The document discusses the anatomy and physiology of teeth. It begins by explaining how proper tooth form and alignment promotes efficiency during chewing. It then describes various protective and functional aspects of tooth form, including proximal contact areas, interproximal areas, embrasures, heights of contour, and curvature of the cementoenamel junction. For each structure, it provides details on their importance, location on different teeth, and comparisons between maxillary and mandibular teeth. It also discusses axial alignment of teeth and compares the anatomical features of maxillary central and lateral incisors. In summary, the document provides an in-depth overview of tooth morphology and its relationship to function.

1. DENTAL
ANATOMY &
PHYSIOLOGY
OF TEETH

2. Form and Function
Normal tooth form, plus proper alignment in the
jaws, promotes efficiency during mastication, but in
addition, the major portion of the form operates to
insure the life of the tooth through stabilization.
Form does not only means shape but also biomechanical
attributes that contributes to maintenance.
The relationship of tooth form to the form of the
supporting structures, including gingiva must be
considered in terms of clinical significance.

3. Protective Functional Form of
the Teeth
Includes:
• Proximal contact areas
• Interproximal areas (formed by proximal surface
in contact)
• Embrasures (spillways)
• Height of contours ( labial & buccal contours at
the cervical 3rd, & lingual contour at the middle 3rd)
• Curvature of the Cemento-enamel junction
( curvature of cervical lines on the mesial & distal
surfaces)

4. Proximal Contact Areas
• All teeth contact adjacent
teeth at a proximal contact
area except:
– distal of the last tooth
In the arch
– diastemas
– pathology (caries)
– faulty restorations

5. Types of proximal contact
• POINT CONTACT- it is nothing but a
misnomer, when the individual is quite young & the
teeth are newly erupted , some of the teeth come
close to having POINT CONTACT only. Eg. Distally
on canines & mesially on premolars.
• CONTACT AREA- it is formed because of wear of
one proximal surface against another during
physiologic tooth movement.

6. Importance:
– Ensures food will not be packed between
teeth causing inflammation to the
supporting tissues thereby causing gingivitis
& periodontitis
– It helps stabilize the dental arches by the
combined anchorage of all the teeth in
either arch in positive contact with each
other (exception - third molars.)
– Each tooth is individually supported by
these contact areas.

7. CONTACTS are OBSERVED from 2 views• Labial /buccal aspectdemonstrates the
cervicoincisal/cervico
-occlusal position
• Incisal /occlusal aspectdemonstrates the
facio-lingual position

8. • Anterior teeth have
contacts that are
generally centered
faciolingually when view
from the incisal
• Posterior teeth have
contacts that are
generally located buccal
to the center of teeth
when viewed from the
occlusal

9. Proximal Contacts
Maxillary
Mesial
Distal
Central incisor
Incisal 1/3
Lateral incisor
1st pre
2nd pre
Junc of
incisal/middle 1/3
Junc of
incisal/middle 1/3
Middle 1/3
Middle 1/3
Junc of
incisal/middle 1/3
Middle 1/3
1st molar
2nd molar
3rd molar
Middle 1/3
Middle 1/3
Middle 1/3
Canine
Middle 1/3
Middle 1/3
Middle 1/3
Middle 1/3
Middle 1/3
n/a

10. Proximal Contacts
Mandibular
Mesial
Distal
Central incisor
Incisal 1/3
Incisal 1/3
Lateral incisor
Incisal 1/3
Incisal 1/3
Canine
Incisal 1/3
Middle 1/3
1st pre
Middle 1/3
Middle 1/3
2nd pre
Middle 1/3
Middle 1/3
1st molar
Middle 1/3
Middle 1/3
2nd molar
Middle 1/3
Middle 1/3
3rd molar
Middle 1/3
n/a

11. 1. Contact area move
cervically from
anterior to posterior
in each quadrant
2. On individual teeth
the distal contact is
more cervically
located then the
mesial contact
3. Contacts increase in
size from anterior to
posterior
2
**Note: Contacts on incisors in incisal1/3,
Where as contacts on molars in middle /3

12. Contacts
• Mandibular Teeth:
Contact their class
counterpart and the tooth
mesial
• Maxillary Teeth: Contact
their class counterpart and
the tooth distal

13. Interdental Areas
• Triangular in shape
• Base=alveolar bone
• Sides=prox. surfaces
of teeth
• Apex=proximal
contact area
• These triangular
shaped areas are
normally filled with
gingival tissues

14. Embrasures
The curvature formed by two adjacent teeth in
an arch form a spillway space that is called
an embrasure
Note the Symmetry of
the embrasure of the
central incisors

15. Embrasures
• Embrasures are named
relative to the contact area
– Facial or lingual views
show the occlusal/
incisal embrasures and
cervical/ gingival
embrasures
– Occlusal views show
the buccal/ labial and
lingual embrasures

16. Significance of Embrasure form
• Serves as a spillway for food material during
mastication
• Prevents food from being forced through the contact
area and injuring the periodontal tissues.
• Also, Enhances the self-cleansing process of the tooth
by exposing the surfaces to oral fluids, mechanical
cleansing, and friction from the tongue, lips, and
cheeks

17. • Facial or lingual aspects:
– The incisal / occlusal
embrasures increase in size
from anterior to posterior
– The cervical embrasure
decreases in size from
anterior to posterior
– The incisal embrasure of the
maxillary lateral/canine
=greatest or longest
– The incisal embrasure of the
maxillary canine/premolar=
widest angle

18. Embrasures
• Mandibular posterior
area occlusal view
• Arrows denote the
facial and lingual
embrasure areas
• The lingual
embrasures are larger
than the facial
embrasures, because
of lingual convergence
of the crown.

19. Heights of Contours
• It is a line encircling a tooth In
more or less horizontal
plane, representing its greatest
circumference.
The facial and lingual contours:
• Protect the gingiva by the
deflection of foods and help
prevent trauma
Buccal
Lingual

20. Buccal
Lingual
The height of contour
on both the facial
and lingual surfaces
of anterior teeth is
located in the
cervical third.

21. • The height of contour of the
buccal surfaces of posterior
teeth is located in the
gingival third
Lingual
Buccal
• The height of contour of the
lingual surface of posterior
teeth is located in the middle
or occlusal third
• The average curvature is
around 0.5mm, with
mandibular posterior having
a lingual curvature of 1mm.
• Mandibular anteriors having
curvature of less than
0.5mm.

22. Height of Contours
Maxillary
Facial
Lingual
Central incisor
Lateral incisor
Canine
1st pre
Cervical 1/3
Cervical 1/3
Cervical 1/3
Cervical 1/3
Cervical 1/3
Cervical 1/3
Cervical 1/3
Middle 1/3
2nd pre
1st molar
2nd molar
3rd molar
Cervical 1/3
Cervical 1/3
Cervical 1/3
Cervical 1/3
Middle 1/3
Middle 1/3
Middle 1/3
Middle 1/3

23. Height of Contours
Mandibular
Facial
Lingual
Central incisor
Lateral incisor
Canine
1st pre
Cervical 1/3
Cervical 1/3
Cervical 1/3
Cervical 1/3
Cervical 1/3
Cervical 1/3
Cervical 1/3
Middle 1/3
2nd pre
1st molar
2nd molar
3rd molar
Cervical 1/3
Cervical 1/3
Cervical 1/3
Cervical 1/3
Middle 1/3
Middle 1/3
Middle 1/3
Middle 1/3

24. • OVERCONTOURED RESTORATIONS- a restoration
containing so much excess restorative material that normal anatomic
structure is altered; may cause plaque retention and open or
deficient gingival margin.
• UNDERCONTOURED RESTORATIONS- a restoration
containing too little restorative material so that a space occurs
between the margin and the cavity wall; may result when either the
matrix band or wedge is improperly placed.

