Maxillary Incisors Flashcards
What are the general characteristics of maxillary central incisors?
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
What is the crown shape of the facial aspect of the maxillary central incisor?
trapezoidal
4-sided planar figure with 2 sides parallel
How long and wide is the crown on the facial aspect?
long: 10-11 mm
wide: 8-9 mm
What is the mesiodistal dimension of the maxillary central incisor?
6-7 mm (2 mm narrower at CEJ than width of crown)
Define height of convexity/contour
point of the greatest convexity on a tooth surface
What is the height of convexity of mesial surface of maxillary central incisor?
incisal 1/3 of tooth
What are the 3 components of the facial aspect of the maxillary central incisor?
cervical 1/3
middle 1/3
incisal 1/3
Which side is more convex - mesial or distal outline?
distal
What is the height of contour on the distal outline?
junction of the middle and incisal 1/3
Newly erupted central incisors present what?
mamelons
What are mamelon?
3 rounded protuberances found on the incisal edges of newly erupted incisors
What is the mesoincisal angle of the maxillary central incisor? What is the distoincisal angle?
MI: right angle
DI: more rounded than MI
What is a line angle?
junction of two tooth surfaces
What is a point angle?
junction of three tooth surfaces
What are the aspects of the root?
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
What is long axis?
is a line extending through the center of an object lengthwise
What is a ridge?
a linear elevation on the surface of a tooth and is named according to location
(mesial and distal marginal ridges)
What is the lingual fossa?
bounded by the incisal edge, mesial and distal marginal ridges, and the cingulum
What is the cingulum?
bulbous convexity on the cervical third of the lingual surface on an anterior tooth
What is a pit?
a small pinpoint depression in the depths of developmental processes
Describe features of the lingual aspect of the maxillary central incisor
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
Describe features of the mesial aspect of the maxillary central incisor
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
What is an interesting fact regarding the mesial cervical line on the maxillary central incisor?
has the greatest amount of curvature of any tooth in the mouth
Describe features of the distal aspect of maxillary central incisor
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
Describe features of the incisal aspect of maxillary central incisor
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
Where is the point of convexity in the cingulum of the maxillary central incisor?
distal to the center of the lingual surface
What is a proximal surface?
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)
Mesiofacial and distofacial line angles are more prominent than
mesial and distal lingual angles
DF line angle is more obtuse/rounded than the MF line angle
Where are developmental depressions present on maxillary central incisor?
labial surface (ridges and depressions)
What are the dimensions of the central incisor?
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
What are the lobes of the central incisor?
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
What marks the junctions of the lobes?
mesiofacial and distofacial developmental depressions
Describe the features of pulp in accordance to facial view and cross sectional view
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
What tooth is most frequently missing?
maxillary lateral incisors
What are the maxillary lateral incisors?
7 (R), #10 (L)
erupt at 8-9 years of age
supplement the central incisor in function
What is an interesting fact regarding the maxillary lateral incisor?
varies in form more than any other tooth in the mouth
are the most frequently congenitally absent anterior tooth
exception: third molars
What are the general characteristics of maxillary lateral incisors?
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
Describe the facial aspects of the maxillary lateral incisor (regarding mesial surface)
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
Describe the facial aspects of the maxillary lateral incisor (regarding distal surface)
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
Describe the facial aspect of the maxillary lateral incisor (regarding the labial surface)
more convex than the central incisor
root is pointed, as long or longer than the central incisor, usually tapers distally
Describe the lingual aspect of the maxillary lateral incisor
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
Describe the mesial aspect of the maxillary lateral incisor
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
Describe the distal aspect of the maxillary lateral incisor
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
Describe the incisal aspects of the maxillay lateral incisor
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
Describe the pulp within the maxillary lateral incisor
single canal
facial view = 2 pulp horns
cross sectional view may be triangular, round, or ovoid
