(Mandibular) Molars & Premolars - Facts & Landmarks.

Question 1

2nd Premolar Occlusal landmarks:

Answer 1

1) Central pit
2) Mesial developmental groove
3) Mesial triangular fossa.
4) Distal developmental groove.
5) Distal triangular fossa.
6) Lingual developmental groove.
7) Supplemental grooves.

3 cusp type - Each cusp is separated by deep developmental grooves, forming Y-shape.
2 cusp type - Appears rounded. H-shape.

Question 2

Which teeth does #30 occlude with?

Answer 2

3 and #4

Question 3

Describe the occlusal outline of the mandibular:

1st Molar:
2nd Molar:
3rd Molar:

Answer 3

1st Molar) Pentagonal occlusal table.
2nd Molar) Rectangular occlusal table.
3rd Molar) Ovoid occlusal table.

Question 4

Pattern of mandibular molar from 1st -> 3rd.

Answer 4

Roots become less divergent as they go from anterior to posterior. Roots become shorter as root trunk becomes longer.

Question 5

Occlusal anatomy of the mandibular molars:

Answer 5

1st Molar: Y-shaped grooves, well defined anatomy.
2nd Molar: + shaped groove pattern. Few supp. grooves.
3rd Molar: Appears more like mand. 1st molar.

Question 6

Describe the furcations as you go posteriorly from 1st mandibular molar to 3rd mandibular molar:

Answer 6

The furcation of the root trunk moves apically from first molar to third molar.

Question 7

Compare the root concavities as you go posteriorly from 1st mand. molar to 3rd mand. molar.

Answer 7

Root concavities become less prominent.

Question 8

Crowns of all mand. molars tip in _________ direction.

Answer 8

Lingual

Question 9

Most obvious difference between Maxillary and Mandibular roots.

Answer 9

Maxillary molars - 3 roots.

Mandibular molars - 2 roots.

Question 10

General Info - Mandibular 1st Molar:

Answer 10

Calcification - At birth.
Eruption: 6 YO.
Completed Root Apex: 9-10 YO.

• Mesiodistally the widest tooth in dentition
• Root lengths are equal in length.
• Di. root is straighter.
• MB, ML, DL, DB, D*
• Fa & DF grooves end in a pit.
• 3mm root trunk (Fa. View).
• 4mm root trunk (Li. View).
• Me. root is wider, and has deeper concavity.
• Li. Cusps are higher than Fa. cusps (M. View)
• Me. surface is straighter (Li. View)

H.O.C - Fa) Cervical 1/3
Li) Middle 1/3
P.C.A - Me) Middle 1/3
Di) Middle 1/3

Question 11

General Info - Mandibular 2nd Molar:

Answer 11

Calcification - Around 2.5 to 3 yrs.
Eruption: 11-13 YO.
Completed Root Apex: 14-15 YO.

• 4 cusps = length.
• M root is longer than D.
• 2 Transverse ridges: MB->ML & DB->DL.
• Few Supplemental grooves.
• C, M, D pits.
• Longer root trunk on Lingual side.
• • shaped occlusal table.

H.O.C - Fa) Cervical 1/3
Li) Middle 1/3
P.C.A - Me) Middle 1/3
Di) Middle 1/3

Question 12

General Info - Mandibular 3rd Molar:

Answer 12

Calcification - Around 8 to 10 yrs.
Eruption: 17-25 YO.
Completed Root Apex: 18-25 YO.

*Could be ovoid.

H.O.C - Fa) Cervical 1/3
Li) Middle 1/3
P.C.A - Me) Middle 1/3
Di) None.

Question 13

Which is the only three-cusped single-rooted tooth in the mouth?

Answer 13

Mandibular 2nd Premolar

Question 14

Which mand. molar is longer Buccolingually on the mesial side?

Answer 14

Mandibular 2nd Molar

Question 15

Eruption dates:

Answer 15

…

Question 16

Which mandibular premolar has an occlusal table that forms an approximate 45 degree angle with the long axis of the tooth?

Answer 16

Mandibular 1st Premolar