This document provides an overview of tooth numbering systems and anatomical landmarks. It describes the primary and permanent dentition, including their numbers, eruption patterns and dental formulas. Two common numbering systems are described for each - the Universal system and FDI system for primary and permanent teeth. Key anatomical features are defined, including crowns, roots, surfaces, ridges, grooves, lobes and line/point angles. The document serves as a comprehensive guide to dental anatomy terminology.

1. Tooth Numbering
System
Dr. Amitha G
Dept of Oral Pathology

2. The Primary (Deciduous) Teeth
◦ The postnatal period of development is
about 2½ years
◦ Remains intact until a child is about 6 years of
age when the transition to the permanent
dentition begins.
◦ The number of primary teeth present in the
child is usually 20(unless congenitally missing
or lost due to disease)

4.  Dental formula for the primary teeth in humans is:
I 2 C 11 M 2 = 10
2 1 2

5. Nomenclature for Deciduous
Teeth
◦ The “Universal System notation for the
entire primary dentition is,
A B C D E F G H I J
T S R Q P O N M L K

7. ◦ Another notation system divides the arches into
quadrants with the entire dentition notated as,
E D C B A A B C D E
E D C B A A B C D E

8. The Permanent Teeth
◦ The number of teeth in adults, including
third molars when present is 32
Transition to permanent dentition begins:
◦ with the eruption and emergence of the
first permanent molars,
◦ shedding of the deciduous incisors and
◦ emergence and eruption of the permanent
incisors

9. ◦ After shedding of the deciduous canines and
molars, emergence and eruption of the
permanent canines and premolars, and
emergence and eruption of the second
permanent molars.
◦ This process requires about 20 years to
complete

11. Nomenclature for Permanent
Teeth
◦ The permanent dental formula is:
I 2 C 1 P2 M 3 = 16
2 1 2 3
◦ Universal notation system
◦ Palmer Notation system

12. Nomenclature for permanent teeth
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17
Thus, the right maxillary first molar is designated as 3, the maxillary left
central incisor as 9, and the mandibular right first molar as 30
Universal System
the maxillary teeth are numbered from 1 through 16,
beginning with the right third molar. Beginning with the
mandibular left third molar,the teeth are numbered 17 to 32.

14. 8 7 6 5 4 3 2 18 7 6 5 4 3 2 1 1 2 3 4 5 6 7 81 2 3 4 5 6 7 8
8 7 6 5 4 3 2 18 7 6 5 4 3 2 1 1 2 3 4 5 6 7 81 2 3 4 5 6 7 8
◦ Another notation system (Palmer Notation)
uses the quadrant system, in which
beginning with the central incisors, the
teeth are numbered 1 through 8 (or more).

16. ◦ Two digit system or FDI system(by Federation Dentaire Internationale)
◦ For both the primary and permanent dentitions has been adopted by
WHO and accepted by other organizations such as the International
Association for Dental Research .
◦ Primary Teeth
55 54 53 52 51 61 62 63 64 65
85 84 83 82 81 71 72 73 74 75

17.  Permanent Teeth
 First digit indicates the quadrant
 Permanent dentition ( 1 to 4)
 Primary dentition ( 5 to 8)
 Second digit indicates the tooth within the quadrant
 Primary dentition (1 to 5)
 Permanent dentition (1 to 8)
18 17 16 15 14 13 12 11 21 22 23 24 25 26
27 28
48 47 46 45 44 43 42 41 31 32 33 34 35 36
37 38

18. The Crown and the Root
◦ The crown is covered
with enamel
◦ Root is covered with
cementum
◦ Join at the cemento
enamel
junction(cervical line)
◦ With pulp chamber
and pulp canals

19. The four tooth tissues
◦ Enamel
◦ Cementum
◦ Dentin
◦ pulp

20. The root portion
◦ Maybe single with one
apex or terminal end
Found in anterior teeth
and some of the
premolars
◦ Or Multiple with a
bifurcation or
trifurcation dividing the
root portion into two or
more extensions or roots
with their apices or
terminal ends found in
all molars and
premolars.

21.  The root portion of the tooth is
firmly fixed in the bony process of
the jaw, so that each tooth is held
in its position relative to the others
in the dental arch
 The alveolar process is the portion
of the jaw which serves as a
support for the tooth

22. The crown portion
◦ is partly covered at the
cervical third in young
adults by soft tissue of
the mouth known as the
gingiva or gingival
tissue.

