Maxillary Incisors Maxillary Incisors Dr. Syed Sadatullah Dr. Syed Sadatullah King Khalid University King Khalid University Abha Abha
Maxillary IncisorsMaxillary Incisors
Dr. Syed SadatullahDr. Syed SadatullahKing Khalid University King Khalid University
AbhaAbha
Contents Morphology of Permanent Maxillary Central Incisor Chronology and dimensions of Maxillary Central Incisor Brief morphology of Maxillary Lateral Incisor
Objectives Identification of maxillary incisors from other teeth Understand the morphology of maxillary central and
lateral incisor Distinguish between the labial, lingual, mesial, distal and
incisal surfaces of the maxillary incisors
Dr.Syed Sadatullah King Khalid University
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Introduction
Maxillary incisors are four in number
Maxillary central incisor and lateral are similar in anatomy and complement each other in function
Their major function is to cut food
Maxillary central incisor erupts between the age of 7 and 8 and it is the second permanent tooth to erupt
Maxillary lateral incisor erupts between the age of 8 and 9
Dr.Syed Sadatullah King Khalid University
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Maxillary Central Incisor
Dr.Syed Sadatullah King Khalid University
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Labial aspect
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Labial aspect The mesial margin is straight and meets the
incisal edge at right angle. The distal margin is shorter and more rounded.
Dr.Syed Sadatullah King Khalid University
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Mesial margin straight
Distal margin shorter & rounded
The distoincisal angle is more rounded than the mesioincisal angle.
Distoincisal angle more rounded
Mesioincisal angle rounded
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The labial surface is marked by two developmental groove and has convexity in cervical third.
Convexity in cervical third a b
a & b: Developmental depressions1,2 & 3: Lobes (4th lobe not visible)Dr.Syed Sadatullah King Khalid
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Maxillary central incisor is the widest anterior tooth mesiodistally
Widest anterior teeth
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Lingual aspect
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Lingual aspect The crown profile is same as that of labial surface
except that there is a broad depression in the central portion called the lingual fossa and a well developed cingulum.
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Lingual fossa
Cingulum
Marginal ridges
Lingual ridge
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The lingual fossa is bordered by mesial and distal marginal ridges on the sides and the cingulum cervically.
The cervical line on labial and lingual surface is convex apically.
Cervical line convex
Lingual aspectLabial aspect
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Mesial aspect
Mesial aspect From the mesial aspect the labial margin is convex
The lingual margin is ‘S’ shaped, being convex near cingulum and concave in the middle
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Labial margin convex
Convex near cingulum
Concave in the middle
Mesial curvature of cervical line (3.5mm) is the most pronounced compared to any other tooth.
The cervical line on the mesial and distal surface is convex incisally
Cervical line
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Dr.Syed Sadatullah King Khalid University
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Distal aspect
Distal aspect Distal surface is very similar to the mesial
surface.
Incisal aspect The crown and incisal margin are centered over
root
Crown profile is almost bilaterally symmetrical
The incisal margin of newly erupted teeth show three elevations called mamelons. They correspond to the developmental lobes
Dr.Syed Sadatullah King Khalid University
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Dr.Syed Sadatullah King Khalid University
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Incisal ridge
Incisal aspect
Bilaterally symmetrical
RootThe root is straight and tapers from the cervical line to the apex giving it a conical shape
The root ends in a blunt apex.
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Straight conical blunt root
3.5 2.5 6.0 7.0 7.0 8.5 13.0 10.5
Curvature of Cervical Line M D
LabiolingualDiameter atCervical Line
LabiolingualDiameter atCrest of Curvature
MesiodistalDiameter atCervical Line
MesiodistalDiameter atContact Area
RootLength
Crown Length
Average Dimensions in millimeters
Contact Area Max C.I
Mesial Distal
I3 JIM3
I3- Incisal thirdJIM3-Junction of incisal & middle third
CHRONOLOGYAppearance of enamel organ 5 m.i.u
First evidence of calcification 3-4 months
Crown completion 4-5 years
Eruption 7-8 years
Root completion 10-11 years
Dr.Syed Sadatullah King Khalid University
Abha
Dr.Syed Sadatullah King Khalid University
Abha
Maxillary Lateral Incisor The general shape is similar to maxillary central
incisors except that they are shorter and narrower.
Next to third molars maxillary lateral incisors are the teeth that show most variation in crown size, shape and form
Maxillary central incisor bigger and lateral incisor smaller
The mesioincisal and distoincisal angles are more rounded than the corresponding angles of the maxillary central incisor
Distoincisal angle more rounded
Mesioincisal angle more rounded
Maxillary Lateral Incisor Maxillary Central
Incisor
Mesioincisal angle
Distoincisal angle
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On the lingual aspect the marginal ridges and cingulum are more prominent
Prominent cingulum
Prominent marginal ridges
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Labial aspect
Lingual aspect
Mesial aspect Distal aspectDr.Syed Sadatullah King Khalid
University Abha