26. Curvature of the CEJ
The CEJ is a stable line
whose curvature is related to
the widths and lengths of the
crown and the location of the
contact areas interproximally
The extent of the curvature
depends on• Height of the contact area
above the crown cervix
• Diameter of the crown
labiolingually.

27. • The CEJ is curved toward the
apical on the facial and lingual
surfaces of teeth
• The CEJ is curved toward the
incisal or occlusal surfaces on
the proximal surfaces of teeth
• The depth of the curvature is
greater on the mesial than on the
distal aspect
• The depth of curvature on the
CEJ on all surfaces is greater on
anterior teeth and decreases
toward the posterior

28. Axial Alignment
The alignment of teeth within the dental arches.
• All teeth are mesially inclined, with the possible
exception of the most distal maxillary teeth.
• Maxillary teeth are inclined facially
• Mandibular posterior teeth are inclined lingually
• Mandibular anterior teeth are inclined facially

29. LMAXILLARY CENTRAL INCISORabial
• It is the widest tooth in the maxillary arch.
• The mesial margin is straight and meets the incisal edge at
right angle. The distal margin is shorter and more rounded.
• The distoincisal angle is more rounded than the
mesioincisal angle.
Distal margin shorter &
rounded
Mesial margin straight
& meets at 90 degree
Distoincisal angle
more
rounded, making an
obtuse angle
Mesioincisal angle
rounded, making
somewht 90 degrees

30. 

The labial surface is marked by two developmental
groove and has convexity in cervical third.
Mesiodistally the crown is narrowest cervically, &
becomes broadest in the incisal 3rd.
Convexity in
cervical third
a
b

31. Lingual aspect
• The crown profile is same as that of labial surface except
that there is a broad depression in the central portion
called the lingual fossa and a well developed cingulum.
 Maxillary incisor with a deep & large lingual fossa &
prominent mesial & distal marginal ridges are called as
SHOVEL SHAPED INCISOR
 Due to the distal displacement of the cingulum, the mesial
marginal ridge is slightly LONGER than the distal marginal
ridge
Cingulum
Lingual fossa
Marginal
ridges
Lingual ridge

32. 

The lingual fossa is bordered by mesial and distal marginal ridges on the
sides and the cingulum cervically.
The cervical line on labial and lingual surface is convex apically.
Cervical line convex
Labial aspect
Lingual aspect

33. Mesial aspect
• From this aspect the crown appears WEDGE SHAPED,
with base of traingle at cervix & apex towards the incisal
edge.
• From the mesial aspect the labial margin is convex
• The lingual margin is ‘S’ shaped, being convex near cingulum
and concave in the middle
Convex near cingulum
Labial margin convex
Concave in the middle

34. 

Mesial curvature of cervical line (3.5mm) is the most
pronounced compared to any other tooth.
The cervical line on the mesial and distal surface is
convex incisally
Cervical line

35. Distal aspect


Distal surface is very similar to the mesial surface.
when central incisor viewed from distal aspect, the
crown gives the impression of somewhat thicker
towards the incisal 3rd, this is because the
distoincisal angle is slightly lingually positioned than
mesioincisal angle.
Distal aspect

36. Incisal aspect
• The crown and incisal
margin are centered over root
• Crown profile is almost
bilaterally symmetrical
• The incisal margin of
newly erupted teeth show
three elevations
called mamelons. The middle
One is smallest.They correspond
to the developmental lobes.
Bilaterally symmetrical
Incisal ridge

37. Root
The root is straight and tapers from the
cervical line to the apex giving it a conical
Straight conical blunt
root
shape
The root ends in a blunt apex.
Root : crown ratio is 1.3:1.05
Average Dimensions in millimeters
Crown
Length
Root
Length
10.5
13.0
Mesiodistal
Diameter of crown
8.5
Mesiodistal
Diameter at
Cervical Line
7.0
Labiolingual
Diameter at
Crest of Curvature
7.0
Labiolingual
Diameter at
Cervical Line
6.0
Curvature of
Cervical Line
M
D
3.5
2.5

38. Maxillary Lateral Incisor

The general shape is similar to maxillary central
incisors except that they are shorter and narrower.
Maxillary central incisor bigger
and lateral incisor smaller

Next to third molars maxillary lateral incisors are
the teeth that show most variation in crown size,
shape and form

39. 
The mesioincisal and distoincisal angles are more
rounded than the corresponding angles of the
maxillary central incisor
Maxillary Lateral Incisor
Distoincisal angle
more rounded
Maxillary Central Incisor
Mesioincisal angle
more rounded
Distoincisal angle
Mesioincisal angle

40. 
On the lingual aspect the marginal ridges and cingulum
are more prominent
Prominent marginal
ridges
Prominent cingulum

41. MAXILLARY CENTRAL INCISOR
MAXILLARY LATERAL INCISOR
1.
CROWN IS LARGER
CROWN IS SMALLER
2.
MESIOINCISAL ANGLE AT 90 DEGREE &
DISTOINCIAL ANGLE SLIGHTLY
ROUNDED
MESIOINCISAL ANGLE IS ACUTE &
DISTOINCISAL ANGLE ROUNDED
3.
MESIAL CONTACT AREA AT INCISAL 3rd
DISTAL CONTACT AREA AT JUNC OF INCISAL &
MIDDLE 3rd.
LABIAL
VIEW

42. LINGUAL
VIEW
1.
LINGUAL FOSSA LARGER & SHALLOWER
LINGUAL FOSSA SMALLER & MORE
CONCAVE.
2.
LINGUAL PITS ARE LESS FREQUENT
LINGUAL PITS ARE COMMON
3.
CINGULUM IS POSTIONED SLIGHTLY
DISTALLY
CINGULUM IS CENTERED

43. PROXIMAL
VIEW
1.
CERVICAL LINE CURVATURES ARE MORE
CURVATURE IS LESS
2.
ROOT IS EVENLY TAPERED
ROOT IS MORE CONVEX

44. INCISAL
1.
CROWN WIDER MESIODISTALLY THAN
FACIOLINGUALLY
CROWN SAME BOTH MESIODISTALLY
& FACIOLINGUALLY
2.
CROWN OUTLINE IS TRIANGLULAR
CROWN OUTLINE IS ROUNDED OR
OVAL
3.
CINGULUM SLIGHTLY DISTAL
CINGULUM CENTERED
4.
INCISAL RIDGE SLIGHTLY CURVED
MESIODISTALLY
INCISAL RIDGE RELATIVELY
STRAIGHTER MESIODISTALLY

45. MANDIBULAR INCISOR
Mandibular central incisor and lateral are similar in anatomy
and complement each other in function.
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

46. 

It is bilaterally symmetrical,that it is difficult to tell
the sides. The only differnce is the greater mesial
than distal curvature.
It is the only incisor where both mesioincisal and
distoincisal angles are sharp and at right angles
Both mesioincisal
and distoincisal
angles are sharp

47. Lingual aspect






The lingual aspect is concave from the incisal edge to the
cervical line
Cingulum is smooth, barely visible & no development lines
mark the cingulum.
Marginal ridges almost absent
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.
No lingual pit is present.
Root is slightly narrower on the lingual side than on the
labial side.

48. Mesial aspect



Crown is wedge shaped, with the labial outline is
almost straight, except near cervical third where it is
convex.
The labial surface is inclined lingually
Root has longitudinal shallow depressions on the
middle 3rd of mesial root surfaces.
Labial surface inclined
lingually

49. 

