--- title: "IOTN Score Explained | Dental Health & Aesthetic Component Guide" url: https://virtualconsultant.online/eligibility/iotn description: "Understand IOTN scoring in full: Dental Health Component grades 1–5, the Aesthetic Component scale. Start online in minutes with Virtual Consultant." updated: 2026-09-18T00:00:00Z publisher: Virtual Consultant Online --- # IOTN scoring explained How the Index of Orthodontic Treatment Need works — what DHC grades measure, what the Aesthetic Component adds, and which scores qualify for NHS treatment. [Check My Eligibility](https://virtualconsultant.online/evaluations/quote) [Eligibility Hub](https://virtualconsultant.online/eligibility) [NHS pathway](https://virtualconsultant.online/eligibility/nhs) • [Adult access](https://virtualconsultant.online/eligibility/adults) • [Check eligibility](https://virtualconsultant.online/eligibility/check) • [IOTN scoring](https://virtualconsultant.online/eligibility/iotn) ## How IOTN works The Index of Orthodontic Treatment Need (IOTN) is a two-component scoring system used by NHS orthodontists across the UK to assess who qualifies for NHS-funded treatment. It was introduced to ensure eligibility decisions are made consistently and based on clinical need rather than subjective judgement. The Dental Health Component (DHC) is the primary scoring tool. It grades the severity of malocclusion on a 5-point scale based on defined clinical measurements. DHC grade is determined by the single most severe dental feature present. The grades are: Grade 1 — no need; Grade 2 — little need (mild malocclusion); Grade 3 — borderline need (moderate); Grade 4 — treatment need (severe); Grade 5 — very great need (most complex cases). DHC grade 5 features include: increased overjet greater than 9mm; severe hypodontia (missing teeth) requiring restorative and orthodontic treatment; impacted teeth other than third molars; extensive hypodontia; cleft palate. These represent the most severe structural and health-impacting malocclusions. DHC grade 4 features include: increased overjet greater than 6mm but not more than 9mm; reverse overjet greater than 3.5mm with masticatory or speech difficulties; anterior or posterior crossbite with greater than 2mm discrepancy between RCP and ICP; severe displacements of teeth greater than 4mm; extreme lateral or anterior open bites greater than 4mm; increased complete overbite with significant gingival trauma. These represent cases where dental health is clearly compromised. DHC grade 3 is the borderline category. It includes cases with: increased overjet greater than 3.5mm but not exceeding 6mm; increased overbite greater than 3.5mm without gingival contact; reverse overjet of 1mm to 3.5mm; anterior crossbite with up to 2mm discrepancy; moderate displacements of teeth greater than 2mm; increased lateral or anterior open bites of greater than 2mm. For grade 3 cases, the Aesthetic Component (AC) is also assessed. The Aesthetic Component (AC) uses a 10-photograph scale developed by Bjorn Kohler. The images depict dentitions of increasing aesthetic impairment, rated 1 (best) to 10 (most impaired). The AC is used for grade 3 DHC cases to determine whether the aesthetic impact is sufficient to justify NHS treatment. AC scores of 6–10 at grade 3 DHC typically qualify. Grades 1 and 2 do not qualify for NHS funding. Grade 1 (no need) has no clinical malocclusion features. Grade 2 (little need) includes minor irregularities, small overjets, mild hypodontia, and minor spacing issues that don't meet the severity thresholds for clinical need. These cases can be treated privately and are often well-suited to clear aligners at reasonable cost. It is important to understand that IOTN scoring is a clinical assessment, not a patient-reported score. You cannot self-assess your IOTN grade with certainty — a dentist examination is required. However, understanding the system in advance helps you have a more informed conversation at your assessment appointment. ### Find out where you stand A photo-based assessment gives an indication of your likely eligibility and treatment options before you visit a clinic. [Start My Assessment](https://virtualconsultant.online/evaluations/quote) Takes 5 minutes • No obligation #### DHC grades 1–5 The Dental Health Component grades malocclusion severity. Grades 4 and 5 qualify for NHS treatment; grade 3 is borderline. ##### Aesthetic Component (AC) Grade 3 DHC cases are also assessed on the 1–10 AC photographic scale. High aesthetic impact at grade 3 can still qualify. ###### Objective scoring IOTN uses defined clinical criteria to make eligibility decisions consistent across NHS orthodontists throughout the UK. ###### Not just about appearance The DHC is primarily a dental health measure — it assesses functional and structural impact, not just how teeth look. NHS ###### NHS Pathway How the NHS orthodontic pathway works: referral, IOTN assessment, waiting list, what's covered, and what to do if the wait is too long. [Explore NHS Route](https://virtualconsultant.online/eligibility/nhs) Adult ###### Adult Eligibility Why adults rarely qualify for NHS braces, what private adult orthodontics involves, and how to start without a waiting list. [Adult Options](https://virtualconsultant.online/eligibility/adults) Self-Assessment ###### Check Eligibility Find out where you stand before visiting a dentist — what the eligibility criteria are and how a photo assessment can give you an early indication. [Check My Case](https://virtualconsultant.online/eligibility/check) ## Keep exploring [Check Eligibility](https://virtualconsultant.online/evaluations/quote) [NHS Pathway](https://virtualconsultant.online/eligibility/nhs) [Adult Access](https://virtualconsultant.online/eligibility/adults) [Check Eligibility](https://virtualconsultant.online/eligibility/check) [IOTN Explained](https://virtualconsultant.online/eligibility/iotn) [Eligibility Hub](https://virtualconsultant.online/eligibility) [NHS Braces