central incisor

Maxillary IncisorsMaxillary Incisors

Dr. Syed SadatullahDr. Syed SadatullahKing Khalid University King Khalid University

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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


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Maxillary Central Incisor


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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.


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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 depressions

1,2 & 3: Lobes (4th lobe not visible)Dr.Syed Sadatullah King Khalid

University Abha

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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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


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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

Labiolingual

Diameter at

Cervical Line

Labiolingual

Diameter at

Crest of Curvature

Mesiodistal

Diameter at

Cervical Line

Mesiodistal

Diameter at

Contact Area

Root

Length

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


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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 aspect


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central incisor

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