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

50. Distalaspect
• Distal surface is very similar to the mesial surface.
• The cervical line is less curved.
Distal aspect

51. Incisal aspect
• This aspect illustrates the bilateral symmetry of this
tooth.
• The incisal edge or ridge is at right angles to the
labiolingual root axis plane.
Labiolingually bigger
than mesiodistally
Bilaterally symmetrical
• The labiolingual diameter is greater than mesiodistal
diameter.
• Newly erupted teeth show mamelons which wear off
Mamelons
upon mastication

52. Root
The root is single and straight.
 The deflection of the root if
present is on the labial or distal side.
Root : crown ratio is more in all mandibular teeth
Average Dimensions in millimeters
Crown
Length
Root
Length
9.5
12.5
Mesiodistal
Diameter at
Contact Area
5.0
Mesiodistal
Diameter at
Cervical Line
3.5
Labiolingual
Diameter at
Crest of Curvature
6.0
Labiolingual
Diameter at
Cervical Line
5.3
Curvature of
Cervical Line
M
D
3.0
2.0

53. Mandibular Lateral Incisor





Mandibular lateral incisor is slightly wider mesiodistally
The distal side of the crown from the labial aspect is
slightly bulging in comparison to mesial flatter surface.
The crown is slightly tilted distally on the root, & due to
this tilt the distal outline of the crown is shorter in length
than the mesial outline.
Bilateral symmetry not seen,
Cingulum slightly towards the distal.

54. 
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
Fan shaped appearance
Cervical portion narrower

55. 

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
Average Dimensions in millimeters
Crown Length
9.5
Root
Length
14.0
Mesiodistal
Diameter at
Contact Area
5.5
Mesiodistal
Diameter at
Cervical Line
4.0
Labiolingual
Diameter at
Crest of Curvature
6.5
Labiolingual
Diameter at
Cervical Line
5.8
Curvature of Cervical Line
M
D
3.0
2.0

56. MANDIBULAR CENTRAL INCISOR
MANDIBULAR LATERAL INCISOR
1.
CROWN MORE SYMMETRICAL
LESS SYMMETRICAL
2.
CROWN & ROOT ARE SHORTER
CROWN & ROOT ARE LONGER
3
NO DISTAL SIDE BULGE ON CROWN
DISTAL SIDE BULGE ON CROWN
4.
CINGULUM CENTERED
CINGULUM DISTAL TO CENTRE
5.
NO DISTOLINGUAL TWIST OF INCISAL
EDGE
DISTOLINGUAL TWIST OF INCISAL EDGE
6.
MARGINAL RIDGES NOT PROMINENT
LONGER MESIAL MARGINAL RIDGE

57. MAXILLARY INCISORS
MANDIBULAR INCISORS
LABIAL
1.
CROWN MESIODISTALLY WIDER & LESS CROWN IS LONG, NARROW & MORE
SYMMETRICAL
SYMMETRICAL
2.
DISTOINCISAL ANGLES MORE
ROUNDED
MESIOINCISAL SHARP, & DISTOINCISAL
ANGLES ARE SLIGHTLY ROUNDED
3.
SHALLOW LABIAL DEPRESSIONS ARE
COMMONLY PRESENT
NOT PRESENT
1.
LARGER CINGULUM
SMALLER CINGULUM
2.
DEEPER LINGUAL FOSSA
SHALLOW FOSSA
3.
SOMETIMES LINGUAL PITS PRESENT
LINGUAL PITS ABSENT
4.
PROMINENT MARGINAL RIDGES
LINGUAL SURFACE SMOOTH, WITHOUT
MARGINAL RIDGES
5
CINGULUM SLIGHTLY DISTAL
CENTRAL ALMOST SYMMETRICAL
1.
CINGULUM IS PROMINENT
VERY SMALL CINGULUM
2.
INCISAL EDGE LABIAL TO ROOT AXIS
INCISAL EDGE LINGUAL TO ROOT AXIS
LINGUAL
PROXIMAL

58. INCISAL
1.
CROWNS ARE WIDER MESIODISTALLY
THAN FACILINGUALLY
CROWNS WIDER FACIOLINGUALLY THAN
MESIODISTALLY
2.
INCISAL EDGE LABIAL TO ROOT AXIS
INCISAL EDGE LINGUAL TO ROOT AXIS
3.
CINGULUM OF CI IS SLIGHTLY DISTAL
CINGULUM OF LI IS IN CENTRE
CINGULUM OF CI IS CENTERED
CINGULUM OF LI IS SLIGHTLY DISTAL
4.
LABIAL SURFACE OF LI IS SLIGHTLY
CONVEX
CENTRAL & LATERALS HAVE ALMOST
FLAT LABIAL SURFACES AT INCISAL &
MIDDLE 3rd.

59. MAXILLARY CANINES
Canines are very long and stable teeth
There are four canines placed at the corner of the mouth
and hence called the ‘corner stones’ of the dentition
They have a single pointed cusp (also called cuspids)

60. Labial aspect
 The crown of maxillary canine is narrower mesiodistally
than that of maxillary central incisor.
• The incisal aspect has a large cusp with a pointed cusp
tip
• It has two slopes (cusp ridges), the mesial slope being
shorter than the distal slope
• The labial surface is smooth and bulky in the middle
because of the labial ridge, which runs cervicoincisally.
All areas lies mesial to this ridge shows more convexity,
while distal shows less convexity.

61. Labial ridge
Distal cusp
ridge
Cusp
tip
Labial aspect
Mesial Cusp
Ridge

62. Lingual aspect
• The crown and root are narrower lingually
• The cingulum is well developed, large and sometimes
pointed like a cusp & in center.
• Occasionally a well developed lingual ridge is seen
that divides the lingual fossa into mesial and distal
lingual fossae
• Heavy marginal ridges are associated with well
formed cingulum and fossae

63. Cingulum
Mesial lingual fossa
Distal marginal ridge
Mesial marginal ridge
Distal lingual fossa
Lingual ridge
Lingual aspect

64. Mesial aspect
• Crown outline is wedge shaped
• From the mesial aspect canine looks similar but
bulkier than maxillary central incisor
• Maxillary canine is the widest anterior tooth
labiolingually
• The cervical line curvature is towards the cusp
(incisally)
• The contact area is near the junction of the incisal
and middle third
• From this aspect the entire labial otline is convex
from the cervical line to the cusp tip, & the lingual
outline is convex at cingulum, thereafter it
straightens out at the middle 3rd & again slight
convex in the incisal 3rd.

65. Mesial aspect

66. Distal aspect
• Distal surface is very similar to the mesial surface
• The cervical line exhibits less curvature
• The contact area is near the middle third,
Distal aspect

67. Incisal aspect
• The labiolingual dimension is greater than the mesiodistal
dimension
• The cusp tip is labial to the centre of the crown labiolingually
and mesial to the centre mesiodistally
• Mesiodistally, the mesial half of the crown is narrower, than the
distal half.
• The labial ridge and the cingulum are very noticeable from this
aspect.
• The mesial half of labial outline is more convex, than the distal
half

68. Root –
only one
The root is the longest and strongest of all the teeth in the dentition
The mesial and distal surfaces of the root have developmental depressions.
Average Dimensions in millimeters
Crown
Length
Root
Length
10.0
17.0
Mesiodistal
Diameter at
Contact Area
7.5
Mesiodistal
Diameter at
Cervical Line
5.5
Labiolingual
Diameter at
Crest of Curvature
8.0
Labiolingual
Diameter at
Cervical Line
7.0
Curvature of
Cervical Line
M
D
2.5
1.5

69. Mandibular Canine
Labial aspect

Mandibular canines are similar to maxillary canines except that
they are slightly narrower mesiodistally

Mesial outline of the crown is almost straight and inline with the
mesial outline of the root. The crown is more towards the distal
to the root axis than mesial to it. Because of this crown appears
to be distally tilted when the roots are held vertical position.
Cusp tip forms a more obtuse line (120 degree)
Labial ridge is very rudimentary, & not as marked as maxillary
canine.
The mesial cusp ridge is smaller than the distal cusp ridge




70. Lingual aspect


The lingual surface of the crown is smooth and flat simulating the
surface of mandibular lateral incisor
Cingulum is less prominent and marginal ridges are less distinct
Mesial and Distal aspects




These aspects are very similar and the cervical line curves more on the
mesial aspect
The contact area on mesial aspect is in the incisal third and a little
higher on the distal third
Incisal ridge is slightly lingual to the root axis.
The distoincisal angle is slightly more lingual in position than the cusp tip
to give turn to the arch.

