University of Palestine
College of Dentistry
Human Dentition I
Classification and Numbering System
Dr. Samir M. Ziara 
B.D.S. (Alexandria Univ.) 
D. D. P. H. Royal Collage of Surgeon (London) 
M. Sc. P. H. Al-Quds Univ. 
Diploma of H. Administration 
Surface Anatomy of
Permanent Teeth
Surface Anatomy of
Permanent Teeth
I, for incisor
C, for canine
I
C
P, for premolar
M
M, for molar
P
M
P
I
Anterior teeth
They are divided into:
Incisors
And
Canines
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.
For easy teeth description
We have to speak about :
• Function (mastication (incising), esthetic,
speaking).
• Chronology.
• Number of lobes (four lobes 3 labially and 1
lingually).
• Geometric outline of the crown.
• Outlines of the crown and root.
• Surface anatomy of the crown and root.
• Pulp cavity.
Chronology:
•Enamel organ appearance.
•Beginning of calcification.
•Crown completed.
•Eruption.
•Root completed.
All teeth have 5 aspects
1
Facial
Lingual
Incisal
Mesial
Distal
2
Labial
Lingual
Mesial
Incisal
Distal
1
Labial
Lingual
Incisal
Mesial
Distal
2
Labial
Lingual
Incisal
Mesial
Distal
Geometric outline of the crown
Facial and lingual aspects have
trapezoid out line.
Smallest uneven side cervically.
Facial and lingual outlines of
the crown
As mentioned before It’s Trapezoid and
is formed of
Cervical outline (convex root
wise)
Distal outline
(more convex)
Mesial outline
(convex)
Sharp mesioincisal
angle
Rounded
distoincisal angle
Incisal (straight and may
have mamelons)
When?
☺You have to note that 2
has two rounded angles but
the distal angle is more.
☺1
has two sharp
angles and straight
out lines mesially
and distally.
D
M
Outlines of the root
• The mesial and distal outline of the
root tapered to a pointed apex
The apex directed distally except the
1 it’s centralized on the long axis so
extraction could be done by rotation
movement
•
Note: the apex of 1 is blunt.
Surface anatomy of the crown and root.
Labial aspect
Elevations:
• The crown surface is smooth and
convex with maximum convexity at
the cervical third (cervical ridge)
Depressions:
•Shallow developmental grooves could
be seen separating mamelons.
•The root surface is smooth and convex
Lingual aspect
Elevations:
•Marginal ridges (mesial and
cingulum
distal)
•Cingulum (cervically)
•Incisal ridge
Depressions:
Lingual fossa
Incisal ridge
Marginal
ridges
Note:
•All elevations are more
developed in upper teeth
than in lower teeth.
•So the fossae appear
shallower in the lower teeth.
•Lingual pit could be
found in the 2 and should
notice that all elevations
are well developed than 1
☺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
Can you tell
*which tooth
*which aspect
*which surface anatomical
landmark
1 , labial aspest, cervical ridge.
2, lingual aspect, lingual pit.
2 , labial aspect, cervical ridge.
2, lingual aspect, cingulum,
M&D marginal ridges
Geometric outline of the crown
Proximal (mesial and distal)
aspects have triangular outline
Base cervically.
Note: the incisal
ridge of 1 &2
inclined lingually.
Why?
Apex
incisally.
Mesial and distal Outlines
It’s Triangular and formed of
•Labial outline: convex with maximum
convixity at the cervical third which
represent …….
•Lingual outline:
convex incisally which represent…….
Concave at the middle which represent…
Convex cervically which represent………
•Cervical outline: Curves incisally.
Note:
•The convexity of labial and lingual
outlines are well developed in the
upper teeth than lower teeth. Why?
•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
Outlines of the root
Upper incisors:
The outlines tapered from the
cervical line to a blunt rounded
apex
Lower incisors:
The outline are nearly straight
from the cervical line to the
middle third then tapered to a
pointed apex
Surface anatomy of the crown and root.
