Endodontic Anatomy

Question 1

Define “pulp chamber”

Answer 1

Portion of pulp space within the anatomic crown of the tooth.

Question 2

Pulp chamber is bordered by?

Answer 2

• Pulp chamber roof = most coronal extent of the pulp chamber
• Pulp chamber floor = most apical extent of the pulp chamber

Question 3

Define “Pulp horn”

Answer 3

Extension of pulp tissue into occlusal/incisal projections that follow the cusp tips.

Question 4

Define “canal orifice”

Answer 4

Opening leading from pulp chamber into root canal

Question 5

Define “root canal”

Answer 5

Channel in the root of tooth extending from the pulp chamber to apical foramen.

Question 6

Define “accessory canal”

Answer 6

Any branch of the main pulp canal that connects with external surface of root.

Question 7

Define “furcation canal”

Answer 7

Accessory canal at furcation

Question 8

Define “lateral canal”

Answer 8

Horizontal accessory canal that branch from the coronal or middle zone.

Question 9

Define “foramen” in apical anatomy

Answer 9

Opening at root apex

Question 10

Define “apical constriction”

Answer 10

Narrowest portion of root canal. Usually 0.5 - 1.0 mm from foramen.

Question 11

Define “apex”

Answer 11

End of tooth root. Not necessarily the end of the canal.

Question 12

Location of “pulp chamber”

Answer 12

• Centered in crown of tooth.

- Reflects outline of tooth at CEJ.

Question 13

Location of “root canals”

Answer 13

• Centered or symmetrically disturbed in roots.

- Reflects the shape of the root.

Question 14

Define “law of centrality”

Answer 14

Outline of the pulp chamber mirrors the outer border of the tooth at the CEJ level. Pulp chamber is always centered in tooth at level of CEJ.

Question 15

Define “law of symmetry 1”

Answer 15

Except for maxillary molars, paired orifices are equidistant from a line drawn in a mesiodistal direction through the pulp chamber floor AND unpaired orifices lie on the line.

Question 16

Define “law of symmetry 2”

Answer 16

Except for maxillary molars, paired orifices lie on a line perpendicular to a line drawn in a mesiodistal direction through the pulp chamber floor.

Question 17

Define “law of colour change”

Answer 17

the colour of the pulp chamber is always darker than the walls.

Question 18

Define “law of orifice location 1”

Answer 18

Orifices are located at the junction of walls and floors

Question 19

Define “law of orifice location 2”

Answer 19

Orifices are located at the angles in the floor-wall junction

Question 20

Define “law of orifice location 3”

Answer 20

Orifices are located at the terminus of the root developmental fusion lines.

Question 21

Maxillary central incisor has:

Answer 21

1 Root

1 Canal

Question 22

Maxillary lateral incisor has:

Answer 22

1 Root

1 Canal

Question 23

Maxillary canine tooth has:

Answer 23

1 root

1 Canal

Question 24

Maxillary first premolar has:

Answer 24

1 or 2 Roots
2 Canals (67%)

Question 25

Maxillary second premolar has:

Answer 25

1 or 2 Roots
2 Canals (50%)

Question 26

Maxillary first molar has:

Answer 26

3 Roots
4 Canals (95%)

Question 27

Maxillary second molar has:

Answer 27

3 Roots
4 Canals (80%)

Question 28

Mandibular central incisor / lateral incisor has:

Answer 28

1 Root
2 Canals (40%)
1 Canal (60%)

Question 29

Mandibular canine tooth has:

Answer 29

1 Root
1 Canal (94%)
2 Canals (6%)

Question 30

Mandibular first premolar has:

Answer 30

1 Root
1 canal + 1 foramen (75%)
2 canals + 2 Foramen (20%)

Question 31

Mandibular second premolar has:

Answer 31

1 root
1 canal + 1 foramen (85%)
2 canals + 2 foramen (10%)

Question 32

Mandibular first molar has:

Answer 32

2 roots
4 canals (60%)
3 canals (40%)

Question 33

Mandibular second molar has:

Answer 33

2 roots

Variable number of canals.