Orthodontics

Front 1

IOTN letter a

Back 1

Increased overjet

2a - 3.6-6mm with competent lips

3a - 3.6-6mm incompetent lips

4a - 6.1-9mm

5a - greater than 9mm

Front 2

IOTN letter b

Back 2

Reverse overjet

2b - 0.1-1mm

3b - 1.1-3mm

4b - greater than 3.5 no function/speech problems

Front 3

IOTN letter c

Back 3

Anterior or posterior crossbite

2c - less than 1mm discrepancy ICP-RCP

3c - 1.1-2mm discrepancy

4c - more than 2mm discrepancy

Front 4

IOTN letter d

Back 4

Displacement of teeth

2d - 1.1-2mm

3d - 2.1-4mm

4d - greater than 4mm

Front 5

IOTN letter e

Back 5

Anterior or posterior openbite

2e - 1.1-2mm

3e - 2.1-4mm

4e - greater than 4mm

Front 6

IOTN letter f

Back 6

Increased overbite

2f - 3.5mm or more without gingivitis contact

3f - increased and complete without gingival trauma

4f - increased and complete with gingival or palatal trauma

Front 7

IOTN letter g

Back 7

Prenormal or postnormal occlusions with no other anomalies. Includes up to half a unit discrepancy

Only in IOTN 2

Front 8

IOTN letter h

Back 8

Hypodontia

4f - one tooth missing in any quadrant (space closure)

5f - more than one tooth missing in any quadrant

Front 9

IOTN letter l

Back 9

Posterior lingual crossfit with no functional occlusal contact in one or both buccal segments

Only IOTN 4

Front 10

IOTN letter m

Back 10

Reverse overjet with masticatory/speech difficulties

4m - 1.1-3.5mm

5m - greater than 3.5mm

Front 11

IOTN letter t

Back 11

Partially erupted teeth, tipped and impacted against adjacent teeth

Only IOTN 4

Front 12

IOTN letter x

Back 12

Supplemental teeth

Only IOTN 4

Front 13

IOTN letter i

Back 13

Impeded eruption of teeth (except 3rd molars) due to crowding, displacement, presence of supernumaries, retained deciduous teeth, any pathological cause

Only IOTN 5

Front 14

IOTN letter p

Back 14

Defects of cleft lip and palate

Only IOTN 5

Front 15

IOTN letter s

Back 15

Submerged deciduous teeth

Only IOTN 5

Front 16

Caucasian sna snb anb values

Back 16

Sna 81 +- 3

Snb 79 +- 3

Anb 3 +- 2

Front 17

Incisors to Max/mand plane angle Caucasian

Back 17

109 +- 6 uppers to Max

93 +- 6 lowers to mand or 120 - mmpa

Front 18

Mmpa value Caucasian

Back 18

27 +- 4

Front 19

Inter-incisal angle Caucasian

Back 19

133 +- 10

Front 20

Adult teeth eruptive sequence

Back 20

6s

Lower 1s

Upper 1s + lower 2s

Upper 2s

Lower 3s

Upper 4s

Lower 4s

Upper 3s

Upper 5s

Lower 5s

7s

8s

Front 21

6s eruption age

Back 21

5-6yrs

Front 22

Lower 1s eruption age

Back 22

6-7yrs

Front 23

Upper 1s eruption age

Back 23

7-8yrs

Front 24

Lower 2s eruption age

Back 24

7-8yrs

Front 25

Upper 2s eruption age

Back 25

8-9yrs

Front 26

Lower 3s eruption age

Back 26

9-10

Front 27

Upper 4s eruption age

Back 27

10-11yrs

Front 28

Lower 4s eruption age

Back 28

10-12yrs

Front 29

Upper 3s eruption age

Back 29

11-12yrs

Front 30

Upper 5s eruption age

Back 30

10-12yrs

Front 31

Lower 5s eruption age

Back 31

11-12yrs

Front 32

7s eruption age

Back 32

12-13yrs

Front 33

Skeletal factors

Back 33

AP (anteroposterior) class 1/2/3

Vertical (face height, growth rotations)

Transverse

Front 34

Soft tissue factors

Back 34

Fullness + tone of lips

Lower lip line

Lip competency

Adaptive swallow patterns

Size/position/function of tongue

Enlarged adenoids (AOB)

Front 35

Local factors

Back 35

Tooth number (hypodontia/supernumaries)

Early loss of baby teeth

Loss of adult tooth to trauma

Macro/microdont (dento-alveolar disproportion)

Tooth impaction

Infraocclusion due to ankylosis

Transposition of teeth

Frenal attachment

Habits - digit sacking