The crowns have smooth convex proximal surfaces.
The contact areas present in the
incisal third.
Mesially, near the mesioincisal
angle.
distally, near the junction of
incisal and middle thirds.
Note: the contact areas mesially and distally
are near to each other but still distal contact
area present more cervically.
Roots
They have convex smooth
surfaces except lower incisors
have longitudinal developmental
depression which is deeper
distally than mesially.
Incisal aspect
Outline and surface anatomy
Upper incisors:
The outline is triangular in shape.
The base is placed labially and apex
lingually.
The mesiodistal dimension (width)
is greater than the labiolingual
dimention (thickness).
Note:
The crown is tapered lingually.
•The elevations and depressions in the crown
lingually and labially appeared in this aspect.
Lower incisors:
The outline is diamond in shape.
The labiolingual dimension Is greater
than the mesiodistal dimension.
•The incisal ridge of 2 tilted distally that allows the
tooth to follow the dental arch curvature.
Pulp cavity.
Pulp cavity is formed of:
Pulp chamber that is present in the crown.
Its outline follows the outline of the crown.
In young teeth, it has pulp horns related to
each mamelon
Root canal that present in the root and
follow its outline. The number of root canals
in incisors is only one. The root canal ends
in an apical foramen
Identify the tooth, the aspects and tell FOUR
differences between the lateral and central incisor.
Answer
A- Upper P. central incisor.
B- Upper P.lateral incisor
Lingual aspect
1- Size.
2- The elevations and
depressions
3- The incisal angles.
A
4- The root.
B
Identify the tooth, the aspect and
the anatomical landmark.
2, lingual aspect, long mesial
marginal ridge, short distal
marginal ridge.
A
1, mesial aspect, contact
area, cervical line.
A is for 2, incisal aspect,
distally tilted cingulum.
B is for 1 , incisal aspect,
lingual fossa.
B
Canine
For easy teeth description
•
•
•
•
•
•
•
let’s make a quick revision;
Function (mastication (tearing), esthetic).
Chronology.
Number of lobes (four lobes 3 labially and 1 lingually).
Geometric outline of the crown.
Outlines of the crown and root.
Surface anatomy of the crown and root.
Pulp cavity.
Chronology:
•Enamel organ appearance.
•Beginning of calcification.
•Crown completed.
•Eruption.
•Root completed
Upper canine has 5 aspects:
Labial
Lingual
Mesial
Incisal
Distal
Lower canine has 5 aspects:
Distal
Labial
Lingual
Mesial
Incisal
Geometric outline of the crown
Facial and lingual aspects have
trapezoid out line.
Smallest uneven
side cervically.
Facial and Lingual Outlines of 3
It’s Trapezoid and formed of
Mesial outline:, convex till the contact
area (at the junction of I 1/3 and O 1/3)
then continues as concave till the cusp
tip.
Distal outline: concave till the contact
area (at the middle third) then continues
as convex till the cusp tip.
Cervical outline: convex root wise.
The mesial slope is shorter than the
distal slope.
The cusp tip pointed and on line with
the long axis but slightly mesially
deviated.
Facial and Lingual Outlines of 3
Mesial outline is straight.
Both contact areas are more
incisally so the crown
appeared longer and thinner
than 3
Cusp tip is less pointed
Mesial outline is convex.
Contact areas are more
cervically.
Cusp tip is more pointed
Outlines of the root
• The mesial and distal
outline of the root tapered
to a pointed distally
curved apex
•The mesial and distal
outline of the root
tapered to a sharply
pointed distally curved
apex
Surface anatomy of the crown and root.
Labial aspect
Elevations:
•It’s convex with maximum convixity at the
cervical ridge.
•There is prominent ridge runs from the tip
of the cusp toward the cervical margin
(Labial ridge).
The middle lobe is well developed giving
the cusp
Depressions:
Shallow longitudinal depressions lie mesial
and distal to the labial ridge.
