Form & Function 2014

1. Introduction
Form and Function of
the Human Dentition
-Terminology -
Dr. George F. Richards
1

2. 2
References:
Wheeler’s Dental Anatomy, Physiology,
and Occlusion
Chapter 1
Woefel’s Dental Anatomy
Chapter 1
Assessment may cover any information in these two chapters as well
as information in ppt. and lecture.

3. Lecture Objectives
• Be able to name each tooth based upon location within
the normal, complete human dentition
• Be familiar with tooth identification systems
• Utilize terminology to describe the parts of the tooth
• Utilize correct terminology to define tooth surfaces
• Utilize correct terminology to describe the morphology of
the tooth
• Understand the terminology related to ideal tooth
alignment in the dental arches
• Apply all appropriate terminology to make clear
communication
3

4. Nomenclature
o Maxillary – refers to upper jaw – the maxilla
(mx; max)
• Maxillary teeth – teeth which reside in the
maxilla
o Mandibular – refers to lower jaw – the
mandible (mand, mnd)
• Mandibular teeth – teeth which reside in the
mandible
4

5. Nomenclature
• Primary Teeth – Deciduous Teeth
o “primary can mean “constituting or belonging to the first stage in
any process.” The term deciduous can mean “not permanent,
transitory.” (Nelson, Stanley J.. Wheeler's Dental Anatomy, Physiology and Occlusion, 9th Edition. W.B. Saunders
Company, 042009. p. 2).
• Permanent Teeth – Succedaneous Teeth
o “ succedaneous can be used to describe a successor dentition
and does not suggest permanence, whereas the term permanent
suggests a permanent dentition, which may not be the case due
to dental caries, periodontal diseases, and trauma.”(Nelson, Stanley J..
Wheeler's Dental Anatomy, Physiology and Occlusion, 9th Edition. W.B. Saunders Company, 042009. p. 2).
5

6. • Incisors
o Central
o Lateral
• Canines (you may also hear the term “Cuspids”)
• Premolars (you may also hear the term “bicuspids”)
o 1st Premolar
o 2nd Premolar
• Molars
o 1st molar
o 2nd molar
o 3rd molar (also known as wisdom teeth)
6
Nomenclature

7. Nomenclature
• Dental formula for primary/deciduous teeth per quadrant
7
o I=Incisors - 2 maxillary, 2 mandibular
• Central
• Lateral
o C=Canines – 1 maxillary, 1 mandibular
o M=Molars – 2 maxillary, 2 mandibular
• 1st Molar
• 2nd Molar
o There are no primary/deciduous premolars
X 2 = 20 teeth in all

8. Primary Teeth
8

9. 9
Nomenclature
• Dental formula for permanent dentition per quadrant
• I=Incisors – 2 maxillary, 2 mandibular
o Central
o Lateral
• C=Canines – 2 maxillary, 2 mandibular
• P=Premolars – 2 maxillary, 2 mandibular
o 1st Premolar
o 2nd Premolar
• M=Molars – 3 maxillary, 3 mandibular
o 1st Molar
o 2nd Molar
o 3rd Molar (wisdom teeth)
32 teeth in all

10. Permanent Dentition
10

11. Tooth Identification
(Numbering) Systems
• Universal Numbering System
• Zsigmondy/Palmer Tooth Notation
System (Palmer)
• Fédération Dentaire Internationale
(World Dental Federation
International) Numbering System
(FDI)
11

12. Universal Numbering
System
• Used almost exclusively in the US
• Permanent teeth
o Number 1-32 beginning with the maxillary right 3rd
molar (1) moving around the arch from right to left to
the left maxillary 3rd molar (16), moving to the left
mandibular 3rd molar (17) around the arch from left to
right to the right mandibular 3rd molar (32).
o A key to learning the numbering system
• 1st molars – 3, 14, 19, 30
• Central incisors – 8-9, 24-25
12

13. Permanent Dentition
13

14. • Primary Dentition
o The alphabet is used to number the primary dentition:
A-T beginning with the right maxillary 2nd molar (A)
moving from right to left to the left maxillary 2nd molar
(J), dropping down to the left mandibular 2nd molar (K)
moving left to right to the right 2nd molar (T).
o Helpful key to learning the system: A, J, K, T – 2nd
molars; central incisors, E-F, O-P.
14
Universal Numbering
System

