This document provides an introduction to dental anatomy, including the objectives, oral structures, types of teeth, dentition classification, dental formula, numbering systems, tooth anatomy, and surfaces. The key points are: 1. There are four types of teeth - incisors, canines, premolars, and molars. Teeth are arranged in the upper and lower jaws. 2. There are two dentition classifications - primary/deciduous and permanent. The permanent dentition has 32 teeth following the dental formula of 2-1-2-3 for each quadrant. 3. Numbering systems identify teeth by quadrant and type, such as the Universal system numbering permanent teeth 1-32 clockwise

1. Dr. Rana Nagah
Lecturer of oral biology
Email: Dr.Rana.Nagah@gmail.com
Introduction
To
Dental Anatomy

2. 1. Introduction to oral structures
2. Types of teeth
3. Classification of dentitions
4. Dental formula
5. Numbering system
6. Macro & micro anatomy
7. Surfaces of teeth
8. Line and point angles
What are our
Objectives?

3. 1. Introduction to oral structures:
Teeth are arranged in the mouth in 2 jaws:
Upper jaw Maxilla Maxillary teeth.
Lower jaw Mandible Mandibular teeth
A midline divides the oral cavity vertically into 2
equal halves.
So the teeth in oral cavity are divided into
4 Quadrants.
Maxillary arch
& teeth
Midline
Mandibular arch
& teeth

4. Maxillary Right quadrant Maxillary Left quadrant
Mandibular Right quadrant Mandibular Left quadrant

5. What are our objectives?
1. Introduction to oral structures
2. Types of teeth
3. Classification of dentitions
4. Dental formula
5. Numbering system
6. Macro &microanatomy of teeth
7. Surfaces of teeth
8. Line and point angles

6. 2. Types of teeth
There are 4 types of teeth:
Two types called Anteriors
The other 2 types are called Posteriors

7. Incisors
There are 2 incisors in each quadrant
1 central next to midline1 lateral
Biting, cutting & incising food
Canines
There is 1 canine in each quadrant
Has 1 cusp so called (cuspid)
Cutting, tearing & holding food
Anterior teeth

8. Posterior teeth
Premolars
• There are 2 in each quadrant
• 1st & 2nd premolars
• Mainly have 2 cusps, so sometimes
called bicuspid
• Tearing, holding & grinding
Molars
• There are 3 in each quadrant
• 1st, 2nd, 3rd
• The are multicuspid and multirooted
• Grinding.

10. What are our objectives?
1. Introduction to oral structures
2. Types of teeth
3. Classification of dentitions
4. Dental formula
5. Numbering system
6. Macro & micro anatomy
7. Surfaces of teeth
8. Line and point angles

11. 3. Classification of dentition:
There are 2 types of dentition in humans:
Permanent dentition
Deciduous dentition

12. 1. Deciduous dentition:
Named so because they shed like the leaves of
deciduous trees in autumn.
They are also called primary, milk, or temporary teeth.
The teeth start to appear at 6 months and continue to
erupt till age of 2.5-3 years.
They are 20 in number. 10 in each arch. 5 for each
quadrant.
2 Incisors.
1Canine.
2 Deciduous Molars.
These teeth are called (Predecessors)

13. 2. Permanent dentition:
They are also called secondary or adult teeth
They start to erupt at 6 years till nearly 21 years with
eruption of permanent 3rd molar (wisdom tooth).
They last for long time and are not replaced.
They are 32 teeth (16 per arch, 8 per quadrant)
In each quadrant:
2 incisors central and lateral (1,2)
1 canine (3)
2 premolars (4, 5)
3 molars (6,7,8)

14. Succedaneous teeth:
20 decideous teeth are replaced by 20 permanent
teeth.
 2 D Incisors are replaced by 2 P Incisors
 1 D Canine is replaced by 1 P Canine
 2 D Molars are replaced by 2 Premolars
 With growth of dental arch, there is a space for
eruption of 3 more teeth in each quadrant.
 The 3 Permanent Molars are considered as
non-succedaneous teeth (have no predecessors)
M
M
Succedaneous
teeth

15. Dentition periods: 1. Primary dentition period:
• Only deciduous teeth are present.
• Extend from 6 months - to - 6 yrs.
• Ends with eruption of first permanent tooth normally
mandibular first molar.
2. Mixed dentition period (Transitional phase):
Both deciduous and permanent teeth are present.
Starts with eruption of 1st permanent molar at 6 yrs.
Ends at 12 yrs with the shedding of last deciduous tooth
normally primary maxillary second molar.
3. Permanent dentition period:
• Only permanent teeth are present.
• Begins at approximately 12 years and continues through
the rest of life.

17. What are our objectives?
1. Introduction to oral structures
2. Types of teeth
3. Classification of dentitions
4. Dental formula
5. Numbering system
6. Macro & micro anatomy
7. Surfaces of teeth
8. Line and point angles

18. 4. Dental formula
A number and letter designation of the various types of teeth found in a
dentition.
It indicates the dentition of only one side of the mouth, but includes both
upper and lower Quadrants, so dental formula includes just half of the teeth
Deciduous Permanent

19. What are our objectives?
1. Introduction to oral structures
2. Types of teeth
3. Classification of dentitions
4. Dental formula
5. Numbering system
6. Macro & micro anatomy
7. Surfaces of teeth
8. Line and point angles

20. 5. Numbering systems
It is used to serve as abbreviations instead of writing the entire
name of a tooth
These symbols will let us know whether the tooth is either
Deciduous or permanent
Upper or lower
Right or left
The tooth type
Quadrant

21. There are 3 numbering systems:
A. Palmer notation system.
B. International (Two Digit) system.
C.Universal numbering system.

