The mandibular lateral incisor is the second tooth from the midline in the lower jaw. It is slightly wider than the central incisor and complements its function. The lateral incisor develops crown completion at 4-5 years and typically erupts around 7-8 years of age. Key distinguishing features are its twisted appearance due to the lingually curved incisal edge and displaced cingulum on the lingual surface. The distal root surface often has a more pronounced concavity compared to the mesial surface.

1. By
Dr. Abhishek Solanki

2. 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

3.  slightly larger in all respects than the mandibular
central incisor
 complements the central in function.
 The distal contact is with the deciduous mandibular
canine until that tooth's exfoliation and then contact is
shared with the permanent canine.

4. Labial aspect Lingual aspect
Mesial aspect
Distal aspect
Incisal aspect

5. TOOTH NUMBERING SYSTEM
UNIVERSAL SYSTEM - 23,26
 ZSIGMONDY / PALMER - 2 2
 FDI SYSTEM - 32, 42

6. CHRONOLOGY
 First evidence of calcification 3-4 months
 Crown completion 4-5 years
 Eruption 7-8 years
 Root completion 10 years

7. DIMENSIONS
Cervico incisal
Length of crown
Length of the
root
Mesiodistal
diameter of
crown
Mesiodistal
diameter
of crown at
cervix
Labio or Buccolingual
diameter 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

8. 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

9.  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

10. 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

11. • Concavity in lingual aspect is slightly more when
compared to mandibular central incisor
• MMR > DMR
Lingual fossa more concave

12. 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

13.  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

14. 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

15. 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

16. Variations and Anomalies:
 Anomalies are rare, but occasionally a bifurcated root is
found

17. References
 CONCISE DENTAL ANATOMY & MORPHOLOGY :
JAMES L FULLER
 DENTAL ANATOMY, PHYSIOLOGY & OCCLUSION:
WHEELER’S
 TEXTBOOK OF DENTAL ANATOMY, PHYSIOLOGY &
OCCLUSION: RASHMI GS (PHULARI)
 INTERNET