The root shows convex smooth surface
Lingual aspect
Elevations:
•Marginal ridges, cingulum,
•Prominent lingual ridge that extend from
the cusp tip till the cingulum in 3 while in
3 it’s restricted to the incisal third.
Depressions:
Lingual fossa that is divided into two
fossae in 3 but still one in 3.
Note:
•The elevations of lower canine are not well
developed as the upper
•The lingual surface is smaller in size than the
labial surface due to the lingual convergence
which accommodate ……….
cingulum
Geometric outline of the crown
Proximal aspects have triangular
Apex of the
outline
triangle
incisally.
Note: the cusp tip of 3
centralized on the long
axis or inclined labially.
while the 3 cusp tip
centralized or inclined
lingually.
The base
cervically.
Apex of the
triangle
incisally.
Mesial and distal Outlines of the crown
It’s wedge in shape:
Labial outline is convex with the
crest of curvature at the cervical
third represent……
Lingual outline is convex cervically
represent...
In the middle it’s straight due to presence
of ridge ……..
In the incisal third it’s convex
again represent……
Cervical outline: curved incisally however, this
curvature is less on the distal than the mesial.
Notes:
•Lingual outline in the middle of 3 is concave
rather than straight due to short lingual ridge.
Outlines of the root
Upper canine:
The outlines tapered from the
cervical line to a blunt pointed apex.
It’s apical third may curved labially.
Lower canine:
The outline are nearly straight
from the cervical line to the
middle third then tapered to a
more pointed apex
Surface anatomy of the crown and root
The crown surface is convex and smooth,
except area cervical to the contact area
shows flattening (mesial surface) or
concavity (distal surface).
Position of contact areas vary from
mesial to distal of same tooth and vary
from upper to lower canine…….identify
their position as mentioned before.
The root surface is broad with longitudinal
depression.
The depression is shallower mesially than
distally of same tooth and is shallower in
upper canine than lower canine.
Note: the depression in lower canine
may be so deep causing bifurcation in
the root. The bifurcation may be apically
or extend up to cervical third.
Enumerate the names
of the following
elevations and
depressions?
Lingual ridge
Cingulum.
Distal marginal
ridge
D.L.F
D.I.Ridge
Mesial marginal
ridge.
M.L.F
M.I.Ridge
Incisal aspect.
Outline and surface anatomy
The thickness is greater than the width.
The labial surface appeared convex and
even more than the incisors
The cingulum forms a short arc.
The elevations and depressions in the
labial and lingual surfaces appeared in
this aspect
Pulp cavity.
Pulp cavity is formed of:
Pulp chamber that present in the crown. Its
outline follows the outline of the crown.
In young teeth, it has pulp horns related to the
cusp
Root canal that present in the root and
follow its outline. The number of root canals
in canines is only one.
Sometimes 3 has two root canals labially
and lingually. The canals open in one apical
foramen or separate foramina.
Premolars
There are four maxillary
and four mandibular
premolars.
4 & 4 contact 3 & 3 mesially
and 5 & 5 distally
5 & 5 contact 4 &4 mesially
and 6 &6 distally.
For easy teeth description
•
•
•
•
•
•
•
We have to speak about :
Function (grinding).
Chronology.
Number of lobes (four lobes 3 buccally and 1 lingually or five lobes 3
buccally and 2 lingually).
Geometric outline of the crown.
Outlines of the crown and root.
Surface anatomy of the crown and root.
Pulp cavity.
Chronology:
•Enamel organ appearance.
•Beginning of calcification.
•Crown completed.
•Eruption.
•Root completed
Maxillary first premolar
It has 5 aspects:
Buccal
Lingual
Mesial
occlusal
Distal
Geometric outline of the crown
• Facial and lingual aspects have
trapezoid out line.
The smallest uneven side
cervically.
Facial Outlines
Mesial and distal outlines are nearly concave
Mesial and distal cusp slopes are also
slightly concave
Contact areas:
D
Mesially at the M third while
Distally it’s occlusally positioned
which is an exception from other
permanent posterior teeth.
