Maxillary Incisors Dr. Syed Sadatullah Ibn Sina National College Jeddah.

Maxillary IncisorsMaxillary Incisors

Dr. Syed SadatullahDr. Syed SadatullahIbn Sina National CollegeIbn Sina National College

JeddahJeddah

IntroductionIntroduction

Maxillary incisors are four in numberMaxillary incisors are four in number

Maxillary central incisor and lateral are similar in Maxillary central incisor and lateral are similar in anatomy and complement each other in functionanatomy and complement each other in function

Their major function is to cut teethTheir major function is to cut teeth

Maxillary central incisor erupts between the age of 7 and Maxillary central incisor erupts between the age of 7 and 8 and it is the second permanent tooth to erupt8 and it is the second permanent tooth to erupt

Maxillary lateral incisor erupts between the age of 8 and Maxillary lateral incisor erupts between the age of 8 and 99

Maxillary Central Incisor

Labial aspect The mesial margin is straight and meets the incisal

edge at right angle. The distal margin is shorter and more rounded.

The distoincisal angle is more rounded than the mesioincisal angle.

The labial surface is marked by two developmental groove and has convexity in cervical third.

Maxillary central incisor is the widest anterior tooth mesiodistally

Labial aspect

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.

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.

Lingual 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

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

Mesial aspect

Distal aspect

Distal surface is very similar to the mesial surface.

Distal aspect

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

Incisal aspect

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.

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

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

The mesioincisal and distoincisal angles are more rounded than the corresponding angles of the maxillary central incisor

On the lingual aspect the marginal ridges and cingulum are more prominent

Labial aspect

Lingual aspect

Mesial aspect Distal aspect