Index of Orthodontic Treatment Need (IOTN)
Objectively assesses the need for orthodontic treatment to guide resource allocation and prioritization
- Highest activation tier
- Available
- How it is scored
- Scored in code; a stated value is compared only from the structured summary or a supplied value
- Scoring type
- classification
- Care settings
- Outpatient
When it activates
Scribeable activates a calculator from the encounter. The Index of Orthodontic Treatment Need (IOTN) can activate when the transcript or pasted chart context documents any of these:
- Orthodontic treatment need assessment
- Orthodontic referral decision
- Treatment priority determination
- Orthodontic funding eligibility
- Dental health component assessment
A coded diagnosis can also activate it. ICD-10 prefixes carried by the registry: K01.1, M26.2.
Note-type scope: it activates on notes whose subject resolves to orthodontic, dental. A note that resolves to another subject does not carry it even when the clinician's specialty matches; a note with no resolvable subject (a generic consultation) falls back to the specialty match.
Inputs the note needs
1 input. Each is resolved from the transcript, the pasted chart context and charted labs; at this calculator’s tier a missing input is never requested, and the code-scoring engine never inserts the score unprompted.
| Input | Type | Unit / options | Guidance |
|---|---|---|---|
| Dental Health Component grade (1-5): objective measure of dental health need | exam |
Scoring
Dental Health Component (DHC): Grade 1: No need — extremely minor irregularities. Grade 2: Little need — minor irregularities (overjet 3.5-6mm without incompetent lips, reverse overjet 0-1mm, displacement 1-2mm). Grade 3: Borderline need — moderate irregularities (overjet 3.5-6mm with incompetent lips, reverse overjet 1-3.5mm, displacement 2-4mm, open bite 2-4mm). Grade 4: Treatment needed — severe irregularities (overjet >6mm but <=9mm, reverse overjet >3.5mm, impeded eruption, extreme displacements >4mm, open bite >4mm). Grade 5: Great need — very severe irregularities (overjet >9mm, impacted teeth, cleft lip/palate, multiple missing teeth).
Interpretation
Grade 1-2: No/little treatment need — generally not funded under public health systems. Grade 3: Borderline — treatment may be justified if Aesthetic Component also indicates need. Grade 4-5: Definite need — treatment recommended, typically funded under public health systems. Aesthetic Component (AC, 1-10 scale) supplements DHC with patient perception. DHC Grade 4-5 or AC 8-10 = definite need. Used extensively in UK NHS and European public orthodontic services for resource allocation.
Evidence
Sources carried in Scribeable's citation registry for this calculator; guideline version: Brook & Shaw 1989.
- Brook PH, Shaw WC. The development of an index of orthodontic treatment priority (IOTN)Brook & Shaw (IOTN) 1989 · 1989 · link last verified 2026-03-28
How Scribeable handles it in the note
Scribeable can list the Index of Orthodontic Treatment Need (IOTN) as available to the note when the clinician's specialty matches and the encounter activates it. Its highest activation tier is available: you are never asked for its inputs, and the code-scoring engine never inserts it into the draft unprompted.
The registry entry carries the inputs, scoring criteria and interpretation above so a score you state is documented against the same reference.
Classified as a questionnaire: a patient-reported or clinician-rated instrument, where a spare activation carries low harm.
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