Cervical line: is convex root wise.
B cusp
pointed
and long
M
Outline and surface anatomy of the root
The M and D outline of the roots tapered to a
pointed apex that curved distally.
If two roots, the buccal root hide the
.
lingual root as it’s shorter and
narrower than the buccal root.
The surface of the root is convex and
smooth
Surface anatomy of the crown
Elevations:
•The surface convex with
maximum convexity at C 1/3
represent……….
•The middle lobe is prominent
buccally forming BUCCAL ridge.
Depressions:
Shallow depressions were
present mesial and distal to
the B ridge
Lingual outline and surface anatomy of the crown
M and D outlines are convex
•The L cusp is shorter by 1 mm but
sharper than the B cusp
•The D slope of L cusp is longer
than M slope
Cervical line: is convex root wise.
The surface is convex with maximum
convixity at the M1/3
M
D
Outline and surface anatomy of the root
The M and D outline of the roots tapered to a
pointed apex that curved distally.
If two roots, the lingual root appears
shorter and narrower than the
buccal root.
The surface of the root is convex and
smooth
Geometric outline of the proximal aspect
Distal aspect
Mesial aspect
Trapezoid in shape
Smallest uneven sides occlusaly
Outlines of proximal aspect
Distal aspect
Mesial aspect
Buccal outline is convex with maximum convexity at C 1/3
represent …….
Lingual outline is convex with maximum convexity at M1/3
Cervical line curves occlusally and decreased distally
Distal aspect
Mesial aspect
Occlusal outline:
B cusp is longer than L cusp by 1mm.
Wide occlusal table.
B cusp tip is below the center of B root.
L cusp tip is on line with L root
MMR present at the junction of O 1/3 and M 1/3, while
DMR more occlusal
Proximal surface anatomy
Mesial aspect
Distal aspect
Contact area:
At the middle third (OC dimension)
and slightly buccal to midline (BL
dimension)
Mesial developmental groove is
crossing MMR and located
lingual to the contact area.
Mesial Developmental depression in the
crown and continue with that on the root
(canine fossa).
Occlusally positioned
and more buccally.
Smooth and convex
surface except for a
small flat area
cervical to contact
area .
Mesial aspect
Distal aspect
In case of two roots (61%).
Root trunk about half the
root length.
Surface is smooth and convex
except deep developmental
depression below bifurcation.
Root trunk is longer as
bifurcation is near apical
1/3
Surface is smooth and
convex except shallow DD
on the root trunk
In case of one root.
The B and L outlines tapered to a blunt
apex on the center of the crown.
The surface is smooth and convex
except shallow depression in the
center that is deeper mesially than
distally.
Geometric outline of the occlusal aspect
It’s hexagonal
•2 equal buccal sides (MB, DB)
D
•M side shorter than D side.
•ML side shorter than DL side.
Thickness is greater than width
The crown is wider buccally than
lingually. Why?
M
Surface anatomy of occlusal aspect:
Elevations:
B triangular ridge.
L triangular ridge.
M & D marginal ridges
Depressions:
Central developmental groove
M and D triangular fossae.
M developmental groove
Can you tell
Which tooth, which aspect.
4 , occlusal aspect.
Triangular ridge of B cusp.
Triangular ridge of L cusp.
M &D marginal ridges
Central developmental groove
M triangular fossa.
D triangular fossa.
Mesial developmental groove
Pulp cavity.
MD section
Root canals:
2 root canals (B&L)
but rare 3 canals
L canal is larger
&more accessible
Narrow
Wider
Pulp chamber:
BL section
Maxillary second premolar
It has 5 aspects:
Buccal
Lingual
Mesial
occlusal
Distal
Geometric outline of the crown
• Facial and lingual aspects have
trapezoid out line.
The smallest uneven side
cervically.
Facial Outlines and surface anatomy of the crown
4
D
M
5
D
M
B cusp is long and pointed
B cusp is short and less pointed
Longer M slope than D
Contact mesial A in the M1/3
while distally more occlusal.
