Index of Orthodontic Treatment Need
Pronunciation: EYE-oh-tee-en
Also written as: IOTN — Index of Orthodontic Treatment Need
A validated two-component index used in the UK to assess and prioritise patients' need for orthodontic treatment on the basis of dental health and aesthetic criteria.
Full Definition
The Index of Orthodontic Treatment Need (IOTN) comprises two components: the Dental Health Component (DHC), graded 1–5 using a ruler, and the Aesthetic Component (AC), graded 1–10 using a photographic scale. It is used by NHS commissioners and clinicians to determine eligibility for publicly funded treatment, with DHC grades 4 and 5 (and AC grades 8–10 without DHC 3 support) generally qualifying. Editors handling NHS referral documents, outcome reports, and commissioning guidelines must accurately reproduce both the grade and the component (DHC or AC) together; stating 'IOTN 4' without the component qualifier is ambiguous. The acronym IOTN is well established and need not be expanded after first use.
Usage
Usage note: Always state both the component (DHC or AC) and the numeric grade; 'IOTN' alone is ambiguous without the subcomponent qualifier.
In Context
- "The referral was triaged as IOTN DHC grade 4h, meeting the threshold for NHS-funded treatment." — NHS referral triage document
- "An IOTN Aesthetic Component score of 7 was recorded, which did not independently justify treatment need." — Assessment report