OHI-S — Simplified Oral Hygiene Index Calculator
Score debris and calculus on the six WHO index teeth and instantly compute Debris Index, Calculus Index and OHI-S per Greene & Vermillion (1964). Standard in BDS / MDS examinations and Indian dental clinical practice.
Debris Index (DI-S) — Score Each Tooth
Calculus Index (CI-S) — Score Each Tooth
Debris Index (DI-S)
0.00
0 – 3 scale
Calculus Index (CI-S)
0.00
0 – 3 scale
OHI-S Score
0.00
Good oral hygiene (0–6 scale)
OHI-S, plaque scores and perio charts in one tap
EasyClinic's perio module supports OHI-S, PI, GI, BOP, CPITN and full-mouth pocket charting with auto-trend graphs — built for Indian dental clinics doing high-volume recalls.
Also Known As
What is the OHI-S?
The Simplified Oral Hygiene Index (OHI-S) was developed by Greene and Vermillion in 1964 as a faster version of the original 1960 OHI. It evaluates only six index tooth surfaces — four posterior buccal/lingual and two anterior labial — making it practical for chair-side use and large-scale epidemiological surveys.
OHI-S is the most frequently asked oral hygiene index in BDS / MDS exams across Indian universities and is part of every dental public health rotation under the Dental Council of India (DCI) curriculum.
Index Teeth and Surfaces
- 16 — Buccal surface of upper right first molar
- 11 — Labial surface of upper right central incisor
- 26 — Buccal surface of upper left first molar
- 36 — Lingual surface of lower left first molar
- 31 — Labial surface of lower left central incisor
- 46 — Lingual surface of lower right first molar
Scoring Criteria (0–3 for Debris and Calculus)
- 0 — No debris / calculus present
- 1 — Soft debris or supragingival calculus covering not more than 1/3 of exposed tooth surface
- 2 — Covers more than 1/3 but not more than 2/3, OR presence of flecks of subgingival calculus around cervix
- 3 — Covers more than 2/3, OR continuous heavy band of subgingival calculus
OHI-S Interpretation
- 0.0 – 1.2: Good oral hygiene
- 1.3 – 3.0: Fair oral hygiene
- 3.1 – 6.0: Poor oral hygiene
Individual DI-S and CI-S share the same band: 0.0–0.6 = good, 0.7–1.8 = fair, 1.9–3.0 = poor.
Frequently Asked Questions
▸When should I prefer OHI-S over the full OHI?
OHI-S is the standard for chairside and survey use because it requires only six surfaces. The full OHI (12 surfaces) is mostly historical. Indian dental colleges teach OHI-S as the working index.
▸Can OHI-S be used in children?
OHI-S requires permanent first molars to be erupted, so it is typically used from age 6–7 upwards. For younger children, the dft/dmft + plaque indices (Silness-Loe, Quigley-Hein) are more appropriate.
▸How does OHI-S relate to gingival health?
OHI-S correlates moderately with gingival inflammation but does not replace gingival indices (GI, BOP). Pair OHI-S with BOP% and CPITN sextant scoring for a complete periodontal screen — EasyClinic does this automatically.
▸What if an index tooth is missing or full-crowned?
Per Greene-Vermillion, substitute with the fully erupted adjacent tooth in the same sextant (e.g., 17 or 15 for missing 16). Do not substitute across the midline. If no scoreable tooth in the sextant, score it as missing and divide by fewer teeth.
▸Is OHI-S accepted by the Indian Dental Association?
Yes. IDA Periodontology and the DCI BDS curriculum recognise OHI-S as a standard oral hygiene status indicator. It is also accepted for thesis work submitted to MUHS, RGUHS, NTRUHS, DU and other Indian health universities.
References
- Greene JC, Vermillion JR. The Simplified Oral Hygiene Index. JADA 1964;68:7-13
- Peter S. Essentials of Public Health Dentistry, 7th Ed — BDS standard textbook (India)
- Indian Dental Association (IDA) Periodontology guidelines
- Soben Peter & Hiremath SS — Public Health Dentistry textbooks (DCI recommended)
Plaque control, tracked patient by patient
EasyClinic logs OHI-S at every recall, plots oral-hygiene trends per patient, prints colour-coded patient education sheets in 11 Indian languages, and reminds patients via WhatsApp — ₹1,999/month.
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