22. A. Palmer notation system:
The system used simple bracket to
represent the four quadrants of the dentition
The permanent teeth are numbered from
1 - 8 on each side starting from midline.
So number 1 will be for central incisor.
while 8 will be for 3rd molar.

23. A. Palmer notation system
Permanent teeth:
Ex: This symbol denotes upper right canine.
What’s ?
This symbol denotes lower left 2nd
premolar.
3
5

24. Deciduous teeth:
It starts also from midline. But for
deciduous teeth we give alphabetic
letters.
 From deciduous central incisor A.
ending with deciduous second molar
E.
Each quadrant has only 5 teeth.

25. Examples:
6
Permanent upper left 1st molar
D
Deciduous lower right 1st molar
4
Permanent lower left 1st premolar

26. B. Two-Digit system (international):
We have 2 numbers
The one on the left is number of quadrant
The other on the right is for the tooth type
permanent dentition deciduous dentition
Left Right

28. Example:
45:
permanent lower right 2nd premolar.
63:
deciduous upper left canine
66
84

29. C. Universal system:
Permanent :
Teeth take numbers from 1-32.
Starting from upper right 3rd molar(1)
proceeding clockwise, and ending by
lower right third molar (32).
It is always preceded by # sign

30. Deciduous:
There are 2 ways
6 7 8 9 10
1 2 3 4 5
15 14 1312 11
20 19181716
R L
#15d
deciduous lower left
central incisor
#O is lower left
deciduous central incisor

31. Notice the difference between two-digit and universal systems:

33. What are our objectives?
1. Introduction to oral structures
2. Types of teeth
3. Classification of dentitions
4. Dental formula
5. Numbering system
6. Macro & micro anatomy
7. Surfaces of teeth
8. Line and point angles

34. 6. Macro &micro anatomy:

35. Anatomical Crown is that part of the tooth that is covered by Enamel or
outer covering of the tooth. Its up to the cement-enamel junction.
Clinical crown is that part of tooth that is visible in the oral cavity.

36. Anatomical root portion of root covered by cementum, defined
by CEJ.
Clinical root: portion of tooth that is not visible in mouth.

38.  Dentin –
The hard tissue, forms the main body of the tooth.
 Enamel –
The hardest living body tissue, covers the dentin of the
anatomical crown of a tooth.
 Cementum –
The layer of hard, bonelike tissue, which covers the
dentin of the anatomical root of a tooth.
 Pulp –
The living soft tissue, which occupies the pulp cavity of a
vital tooth. It contains the tooth's nutrient supply in the
form of blood vessels as well as the nerve supply.
Micro-anatomy of tooth

39. PULP CAVITY: Consists of:
• Pulp canals: Located in the root(s) of tooth called root canal.
• Pulp chamber: located mostly in the anatomical crown of the tooth.
• Pulp horns: pointed elongation corresponding to incisal or occlusal
projections
• Apical foramen: is the tooth's natural opening, found at the root's
very tip—that is, the root's apex—whereby an artery, vein, and nerve
enter the tooth

40. Supporting structures:
1. Alveolar process: bone
surrounding and supporting
teeth.
2. Periodontal ligament:
fibrous attachment between
tooth cementum and
alveolar bone.
3. Gingiva: (gum) mucous
membrane covering alveolar
process and surrounding
neck of teeth
N.B : These 3 tissues +
cementum are called
periodontium

41. What are our objectives?
1. Introduction to oral structures
2. Types of teeth
3. Classification of dentitions
4. Dental formula
5. Numbering system
6. Macro & micro anatomy
7. Surfaces of teeth
8. Line and point angles

42. 7. Surfaces of teeth
•Crowns of anterior teeth have 4 surfaces and edge.
•While those of posterior surfaces have 5 surfaces
1. Facial (Labial or Buccal)
2. Lingual or palatal
3. Proximal
(Mesial or Distal)
4. Masticatory surface
(Incisal or occlusal)

43. 1. Facial surface
labial surface
The outside surface of
anterior teeth facing lip
Buccal surface
The outside surface of
posterior teeth facing
cheeks (buccinator
muscle)

44. 2. lingual/ palatal surface:
The inner surface of teeth facing palate (palatal) in maxillary teeth or
tongue (lingual) in mandibular teeth .

45. Palatal
Lingual
Labial
Buccal

46. 3. Proximal surfaces
 Mesial surface:
toward Midline
 Distal surface:
Distant from midline

47. Incisal edge
Biting edge of anterior
teeth
Occlusal surface
Chewing surface of
posterior teeth
Masticatory
surfaces

48. Divisions into Thirds
• Crowns and roots of teeth have been
divided into thirds.
• These thirds are named according to
the surface close to them.
• HORIZONTALY, the crown is divided
into an incisal or occlusal third,
middle third, and cervical third.
• The root is divided into a cervical
third, middle third, and apical third.
• VERTICALLY, Mesiodistally, the crown
is divided into the mesial, middle, and
distal thirds. Faciolingually, it is
divided into the labial or buccal,
middle, and lingual thirds.

50. Line and point angles:
Line angle: is the junction between 2
adjacent surfaces and it is named
according to the 2 surfaces sharing in its
formation.
Point angle: is the junction between 3
adjacent surfaces and it is named
according to the 3 surfaces sharing in its
formation meeting in a point

51. 6 8
Line angles

52. 4 4
Point angles

54. Thank
you