1. PREVENTIVE AND COMMUNITY DENTISTRY
INDICES
PREVENTIVE AND COMMUNITY DENTISTRY

2. DENTITION CHART
Deciduous teeth

3. DENTITION CHART
Permanent teeth

5. DENTAL INDICES
An index is defined as a numerical value describing the relative status of a population on a graduated scale with a definite upper and lower limits designed to permit and facilitate comparison with other populations classified by the same criteria and methods.

6. IDEAL REQUIREMNTS OF AN INDEX
Simple
Clear
Reproducible
Quantifiable or measurable
Acceptable
High validity and reliability OR High sensitivity and specificity
Valid means that the data measure something that truly exist accurately. Reliable means that if measurement are taken on a different occasion the same answer is obtained.

7. COMMONNLY USED INDICES IN DENTISTRY
DMFT/dmft
OHI-S
CPITN
Plaque index of Silness and Loe
Gingival index of Silness and Loe

8. DMFT / dmft
This index gives a total score of all the affected teeth and provides a caries experience score for an individual D =
Decayed 1 M
Missing F
Filled

9. DMFT INDEX & SCORES D = Decayed = 1 M = Missing = 1 F = Filled = 1
Examples done for you
Say if 44 pupils have 35 decayed 21 missing and 8 filled teeth then the average DMFT is D+M+F/ No of pupil = 1.45

10. ORAL HYGIENE INDEX - SIMPLIFIED
One of the most popular indicators for determining oral hygiene status in epidemiologic study
The OHI was developed in 1960 by Greene and Vermilion and a simplified version of the OHI called OHI-S was proposed in 1964
The OHI-S differ from the OHI in the number of tooth surface scored ( 6 rather than 12)

11. ORAL HYGIENE INDEX - SIMPLIFIED
The OHI-S has 2 components
The Debri score
The Calculus score
The term oral debri include plaque, materia alba and food remnants

12. Selection of tooth surfaces
The six surfaces examined for the OHI-S are selected from the 4 posteriors and 2 anterior teeth
In the posterior portion of the dentition, the buccal surface of the upper 1st molars (16, 26) and the lingual surface of the lower 1st molars (36,46) are examined
In the anterior portion of the mouth, the labial surfaces of the upper right (11) and lower left central incisors (31) are examined 16 11 26 46 31 36

13. Criteria for classifying debris
Score
Criteria
No debris or stain present 1
Soft debris covering not more than 1/3 of the tooth surface, or presence of extrinsic stain without other debris regardless of surface area covered 2
Soft debris covering more than 1/3 but not more than 2/3 of the exposed tooth surface 3
Soft debris covering more than 2/3 of the exposed tooth surface

14. CRITERIA FOR CLASSIFYING CALCULUS
Scores
Criteria
No calculus present 1
Supragingival calculus covering not more than 1/3 of the exposed tooth surface 2
Supragingival calculus covering more than 1/3 but not more than 2/3 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 2/3 of the exposed tooth surface or a continuous heavy band of subgingival calculus around the cervial portion of the tooth or both

15. CALCULATING OHI-S Oral Hygiene Index (OHI-S) = D I + C I 6
In OHI-S the minimum score is 0 and the maximum score can be 6

16. ORAL HYGIENE INDEX-S Advantages: It takes less time to score.
It is easy to score.
It is useful in survey work
Disadvantages:
Results are biased
The index is not sensitive.
It is not ideal for clinical trials {Research}.

17. PLAQUE INDEX of SILNESS AND LOE
Plaque Index (PI) was developed by silness and Loe to be used along with gingival index (GI) to help correlate plaque accumulation with gingival inflammation
the same surfaces of the teeth are scored as in the GI and the same scoring system of 0 to 3 is used.
This index is applied to longitudinal studies and clinical trials because it is very sensitive to small changes in the amount of dental plaque
The principal difference between the Plaque Index and OHI-S is that the PI assesses only the thickness of plaque at the gingival margin rather than its coronal extent on the tooth surface area. It has been proved that measuring plaque thickness is more valid than measuring its coronal extent.