71. Incisal aspect




Like maxillary canine the labiolingual dimension is more than the
mesiodistal dimension
The cusp tip appears inclined in a lingual direction
The root is shorter by 1 or 2 mm
The developmental depression is more pronounced on the lower canine
Average Dimensions in millimeters
Crown
Length
Root
Length
11.o
16.0
Mesiodistal
Diameter at
Contact Area
7.0
Mesiodistal
Diameter at
Cervical Line
5.5
Labiolingual
Diameter at
Crest of Curvature
7.5
Labiolingual
Diameter at
Cervical Line
7.0
Curvature of
Cervical Line
M
D
2.5
1.0

72. MAXILLARY CANINE
MANDIBULAR CANINE
1.
APICAL ROOT TIP IS DISTALLY BENT
CROWN IS SLIGHTLY TIPPED DISTALLY ON
ROOT
2.
MESIAL SIDE OF THE CROWN IS LESS
CONVEX, WHILE DISTAL IS MORE
CONVEX
MORE ACUTE CUSP TIP i.e 105 DEGREE
LABIAL RIDGE IS MORE PRONOUNCED
BLUNT ROOT TIP
MESIAL SIDE OF CROWN IS ALMOST IN
STRAIGHT LINE WITH THE MESIAL SIDE
OF THE ROOT.
120DEGREE
LABIAL RIDGE IS LESS PRONOUNCED
POINTED ROOT TIP
LABIAL
3.
4.
5.
120 degree
105 degree

73. LINGUAL
1.
CINGULUM IN CENTRE
SLIGHTLY DISTAL TO THE CENTRE
2.
STRONG LINGUAL RIDGE & POOR DISTAL
MARGINAL RIDGES.
DISTAL MARGINAL RIDGE IS MORE
PROMINENT & SMOOTH SURFACE

74. PROXIMAL
1.
ROOT DEPRESSION IS MORE DISTINCT
ON THE DISTAL SIDE THAN ON THE
MESIAL SIDE
DISTAL ROOT DEPRESSION IS LESS
2.
CUSP TIP LABIAL TO ROOT AXIS
CUSP TIP LINGUAL TO ROOT AXIS

75. INCISAL
1.
2.
CROWN IS ASYMMETRICAL, WITH
DISTAL HALF IS SLIGHTLY THICKER.
MORE BUCCOLINGUAL BULK IN MESIAL
HALF, DISTAL HALF IS THINNER.
LESS DISTLINGUAL CROWN TWIST
MORE DISTOLINGUAL CROWN TWIST.
3.
ATTRITION OF CUSP TAKES PLACE
LINGUALLY
ATTRITION OF CUSP TAKES PLACE LABIALLY
4.
INCISAL OUTLINE IS ASYMMETRICAL
INCISAL OUTLINE IS SYMMETRICAL
5.
CUSP TIP- LABIAL TO CENTER
LINGUAL TO CENTER
6.
MORE BULKY CUSP TIP DUE TO HEAVY
LINGUAL RIDGE
CUSP TIP & LINGUAL RIDGE IS LESS BULKY

76. MAXILLARY PREMOLARS
Premolars are so named because they are placed
between the anterior teeth and the molars
Maxillary premolars have two cusps and sometimes one
or two roots
They develop from four lobes, like anterior teeth.

77. Buccal aspect
• The crown is roughly TRAPEZOIDAL
• This tooth has two cusps, buccal and lingual cusps.
The buccal cusp is long with a pointed tip resembling
the cusp of a canine
 TIP of buccal cusp lies DISTAL to the line bisecting
the buccal surface of crown.
 The mesial slope of the buccal cusp is longer
than the distal slope, which is the opposite of canine

The buccal surface is convex, showing a
strong buccal ridge
The crown exhibits little cervical line curvature
 Mesial & distal side of the buccal ridge from the occlusal to
the middle 3rd, shows development depressions k/a mesiobuccal &
distobuccal development depressions.


78. Lingual aspect






crown tapers towards the lingual aspect
Mesial outline of the crown is convex.
Distal outline is straight.
The lingual cusp is shorter than the
buccal cusp
The lingual cusp is smooth from the cervical
portion to the area near the cusp tip
The cusp tip is pointed with mesial and
distal slopes meeting at an angle of about
90 degrees
90 degree

79. Sometimes lingual ridge is present,
formed by termination of crest of
lingual portion at a point.
 Small portion of the buccal cusp
can be seen from this aspect
• Lingual root is slightly shorter
than the buccal root.
• Apex of lingual root- more blunt
buccal root- pointed.


80. Mesial aspect
From this aspect crown appears roughly
TRAPEZOIDAL, with longest uneven arm
Towards the cervical 3rd, while shortest
Arm at occlusal 3rd.
 From this aspect both
the buccal and lingual cusps are visible
 Tips of cusp are within the confines of
root trunk of the same side
 A well developed mesial marginal ridge and
a mesial marginal developmental groove is
present
 Buccal outline- curves outwards from the cervical line till
the crest of curvature, & from crest of curvature it shows
less convexity.


81. 

Lingual outline from cervical 3rd to the lingual cusp tip forms
a smooth curve.
There is a depression at just cervical to the mesial contact
area k/a MESIAL DEVELOPMENTAL DEPRESSION.. This
feature differentiates it from right & left & also from
second premolar
ROOT•The outline of the crown bucally is straight,
with a tendency towards the lingual inclination
•
Lingual outline also straight.
Bifurcation is present at half of total length
of root.
•

82. Distal aspect
 There is no developmental depression
or groove on this aspect, instead it is
convex at almost all points
 The curvature of the cervical line
is less on this aspect
 The contact area is near the
junction of occlusal and middle third.
 Bifurcation of root is more towards
the apical 3rd.

83. Occlusal aspect



The occlusal aspect is roughly hexagonal(6 sided i.e MB,
M,ML,DB,D,DL) in shape. With mesial side shorter than
the distal side. Buccal sides are nearly equal. Mesiolingual
side is shorter than distolingual side.
The buccolingual dimension of the crown is much greater
than the mesiodistal dimension
The occlusal surface is circumscribed by the cusp ridges
and marginal ridges

84. Following structures can be seen• The distance from the buccal crest to the distal crest is
shorter than the distance from the buccal crest to mesial
crest.
• The distance from the mesial crest
to the lingual crest is much shorter
than the distance from the distal
crest to the lingual crest.
• Buccal portion of the crown is
more wider than the lingual portion.
• Central developmental grooveRuns mesiodistally with pits at both
ends. The length of central groove is
more than one third of the mesiodistal
width of occlusal surface.

85. Mesial marginal developmental Grooveit crosses the mesial marginal ridge.
This groove connects the central
groove in the mesial triangular fossa.
•
Distal marginal groove may be
found, but less frequent than
mesial marginal groove
•
Mesial and distal developmental pit
are closer to each other than in
2nd premolar.
•
Mesial and distal triangular fossa
•
Buccal and lingual triangular ridge,
buccal ridge more prominent arising from the central groove &
converging with the tip of the buccal cusp.
•
Lingual cusp is more pointed, than buccal cusp.
•

86. Root
Most Maxillary first premolars have 2 roots, but one and
three roots can also be seen. Two roots; buccal and lingual
 The buccal portion of the root resembles canine
 The root when viewed from the proximal side shows a big
trunk and bifurcation area from where the buccal and
lingual root separate
A developmental depression is seen on the mesial aspect
of the trunk.

