Maxillary Incisors

Question 1

What are the general characteristics of maxillary central incisors?

Answer 1

member of the incisor classification of teeth
used to cut or incise food
shovel shaped
2 in maxillary arch (#8,9)
succedaneous teeth
erupt at 7-8 years

Question 2

What is the crown shape of the facial aspect of the maxillary central incisor?

Answer 2

trapezoidal
4-sided planar figure with 2 sides parallel

Question 3

How long and wide is the crown on the facial aspect?

Answer 3

long: 10-11 mm
wide: 8-9 mm

Question 4

What is the mesiodistal dimension of the maxillary central incisor?

Answer 4

6-7 mm (2 mm narrower at CEJ than width of crown)

Question 5

Define height of convexity/contour

Answer 5

point of the greatest convexity on a tooth surface

Question 6

What is the height of convexity of mesial surface of maxillary central incisor?

Answer 6

incisal 1/3 of tooth

Question 7

What are the 3 components of the facial aspect of the maxillary central incisor?

Answer 7

cervical 1/3
middle 1/3
incisal 1/3

Question 8

Which side is more convex - mesial or distal outline?

Answer 8

distal

Question 9

What is the height of contour on the distal outline?

Answer 9

junction of the middle and incisal 1/3

Question 10

Newly erupted central incisors present what?

Answer 10

mamelons

Question 11

What are mamelon?

Answer 11

3 rounded protuberances found on the incisal edges of newly erupted incisors

Question 12

What is the mesoincisal angle of the maxillary central incisor? What is the distoincisal angle?

Answer 12

MI: right angle
DI: more rounded than MI

Question 13

What is a line angle?

Answer 13

junction of two tooth surfaces

Question 14

What is a point angle?

Answer 14

junction of three tooth surfaces

Question 15

What are the aspects of the root?

Answer 15

single root
cone shaped with a blunt apex
13 mm long
apex of the root is slightly to the distal of the long axis of the tooth

Question 16

What is long axis?

Answer 16

is a line extending through the center of an object lengthwise

Question 17

What is a ridge?

Answer 17

a linear elevation on the surface of a tooth and is named according to location
(mesial and distal marginal ridges)

Question 18

What is the lingual fossa?

Answer 18

bounded by the incisal edge, mesial and distal marginal ridges, and the cingulum

Question 19

What is the cingulum?

Answer 19

bulbous convexity on the cervical third of the lingual surface on an anterior tooth

Question 20

What is a pit?

Answer 20

a small pinpoint depression in the depths of developmental processes

Question 21

Describe features of the lingual aspect of the maxillary central incisor

Answer 21

root is cone shaped
tapers toward distal slightly
crown and root taper to lingual
part of the medial and distal aspect of the tooth can be seen from the lingual aspect
CEJ is curved convex toward the root

Question 22

Describe features of the mesial aspect of the maxillary central incisor

Answer 22

triangular or wedge shape
base in cervical area
apex at the incisal edge
facial outline is slightly curved
flat incisally
lingual outline is concavo-convex
root is cone shaped
apex is blunted
incisal surface slopes towards the lingual

Question 23

What is an interesting fact regarding the mesial cervical line on the maxillary central incisor?

Answer 23

has the greatest amount of curvature of any tooth in the mouth

Question 24

Describe features of the distal aspect of maxillary central incisor

Answer 24

similar to mesial aspect except the crown looks thick in incisal 1/3
curvature of the cervical line or CEJ is less than on the mesial

Question 25

Describe features of the incisal aspect of maxillary central incisor

Answer 25

triangular in shape tooth is wider facially than lingually facaial surface is broad and flat lingual surface is narrower and curved incisal edge bisects the faciolingual diameter

Question 26

Where is the point of convexity in the cingulum of the maxillary central incisor?

Answer 26

distal to the center of the lingual surface

Question 27

What is a proximal surface?

Answer 27

the surface of a tooth that adjoins the surface of another tooth in the same arch (e.g. mesial and distal surfaces of adjacent teeth)

Question 28

Mesiofacial and distofacial line angles are more prominent than

Answer 28

mesial and distal lingual angles DF line angle is more obtuse/rounded than the MF line angle

Question 29

Where are developmental depressions present on maxillary central incisor?

