5 adn 12: maxillary 1st PM

Question 1

5 adn 12 eruption age

Answer 1

max 1st PM

10-11

Question 2

devo lobes, 5/12

Answer 2

4: 3 for buccal cusp adn 1 for lingual

Question 3

5/12 buccal cusp slope

Answer 3

twisted because the mesial side is kind of pinched in; not parallel to lingual cusp slope

Question 4

5/12 proximal contacts

Answer 4

• distal is much broader than mesial because the mesial surface is pinched in
• mesial contact is in middle third, at jxn with occlusal
• distal contacts are more cervical

Question 5

5/12: buccal cusp

Answer 5

• buccal cusp tip is distal
• lingual cusp tip is mesial
• from the buccal, mesial slope is longer

Question 6

5/12: occlusal groove patter

Answer 6

• -central groove with distobuccal groove and mesiobuccal groove
• -on lingual side of central groove is mesial marginal groove, which can go to crown surface

Question 7

boundaries of 5/12 occlusal table

Answer 7

–marginal ridges: mesial adn distal (MMR has groove) on the mesial adn distal sides

–cusp tips and slopes on the buccal adn lingual sides

Question 8

marginal ridges vs cusp slopes

Answer 8

• mesial marginal ridge is actually along the mesial side

- mesial cusp slope can be seen from buccal view

Question 9

triangular anatomy of 5/12

Answer 9

triangular ridges: flat part along cnetral groove and point up to cusp slope (one B and one L)

triangular fossae: on mesial and distal ends of central groove, go down into tooth and deepest parts have pits

Question 10

roots of 5/12

Answer 10

• usually 2
• sometimes 3
• devo groove on buccal root on the inside (lingual side)

Question 11

key features of 5/12 mesial view

Answer 11

1. mesial menace - danger zone; depression
2. MMR groove on lingual side
3. CEJ slightly curved down
4. buccal cusp bigger than linugal
5. triangular ridges visible (convex)
6. root bifurcation & root trunk

Question 12

mesial menace

Answer 12

5/12 mesial depression involves both crown adn root

from MM devo groove to root

-hard to clean/restore adn easily perforated during endo

Question 13

distal view of 5/12 (vs mesial)

Answer 13

• CEJ little flatter
• DMR is more cervical (so you cannot see as much occlusal surface)
• no devo depression
• less of a root devo depression in middle third **UNIQUE bc normally more depression distally

Question 14

buccal and lingual views, 5/12

Answer 14

• from buccal, you only see buccal cusp and the mesial slope is longer
• from lingual, you see both cusps (and buccal triangular ridge) adn proximal surfaces because shorter and tapered