4. Incisors
There are four maxillary incisors
and four mandibular incisors.
♥ Two central incisors
contact with each other in the
midline (mesially) and with
the lateral incisors distally.
♥ Two lateral incisors contact
with the central incisor mesially
and with the canine distally.
10. For easy teeth description
We have to speak about :
Geometric outline of the crown.
Outlines of the crown and root.
Surface anatomy of the crown and root
(anatomical landmarks).
Convex Concave
11. All teeth have 5 aspects
Facial Lingual Mesial Distal
Incisal
1
12. 1
Maxillary central incisor is the first tooth from the midline.
The two upper centrals are the widest of all the incisors.
The crown is the longest of all human teeth.
13. Geometric outline of the crown
Facial and lingual aspects have
trapezoidal out line.
Smallest uneven side cervically.
14. Mesial outline
(convex)
Distal outline
(more convex)
Cervical outline (convex root
wise)
Incisal (straight and may
have mamelons) When?
Sharp mesioincisal
angle
Rounded
distoincisal angle
Facial and lingual outlines of
the crown
At the junction
of M& I 1 3.In the I 1 3.
M
D
15. The mesial and distal outline of the
root tapered to a blunt apex
• The apex is centralized on the long
axis so extraction could be done by
rotation movement
Outlines of the root
16. Surface anatomy of the crown and root.
The crown surface is smooth and
convex with maximum convexity at
the cervical third (cervical ridge)
•The root surface is smooth and convex
•Shallow developmental grooves could
be seen separating mamelons.
Labial aspect
Elevations:
Depressions:
18. ☺You have to notice that 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
20. Mesial and distal Outlines
It’s Triangular and formed of
•Labial outline: convex with maximum
convexity at the cervical third which
represent …….
•Cervical outline: Curves incisally.
•Lingual outline:
convex incisally which represent…….
Concave at the middle which represent…
Convex cervically which represent………
21. Outlines of the root
The outlines tapered from the
cervical line to a blunt rounded
apex
22. M D
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.
24. Incisal aspect
Outline and surface anatomy
The outline is triangular in shape.
The crown is tapered lingually.
•The base is placed labially and apex lingually.
•The mesiodistal dimension (width) is
greater than the labiolingual
25. Note:
•The elevations and depressions in the crown
lingually and labially appeared in this aspect.
Lingual fossa
28. 1 2
*Its crown is the broadest of the
anterior teeth
*It is the longest tooth of all
human teeth
*Its crown is smaller in all
dimensions than 1 except its
root is longer
29. 1 2
sharp M I angle. rounded M I angle.
rounded D I
angle.
more rounded D I angle.
Labial aspect
Incisal outline
Straight Rounded (curved)
M D MD
30. 21
MCA-----in incisal1/3 near the
mesio-incisal angle
DCA-----at the junction of
incisal and middle 1/3s
MCA---- at the junction of
Incisal and middle 1/3s
DCA-----in the center of middle
1/3.
31. 1 2
Root has cone shape with
Blunt apex
Root is longer, narrower and has
developmental depression on its
mesial surface
-Root tapers evenly to apical 1/3
then curve distally with a
pointed apex.
32. Lingual aspect
Elevations are well
developed
Depressions:
Lingual fossa, more concave and
circumscribed
Cingulum
Marginal
ridges
Incisal ridge
34. Identify the tooth, the aspects and tell FOUR
differences between them.
Lingual aspect
Answer
1- Size.
BA
A- Upper P. central incisor.
B- Upper P.lateral incisor
2- The elevations and
depressions
3- The incisal angles.
4- The root.
35. 1 2
The crown long and thick
labiolingually.
Shorter and thinner.
The mesial surface is flat The surface is flatter.
Contact area at I 13 near
the M I angle.
Near or at the junction of
I & M 13
Mesial
aspect
Lb Lg Lb Lg
37. 1 2
Incisal aspect
When palatal pit is present;
it is located in the depth of
the lingual fossa
*Geometric outline----
triangular
*M-D> Lab-Ling
*The cingulum is shifted
distally
Geometric outline---
rounded or oval
*M-D = Lab-Ling
*The cingulum is centered
38. ►Mesio-distal section
- The pulp chamber is wide
conforming the shape of the
crown.
- It presents three pulp horns
corresponding to the three
mamelons.
- The root canal tapers towards
the apex.
►Labio-lingual section
- The pulp chamber
pointed incisally, then
follows the increase in
the crown dimension
cervically.
- The root canal tapers gradually
as it traverse the root ending in a
constriction at the apex (the
apical foramen).
☻Pulp cavity of Upper
central incisor
Triangular
Trapezoidal
41. Is similar but smaller than that of central
incisor.
It consists of a single root canal and a pulp
chamber.
☻Pulp cavity of upper
lateral incisor
42. Malformations Of The Upper Permanent
Lateral Incisor
Peg-shaped
lateral
incisor.