Shorter M slope than D
Contact mesial A in O1/3 while
distally more cervically.
Cervical line curved root wise.
Cervical line less curved.
4
D
M
Prominent B ridge
Narrow cervical portion.
Short root.
5
D
M
Less prominent B ridge
Wider cervical portion.
Longer root.
Lingual outline and surface anatomy of the crown
4
The L cusp is shorter
by 1 mm than the B
cusp.
61% has 2 roots with
L root is shorter than
B root and its apex is
pointed.
5
The L and B cusps
are nearly of same
height.
Rare to has 2 roots
In case of two roots the
L root is shorter and its
apex more blunt.
Mesial aspect
4
5
B cusp is longer than L
cusp by 1mm
The cusps are nearly at
the same level.
The occlusal table is
wide.
The occlusal table is
narrow.
Mesial DG and canine
fossa.
The crown surface is smooth
and convex while root has
shallow developmental
depression.
Mesial aspect
4
MMR at the junction of
M1/3 &O1/3
Contact area:
At the middle third (OC
dimension) and slightly
buccal to midline (BL
dimension)
5
MMR positioned more
occlusal.
At the occlusal third (OC
dimension) and slightly
buccal to midline (BL
dimension)
Distal aspect
4
5
DMR more occlusal than MMR
DMR more cervical than MMR
CA occlusally positioned and
more buccally than MCA.
CA cervically positioned and
more buccally than MCA.
Smooth and convex surface
except for a small flat area
cervical to contact area.
Smooth and convex surface.
Distal aspect
4
Root trunk is long as
the bifurcation is near
apical 1/3
Surface is smooth and
convex except shallower
DD on the root trunk than
mesially.
5
One root and if 2 the
bifurcation will be
more apically.
Surface is smooth and
convex except deeper
DD in the middle of the
root than mesially.
Occlusal aspect
5
4
D
M
It’s hexagonal
D
M
It’s oval
B & L triangular ridges.
B & L triangular ridges.
M & D marginal ridges
Thicker M & D MRs
4
5
Long Central DG
Shorter Central DG.
M developmental groove
Not present.
M and D
M and D
fossae.
fossae.
Mandibular first premolar
It has 5 aspects:
Buccal
Lingual
Mesial
occlusal
Distal
Geometric outline of the crown
• Facial and lingual aspects have
trapezoid out line.
The smallest uneven side
cervically.
Facial Outlines
Mesial and distal outlines are nearly concave
Mesial and distal cusp slopes are also
slightly concave
D
Contact areas:
Mesially at the junction of O and M
thirds while Distally it’s cervically
positioned.
Cervical line: is convex root wise.
B cusp
pointed
and long
M
Outline and surface anatomy of the root
The M and D outline of the roots tapered to a
pointed apex that curved distally.
The surface of the root is convex and
smooth
Surface anatomy of the crown
Elevations:
•The surface convex with
maximum convexity at C 1/3
represent……….
•The middle lobe is prominent
buccally forming BUCCAL ridge.
Depressions:
Shallow depressions were
present mesial and distal to
the B ridge
Lingual outline and surface anatomy of the crown
M and D outlines are convex
The L cusp is short and small reaching 2/3
the crown length and has a pointed tip.
Cervical line: is convex root wise.
M
Elevations: The lingual surface is convex
with maximum convixty at M 1/3
Depessions: ML developmental groove at
the ML line angle.
D
Geometric outline of the proximal aspect
Distal aspect
Rhomboid in shape
With narrow occlusal table
Lingual inclination well prominent
Mesial aspect
Outlines of proximal aspect
Distal aspect
Mesial aspect
Buccal outline is convex with maximum convexity at
C 1/3 represent …….
Lingual outline is convex with maximum convexity at
M1/3
Cervical line curves occlusally and decreased distally
Outlines of proximal aspect
Distal aspect
Mesial aspect
Occlusal outline: the two cusps are not in same
level (what’s the relation in between?)
