Introduction To Dental Anatomy 675a2v

Introduction to Dental Anatomy Dental Anatomy 2nd year dental students Summer semester 2006/2007

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

Deciduous & permanent dentitions

• Why do

we have to have 2 sets of teeth?

Why 2 sets of dentitions? •The jaws have to

accommodate the increased number of permanent teeth and their bigger size

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

Human dental formula •Deciduous 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

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 1 - 4 and in deciduous have the numbers 5 - 8

Quadrants 1 or 5

2 or 6

4 or 8

3 or 7

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 EDCB A

ABCD E

8765432 1

1234567 8

EDCBA

ABCD E

8765432 1

1234567 8

Dental nomenclature

• By words

– 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

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:

1

– Maxillary right central incisor E – Mandibular left second deciduous molar

EDCB A EDCB A

ABCD E ABCD E

8765432 1 8765432 1

1234567 8 1234567 8

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 ABCD E TSRQ P

FGHI J ONML K

1 2 3 4 5 6 7 8 32 31 30 29 28 27 26 25

9 10 11 12 13 14 15 16 24 23 22 21 20 19 18 17

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 55 54 53 52 51

61 62 63 64 65

18 17 16 15 14 11

13 12

85 84 83 82 81

71 72 73 74 75

48 47 46 45 44 43 42 41

21 22 23 24 25 26 27 28 31 32 33 34 35 36 37 38