Premolar Comparisons

Question 1

Maxillary buccal view: crown symmetry

Answer 1

Greater symmetry on maxillary 2nd premolar

Question 2

Maxillary buccal view: occlusal-cervical dimension

Answer 2

Larger on maxillary 1st premolar

Question 3

Maxillary buccal view: cervical width

Answer 3

Wider cervical neck on maxillary 2nd premolar

Question 4

Maxillary buccal view: buccal cusp sharpness

Answer 4

Sharper on maxillary 1st premolar

Question 5

Maxillary buccal view: buccal cusp ridge lengths

Answer 5

Mesial cusp ridge on maxillary 1st premoler is longer

Mesial cusp ridge on maxillary 2nd premolar is shorter

Question 6

Maxillary buccal view: buccal cusp ridge depressions

Answer 6

More often found on maxillary 1st premolar

Question 7

Maxillary buccal view: buccal ridge prominence

Answer 7

More prominent on maxillary 1st premolar

Question 8

Maxillary mesial view: cusp height difference

Answer 8

Larger on maxillary 1st premolar

Question 9

Maxillary mesial view: mesial crown concavity

Note its significance

Answer 9

Present on maxillary 1st premolar (good place for bacteria deposit –> cavities)

Question 10

Maxillary mesial view: mesial marginal ridge groove

Answer 10

Present on maxillary 1st premolar

Question 11

Maxillary mesial view: number of roots

Answer 11

Maxillary 1st premolar = 2 (buccal and pharyngeal)

Maxillary 2nd premolar = 1 root

(Important to know for root canals)

Question 12

Maxillary mesial view: developmental root depression

Give the significance of this morphology

Answer 12

Deeper on maxillary 1st premolar (can be area for caries)

Question 13

Occlusal view: outline form

Answer 13

More rounded on maxillary 2nd premolar

Question 14

Maxillary occlusal view: lingual cusp displacement

Answer 14

Greater mesial displacement of lingual cusp on maxillary 1st premolar

Question 15

Maxillary occlusal view: mesial surface convexity

Answer 15

Greater on maxillary 2nd premolar

Question 16

Maxillary occlusal view: buccal ridge prominence

Answer 16

More prominent on maxillary 1st premolar

Question 17

Maxillary occlusal view: mesial marginal ridge groove

Answer 17

Present on maxillary 1st premolar

Question 18

Maxillary occlusal view: central developmental groove lengths

Answer 18

Slightly longer on maxillary 1st premolar

Question 19

Maxillary occlusal view: marginal ridge width

Answer 19

Wider on maxillary 2nd premolar

Question 20

Maxillary occlusal view: location of pits

Answer 20

Maxillary 1st premolar = closer to marginal ridges

Maxillary 2nd premolar = closer to center of tooth

Question 21

Maxillary occlusal view: mesio-buccal and disto-buccal line angles

Answer 21

More prominent and angular on maxillary 1st premolar

Question 22

Mandibular buccal view: occlusal cervical crown dimension

Answer 22

Greater on mandibular 1st premolar

Question 23

Mandibular buccal view: buccal cusp height

Answer 23

Greater on mandibular 1st premolar

Question 24

Mandibular buccal view: buccal cusp sharpness

Answer 24

Greater on mandibular 1st premolar

Question 25

Mandibular lingual view: llingual cusp heights

Answer 25

Greater on mandibular 2nd premolar

Question 26

Mandibular lingual view: occlusal surface visibility

Answer 26

Greater on mandibular 1st premolar

Question 27

Mandibular lingual view: lingual groove presence

Answer 27

Present on mandibular 2nd premolar with 3 cusps (1 buccal, 2 lingual)

Question 28

Mandibular lingual view: marginal ridge positions

Answer 28

1st premolar = mesial is more cervical than distal 2nd premolar = distal is slightly more cervical than mesial

Question 29

Mandibular mesial view: lingual cusp heights

Answer 29

Greater on mandibular 2nd premolar

Question 30

Mandibular mesial view: buccal cusp locations

Answer 30

2nd premolar = slightly more buccal

Question 31

Mandibular mesial view: marginal ridge angulations

Answer 31

1st premolar = lingual slope 2nd premolar = horizontal

Question 32

Mandibular mesial view: mesio-lingual groove

Answer 32

Present on mandibular 1st premolar (do not confuse with 2nd premolar lingual groove)

Question 33

Mandibular mesial view: difference in cusp heights

Answer 33

Greater on mandibular 1st premolar

Question 34

Mandibular mesial view: occlusal surface visibility

Answer 34

Greater on mandibular 1st premolar

Question 35

Mandibular occlusal view: number of cusps

Answer 35

1st premolar = 2 cusps 2nd premolar = 2 or 3 cusps

Question 36

Occlusal view: bucco-lingual crown dimension

Answer 36

Greater on mandibular 2nd premolar

Question 37

Mandibular occlusal view: crown outline form

Answer 37

1st premolar = diamond shaped 2nd premolar = square or oval

Question 38

Mandibular occlusal view: pits locations

Answer 38

1st premolar = mesial and distal 2nd premolar = mesial, distal and central

Question 39

Mandibular occlusal view: occlusal table size

Answer 39

Larger on mandibular 2nd premolar

Question 40

Mandibular occlusal view: developmental groove form

Answer 40

1st premolar = straight line 2nd premolar = Y-shaped

Question 41

Tooth numbers of premolars

Answer 41

maxillary premolars = 1.5, 1.4, 2.4, 2.5 mandibular premolars = 3.5, 3.4, 4.4, 4.5