15. Primary Teeth
15

16. Palmer Tooth Notation
• Used mainly by orthodontists and oral surgeons. It
utilizes four different bracket shapes to denote each of
the four quadrants
o Upper right quadrant Upper Left quadrant
1 1
o Lower right quadrant Lower left quadrant
16
∟
∟
∟
∟
Primary designation is:
E D C B A A B C D E
E D C B A A B C D E
1
1

17. World Dental Federation (International)
Numbering System
17
Fédération Dentaire Internationale (FDI)
This system numbers each quadrant
with a number – #1 Maxillary R, #2
Maxillary L, #3 Mandibular L, #4
Mandibular R followed by the tooth
number 1-8 starting with the central
incisors.
Example: Upper Right Canine = 13,
Upper Left Canine = 23, etc.
Primary teeth are prefixed with 5 for upper right, 6 for upper left, 7 for
lower left, and 8 for lower right.
Example: Lower left canine would be 73
Photo

18. The arrow points to which tooth?
18
1. 11
2. C
3. H
4. I
5. M
6. None of the above

19. The deciduous dental formula of man is:
19
A
B
C
D
1. A
2. B
3. C
4. D
5. None

20. The permanent dental formula of man is
20
A
B
C
D
1. A
2. B
3. C
4. D
This question is right from Dental
Decks 2012-2013 – Do you notice some
change in nomenclature?

21. Assuming the x-ray is mounted correctly, which tooth is
this?
21
You are looking from the buccal to the
lingual
1. 14
2. 36
3. 19
4. 18
5. 2 & 3

22. This symbol and notation equates to which tooth?
22
5 ∟
1. Maxillary second
premolar
2. Maxillary left first
premolar
3. Mandibular right
second premolar
4. Mandibular left
second premolar

23. Terminology to Describe
the Parts of the Tooth
23
Four Tissues of Tooth:
Enamel
Dentin
Cementum
Pulp
Blood vessels
Nerves
Connective tissues
(Pulp Canal)

24. Four Tissues of a Tooth on
a Radiograph

25. 25
Apex of root
Root
Cementoenamel junction or
cervical line
Enamel Crown
Incisal Edge

26. A –Apex of tooth
AF – Apical foramen
SC – Supplemental canal
B – Alveolar bone
C – Cementum
PM – Periodontal ligament
PC – Pulp canal (Root Canal)
G – Gingiva
GC – Gingival crevice (sulcus)
GM – Gingival margin
PCH – Pulp chamber
D – Dentin
E- Enamel & cusp tip
CR – Anatomical crown
R - Anatomical root
26
R
Lingual Labial
(Palatal) (Facial)
Photo – Wheeler’s Dental Anatomy

27. A – apex
BI – bifurcation of
roots (furca)
PC – pulp canal
PCH – Pulp chamber
PH – Pulp horn
F – Enamel fissure
CU – Cusp
CEJ – Cementoenamel
junction
Photo – Wheeler’s Dental Anatomy 27
Anatomical Crown Anatomical Root

28. Anatomical Crown vs.
Clinical Crown
• Anatomical Crown
o The part of the tooth covered with enamel extending to the cementoenamel
junction of the tooth
o Its dimension only changes due to wear or trauma
• Clinical Crown
o This determination is made depending upon the position of the periodontal
tissues and the amount of the tooth visible
28

29. Anatomic Terms
• Occlusal surface – the chewing
surface of premolars and molars
• Mesial surface – that surface closest
to the midline of the mouth
• Distal surface – that surface farthest
from the midline of the mouth
29
All of these terms can also be used to indicate navigation through the dental arches and
mouth. Ex: It appears that the facial lesion on tooth #30 started in the buccal groove and
continued mesially at the cervical line into the interproximal space.

30. Anatomic Terms
• Lingual surface – that surface closest to the
tongue
• Palatal surface – that surface closest to the
palate
• Labial surface – the “facial” or cheeks and lip
surface of the anterior teeth - incisors and
canines
• Buccal surface – the “facial” or cheek surface
of premolars and molars
30

31. The chewing surface of
31
1. The mesial surface
2. The occlusal
surface
3. The incisal edges
4. The buccal surface

32. Surfaces
32
Mesial Surface
Distal Surface
Interproximal space:
Space formed where 2 teeth
approximate one another
Question:
Is there ever
a situation
when two
mesial
surfaces
approximate
one another?
When two
distal
surfaces
approximate
one another?
Figure courtesy Wheeler’s Dental Anatomy
Occlusal
Occlusal
Occlusal
Incisal
Incisal
Incisal
Occlusal