Guide](https://virtualconsultant.online/nhs) [Treatments](https://virtualconsultant.online/treatments) [Orthodontic Costs](https://virtualconsultant.online/costs) [Fixed Braces](https://virtualconsultant.online/braces) [Clear Aligners](https://virtualconsultant.online/aligners) [Common Problems](https://virtualconsultant.online/problems) [Locations](https://virtualconsultant.online/locations) ### Frequently asked questions What is IOTN and why does it matter? IOTN (Index of Orthodontic Treatment Need) is the scoring system that determines whether you qualify for NHS orthodontic treatment. Grades 4 and 5 typically qualify; grade 3 is borderline. What is the Dental Health Component (DHC)? The DHC grades malocclusion severity from 1 (no need) to 5 (very great need) based on specific clinical measurements including overjet, overbite, crossbite, displacement, open bite, and dental anomalies. What is the Aesthetic Component (AC)? The AC is a 10-image photographic scale used alongside the DHC for borderline grade 3 cases. High AC scores (6–10) at grade 3 DHC may still qualify for NHS treatment. What overjet qualifies for NHS treatment? An overjet greater than 6mm qualifies as DHC grade 4. Overjet over 9mm qualifies as grade 5. Overjet between 3.5mm and 6mm falls into borderline grade 3 territory. What DHC grade is borderline for NHS? Grade 3 is the borderline band. It qualifies only if the Aesthetic Component score is also 6 or above. Grades 1 and 2 do not qualify under any circumstances. Can I calculate my IOTN grade myself? Not precisely. IOTN requires clinical measurement tools and training. You can get a general idea by understanding what each grade describes, but a dentist assessment is needed for the official score. Does crowding alone qualify for NHS treatment? Crowding can contribute to a higher IOTN score if severe enough. Mild-moderate crowding alone typically falls within grades 2–3. Severe displacement greater than 4mm falls into grade 4. What happens if I disagree with my IOTN grade? You can ask your dentist to explain which specific DHC criteria they applied. If you remain unconvinced, you can request a second opinion from another dentist before accepting that NHS treatment is not available. --- Explore [Get Quote](https://virtualconsultant.online/evaluations/quote) [Costs](https://virtualconsultant.online/costs) [Browse Treatments](https://virtualconsultant.online/treatments) [Teeth Straightening](https://virtualconsultant.online/treatments/teeth-straightening) [Browse Problems](https://virtualconsultant.online/problems) [Locations](https://virtualconsultant.online/locations) [Near Me](https://virtualconsultant.online/locations/orthodontic-treatment-near-me) [NHS Eligibility Checker](https://virtualconsultant.online/about/do-i-qualify-for-nhs-treatment) [IOTN Score Checker](https://virtualconsultant.online/about/iotn-score-checker) [How To Take Orthodontic Photos](https://virtualconsultant.online/about/process/how-to-take-orthodontic-photos) [Online Orthodontist](https://virtualconsultant.online/guides/online-orthodontist-uk) [Research Papers](https://virtualconsultant.online/research) [Social Channels](https://virtualconsultant.online/social) ## How It Works ### Capture guided photos Use your phone or webcam to follow guided prompts and capture the right angles in around 5 minutes. [Photo guide](https://virtualconsultant.online/about/process/how-to-take-orthodontic-photos) ### Clinician review and options An orthodontic team reviews your assessment and creates a digital quote with options like braces and clear aligners. [Explore treatments](https://virtualconsultant.online/treatments) ### Accept when you’re ready Compare your options in your own time. If you accept, a coordinator contacts you to arrange next steps and get you started. [Understand costs](https://virtualconsultant.online/costs) 100% online to start. No pressure. Move forward only when it feels right. Explore your options Quick links Not sure where to start? Use these quick links to explore orthodontic treatments, typical costs, and helpful guides that explain what different options involve. Whether you're researching braces or clear aligners, comparing pricing, or just getting a feel for what comes next, you can browse at your own pace and come back when you're ready to request a quote. Explore [Get Quote](https://virtualconsultant.online/evaluations/quote) [Costs](https://virtualconsultant.online/costs) [Browse Treatments](https://virtualconsultant.online/treatments) [Teeth Straightening](https://virtualconsultant.online/treatments/teeth-straightening) [Browse Problems](https://virtualconsultant.online/problems) [Locations](https://virtualconsultant.online/locations) [Near Me](https://virtualconsultant.online/locations/orthodontic-treatment-near-me) [NHS Eligibility Checker](https://virtualconsultant.online/about/do-i-qualify-for-nhs-treatment) [IOTN Score Checker](https://virtualconsultant.online/about/iotn-score-checker) [How To Take Orthodontic Photos](https://virtualconsultant.online/about/process/how-to-take-orthodontic-photos) [Online Orthodontist](https://virtualconsultant.online/guides/online-orthodontist-uk) [Research Papers](https://virtualconsultant.online/research) [Social Channels](https://virtualconsultant.online/social) ## Ready to get your quote? Upload your photos and get clinician-reviewed options for braces or clear aligners. [Start My Free Quote](https://virtualconsultant.online/evaluations/quote) [Find an Orthodontist](https://virtualconsultant.online/locations) Prefer to learn first? Explore [treatments](https://virtualconsultant.online/treatments), [problems](https://virtualconsultant.online/problems), and [costs](https://virtualconsultant.online/costs). Citation details Title IOTN Score Explained | Dental Health & Aesthetic Component Guide Publisher Virtual Consultant Online Published 2024-06-01 Updated 2026-09-18 URL [https://staging.virtualconsultant.online/eligibility/iotn](https://staging.virtualconsultant.online/eligibility/iotn)