Answer 29

labial surface (ridges and depressions)

Question 30

What are the dimensions of the central incisor?

Answer 30

crown length = 10-11mm crown width = 8.5 mm labiolingual width = 7 mm rooth length = 13 mm crown is longer than it is wide root is longer than the crown crown is wider mesiodistally than faciolingually

Question 31

What are the lobes of the central incisor?

Answer 31

mesial lobe: mesial marginal ridge and mesial part of labial surface distal lobe: distal marginal ridge and distal part of labial surface labial lobe: slightly prominent ridge lingual lobe: forms the cingulum

Question 32

What marks the junctions of the lobes?

Answer 32

mesiofacial and distofacial developmental depressions

Question 33

Describe the features of pulp in accordance to facial view and cross sectional view

Answer 33

facial view: pulp chamber with three pulp horns, pulp horns disappear as patient ages cross sectional view: triangular in view, mesial distal and facial wall, mesial wall is longer than the distal

Question 34

What tooth is most frequently missing?

Answer 34

maxillary lateral incisors

Question 35

What are the maxillary lateral incisors?

Answer 35

#7 (R), #10 (L) erupt at 8-9 years of age supplement the central incisor in function

Question 36

What is an interesting fact regarding the maxillary lateral incisor?

Answer 36

varies in form more than any other tooth in the mouth are the most frequently congenitally absent anterior tooth exception: third molars

Question 37

What are the general characteristics of maxillary lateral incisors?

Answer 37

similar in shape to central incisors (trapezoidal) smaller in all dimensions (by 2mm), except root length more rounded more pronounced mesial and distal marginal ridges (lingual surfaces) lingual fossa is deeper

Question 38

Describe the facial aspects of the maxillary lateral incisor (regarding mesial surface)

Answer 38

smaller in all dimensions by 2 mm trapezoidal incisal outline is more rounded mesial outline is slightly convex mesial height of contour is at the junction of the middle and incisal 1/3 mesioincisal angle is a slightly rounded angle

Question 39

Describe the facial aspects of the maxillary lateral incisor (regarding distal surface)

Answer 39

distal outline is more rounded than the central distal height of contour is middle 1/3 distoincisal angle is more rounded than MI DI angle is more rounded tahn the DI angle in the central incisor

Question 40

Describe the facial aspect of the maxillary lateral incisor (regarding the labial surface)

Answer 40

more convex than the central incisor root is pointed, as long or longer than the central incisor, usually tapers distally

Question 41

Describe the lingual aspect of the maxillary lateral incisor

Answer 41

trapezoidal in shape lingual fossa is deeper than central incisor (often with a lingual pit) prominent mesial and distal marginal ridges pronounced cingulum deep developmental grooves (lingual development grooce on distal of cingulum) tooth tapers to the lingual

Question 42

Describe the mesial aspect of the maxillary lateral incisor

Answer 42

triangular in outline labial outline is slightly convex lingual outline is concavo-convex greatest curvature (height of contour) on the facial and lingual surfaces is located in the cervical 1/3 incisal surface/edge is angled lingually cervical curvature curves incisally - less than the central incisor root is cone shaped and tapers apically line through the center of the root bisects the incisal surface

Question 43

Describe the distal aspect of the maxillary lateral incisor

Answer 43

triangular in outline appears wider than mesial view (distal of tooth curved lingually to conform to arch shape) cervical line curvature (1mm less than the medial curvature) may have a developmental groove on the distal of the crown extending down the root

Question 44

Describe the incisal aspects of the maxillay lateral incisor

Answer 44

contour is more convex ovoid in shape crest of the cingulum slightly to the distal of center of the tooth DL line angle is more rounded than ML line angle (both these line angles more rounded than in the central incisor) mesial and distal contact areas are centered labiolingually

Question 45

Describe the pulp within the maxillary lateral incisor

Answer 45

single canal facial view = 2 pulp horns cross sectional view may be triangular, round, or ovoid