Presence of extrinsic stains are measured in which of the following criteria of OHI - S
Oral hygiene index - simplified (OHI-S) was given by Jack Green and Vermillion in 1964. This index is the modification of OHI given by Green and vermillion of 1960 as this original OHI was a full mouth index which required more time for scoring and this resulted in discrepancies in examiner reliability. To overcome this major limitation, OHI was modified to OHI-S where on selected teeth and selected surfaces are examined.
Purpose of OHI-S:
To assess the oral hygiene status of the individual using debris and calculus scores.
Index teeth, surfaces and their substitution:
This index makes use of only 6 index teeth, with specific surfaces. If any of the index teeth are missing then the substitution is made. If that substitution is also not possible then the sextant is excluded from scoring.
Criteria for teeth Exclusion:
1. Natural teeth with full-crown restorations are excluded.
2. Tooth surfaces reduced in height due to caries or trauma are excluded.
Components for scoring OHI-S:
1. Debris component and
2. Calculus component
Debris criteria: DI -S (Debris Index - Simplified)
|0||No debris or stain present|
|1||Soft debris covering not more than one third of the tooth surface, or presence of extrinsic stains without other debris regardless of surface area covered|
|2||Soft debris covering more than one third, but not more than two thirds, of the exposed tooth surface|
|3||Soft debris covering more than two thirds of the exposed tooth surface|
Calculus criteria: CI-S (Calculus Index -Simplified)
|0||No calculus present|
|1||Supragingival calculus covering not more than third of the exposed tooth surface|
|2||Supragingival calculus covering more than one third but not more than two thirds of the exposed tooth surface or the presence of individual flecks of subgingival calculus around the cervical portion of the tooth or both.|
|3||Supragingival calculus covering more than two third of the exposed tooth surface or a continuos heavy band of subgingival calculus around the cervical portion of the tooth or both.|
Method of calculation:
After the scores of Debris and calculus are recorded, the DI-S and CI-S values are calculated separately. DI-S scores of each index teeth are totaled and it is divided by the number of teeth examined. Same is followed for arriving at CI-S value.
After obtaining DI-S and CI-S values, now OHI-S value is calculated by adding DI-S scores and CI-S values.
OHI-S = DI-S + CI-S
Interpretation of OHI-S: