morphology of mandibular central and lateral incisors teeth
1.
2. Contents
Morphology of Permanent Mandibular Central Incisor
Chronology and dimensions of Mandibular Central
Incisor
Brief morphology of Mandibular Lateral Incisor
Objectives
Identification of mandibular incisors from other teeth
Understand the morphology of mandibular central and
lateral incisor
Distinguish between the labial, lingual, mesial, distal and
incisal surfaces of the mandibular incisors
3. Introduction
Mandibular incisors are four in number
Mandibular central incisor and lateral are similar in
anatomy and complement each other in function
They are smaller than the maxillary incisors
Mandibular central incisor erupts between the age of 6
and 7
Mandibular lateral incisor erupts between the age of 6
and 8
7. Labial aspect
Labial surface of mandibular central incisor is very
small. It is the narrowest tooth mesiodistally of all
the permanent teeth
Narrowest tooth in the dentition
8. It is bilaterally symmetrical
It is the only incisor where both mesioincisal and
distoincisal angles are sharp and at right angles
Labial aspect
Both mesioincisal and
distoincisal angles are sharp
10. Lingual aspect
The lingual aspect is concave from the incisal edge to
the cervical line
Cingulum is smooth and barely visible
Shallow lingual fossa and
smooth cingulum
11. The surface is smooth and devoid of any grooves. No
other tooth in the mouth, except the mandibular
lateral incisor, shows so few developmental lines and
grooves.
13. Mesial aspect
The labial outline is almost straight, except near
cervical third where it is convex
The labial surface is inclined lingually
Labial surface inclined
lingually
14. The lingual margin is ‘S’ shaped
The cervical line on the mesial and distal surface is
convex incisally
‘S’ shaped lingual surface
Cervical line convex incisally
17. ncisal aspect
his aspect illustrates the bilateral symmetry of this
tooth.
he labiolingual diameter is greater than mesiodistal
diameter.
Bilaterally symmetrical
Labiolingually bigger
than mesiodistally
18. Newly erupted teeth show mamelons which wear off
upon mastication
Mamelons
19. Root
The root is single and straight.
The deflection of the root if present is on the labial or
distal side.
Single and straight root
20. 3.0 2.05.36.03.55.012.59.0
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
CHRONOLOGY
Appearance of enamel organ 5 m.i.u
First evidence of calcification 3-4 months
Crown completion 4-5 years
Eruption 6-8 years
Root completion 10 years
Contact Area
Man L.I
Mesial Distal
I3 I3
I3- Incisal third
22. The cervical portion of the lingual aspect is narrower
while the incisal portion is wider. This gives the crown
a more or less a fan shaped appearance
Cervical portion narrower
Fan shaped appearance
23. The concavity in the lingual aspect is slightly more
when compared to mandibular central incisor
The incisal edge follows the mandibular arch, giving
the crown a slightly twisted appearance on its root
Lingual fossa more concave