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abhishek-solanki
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INTRODUCTION Second tooth from the midline in each lower quadrant
Shares a mesial contact area with the central incisor.
Mandibular lateral incisor is slightly wider mesiodistally
slightly larger in all respects than the mandibularcentral incisor
complements the central in function.
The distal contact is with the deciduous mandibularcanine until that tooth's exfoliation and then contact isshared with the permanent canine.
CHRONOLOGY
First evidence of calcification 3-4 months
Crown completion 4-5 years
Eruption 7-8 years
Root completion 10 years
DIMENSIONS
Cervico incisal Length of crown
Length of the root
Mesiodistal diameter of crown
Mesiodistal diameter of crown at
cervix
Labio or Buccolingualdiameter of
Crown Cervix
Curvature of cervical line –
Mesial Distal
9.5 mm 14.0 mm 5.5 mm 4.0mm 6.5 mm 5.8 mm 3 mm 2 mm
Labial Aspect Incisal margin may slope slightly gingivally toward distal,
which results in a distoincisal angle that is more rounded
than same angle of central incisor
This feature creates a slightly shorter distal margin, when
compared to mesial outline
Contact area on distal is more cervically located than on
the mesial, thus creating a more cervically located height
of contour on distal outline
Both heights of contour are still in incisal third
Lingual Aspect Lingual outlines are similar to those of labial aspect
Structures of lingual surface are similar to their
counterparts on the central incisor except cingulum is
more offset to distal, and as a result curvature of
cervical line is also offset distally
Mand. Lat. InciosorMand. Central Incisor
M D D M
• Concavity in lingual aspect is slightly more when
compared to mandibular central incisor
• MMR > DMR
Lingual fossa more concave
Mesial & Distal Aspects Two surfaces are similar to their counterparts on central
incisor, with a few minor exceptions.
Lateral's distal surface is slightly shorter inciso-cervically
than mesial surface.
Both cervical line curvatures are slightly less than their
counterparts in the central.
MESIAL DISTAL
Mesial cervical line shows greater incisal curvature than
does the distal
At distal contact area, height of contour is more
cervically located than on mesial
In incisal third, distal contact area is very near to junction
of incisal & middle thirds & is most cervically located of
any mandibular incisor contact
Incisal Aspect Incisal edge is not straight mesiodistally, as it is in
central, rather it curves toward lingual in its distal portion
Lingual contour (cingulum) appears displaced toward
distal. These factors give crown the appearance of being
slightly twisted on its root
Best identifying features, when differentiating this tooth
from central incisor
M D
Root Root length is normally a little greater than in central
incisor
Root is also slightly thicker and wider
Root concavities may be found on the mesial and distal
root surfaces, and if present, concavity in distal is usually
more pronounced