buccolingual contact location is more lingual than the mesial contact location.

15
Q

For the mandibular second premolar, of the two lingual cusps, which is larger?

A

The mesial cusp is larger and extends higher occlusally.

16
Q

For the mandibular second premolar, what groove separates the two lingual cusps?

A

The lingual groove

17
Q

For the mandibular second premolar, what are the names of the 3 developmental grooves present on the 3 cusp occlusal surface? Which way do they travel?

A

Mesial developmental groove travels MB from central fossa
Distal developmental groove travels DB from the central fossa
Lingual developmental groove travels in a lingual direction from the central fossa.

18
Q

For the mandibular second premolar, what is the developmental groove on the two cusp occlusal surface?

A

Central developmental groove. Connects the mesial and distal fossa crossing the transverse ridge to get there.

19
Q

For the mandibular second premolar, what is the crown shape as seen from the mesial view?

A

Rhomboidal.

20
Q

For the mandibular second premolar, is the occlusal table centered over the root trunk?

A

NO due to its lingual tilt leading to it’s classification as a rhombus.

21
Q

For the mandibular second premolar, how do the O-C crown dimensions and the B-L crown dimensions compare?

A

They are almost the same with the O-C being just slightly longer. Shorter and wider crown than mandibular 1st premolar.

22
Q

For the mandibular second premolar, describe the facial and lingual outlines as seen from the mesial view.

A

Facial outline: Convex; height of contour in cervical 1/3. Slants to the lingual. Blunted cusp.
Lingual outline: Convex; height of contour in middle 1/3 of crown and occlusal 1/3 of crown. Lingual cusp is shorter than buccal cusp but larger than lingual cusp on man 1st premolar.

23
Q

For the mandibular second premolar, what are the heights of contour for the buccal and lingual surfaces as seen from the proximal view?

A

Buccal: Cervical 1/3
Lingual: Middle 1/3 of crown; occlusal 1/3 of lingual cusp.

24
Q

For the mandibular second premolar, number of roots? Shape? Dilaceration?

A

1 conical shaped mandibular secondary premolar root that dilacerates to the distal

25
Q

For the mandibular second premolar, number of pulpal canals? shape in cross section of pulpal chamber?

A

1, oval