The document describes the anatomy and development of human incisor teeth. It discusses: - Incisor teeth have 5 aspects (facial, lingual, mesial, distal, incisal) and develop over time, with the crown completing between 4-5 years and erupting around 7-8 years. - Key anatomical features include marginal ridges, cingulum, and incisal ridge on the lingual surface, as well as convex mesial and distal outlines that converge lingually. - Variations like Hutchinson's incisors and talon cusps are also mentioned. The document provides detailed descriptions and diagrams of incisor tooth morphology.

2. byby
prof. Dr.prof. Dr.
Youssry El-HawaryYoussry El-Hawary

3. CHRONOLOGY:CHRONOLOGY:
Appearance of enamel organ 5 m.i.u.Appearance of enamel organ 5 m.i.u.
First evidence of calcification 3-4 m.First evidence of calcification 3-4 m.
Crown completed 4-5 y.Crown completed 4-5 y.
Eruption 7-8 y.Eruption 7-8 y.
Root completed 10-11 yRoot completed 10-11 y

4. All teeth have 5 aspectsAll teeth have 5 aspects
Facial Lingual Mesial Distal
Incisal

6. Mesial outline
(convex(
Distal outline
(more convex(
Cervical outline (convex root
wise(
Incisal (straight and may
have mamelons(
Sharp mesioincisal
angle
Rounded distoincisal
angle
At the junction
of M& I 1 3.In the I 1 3.
M
D

7. Facial

10. Lingual aspect
Elevations:
•Marginal ridges (mesial and
distal)
•Cingulum (cervically at cervical third)
•Incisal ridge (incisally)
Depressions:
Lingual fossa
cingulum
Marginal
ridgesIncisal ridge
Lingual fossa

11. Lingua
l

13. ☺The lingual surface of all teeth is smaller in
size than the labial due to the lingual
convergence.
This convergence of
the teeth is to
accommodate the
larger arch size
facially than lingually

15. Mesial and distal Outlines
It’s Triangular and formed of
•Labial outline: convex with maximum
convexity at the cervical third which
represent crest of curvature
•Cervical outline: Curves incisally.
•Lingual outline:
convex incisally which represent incisal
ridge
Concave at the middle which represent
lingual fossa
Convex cervically which represent cingulum

16. Mesial

19. M D
Both: The crown has
smooth convex
proximal surfaces.
Contact areas:
Near the MI angle.
Near the junction of I &
M 1 3.
Cervical line:
Curved incisally.
The curvature is shallower
than mesially.
Contact areas:
Cervical line:

20. Distal

23. Outline and surface anatomy
 The outline is triangular in shape.
 Labial outline: broad and flat
 Lingual outline: narrower because of the convergence of
mesial and distal sides.
The crown is tapered
lingually.
•The base is placed
labially and apex
lingually.
•The mesiodistal
dimension (width) is
greater than the
labiolingual

24. Incisa
l

26. Variations and Anomalies:Variations and Anomalies:
Of all the crown surfacesOf all the crown surfaces
When viewed from the labial or lingualWhen viewed from the labial or lingual
aspectsaspects
Root lengthRoot length
Hutchinson's incisorsHutchinson's incisors
Talon cuspTalon cusp
supernumerary teethsupernumerary teeth

27. Hutchinson'sHutchinson's
incisorsincisors

28. Talon cuspTalon cusp