23. Surfaces and ridges
◦ Crowns of the incisors
and canines have four
surfaces and a ridge
◦ Crowns of the
premolars and molars
have five surfaces
◦ Surfaces are named
according to their
positions and uses
◦

24. Labial,buccal (facial
surfaces)lingual
,proximal
(mesial/distal) incisal
occlusal
Contact area- the area
of the mesial or distal
surface of the tooth
which touches its
neighbor in the arch

25. Other Landmark
◦ Cusp- is an elevation or
mound on the crown portion
of a tooth making up a
divisional part of the occlusal
surface

26. Cingulum
◦ - is the lingual lobe of an
anterior tooth. It make up the
bulk of the cervical third of
the lingual surface.

27. Tubercle
◦ is a smaller elevation on
some portion of the crown
produced by an extra
formation of enamel

28. Ridge
◦ is any linear elevation on the
surface of the tooth and is
named according to its
location (buccal ridge,
incisal ridge, marginal ridge)

29. Marginal ridge
◦ are those rounded borders of
the enamel that form the
mesial and distal margin of
the occlusal surfaces of
premolars and molars and
the mesial and distal margins
of the lingual surfaces of the
incisors and canines.
10. Distal Marginal Ridge10. Distal Marginal Ridge
11.11.Mesial Marginal RidgeMesial Marginal Ridge

30. Oblique ridge-
◦ is a ridge crossing
obliquely the occlusal
surfaces of maxillary
molars.
15. Oblique Ridge

31. Transverse ridge
◦ A transverse ridge is the
union of a buccal and
lingual triangular ridge
that crosses the surface
of a posterior tooth
transversely (roughly 90
degrees to both the
buccal and lingual
tooth surfaces).

32. Fossa- is an irregular depression or concavity
 Lingual fossae are on the
surface of incisors
 Centrasl fossae are on the
occlusal surface of molars
 Triangular fossae- are
found on molars and
premolars on the occlusal
surfaces mesial or distal to
marginal ridges
11. Mesial Triangular Fossa
12. Distal Triangular Fossa
13. Central Fossa

33. Sulcus
◦ is a long depression or valley
in the surface of a tooth
between ridges and cusps
the inclines of which meet at
an angle.

34. Developmental groove
◦ is a shallow groove or line
between the primary parts of
the crown or root.
◦

35.  Supplemental grooves- less
distinct, is also a shallow
linear depression on the
surface of the tooth, but it
is supplemental to a
developmental groove
and does not mark on the
buccal and lingual
surfaces of posterior teeth.


36. Pits
◦ are small pinpoint depression
located at the junction of the
developmental grooves or at
terminals of those grooves.
Central pit-Central pit- use to describe ause to describe a
landmark at the centrallandmark at the central
fossa of molars wherefossa of molars where
developmental grooves joindevelopmental grooves join

37. Lobe
◦ is one of the primary section
of formation in the
development of the crown.

38. ◦ Lobe- is one of the
primary section of
formation in the
development of the
crown.
◦ Mamelons is any one of
the three rounded
protuberances found
on the incisal ridges of
newly erupted incisor
teeth

39. For purposes of
description
◦ the crowns and roots of teeth
have been divided into thirds
and junctions of the crown
surfaces are described as line
angle and point angle

40. Line angle
◦ is formed by the junction of two surfaces and derives its name
from the combination of the two surfaces that join
Line angles of anterior teeth are:
Mesiolabial distolingual
Distolabial labioincisal
Mesiolingual linguoincisal

41. The line angles of the posterior
teeth
mesiobuccal distolingual bucco-occlusal
distobuccal mesio-occlusal linguo-occlusal
mesiolingual disto-occlusal

42. Point angles
◦ is formed by the junction of the three surfaces
◦ Ex. The junction of the mesial,buccal, and occlusal surfaces of a
molar is called the mesiobucco-occlusal point angle.

43. ◦ Point angles of the anterior teeth are:
mesiolabioincisal mesiolinguoincisal
distolabioincisal distolinguoincisal
◦ The point angles of the posterior teeth are:
mesiobucco-occlusal mesiolinguo-occlusal
distobucco-occlusal distolinguo-occlusal

44. THANKYOU
Reference:
Wheelers – Dental Anotomy, Physiology and Occlusion- 9th
edition.