33. Learn the Jargon
• When referring to more than one surface of the tooth at a
time, particularly when referring to surfaces that are restored
or are to be restored, there is an accepted protocol. Often
times computers confuse this issue, but the sequence is this:
• When referring to the occlusal and mesial surfaces, the
abbreviation is MO, not OM
• When referring to the occlusal and distal surfaces, the
abbreviation is DO, not OD
• When referring to the occlusal, mesial and distal surfaces, the
abbreviation is MOD, not DOM or ODM or DMO or OMD
33

34. Jargon
• When referring to the distal and lingual surfaces of the
anterior teeth, the abbreviation is DL, not LD
• When referring to the mesial and lingual surfaces of
anterior teeth, the abbreviation is ML, not LM
• The rule, if there were a rule, would be the interproximal
surface is stated first then the facial (labial) or lingual
surface. Generally the labial surface of the anterior teeth
when referring to more than one surface of the tooth is
referred to as the “facial” surface. For example MF, or
DF. Referring to that surface as the “labial” surface in
this instance would confuse “labial” with “lingual”.
34

35. Jargon
• The buccal and lingual surfaces of the premolars and
molars are normally second in the abbreviation.
Example: OL or OB not LO or BO. Also note that the
palatal surface is rarely noted as palatal (P) when
describing more than one surface – not OP, rather OL
• Note that if the surfaces were the mesial, occlusal, distal
and buccal, the abbreviation would be MODB or in the
case of the lingual, MODL
• For anterior teeth when referring to 4 surfaces it would
take the following form – MFLI, DFLI- with the incisal
usually notated last
35

36. Upon examination of a patient you notice an amalgam
restoration which involves the distal surface of the tooth,
part of the occlusal surface of the tooth and extends
through the lingual groove of tooth #3. How would you
describe that restoration?
36
1. ODL Am
2. DOL Am
3. LOD Am
4. LDO Am
5. DLO Am

37. More Surfaces
Tooth Surface Junctions
• Line angles – junction line where two tooth
surfaces meet
37
Mesiofacial
acceptable
Distofacial
acceptable

38. 38

39. • Surface junctions = two surfaces that join, such
39
as:
o Distolabial (Distofacial acceptable)
o Mesiobuccal (Mesiofacial acceptable)
• Dimension = the distance between two opposite
walls, such as:
o Mesiodistal dimension

40. Point Angles
• A point angle is formed by the junction of three surfaces.
40 All teeth have 4 point angles

41. Point Angles
41
From the schematic it appears that the point angle may be the cusp tip. That is
not the case. The point angle derives it name from the combination of names of
the surfaces forming it. For example, the junction of the mesial, buccal and
occlusal surfaces of a molar is called the mesiobucco-occlusal point angle.

42. Each tooth has :
42
1. Two point angles
2. Six point angles
3. Four point angles
4. Eight point angles

43. Divisions of the Crown or Root of a
Tooth (for Purposes of Description)
• Crowns from facial (or
lingual) views
o Mesial, middle, distal
o Occlusal/incisal,
middle, cervical
• Crowns from proximal
views
o Facial (labial or
buccal), middle, lingual
o Occlusal/incisal,
middle, cervical

45. Root-to-Crown Ratio
or, Crown-to-Root Ratio, or
Crown:Root Ratio
Compare Maxillary Central
Incisor to Maxillary Canine
• Small ratio (1.16:1)
denotes nearly equal
crown and root length
• Larger ratio (1.56:1)
denotes a relatively larger
root compared to the
crown
1.56:1 1.16:1

46. Morphology
of an
Anatomic
Crown

47. Elevations (Rounded) and
Ridges (Linear)
• Cusp is rounded, pyramid
shaped with four ridges
o Mesial cusp ridge
o Distal cusp ridge
o Buccal cusp ridge
o Triangular ridge (from cusp
tip to middle of tooth)
Cusp – an elevation or mound on the crown portion of a tooth
making up a divisional part of the occlusal surface

48. Cusps (Rounded Pyramid Bulges)
• Canines and posterior teeth have from one to five cusps
• Most cusps are named after the closest tooth surface or line angle

50. If the root-to-crown ratio of #14 is 1.72:1 and the
root-to-crown ration of #16 is 1.49:1, which tooth
has the longest root relative to its crown?
50
1. #14
2. #16
3. #9
4. Not enough
information