87. Average Dimensions in millimeters
Crown
Length
Root
Length
8.5
14.0
Mesiodistal
Diameter at
Contact Area
7.0
Mesiodistal
Diameter at
Cervical Line
5.0
Labiolingual
Diameter at
Crest of
Curvature
9.0
Labiolingual
Diameter at
Cervical Line
8.0
Curvature of
Cervical Line
M
D
1.0
0

88. Maxillary 2nd Premolar
Buccal aspect
The maxillary second premolar resembles the maxillary first
premolar in form and function
 The buccal cusp is not as long
as that of maxillary 1st premolar
 It is less pointed.
 The mesial slope of the buccal
cusp ridge is shorter than the distal
cusp ridge, as in maxillary canine.
 Crown & root are thicker at the
cervical portion.


89. Lingual aspect


The lingual cusp is more or less the same size as the buccal cusp
Root is single, & tapered towards apex & towards the lingual side.
Mesial and Distal aspects
There is greater distance between the cusps
which widens the occlusal surface buccolingually.

No developmental depression is
present nor any developmental groove
crossing the marginal ridge on the
mesial aspect

On the distal aspect there is a
developmental depression which is
deeper than the depression on the
mesial surface of maxillary 1st premolar


90. Occlusal aspect
The occlusal aspect is more rounded/ oval

The central developmental groove
is shorter, & mesial marginal groove is absent.

Triangular fossae are smaller
& farther from marginal ridges.

Mesiodistal diameter is more
on the buccal side than the lingual side.

There are multiple supplementary
grooves radiating from the central groove


91. •
Root
 Maxillary 2nd premolar has one root, which is usually
as long or a millimeter longer than the root of
maxillary 1st premolar
Average Dimensions in millimeters
Crown
Length
Root
Length
8.5
14.0
Mesiodistal
Diameter at
Contact Area
7.0
Mesiodistal
Diameter at
Cervical Line
5.0
Labiolingual
Diameter at
Crest of
Curvature
9.0
Labiolingual
Diameter at
Cervical Line
8.0
Curvature of
Cervical Line
M
D
1.0
0

92. MAXILLARY 1ST PREMOLAR
MAXILLARY 2ND PREMOLAR
1.
BUCCAL RIDGE IS PROMINENT
NOT PROMINENT
2.
MESIAL CUSP SLOPE IS LONGEST
MESIAL CUSP SLOPE SHORTEST
3.
CERVIX NARROW & TAPERS MORE
CERVIX BROAD & TAPERS LESS
BUCCAL

93. LINGUAL
1.
LINGUAL CUSP SHORTER THAN BUCCAL
CUSP
LINGUAL CUSP ALMOST EQUAL TO
BUCCAL CUSP
2.
CROWN NARROWER & MORE TAPERS
TOWARDS LINGUAL
LESS TAPER TOWARDS LINGUAL

94. PROXIMAL
1.
TWO ROOTS
ONE ROOT
2.
BUCCAL CUSP IS LONGER THAN
LINGUAL
BUCCAL & LINGUAL OF SAME LENGTH
3.
CUSP TIP ARE CLOSE TOGETHER
CUSP TIPS ARE SPREAD APART
4
MESIAL MARGINAL RIDGE GROOVE IS
PRESENT
MESIAL MARGINAL RIDGE GROOVE IS
ABSENT

95. OCCLUSAL
1.
LONGER CENTRAL GROOVE
SHORTER CENTRAL GROOVE
2.
MORE CONVERGENCE OF PROXIMALS
TOWARDS LINGUAL
SLIGHT CONVERGENCE TOWARDS
LINGUAL
3.
PROMINENT BUCCAL RIDGE
LESS PROMINENT RIDGE
4.
BUCCAL CUSP INCLINES ARE LONGER THAN LINGUAL CUSP INCLINES ALMOST
LINGUAL
EQUAL TO BUCCAL

96. 6.
VERY FEW SUPPLEMENTARY GROOVES
MORE SUPPLEMENTARY GROOVES
7.
MESIAL SIDE SHORT & SLIGHTLY CONCAVE OR
FLAT
DISTAL SIDE CURVED OR CONVEX OR LONGER
BOTH MESIAL & DISTAL OUTLINES OF
CROWN ARE MORE SYMMETRICAL
8.
CROWN OUTLINE HEXAGONAL
CROWN OUTLINE IS OVAL
9.
MESIAL MARGINAL RIDGE GROOVE IS PRESENT LESS COMMON, PRESENT IN ONLY 37% OF
IN 97% OF CASES
CASES
10 MESIOBUCCAL CUSP RIDGE & MARGINAL
.
RIDGE MEETS AT RIGHT ANGLE
MESIOBUCCAL CUSP RIDGE & MARGINAL
RIDGE MEETS AT OBTUSE

97. Mandibular First Premolar

98. Buccal aspect
 A large well formed, pointed buccal cusp is seen..
 The mesiobuccal cusp ridge is
shorter than the distobuccal cusp
ridge (similar to canines)
 Tip of buccal cusp is located
a liitle MESIAL to the centre of
the crown buccally.
 The mesial and distal slope
of the buccal cusp sometimes show
concavity.
 Mesial & distal outline of the crown is
Slightly concave above the cervical line.

99. Lingual aspect
The crown tapers and inclines lingually,
Making it narrower mesiodistally

The lingual cusp is small, pointed and
nonfunctional and in some specimens it
is no longer than the cingulum of maxillary
canine.

Between the mesiobuccal and lingual
lobe is the mesiolingual developmental
groove, & extends into the mesial fossa of
Occlusal surface.
•
This grooves separates the mesial marginal ridge
from mesial slope of lingual cusp.
•
Occlusal surface slopes greatly towards
the lingual in a cervical direction down to
the short lingual cusp.


100. • Root tapers more on the lingual side.
• A smooth convex narrow linear ridge runs along the full length of the
root, because of this ridge & lingual taper most of the proximal
surface is visible from this aspect.

101. Mesial aspect
The lingual inclination of the crown can be
seen from this aspect,because of which the
tip of buccal cusp is nearly centered over the root axis
•
Buccal outline is prominently curved.
•
Crest of curvature on buccal side- just occlusal
To the cervical line, lingual side- near the tip of
the lingual cusp.
 The lingual cusp is approximately two
thirds the size of the buccal cusp
 The mesial marginal ridge has extreme
lingual slope, it is located cervically as compared
to distal marginal ridge.
 The mesial marginal ridge is almost parallel to the
triangular ridge of the buccal cusp, & slopes cervically
From bucccal towards the centre of occlusal surface at 45
Degree angle.

2/3rd

102. Mesiolingual developmental groove
is present between the mesial
marginal ridge and the mesiolingual
cusp ridge
 The distal contact
areas are in the middle third,.

Root- buccal & lingual outline almost
runs parallel in cervical & middle 3rd,
then tapers apically to end in a pointed
apex, situated in line with buccal cusp tip.
•

103. Distal aspect
 Convexity on the distal surface
is less as compared to mesial surface.
 Distal marginal ridge is higher
( occlusal) and does not have the extreme
lingual slope
 The cervical line curvature is less curved.
 Root surface is more convex as compared
to mesial surface.
 A shallow linear developmental depression
On distal root surface.

104. Occlusal aspect




The crown converges sharply to the centre of the lingual
surface
Crown appears asymmetrical, being somewhat DIAMOND
SHAPE.
distal outline is more convex, there appears to be more
bulk in the distal half of occlusal aspect.
Most common form of mandibular 1st premolar shows a
mesiolingual depression and mesiolingual developmental
groove.

105. • The occlusal surface has two depressions; mesial and distal
fossae, both of them are circular in shape, hence not
termed as triangular fossae
• Mesial fossa is more linear, & contains mesial developmental
groove, extending buccolingually.
• Distal fossa is more circular in shape & harbours a cresent
shaped distal developmental grove.
• Mesial marginal ridge is at an acute angle with the
mesiobuccal cusp ridge
• Distal marginal ridge is at
right angle to the distobuccal
cusp ridge.
• Distal ridge more bulky than
mesial marginal ridge.

