Overview

index of orthodontic treatment need


Related Overviews

 

More Like This

Show all results sharing this subject:

  • Dentistry

GO

Show Summary Details

Quick Reference

(IOTN)

An index used to assess a patient's need and priority for orthodontic care, used in the UK as a basis for determining whether a patient should be accepted for treatment within the National Health Service (NHS) healthcare system. The index is based on an assessment of malocclusion and has aesthetic and dental health components. The aesthetic component is based on a comparison of the malocclusion with ten centric view photographs graded from 1 to 10 to indicate a scale of increasing need for treatment based on psycho-social impairment. The dental health component defines the malocclusion into five grades determined by the potential harm that a particular malocclusion can have on the longevity of the dentition.

Further Reading:

Ferguson J. W. IOTN (DHC): is it supported by evidence? Dent Update 2006;33(8):478–80, 483–4, 486.

IOTN dental health component

Category

Description

Treatment need

Grade 1

Extremely minor malocclusions including displacements less than 1mm

None

a

Increased overjet 3.6–6mm with competent lips

b

Reverse overjet 0.1–1mm

Grade 2

c

Anterior or posterior crossbite with up to1mm discrepancy between retruded contact position and intercuspal position

Little

d

Displacement of teeth 1.1–2mm

e

Anterior or posterior open bite 1.1–2mm

f

Increased overbite 3.5mm or more without gingival contact

g

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

a

Increased overjet 3.6–6mm with incompetent lips

b

Reverse overjet 1.1–3.5mm

Grade 3

c

Anterior or posterior crossbites with 1.1–2mm discrepancy between the retruded contact position and the intercuspal position

Moderate

d

Displacement of teeth 2.1–4mm

e

Lateral or anterior open bite 2.1–4mm

f

Increased and incomplete overbite without gingival or palatal trauma

a

Increased overjet 6.1–9mm

b

Reverse overjet greater than 3.5mm with no masticatory or speech difficulties

c

Anterior or posterior crossbites with greater than 2mm discrepancy between the retruded contact position and intercuspal position

d

Severe displacements of teeth greater than 4mm

e

Extreme lateral or anterior open bites greater than 4mm

Grade 4

f

Increased and complete overbite with gingival or palatal trauma

Great

h

Less extensive hypodontia requiring pre-restorative orthodontics or orthodontic space closure to avoid the need for a prosthetic appliance

l

Posterior lingual crossbite with no functional occlusal contact in one or more buccal segments

m

Reverse overjet 1.1–3.5mm with no recorded masticatory and speech difficulties

t

Partially erupted teeth, tipped and impacted against adjacent teeth

x

Existing supernumerary or supplemental teeth

a

Increased overjet greater than 9mm

h

Extensive hypodontia with restorative implications (more than one tooth missing in any quadrant) requiring pre-restorative orthodontics

Grade 5

i

Impeded eruption of teeth (apart from third molars) due to crowding, displacement, the presence of supernumerary teeth, retained deciduous teeth, and any pathological cause

Very great

m

Reverse overjet greater than 3.5mm with reported masticatory and speech difficulties

p

Defects of cleft lip and palate

s

Submerged deciduous teeth

Subjects: Dentistry.


Reference entries

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.