51. Other Landmarks
• Ridge – any linear elevation on the surface of a
tooth and is named according to its location
(e.g., buccal ridge, incisal ridge, marginal ridge)
• Marginal ridges – those rounded borders of
enamel that form the mesial and distal margins
of the occlusal surfaces of premolars and molars
and the mesial and distal margins of the lingual
surfaces of the incisors and canines
51

52. Other Landmarks
• Triangular ridges – descend from the tips of
cusps of molars and premolars toward the
central part of the occlusal surfaces and are so
named because the slopes of each side of the
ridge are inclined to resemble two sides of a
triangle. They are named after the cusps to
which they belong. Ex: triangular ridge of the
buccal cusp of the maxillary first premolar.
52

53. Ridges (Linear Bulges): Mesial and
Distal Cusp Ridges (also Called Cusp Slopes or Cusp Arms)
Note the
term
“slope”
substituted
with
“ridge”

54. 54
Note the term “slope” substituted with “ridge”

55. Ridges (Linear Bulges):
Mesial and Distal Marginal
Ridges

56. Any linear elevation on the surface of a
tooth is called
56
1. An incline
2. A Prominence
3. A ridge
4. A tuberosity

57. Other Landmarks
• Transverse ridge – when buccal and lingual
triangular ridges join transversely across the
occlusal surface
• Oblique ridge – a ridge crossing obliquely the
occlusal surface of the maxillary molars –
formed by the union of the triangular ridge of the
distobuccal cusp and the distal cusp ridge of the
mesiolingual cusp
57

58. Ridges: Two Ridges May Join to
Form One Transverse (or Oblique)
Ridge
The oblique ridge is
a ridge crossing
obliquely the
occlusal surfaces of
maxillary molars
and formed by the
union of the
triangular ridge of
the distobuccal cusp
and the distal cusp
ridge of the
mesiolingual cusp

59. 59

60. Any union of two triangular ridges
produces a single ridge which is called
60
1. A cusp ridge
2. A marginal ridge
3. A transverse ridge
4. A proximal ridge
5. A oblique ridge

61. Other Landmarks
• Tubercle – a smaller elevation on some portion
of the crown produced by an extra formation of
enamel – deviations from the typical form
61
T – this demonstrates a
deviation from a normal
cingulum of the incisor – and
therefore is classified as a
tubercle
T-tubercle
LF-lingual fossa
MR-marginal ridges
IR-incisal ridge or incisal
edge
Carabelli’s
Cusp-tubercle
on a
maxillary
molar

62. Other Landmarks
• Cingulum – the lingual lobe of an anterior tooth, makes
up the bulk of the cervical third of the lingual surface
62

63. Fossa & Pits
• Fossa – an irregular depression or concavity
o Lingual fossae – lingual surface of incisors
o Central fossae – on the occlusal surface of molars
o Triangular fossae – on molars and premolars on the occlusal surfaces
mesial or distal to marginal ridges
63

64. 64

65. 65
The unique occlusal feature of this molar is
the
1. Transverse ridge of a
lower left first molar
2. The oblique ridge of a
maxillary right molar
3. The oblique ridge of a
maxillary left molar
4. The transverse ridge of a
maxillary right molar

66. Fossae & Pits
66
• Three-cusped
premolars and most
molars have three
fossae
o Mesial
o Central
o Distal

67. Sulcus
• Sulcus – a long depression
or valley in the surface of a
tooth between ridges and
cusps, the inclines of which
meet at an angle. A sulcus
has a developmental
groove at the junction of its
inclines (The term sulcus
should not be confused
with the term groove.)
67
The sulcus is the broad trough running mesio-distally with the
developmental groove at its base.

68. Team Breakout
68

69. Other Landmarks
• Developmental groove – a shallow groove or
line between the primary parts of the crown or
root
o Supplemental groove – less distinct, a shallow linear depression on
the surface of a tooth - supplemental to a developmental groove
o Buccal and lingual grooves – developmental grooves found on the
buccal and lingual surfaces of posterior teeth
• Pits – small pinpoint depressions located at the
junction of developmental grooves or at
terminals of those grooves
o Central pit - a term used to describe a landmark in the central fossa of
molars where developmental grooves join
69

70. Grooves (Linear
Depressions)
• Major (developmental)
o Central groove
o Fossa grooves
• Minor (supplemental)
o Marginal ridge grooves
o Extra grooves
A developmental groove is a shallow groove or
line between the primary parts of the crown or root.
A supplemental groove, less distinct, is also a
shallow linear depression on the surface of a tooth,
but it is supplemental to a developmental groove
and does not mark the junction of primary parts.
Buccal and lingual grooves are developmental
grooves found on the buccal and lingual surfaces
of posterior teeth.