106. Root
The mandibular 1st premolar has one root
The root is approximately (3-4mm)shorter than the root
of mandibular canine but the outline bears a close
resemblance to the canine
A deep developmental groove is seen on the mesial aspect
on the root
On the distal aspect there is a shallow depression devoid
of any developmental groove.

107. Average Dimensions in millimeters
Crown
Length
Root
Length
8.5
14.0
Mesiodistal
Diameter at
Contact Area
7.0
Mesiodistal
Diameter at
Cervical Line
5.0
Labiolingual
Diameter at
Crest of Curvature
7.5
Labiolingual
Diameter at
Cervical Line
6.5
Curvature of Cervical
Line
M
D
1.0
0

108. Mandibular Second Premolar

Mandibular 2nd premolar resembles the mandibular 1st
premolar from the buccal aspect only
The crown assumes two common types.
more common 3-cusp type- more angular
2-cusp type- more rounded


The two differ mainly in the occlusal design
Buccal aspect

The buccal cusp is shorter with the cusp slopes presenting
less degree of angulations

109. Lingual aspect
There may be one or two lingual cusps –
mesiolingual and distolingual cusps

The cusp are more developed
than the lingual cusp of lower first
premolar
•
groove separates the two lingual cusps.

2 cusp type- no groove but a
distolingual developmental depression
appears where the lingual cusp ridge
joins the distal marginal ridge

3 cusp type- there is a longer
mesiolingual & a comparatively
smaller distolingual cusp. A groove
is present between the two cusps


110. Mesial and Distal aspects
The crown and root are wider buccolingually

Buccal cusp is shorter.

Mesiolingual developmental groove absent

More of occlusal surface is visible
form the distal aspect because the
distal marginal ridge is at lower level
than the mesial marginal ridge


111. Occlusal aspect
From the occlusal aspect the 3-cusp type appears square
and the 2-cusp type appears rounded.
3-cusp type:
each cusp is separated by deep developmental grooves
forming a “Y” shape in the centre
- BUCCAL cusp largest, then ML & DL shortest.
- the occlusal surface also includes
a. central pit
b. mesial developmental groove travels in a mesiobuccal
direction & ends in mesial triangular fossa
c. mesial triangular fossa
d. distal developmental groove travels
in a distobuccal direction & end in
distal triangular fossa.
e. distal triangular fossa
f. lingual developmental groove
g. supplemental grooves


112. 2-cusp type:
- one buccal cusp and one well developed lingual cusp is
present
- crown outline is less oval on the lingual side.
- a central groove travels in a mesiodistal direction
and end in mesial and distal fossa (forming ‘H’ shape)
- buccolingual bulk is more in the mesial half than the
distal half
Root-
Mandibular 2nd premolar has a single root which is larger and
longer than the root of mandibular 1st premolar
The root is usually wide with a blunt apex

113. MANDIBULAR 1ST PREMOLAR
MANDIBULAR 2ND PREMOLAR
1.
PRESENCE OF LONGER BUCCAL CUSP
CROWN IS SHORTER BUT WIDER.
2.
MORE POINTED CUSP(110 DEGREE)
ROUNDED CUSP (130 DEGREE)
3.
NOTCH PRESENT ON MESIAL CUSP SLOPE
NOTCH ON DISTAL CUSP SLOPE
4.
LINGUAL SURFACE MORE TAPER FROM
CONTACTS TO CERVIX
LINGUAL SURFACE RELATIVELY WIDER AT
CERVIX
5.
ROOT IS SHORTER WITH POINTED APEX
ROOT IS LONGER WITH BLUNT APEX
6.
BUCCAL RIDGE MORE PROMINENT
LESS PROMINENT
BUCCAL
110 DEGREE
130 DEGREE

114. LINGUAL
1.
CROWN IS NARROWER THAN SECOND
PREMOLAR
CROWN IS WIDER
2.
LINGUAL CUSP IS SHORT & NARROW &
NONFUNCTIIONAL
LINGUAL CUSP LARGER & FUNCTIONAL
3.
FROM THIS ASPECT MORE OF OCCLUSAL
SURFACE IS VISIBLE
VERY LESS OCCLUSAL SURFACE IS VISIBLE
4
MESIAL MARGINAL RIDGE IS DIVIDED BY
MESIOLINGUAL GROOVE
MESIAL MARGINAL GROOVE IS ABSENT

115. PROXIMAL
1.
LINGUAL CUSP MUCH SHORTER THAN
BUCCAL CUSP & NON FUNCTIONAL
LINGUAL CUSP ONLY SLIGHTLY SHORTER
THAN BUCCAL CUSP & IS FUNCTIONAL
2.
CROWN IS MORE TILTED TO LINGUAL SIDE
CROWN IS LESS TILTED TO LINGUAL SIDE
3
MESIAL MARGINAL RIDGE IS LOWER &
MESIAL MARGINAL RIDGE IS HIGH & IS IN
PARALLEL TO TRIANGULAR RIDGE OF BUCCAL HORIZONTAL PLANE, HENCE ONLY LITTLE
CUSP, HENCE MUCH OF OCCLUSAL SURFACE
OCCLUSAL SURFACE IS VISIBLE
IS VISIBLE
4.
ROOTS HAVE DEEP LONGITUDINAL
DEPRESSIONS
NO DEPRESSIONS PRESENT.

116. OCCLUSAL
1.
CROWN OUTLINE IS ASYMMETRICAL
OUTLINE IS SQUARE
2.
SMALL OCCLUSAL & LESS GRINDING SURFACE
LARGE OCCLUSAL & MORE GRINDING
SURFACE.
3.
CONVERGENCE OF MESIAL SIDE TOWARDS
LINGUAL IS MORE
VERY SLIGHT CONVERGENCE.
3 CUSP - CROWN WIDER LINGUALLY.
4.
PRESENCE OF TWO CIRCULAR FOOSAE, TWO
GROOVES( MESIAL & DISTAL)
2 CUSP- 2 CIRCULAR FOSSAE
3 CUSP-3 FOOSAE, & 3 GROOVES ( MESIAL,
DISTAL & LINGUAL)

117. SOME TERMINLOGIES• RIDGE- is any linear elevation on the surface
•
•
•
•
of a tooth
& is named according to its location i.e buccal,incisal or
marginal ridge
FOSSA- it is an irregular depression or concavity. Eg
central fossa are on the occlusal surface of molars, formed
by the convergence of ridges terminating at a central point
in the bottom of the depression where a junction of grooves
occurs.
SULCUS- it is a long depression or valley in the surface of a
tooth between ridge or cusp
GROOVE- it is a shallow linear depression on the surface of
the tooth
DEVELOPMENTAL GROOVE- it is a shallow groove or line
between the primary part of the crown or root.

118. • SUPPLEMENTAL GROOVES- it is less distinct & does not
mark the junction of primary parts
• PITS- a small pinpoint depression located at the junction of
developmental grooves or at terminals of those grooves

119. Maxillary First Molar
It has a large crown with four well
developed cusps and occasionally a small
fifth cusp. In addition to the cusps it has
three well formed roots; two buccal and one
lingual.

120. Buccal aspect
 The crown is roughly trapezoidal
• two buccal cusp. Mesiobuccal & distobuccal
cusp
• MB cusp is broader, as its mesial slope
Meets its distal slope at an obtuse angle.
• DB cusp- its mesial slope meets the distal
Slope at approx rite angles. Therefore the
DB cusp is sharper.
 MB surface of crown is longer & wider
than DB surface.
• Part of mesiopalatal and distopalatal
cusps are seen from this aspect as
the distopalatal line angle is obtuse
• The buccal developmental groove
divides the two buccal cusps.this grooves
mostly ends in a buccal pit.

121. • Mesial outline of crown is straight, while distal outline is
convex from this aspect.
• All 3 roots are visible from the
buccal aspect.
• MB root curves distally,
starting at the middle 3rd.
distal root is straighter.
• Point of bifurcation of the 2
4mm
buccal roots is approx at 4mm
from the cervical line.
• Point of bifurcation of the
palatal root is approx 3mm
• The common root base is
k/a root trunk.