The B cusp centered over the root. This is due to
the prominent lingual inclination.
The L cusp tip in line with lingual border of the root.
Outlines of proximal aspect
Distal aspect
DMR in 4 is straight
and at right angle to
the axis of the tooth.
Mesial aspect
MMR inclined from
B to L surface \\ to B
cusp ridge.
DMR is occlusal than MMR (unique characteristic of this
tooth).
Proximal surface anatomy
Distal aspect
Mesial aspect
M & D surfaces are smooth and convex except area
cervical to contact area it’s concave.
nearly at same level
Contact area
it’s broder, cervically
and lingually
positioned.
ML developmental groove
present at the junction of L
and M surfaces.
Outline and surface anatomy of the root
Distal aspect
Mesial aspect
B & L outlines are nearly straight cervically
then taper to apically to a blunt apex
The surface is smooth
The surface is more
and flat with deep
convex
developmental groove
Note: The root may divided apically B & L
Geometric outline of the occlusal aspect
It’s diamond-shaped.
D
Lingual convergence is sharp.
Mesial outline is slightly curved.
Distal outline is more convex.
M
Surface anatomy of occlusal aspect:
Elevations:
B triangular ridge.
L triangular ridge.
M & D marginal ridges
Transverse ridge
Depressions:
Central developmental groove
M and D triangular fossae.
Mesiolingual developmental groove
Mandibular second premolar
It has 5 aspects:
Buccal
Lingual
Mesial
occlusal
Distal
Geometric outline of the crown
• Facial and lingual aspects have somewhat
square shape due to wide cervical third
than 4.
Facial Outlines and surface anatomy
4
5
B cusp
B cusp
pointed and long
short and less pointed
Well prominent B ridge
Not well prominent B ridge
Pointed apex
Blunt apex
Lingual outline and surface anatomy
4
5
Two cusp type
The L cusp is short and small
reaching 2/3 the crown length
and has a pointed tip.
L cusp is shorter and
smaller than B cusp but
larger than of 4
The lingual surface is convex
with maximum convixty at M 1/3
The surface convex with
maximum convixty at
O1/3.
No MLDG
ML developmental groove at
the ML line angle.
Three cusp type:
5
ML cusp is longer and larger than M
DL cusp. They both shorter than B
cusp and less pointed.
The surface convex with maximum
convixty at O1/3.
The L developmental groove between
the 2 cusps
D
Proximal outlines
4
5
Rhomboid in shape with
Rhomboid in shape with
narrow occlusal table.
narrow occlusal table.
Lingual inclination less
prominent
Lingual inclination well
prominent
4
5
Maximum convexity at M1/3
Maximum convexity at O1/3
The L cusp is short and small
reaching 2/3 the crown length
L cusp is shorter and
smaller than B cusp but
larger than of 4
The B cusp centered over the B cusp tip on line with junction
root.
of B & M 1/3 of the root.
The mesial MR is oplique
while distally is straight
The mesial and distal
marginal ridges are straight
Mesial aspect
Distal aspect
Three cusp type:
ML cusp is longer and
larger than DL cusp.
DL cusp is shorter and
smaller than ML cusp.
Both lingual cusps are shorter than the buccal cusp
and less pointed
Surface anatomy is simillar to that of 4
Geometric outline of the occlusal aspect
Two cusp type:
4
It’s diamond-shaped.
Lingual convergence is sharp.
Three cusp type:
The outline is square
5
The outline is oval
Slight lingual convergence
Surface anatomy of occlusal aspect:
4
Elevations:
5
B triangular ridge.
L triangular ridge.
Transverse ridge
M & D marginal ridges
4
Depressions:
Central developmental groove
5
Central developmental groove
H or U shapped.
M and D triangular fossae.
Mesiolingual developmental groove
M and D triangular fossae.
Three cusp type:
Elevations:
B triangular ridge.
L triangular ridges (ML &DL).
M & D marginal ridges
Depressions:
Central developmental groove Y shape
M and D triangular fossae.