Lower central incisor
It is the smallest of all teeth; the crown fits into a trapezoid with a large upper base.
The cervical edge is semicircular; the proximal mesial and distal edges are very noticeably convergent in the apical direction but almost straight, which makes the free edge almost horizontal.
I- chronology:
Start of calcification 3 to 4 months
Crown completed 4 to 5 years
Age of eruption 6 to 7 years
Root completed 9 years
II- average measurements :
Total tooth height: 21.5 mm
Crown height: 9 mm
Root height: 12.5 mm
Coronal mesio-distal diameter 5 mm
Cervical mesio-distal diameter 3.5 mm
Coronal vestibulo-lingual diameter: 6 mm
Cervical vestibulo-lingual diameter: 5.3 mm
DESCRIPTION
1- Vestibular view : the mesial and distal incisal angles are acute and the mesial and distal flanks of the crown are parallel in the occlusal 1/3 up to the points of contact with the adjacent teeth.
The mesial and distal root contours are aligned with those of the crown and it is almost always impossible to distinguish a more closed distal angle at this radiculo-coronal junction.
The apical 1/3 of the root is sometimes involved distally, most often it is straight.
2- lingual view: generally presents a more or less limited concavity between the ridges
marginals and the cingulum.
3- mesial and distal view: their
Silhouettes are reminiscent of incisors
superiors.
The vestibular contour is strongly convex
In his cervical quarter;
the lingual contour has an S shape.
4- occlusal view : more symmetrical than the upper central incisor in
vestibulo-ligual direction, the pulp cavity follows the contour
root.
5- the root: it is tapered, thin and very flattened in
the mesio-distal direction, tilts very slightly towards the distal side.
Pulp chamber : very small and has 3 small horns which correspond to the 3 lobes.
Situation in the mouth : the vestibular face is inclined towards the lingual side, the root is inclined very slightly towards the distal side by about 1° compared to the vertical.
Lower central incisor
Early cavities in children need to be treated promptly.
Dental veneers cover imperfections such as stains or cracks.
Misaligned teeth can cause difficulty chewing.
Dental implants provide a stable solution to replace missing teeth.
Antiseptic mouthwashes reduce bacteria that cause bad breath.
Decayed baby teeth can affect the health of permanent teeth.
A soft-bristled toothbrush preserves enamel and gums.