122. Lingual aspect
• General outline of lingual aspect is reverse of buccal aspect
• The mesiopalatal, distopalatal and
fifth cusp are the only cusps seen
from this aspect
• Mesiopalatal cusp is largest of all
the cusps. Its MD width is about
3/5th of the MD crown diameter.
Its mesial & distal slopes meet at
90degree or so.
• Distopalatal cusp is small and
spheroidal & smooth.
The lingual developmental
groove separates the lingual cusps

3/5th

123. • Sometimes a fifth cusp called the cusp of carebelli may be
present.When present it attached to the mesiopalatal
surface of the mesiopalatal cusp. This morphological trait
can take the form of a well developed fifth cusp, or it can
grade down to a series of grooves, depressions, or pits on
the mesial portion of the lingual surface.
• All 3 roots are visible,palatal
root is the largest, with bluntly
rounded apex.

124. Mesial aspect
• Mesiobuccal, mesiopalatal and fifth
cusps are visible from this aspect also
• Mesial marginal ridge is placed
Higher & is confluent
with the mesiobuccal and
mesiopalatal cusp ridges and
is curved cervically
• The cervical line is irregular, curving
occlusally
Mesial aspect

125. Distal aspect
 Distobuccal and distopalatal cusps are seen
 The marginal ridge dips sharply cervically, exposing
triangular ridges on the distal portion.
 The cervical line is almost straight.
 Concavity present on the distal
Surface of the DB root,from the
cervical line to the area of the root
that is on a level with birfurcation
separating the DB & lingual roots.

126. Occlusal aspect
•
•
•
•
•
1.
The occlusal aspect is roughly rhomboidal in shape. Acute
angles- MB,DL obtuse angles-ML & DB.
Lingual side of crown is slightly wider than the buccal side, &
mesial side is wider than the distal side.
Maxillary first molar crown is wider mesially than distally and
wider lingually than buccally
The triangular arrangement of 3 imp molar cusp is called as the
MAXILLARY MOLAR PRIMARY CUSP TRIANGLE.
The elevations and depression on this surface are:
Cusps
• Mesiopalatal cusp is the
largest followed by mesiobuccal,
distopalatal, distobuccal, and
the smallest being the fifth
cusp.

127. 2.
3.
4
Ridges
 Mesial marginal ridge and distal marginal ridge
 Oblique ridge( union of MP & DB cusp ridges)
Fossae
 Major fossae: central fossa (roughly triangular &
mesial to the oblique ridge) and distal fossa (roughly
linear & distal to the oblique ridge)
 Minor fossae: mesial triangular (immediately distal to
the MMR) and distal triangular( immediately mesial to
the DMR)
Grooves
 Central developmental groove
 Buccal developmental groove
 Lingual developmental groove

128. 

Fifth cusp groove
Pit
 Central developmental pit( from it the buccal
development groove radiates bucally)

5.
Transverse groove of the oblique ridge (
runs mesiodistally across the oblique ridge)
Supplemental grooves

129. Root
Maxillary first molar has three roots; two buccal and one
palatal
The palatal root is long and slender with bluntly round
apex
 Mesiobuccal root is broader and curves distally while the
distobuccal root is narrower at the base and a lot
straighter

130. Both the buccal roots are of equal size but smaller than
the palatal root
The level of bifurcation area is more closer to the
cervical area on the mesial side than on the distal side.
Average Dimensions in millimeters
Crown
Length
7.5
Root
Length
B L
12 13
Mesiodistal
Diameter at
Contact Area
Mesiodistal
Diameter at
Cervical Line
10.0
8.0
Labiolingual
Diameter at
Crest of Curvature
11.0
Labiolingual
Diameter at
Cervical Line
10.0
Curvature of Cervical
Line
M
D
1.0
0

131. Maxillary Second Molar
The crown is shorter cervico-occlusally(0.5mm) and about the
same width buccolingually when compared with maxillary first
molar.
 The distobuccal cusp is not as well developed and the
distolingual cusp is also small. The fifth cusp is absent
The roots are almost the same size as that of the first molar.
Roots are more inclined distally
The apex of the lingual root is in line with the DL cusp tip
instead of the lingual groove as was found on 1st molar- buccal
aspect.

132. • Less prominent oblique ridge is present.
• Occlusal parallelogram is more twisted & is
faciolinguallly more oblong, whereas the first molar
is wider & squarish.
• Buccal groove is shorter & mostly without a buccal
pit.

133. MAXILLARY 1ST MOLAR
MAXILLARY 2ND MOLAR
1.
CROWN IS LARGER
CROWN IS SMALLER
2.
OCCLUSAL OUTLINE IS ROUGHLY
RHOMBOIDAL
OCCLUSAL OUTLINE- MORE OBLONG,
BECAUSE OF THE REDUCED MESIODISTAL
DIMENSIONS
3.
CUSP OF CARABELLI IS PRESENT
CUSP OF CARABELLI IS ABSENT
4.
PROMINENT OBLIQUE RIDGE
LESS PROMINENT OBLIQUE RIDGE
5.
DISTOPALATAL CUSP IS LARGER THAN
DISTOBUCCAL CUSP
BOTH DISTAL CUSPS ARE COMPARATIVELY
SMALLER
6.
OCCLUSAL TABLE IS WIDER & MORE
SQUARISH
OCCLUSAL PARALLELOGRAM IS MORE
TWISTED
7.
BUCCAL GROOVE LONGER & ENDING IN
A BUCCAL PIT
BUCCAL GROOVE SHORTER & WITHOUT A
BUCCAL PIT.
8.
LESS PROMINENT BUCCAL CERVICAL
RIDGE
MORE PROMINENT BUCCAL CERVICAL
RIDGE

134. Mandibular Molars
Mandibular molars are the biggest teeth in the
mandibular arch.
They have two broad roots for superior
anchorage.
The crown of lower molars are wider
mesiodistally than buccolingually, the opposite is
true of upper molars.

135. Mandibular First Molar
It has five cusps ; two buccal, two lingual and one
distal
It has two roots; one mesial and one distal

136. Buccal aspect
 The crown is roughly trapezoidal from this aspect
• MB cusp is largest, widest & highest on buccal side
• DB cusp is slightly smaller, shorter & may be
Sharper than the MB cusp.
• Distal cusp is present
On the distobuccal angle of the crown.
• Two developmental grooves appear on
this aspect; mesiobuccal (longer & deeper)
and distobuccal developmental grooves.
3mm
• A cervical ridge is found near
the cervical line.
• Point of bifurcation 3mm from the cervical line.
• Mesial root- curved mesially from the cervical portion to the middle 3rd.
& then curved distally upto the apex.
•
Distal root- less curved, distally from cervical line till apex.

137. Lingual aspect
• Three cusps may be seen; two lingual and the lingual portion of the
distal cusp
• The mesiolingual and distolingual
cusps are pointed and have cusp
ridges that are high enough to hide
4mm
the buccal cusps
• The lingual developmental groove
separates the lingual cusps
• The cervical line lingually is irregular.
• ML cusp is widest MD,with its cusp tip higher than the DL cusp.
• Mesial outline- convex, from cervical to the marginal ridge.
• Distal outline-straight from cervical line to a point immediately below
the distal contact area.
• Roots appear 1mm longer lingually than bucally,coz the cusp ridges &
cervical lines are at higher level. & MD dimension of the root trunk is
less, therefore this slenderness makes roots appear longer.
• Root bifurcation is 4mm below the cervical line.