Missing lateral
incisor.
13
43. Mandibular incisors
They are smaller than maxillary incisors.*
*1 is smaller than 2 which is the reverse
Of the situation in 1 & 2.
*The width is smaller than the thickness.
*The mamelons worn off soon after eruption.
*The incisal ridges are inclined lingually to the root axis.
**
46. Mandibular central incisor
Is the first mandibular tooth from the midline.
It is the smallest tooth in the permanent dentition.
*Its crown has fan shaped appearance
It is the most symmetrical tooth in the permanent
dentition.
48. Geometric outline of the crown
Facial and lingual aspects have trapezoid
out line.
Smallest uneven side
cervically.
49. Facial and lingual outlines of the crown
D M
Mesial & distal outlines are straight
tapering evenly to the narrow cervix.
Its crown has also fan shaped
appearance
Its crown is less symmetrical
D M
21
Its crown has fan shaped
appearance
It is more symmetrical
Incisal edge is straight and
perpendicular to the long axis
of the tooth.
* The incisal edge is straight and
slop downward in a distal
direction.
50. MDD M
*Mesio-incisal angle----sharp
*Disto-incisal angle-----rounded
*DCA is more cervically than
MCA
1
*Mesio-incisal angle----sharp
*Disto-incisal angle-----sharp
2
MCA &DCA-----at the same
level (incisal to the junction of
incisal and middle 1/3s )
51. Outlines of the root
*The root of lower central incisor
tapers toward the pointed apex
-Its apical third curved distally
-It has mesial and distal
developmental depressions
The root of lower lateral incisor
Is the same but longer
1 2
52. Surface anatomy of the crown and root.
The crown surface is smooth and convex
with maximum convexity at the cervical
third (cervical ridge)
•The root surface is smooth and convex
•Shallow developmental grooves could
be seen separating mamelons in newly
errupted teeth.
Labial aspect of 1&2
Elevations:
Depressions:
54. Lingual aspect
The elevations (cingulum,
marginal ridges and incisal
ridge are poorly developed
than in 1
The cingulum is centered
*The same but the MMR is
longer than DMR as the
mesial outline is longer than
the distal one.
*The cingulum is deviated
distal to the center of the
lingual surface.
1
2
•The fossae appear shallower in
the lower teeth.
56. Mesial and distal Outlines
It’s Triangular and formed of
•Labial outline: convex with maximum
convixity at the cervical third which
represent …….
•Cervical outline: Curves incisally.
•Lingual outline:
convex incisally which represent…….
Concave at the middle which represent…
Convex cervically which represent………
57. Note:
•The convexity of labial and lingual
outlines are well developed in the
upper teeth than lower teeth. Why?
58. •The curvature of cervical lines in all teeth
distally is less than mesially. The height of
curvature decreased also from upper teeth to
lower teeth
59. The incisal ridge is lingual to the root axis
This lingual inclination facilitates
proper occlusion.
The lingual inclination is a characteristic
feature of lower teeth
60. 2
Mesial aspect distal aspect
Contact area at the I 13 Contact area more cervically
to contact the lower canine
Note: the distal aspect is shorter than mesially due
to distal tilting of the incisal ridge
61. Roots
Root surface showed longitudinal developmental
depression which is deeper distally than mesially.
62. Incisal aspect
The outline is diamond in shape.
The crown is tapered lingually.
The labiolingual (thickness) is greater than the
mesiodistal dimension.
The incisal ridge in 1 is at right
angles to a line bisecting the
crown labiolingually.
The cingulum is centered.
63. The incisal edge is not at right
angle to the line bisecting the
crown Lab- Ling
The cingulum is displaced
distally
64. Crown is twisted disto-lingually
on its root to allow the incisal
ridge to follow the curve of dental arch
(characteristic feature)
66. Convex out lines Straight outlines
Incisal edge
straight curved StraightTilted
Incisal angles
Sharp MI,
rounded DI
Rounded
angles
Sharp angles
Sharp MI,
rounded DI
67. They all have the same elevations and depressions.
Enumerate and state the differences:
Upper central
Upper lateral
Lower incisors
Well developed elevations
but the lateral more
developed.
Less developed.
Fossa ?
Fossa ?
70. 2121
Geometric
line
Cervical
line
between M
& I third
near the MI
angle
between
M & I third
near the
MI angle
Contact
area
Incisal
ridge
Triangular
Convex incisally
Perpendicular on
the long axis
Inclined lingually
Mesial Aspect
74. Identify the tooth, the aspect and
the anatomical landmark.
2, lingual aspect, long mesial
marginal ridge, short distal
marginal ridge.
1, mesial aspect, contact
area, cervical line.
A
BA is for 2, incisal aspect,
distally tilted cingulum.
B is for 1 , incisal aspect,
lingual fossa.