1. Introduction to Dental Anatomy
Dr. Firas Alsoleihat, BDS, PhD
Department of Conservative Dentistry

2. Introduction Human dentition is diphyodont 2 sets of dentitions
Primary/deciduous
20 teeth in total
Incisors/canines/molars
Smaller size
Secondary/permanent
32 teeth in total
Incisors/canines/premolars/molars
Bigger size

3. Deciduous & permanent dentitions
Why do we have to have 2 sets of teeth?

4. Why 2 sets of dentitions?
The jaws have to accommodate the increased number of permanent teeth and their bigger size

5. Dental formula I for incisors C for Canines PM for premolars
M for molars
Deciduous teeth are indicated by the letter D before the initial

6. Human dental formula Deciduous teeth Permanent teeth
DI 2/2 DC 1/1 DM 2/2 = 10
Permanent teeth
I 2/2 C 1/1 PM 2/2 M 3/3 = 16
The numbers following the letter refer to the number of teeth of each type in the upper then the lower dentition for one side only

7. Quadrants
Tooth-bearing region of the jaw can be divided into 4 quadrants
Right maxillary (1 or 5)
Left maxillary (2 or 6)
Left mandibular (3 or 7)
Right mandibular (4 or 8)
Quadrants in permanent dentition have the numbers and in deciduous have the numbers 5 - 8

8. Quadrants
1 or 5
2 or 6
4 or 8
3 or 7

10. Teeth order
Each tooth in a quadrant takes a letter (A – E for deciduous) or a number (1 – 8 for permanent) indicating its order when counting from the midline
E D C B A
A B C D E
E D C B A
A B C D E

11. Dental nomenclature By words By numbers, letters and/or symbols Set
Deciduous or permanent
Jaw
Maxillary or mandibular
Class
Incisor/canine/premolar/molar
Order within a class
Central or lateral
First/second/third
Side
Right or left
By numbers, letters and/or symbols
Palmer notation system
Universal numbering system
FDI numbering system

12. Palmer/Zsigmondy notation system
American Dental Association in 1947
Tooth is represented by a number 1 – 8 (permanent) or a letter A – E (deciduous)
Two lines; indicates which quadrant the tooth belongs to
a horizontal representing the occlusal plane and
a vertical representing the midline
Examples:
Maxillary right central incisor
Mandibular left second deciduous molar 1 E
E D C B A
A B C D E
E D C B A
A B C D E

13. Universal numbering system
Palmer – difficulty in keyboard typing
ADA adopted the universal system in 1968
Uppercase letters for deciduous teeth
Consecutive from A to T
Following a clockwise order from maxillary right second molar to mandibular right second molar
Numbers for permanent teeth
Consecutive from 1 to 32
Following a clockwise order from maxillary right third molar to mandibular right third molar
A B C D E
F G H I J
T S R Q P
O N M L K

14. FDI numbering system Proposed by FDI & adopted by WHO
Each tooth is allocated a two-digit number; the left designates the quadrant and the right designates the tooth order
Examples
Mandibular right permanent canine 43
Maxillary left deciduous lateral incisor 62

15. Types of dentitions:
Diphyodont. Most mammals--humans included--typically develope and erupt into their jaws two generations of teeth. The term literally means "two generations of teeth."
Monophyodont. Some mammals--such as the manatee, seals, and walruses have only a single generation of teeth.

16. Polyphyodont. Most reptiles and fishes develope a lifetime of generations of successional teeth--Such teeth have a brief functional life and are anatomically simple in design.
Homodont. In many vertebrates, all of the teeth in the jaw are alike. They differ from each other only in size. The alligator is an example of homodontism.

17. Heterodont. Most mammals, humans included, develope distinctive classes of teeth that are regionally specialized. We will discuss classes of teeth in the next unit.
Anodontia is the developmental absence of teeth. Among mammals, the whalebone whale and the anteater are toothless; their ancestors had teeth. In humans, anodontia is a pathological condition. Partial anodontia is one or a few teeth missing.