71. Grooves (Linear Depressions)
• Central grooves run
mesiodistally
• Major grooves are
named for the
surface or line angle
they “aim” toward

72. Pits are Often Found within
Fossae (Depressions)
• Two-cusped premolars have two
fossae
o Mesial
o Distal
• Incisors (especially maxillary) have
one broad, shallow fossa
(sometimes with a lingual pit)
Pits are located at the junction of developmental grooves or at the
terminus of these grooves

73. Developmental grooves are broad, deep, linear
depressions.
73
1. True
2. False

74. Tooth Development from
Lobes
• Lobe – one of the primary
sections of formation in the
development of the crown.
Cusps and mamelons are
representatives of lobes
• Anterior teeth form from four
lobes (three facial and one
lingual)
• Premolars form from three facial
lobes and one lobe per lingual
cusp
• Molars form from one lobe per
major cusp

75. Mamelon
• Mamelon – any one of the three rounded protuberances
found on the incisal ridges a newly erupted incisor teeth-maxillary
and mandibular
75

76. Upon examination the dentist notes an anomalous
enamel outcropping on a molar. This enamel
projection would be classified as a
76
1. Mamelon
2. Ridge
3. Developmental
depression
4. Tubercle

77. Height of Contour
77

78. Height of
Contour
78

79. Heights of Contour
79

80. Importance of Height of
Contour

81. Diastema
Spaces between anterior teeth

82. Embrasure Spaces are only Present when Two
Adjacent Teeth approximate one another
• Four embrasures
o Facial
o Lingual (larger than
facial)
o Occlusal or incisal
(often quite small)
o Cervical =
interproximal space
(filled with gingiva)

83. The sulcus of a premolar or molar and the
central groove are the same anatomical
landmark.
83
1. True
2. False

84. Additional Terminology
Anteroposterior
Curve (of Spee)
• Maxillary curve is convex
• Mandibular curve is concave

85. Mediolateral Curve
(of Wilson)
• Maxillary curve is convex
• Mandibular curve is concave

86. Overbite – Vertical Overlap
Overjet – Horizontal Overlap
86
Vertical Overbite
Horizontal Overjet

87. This method of tooth notation is
87
Primary designation is:
E D C B A A B C D E
E D C B A A B C D E
1. Palmer
2. Universal
3. Federation
Dentaire
Internationale
4. None of the above

88. Mesial, distal, buccal, lingual, palatal, facial
indicate
88
1. Surfaces of the
teeth
2. Types of
restoration
3. Types of cusps
4. Direction
5. 1 & 4

89. Using all tooth numbering systems, the arrow
points to which tooth?
89
1. 7
2. 22
3. 10
4. 25
5. 2&3
6. 1

90. The line marks the mesial surface
90
1. 24
2. 25
3. 24 & 25
4. 23
5. 26

91. This formula is for
91
1. Deciduous teeth
2. Permanent teeth
3. Succedaneous
teeth
4. Mixed dentition

92. Which numbering system is used
almost exclusively in the United States?
92
1. FDI
2. Universal
3. Zsigmondy/
Palmer
4. Palmer
5. Federation
Dentaire
Internationale

93. The universal system for tooth numbering
93
1. Counts from the
midline 1-16
2. Counts from the
max left 3rd molar
moving to the right
1-16
3. Counts 1-32
4. Counts from left to
right

94. What is the universal notation
94
1. 23
2. 25
3. 42
4. 81
5. 1

95. The Palmer numbering system is
frequently used by
95
1. Pedodontists
2. Orthodontists
3. Oral surgeons
4. None of the above
5. 2 & 3

96. The FDI numbering system
96
1. Is used by most of
the world
2. Uses numbers and
letters
3. Is used primarily in
the US
4. None of the above

97. 97
Horizontal overlap of the anterior teeth is
also called:
1. Overlap
2. Overbite
3. Overjut
4. Overjet
5. None of the
above

98. Questions
98