Dental Anatomy: Maxillary First Premolars

Front 1

Maxillary vs. mandibular premolars:

1) Mesiodistally and faciolingually
2) Cusps
3) Occlusal table
4) Height of contour
5) Roots in cross section
6) Buccal surface angles

Back 1

1) ~same size mesiodistally/lengthwise, maxillary premolars have greater faciolingual diameter

2) Maxillary have more distinct lingual cusps, mandibular buccal cusps more towards faciolingual midpoint.

3) Maxillary occlusal table centered faciolingually, mandibular occlusal table lingually displaced

4) Maxillary buccal @ cervical/lower 1/3 of crown, mandibular lower at about cervical line. Maxillary lingual @ junction of cervical and middle 1/3s, lingual higher in upper middle.

5) Mandibular premolar roots rounder, maxillary have mesial root concavities

6) Maxillary buccal surface straighter from height of contour to cusp tip - mandibular more convex.

5)

Front 2

Maxillary first premolars

Proximal contacts

Back 2

Mesial/distal; middle third

Front 3

Maxillary first premolars

Shoulders

Back 3

Prominent

Front 4

Maxillary first premolars

Buccal cusp location
Lingual cusp location

Back 4

Buccal cusp towards distal
Lingual cusp towards mesial

Front 5

Maxillary first premolars

Cusp ridges

Back 5

Longer mesial ridge

Front 6

Maxillary first premolars

Cusp size/height compared to second molars

Back 6

Slightly wider/longer

Front 7

Maxillary first premolars

Buccal surface vs. lingual surface (width wise)

Back 7

Buccal surface is wider than lingual surface.

Front 8

Maxillary first premolars

What is a significant, distinguishing feature on the mesial side

Back 8

Mesiomarginal groove, mesial concavity that is in the root AND crown **distinguishing feature**

Front 9

Maxillary first premolars

Shape of profile from occlusal aspect

Back 9

Hexagonal

Front 10

Maxillary first premolars

Central groove

Back 10

Long

Front 11

Maxillary first premolars

Supplemental grooves

Back 11

Usually not present

Front 12

Maxillary first premolars

# of lobes

Back 12

4

Front 13

Maxillary first premolars

# of pulp horns

Back 13

2

Front 14

Maxillary first molars

Mesiodistal

Back 14

7.0

Front 15

Maxillary first premolars

Crown length

Back 15

8.5

Front 16

Maxillary first premolars

Buccolingual

Back 16

9.0

Front 17

Maxillary first premolars

Facial height of contour

Back 17

Cervical third

Front 18

Maxillary first molars

Lingual height of contour

Back 18

Middle third

Front 19

Maxillary first premolars

Root length

Back 19

14

Front 20

Maxillary first molars

Root grooves

Back 20

Distinct, longitudinal

Front 21

Maxillary first premolars

# of roots

Back 21

Usually 2

Front 22

Maxillary first premolars

# of pulp canals

Back 22

Often 2

Front 23

Maxillary first premolars

Age of eruption

Back 23

10-11

Front 24

Maxillary first premolars

Root completed

Back 24

12-13

Front 25

Maxillary first premolars

Where are bifurcated roots located

Back 25

Buccal and lingual

Front 26

Maxillary first premolars

Cross section shape

Back 26

Kidney bean shape because of concavity

Front 27

Maxillary first premolars

Buccal cusp vs. lingual cusp size

Back 27

Buccal cusp is longer/sharper than lingual

Front 28

Maxillary first premolars

Shape from buccal aspect

Back 28

Trapezoid

Front 29

Maxillary first premolars

vs. anterior teeth

Back 29

Wider faciolingually than mesiodistally, broader contact areas

Front 30

Maxillary first premolars

What is an identifying characteristic from the facial aspect?

Back 30

Mesial cusp slope is longer than the distal cusp slope. Only tooth in the mouth with a longer mesiobuccal cusp than distobuccal.

Front 31

When viewed from the mesial, an identifying characteristic of the maxillary first premolar is?

Back 31

Presence of a mesial developmental depression