138. Mesial aspect
Two cusps; mesiobuccal and distobuccal cusps, and one
root; mesial root, are visible from this aspect
• Crown of mand. 1st molar are slightly
lingually tilted.Because of this they
fit beneath & lingual to the maxillary
Buccal cusps.
• Crown outline is roughly rhomboidal.
• The mesial aspect of the tooth is broader
and the mesial cusps are higher hence
the distal portion cannot be seen
•
• The mesial marginal ridge is confluent
with the mesial ridges of the mesial cusps
It is occlusally positioned hence triangular ridges not
Visible.

139. • The contact are is in near the junction
of middle and occlusal third.
• Buccal outline CONVEX immediately above the cervical line.
• Lingual outline is STRAIGHT from cervical to the middle
3rd.
• Cervical line slopes occlusally.

140. Distal aspect
• The gross outline is similar to the mesial aspect
• More of the tooth is seen from this
aspect because the distal portion is
smaller & distal sloping of occlusal surface.
and the buccal and lingual surfaces
converge distally
• DMR is short & made up of DCR of the
distal cusp & DLCR of the DL cusp.
• Surface is CONVEX, & apical portion of the root appears to
be more rounded.
• The cervical line is usually straight
• Distal root is more narrower BL than the mesial root.

141. Occlusal aspect
•
The occlusal aspect is roughly hexagonal in shape
•
The crown is wider mesiodistally than buccolingually
•
The buccolingual measurement on the mesial portion is
bigger than on the distal portion
Two mesial cusp are larger than the two distal cusp.
From a development point- all mandibular molars have 4
major cusps, while maxillary molars have 3 major cusps.
•
•
2
4
3
1

142. 
1.
2.
3.
The elevations and depressions on this surface are:
Cusps

Mesiobuccal cusp is the largest followed by the two lingual cusps,
then the distobuccal, and the smallest being the distal cusp.
Ridges-Mesial marginal ridge and distal marginal ridge. Two
transverse ridges are present formed by the TRIANGULAR RIDGES
OF MB & ML CUSPS, & DB & DL CUSPS.
Fossae

Major fossae: central fossa( roughly circular, & placed
centrally between the buccal & lingual cusp ridges)

Minor fossae: mesial triangular(distal to MMR) and distal
triangular fossae( mesial to DMR)

143. 4.
5
Grooves
 Central developmental groove
 Mesiobuccal developmental groove
 Distobuccal developmental groove
 Lingual developmental groove
 Supplemental grooves
Pit
 Central developmental pit
Roots
Mandibular first molar has two roots; mesial and distal roots
The apical third of the both the roots tend to curve distally
Both roots are wider buccally than they are lingually
Deep developmental depression is found on the root trunk

144. Average Dimensions in millimeters
Crown
Length
Root
Length
7.5
14.0
Mesiodistal
Diameter at
Contact Area
11.0
Mesiodistal
Diameter at
Cervical Line
9.0
Labiolingual
Diameter at
Crest of Curvature
10.5
Labiolingual
Diameter at
Cervical Line
9.0
Curvature of Cervical
Line
M
D
1.0
0

145. MANDIBULAR SECOND MOLAR
• Crown is wider mesiodistally than cervicoincisally or
buccolingually
• 2 buccal cusps & 2 lingual cusps are present. MB cusp
WIDER than DB CUSP.
• The tip of ML & DL cusp are visible from the buccal aspect.
• Only one buccal groove, separating the MB & DB CUSPS.
• Cervical line almost straight
• Mesiolingual cusp is longest & wider than the distolingual
cusp.
• Both lingual cusps are pointed.
• Mesiodistal width at the cervix is greater than that of 1st
molar.
• Crown & root both converges lingually.

146. Occlusal aspect of Mandibular 2nd molar

The occlusal aspect of 2nd molar differs considerably from
the 1st molar
Shape is roughly rectangular.

The distal cusp and distobuccal groove are absent


The buccal and lingual grooves meet in the centre at right
angles. The occlusal surface is roughened by numerous
supplemental grooves

147. The elevations and depressions on this surface are:
1.
Cusps

Mesiobuccal, distobuccal, mesiolingual and distolingual cusps
2.
Ridges

Mesial marginal ridge and distal marginal ridge
3.
Fossae

Major fossae: central fossa

Minor fossae: mesial triangular and distal triangular fossae
4
Grooves
 Central developmental groove
 buccal developmental groove
 Lingual developmental groove
 Supplemental grooves
5
Pit
 Central developmental pit
Occlusal aspect of Mandibular Second
Molar

148. MANDIBULAR 1ST MOLAR
MANDIBULAR 2ND MOLAR
1.
MORE CONVERGENCE OF CROWN
LESS CERVICAL CONVERGENCE OF CROWN.
2.
TWO BUCCAL GROOVES
ONLY ONE BUCCAL GROOVE
3.
CONTACT AREA NOT LOCATED CERVICALLY
MORE CERVICALLY LOCATED CONTACT AREA
4.
LONGER ROOT TRUNK & CURVED ROOTS
SHORTER ROOT TRUNKS & STRAIGHTER ROOTS
5.
ROOTS ARE NOT CLOSER TOGETHER
ROOTS ARE CLOSER TOGETHER
BUCCAL

149. OCCLUSAL
1.
CROWN OUTLINE ROUGHLY
PENTAGON
MORE RECTANGULAR OUTLINE
2.
CROSS SHAPED GROOVE PATTERN
NOT OBSERVED
A CROSS SHAPED GROOVE PATTERN
3.
CROWN TAPERS MORE FROM BUCCAL CROWN TAPER FROM BUCCAL TO LINGUAL
TO LINGUAL.
IS LESS
4.
CENTRAL GROOVE IS ZIG-ZAG
CENTRAL GROOVE IS STRAIGHT
5.
LESS PROMINENT BUCCCAL CERVICAL
RIDGE
A MORE PROMINENT BUCCAL CERVICAL
RIDGE

150. MAXILLARY MOLARS
MANDIBULAR MOLARS
1.
CUSPS MOSTLY FOUR, SOMETIMES THREE,
ROOTS THREE (MB,DB,& PALATAL)
CUSPS MAINLY FOUR, SOMETIMES FIVE &
TWO ROOTS ( MESIAL & DISTAL)
2.
CROWN WIDER FACIOLINGUALLY THAN
MESIODISTALLY
CROWN WIDER MESIODISTALLY THAN
BUCCOLINGUALLY
3.
LARGE & SMALL LINGUAL CUSP
2 NEARLY EQUAL SIZED LINGUAL CUSPS.
4.
1ST MOLARS- WIDER ON LINGUAL THAN
BUCCAL
1ST MOLARS- TAPER FROM BUCCAL TO
LINGUAL
5.
ONE BUCCAL GROOVE PRESENT
TWO BUCCAL GROOVES ARE PRESENT ON
1ST MOLAR
6.
OBLIQUE RIDGE IS PROMINENT
NO OBLIQUE RIDGE, BUT HAS TWO
TRANSVERSE RIDGES
7.
FOUR FOSSA, INCLUDING LARGE DISTAL
FOSSA
THREE FOSSA (LARGE CENTRAL FOSSAE)
8.
OCCLUSAL SURFACE- PARALLELOGRAM
IN FOUR CUSP- RECTANGULAR
IN 5 CUSP- PENTAGONAL
9.
ROOT TRUNK SHORTER IN 1ST MOLAR
ROOT TRUNK LONGER
10.
3 ROOTS- MB, DB, PALATAL
2 ROOTS- MESIAL & DISTAL
11.
ON VIEWING FROM PROXIMAL SIDECROWN ARE CENTERED ON ROOTS
CROWN APPEARS TO BE SLIGHTLY
LINGUALLY TILTED.
12.
NEAR CERVIX CROWNS ARE NARROW
CROWNS ARE NOT NARROW ON CERVIX.

151. REFERENCES1. WOELFEL – Dental anatomy & its relevance to dentistry
5th edition
2. WHEELERS- Dental anatomy, Physiology, & Occlusion
8th edition
3.SATISH CHANDRA- Textbook of Dental & oral anatomy,
physiology & occlusion.