Lecture 4 Mandibular Incisors

Question 1

what are the numbers of the mandibular central incisors

Answer 1

24 and 25

Question 2

what number is the right lateral mandibular incisor

Answer 2

23

Question 3

what number is the left mandibular lateral incisor

Answer 3

26

Question 4

what are embrasures

Answer 4

the spaces that widen out from the contact

Question 5

what is the interproximal contact

Answer 5

where two adjacent teeth contact each other

Question 6

what are the embrasure spaces of anterior teeth

Answer 6

incisal, gingival, facial, lingual

Question 7

what are the embrasure spaces of the posterior teeth

Answer 7

occlusal, gingival, facial, lingual

Question 8

what are the relationships between embrasures in the anterior teeth

Answer 8

-incisal < gingival
- facial = lingual

Question 9

what are the relationships between embrasures in the posterior teeth

Answer 9

• occlusal = gingival
• facial < lingual

Question 10

what makes up the gingival embrasure

Answer 10

the interdental papilla

Question 11

what are mandibular incisors used for

Answer 11

incise or cut food

Question 12

what tooth is the smallest tooth in the mouth

Answer 12

the mandibular central incisors

Question 13

which incisors in the mandible are smaller

Answer 13

the central incisors

Question 14

which tooth has the smallest mesiodistal diameters

Answer 14

mandibular central incisors

Question 15

describe the relationship between buccolingual measurement and mesiodistal measurement of the mandibular incisors

Answer 15

broader buccolingually than mesiodistally

Question 16

describe the shape of the mandibular central incisor from the facial view

Answer 16

trapezoidal, tapers cervically

Question 17

describe the incisal outline of the mandibular central incisor

Answer 17

straight, mamelons are present when the tooth erupts

Question 18

describe the mesioincisal and distoincisal angles of the mandibular central incisor

Answer 18

both are 90 degrees

Question 19

what tooth is the only symmetrical tooth in the mouth

Answer 19

mandibular central incisor

Question 20

where are the mesial and distal contact areas for the mandibular central incisor

Answer 20

both contacts are at the same level in the incisal 1/3

Question 21

describe the labial surface of the mandibular central incisor

Answer 21

-smooth, no developmental depressions
- flat in incisal 1/3 and becomes for convex cervically

Question 22

describe the root of the mandibular central incisor

Answer 22

single root, narrow mesiodistally, curves distally in some cases
- root length is greater than crown length

Question 23

describe the shape of the central incisor from the lingual view

Answer 23

-trapezoidal in outline
-smooth and rounded, slightly concave but no lingual fossa

Question 24

describe the ridges and the cingulum of the mandibular central incisor from the lingual view

Answer 24

-mesial and distal marginal ridges are only minor elevations
- cingulum is much less distinct than in the maxillary incisors
- no developmental grooves

Question 25

describe the shape of the mandibular central incisor from the mesial view and the height of contour

Answer 25

-triangular in outline -labial outline is convex - height of contour is in the cervical 1/3rd

Question 26

from the mesial view of the mandibular central incisor where does the incisal edge lie in respect to the line bisecting the root

Answer 26

lingual

Question 27

describe the CEJ of the mandibular central incisor from the mesial view

Answer 27

CEJ curves incisally about 1mm more than on the distal

Question 28

what happens to the mandibular central incisor when worn

Answer 28

the incisal edge angles to the facial

Question 29

describe the cervical line of the mandibular central incisor from the mesial aspect (Lingual vs labial)

Answer 29

cervical line extends 1mm more apically on the lingual than on the labial

Question 30

describe the root of the mandibular central incisor

Answer 30

extends straight from CEJ and tapers apically from middle 1/3 - may have broad developmental depression along its length (depression is greater on distal root than mesial)

Question 31

describe the differences of the mandibular central incisor from the distal view compared to the mesial view

Answer 31

-cervical lines curves incisally 1 mm less distally than on mesial - developmental depression on distal of root is greater than on mesial

Question 32

describe the incisal edge in comparison to a line bisection the crown labiolingually of the mandibular central incisor

Answer 32

incisal edge is at right angles to the line - incisal edge lies lingual to center of the tooth

Question 33

where are the contact areas of the mandibular central incisor from the incisal view

Answer 33

they are centered labiolingually

Question 34

describe the width of the labial surface vs the lingual surface from the incisal view of the mandibular central incisor

Answer 34

the MD width of the labial surface is wider than the MD width of the lingual surface

Question 35

describe the root and pulp of the mandibular central incisor

Answer 35

single root, root is broader FL than MD - developmental depressions on mesial and distal (D > M) -usually one pulp canal but 40% of population has 2 pulp canals (facial and lingual canals if 2)

Question 36

how is the mandibular lateral incisor bigger than the central incisor

Answer 36

wider MD than the central incisor, all extra width appears to be added to the distal aspect of the tooth

Question 37

describe the crown height of the mandibular lateral incisor from the facial view

Answer 37

distal crown height is often shorter than the mesial crown height, incisal edge slopes downward distally

Question 38

describe the distoincisal angle and the mesioincisal angle of the mandibular lateral incisor from the facial view

Answer 38

mesioincisal is 90 distoincisal is rounded

Question 39

where are the mesial and distal contacts of the mandibular lateral incisor from the facial view

Answer 39

incisal 1/3. distal contact is more cervical than the mesial

Question 40

describe the lingual view of the mandibular lateral incisor compared to the mandibular central incisor

Answer 40

same

Question 41

describe the difference between the distal view and mesial view of the mandibular lateral incisor

Answer 41

the distal aspect is twitsed lingually. the lingual surface is not visible from distal

Question 42

describe the incisal edge of the mandibular lateral incisor

Answer 42

lingual to the center of the tooth

Question 43

describe the distofacial line angle of the mandibular lateral incisor from the incisal view

Answer 43

DF is more lingual

Question 44

describe the pulp canal on the manibular lateral incisor

Answer 44

typically one canal, but can have 2 40% of the time