Premolars

Question 1

How many roots does a maxillary first premolar have

Answer 1

Usually 2 roots

Question 2

Premolars vs anterior teeth

Answer 2

No cingulum
One Buccal and one lingual cusp (except mandibular second premolars that have 2 lingual cusps)

The marginal ridges of most premo- lars are oriented in a horizontal plane versus a more lin- gually sloping plane in the anterior teeth

Crowns are shorter in premolars

Question 3

Difference between mandibular and maxillary premolars

Answer 3

Mandibular premolars lingual inclined

Crown shape in maxillary is oval, crown shape in mandibular is round

Question 4

How to know if it’s a right or left maxillary first premolar

Answer 4

• Buccal cusp higher than palatal cusp
• canine fossa on MESIAL!! (Concavity on the mesial surface, think of surface next to canine)
• Sharp fissure does NOT reach distal marginal ridge, only mesial marginal ridge

Question 5

One is one common feature of upper premolars

Answer 5

mesial displacement of the lingual cusp (especially apparent for mandibular first premolars)

Question 6

How to differentiate between maxillary 4 and 5?

Answer 6

4 has 2 roots 5 has 1 root
5 has no canine fossa
Sharp fissure does NOT reach either of the two marginal ridges in 5
Buccal cusp is higher in 4s but same height as lingual cusps in 5s

Question 7

Something unique about maxillary first premolar

Answer 7

The mesial cusp ridge is longer than the distal cusp ridge. Unlike canines and second premolars (upper)

Question 8

Canine fossa

Answer 8

Only present in 4s

Question 9

Another name for canine fossa

Answer 9

Mesial marginal ridge groove

Question 10

Is distal marginal ridge more or less cervical in maxillary premolars

Answer 10

More

Question 11

How to differentiate mandibular 4 and 5

Answer 11

4 has very short lingual cusp.

5 can have either 2 or 3 cusps (with 2 lingual)

Question 12

How to know whether it is a right or left mandibular first molar

Answer 12

There is a small groove running from the mesial pit to the mesiolingual surface. This is called the Mesiolingual developmental groove

Question 13

How to differentiate left from right for 3 cusp type mandibular 5s

Answer 13

Mesiolingual cusp bigger than distolingual cusp

Question 14

How to differentiate between left and right for 2 cusp type mandibular 5s

Answer 14

The lingual cusp TIP is displaced mesially