18. CRITERIA FOR PLAQUE INDEX
Score
Criteria
No plaque in gingival area 1
Film of plaque adhering to free gingival margin and adjacent area of tooth, plaque
may be noticed by running a probe across tooth surface 2
Moderate accumulation of soft deposits within gingival pocket, on gingival margin, and or on adjacent tooth surface, which can be seen by naked ey 3
Abundance of soft matter within gingival pocket and\or on gingival margin and
adjacent tooth surface

19. GINGIVAL INDEX OF LOE AND SILNESS
The most frequently used index for evaluating gingivitis is the Loe & Silness gingival index.
With this index, it is possible to measure
bleeding tendencies
color, contour changes of the gingiva
alternations in the consistency of tissue
and the presence of ulcerations.
Bleeding is the most important criterion of inflammation in this index; however, the distinction between normal {0} and mild inflammation {l} is based on visual appearance of the tissues
The gingival condition around each tooth is examined, and a score for the mesial, distal, buccal, and lingual areas is recorded. If desired, the gingival index can also be used on only selected teeth in the mouth

20. GINGIVAL INDEX OF SILNESS AND LOE
Score
Criteria
Normal gingival 1
Mild inflammation-slight change in color, slight edema, no bleeding on probing 2
Moderate – bleeding on probing 3
Severe inflammation, marked redness and edema ulceration, tendency toward spontaneous bleeding

21. SCORING FOR GINGIVAL INDEX
The sums of scores from the four areas of each tooth are divided by the number of teeth examined to produce a gingival index for the individual.
Because bleeding on probing can be scored more objectively than a visual assessment of change in color, from and consistency of gingival tissues, the intensity of probing with a blunt instrument must be carefully controlled.
The basic intention of this index is not to assess the depth or extent of a pocket or to determine bone loss but only to evaluate the status of gingival health

22. CPITN INDEX
3 indicators of periodontal status are used for this assessment
Presence or absence of gingival bleeding
Supra or subgingival calculus
Periodontal pockets-subdivided into shallow (4-5 mm) and deep (6mm or more)

23. CPITN probe
A specially designed light weight probe with a 0.5-mm ball tip is used, bearing a black band between a 3.5 and 5.5 mm from the ball tip.

24. SEXTANT
The mouth is divided into 6 sextant defined by the teeth number
A sextant should be examined only if there are two or more teeth present and not indicated for extraction.
When only 1 tooth remain in a sextant it shuld be included in the adjacent sextant
Upper right posterior
18-14
Upper anterior
13-23
Upper left posterior
24-28
lower right posterior
44-48
Lower anterior
33-43
lower left posterior
38-34

25. TEETH TO BE EXAMINED
For adults aged 20 years and over, the teeth to be examined are
The 2 molars in each posterior sextant are paired for recording, and if one is missing, there is no replacement. If no index teeth or tooth is present in a sextant qualifying for examination, all the remainng teeth in that sextant are examined
For young people up to the age of 19 years, only six teeth 16,11,26,36,31 and 46 are examined
For children under 15 recording for pocket should not be attempted. ie., only bleeding and calculus should be considered
If no index tooth is present in a sextant qualifying for examination, single fully erupted incisor or premolar may be substituted 17 16 11 26 27 47 46 31 36 37

26. SENSING GINGIVAL POCKET
The sensing force used should be no more than 20 gms
A practical test for establishing this force is to place the probe point under he thumb nail and press until blanching occurs
For sensing sub gingival calculus, the lightest force that will allow movement of the probe ball point along the tooth surface should be used
The depth of insertion read against the colour coding.
Atleast 6 point on each tooth should be examined

27. EXAMINATION AND RECORDING
Score
Criteria 4
Pocket > 6 mm (black area of probe not visible 3
Pocket 4 or 5 mm (gingival margin situated on black area of probe 2
Calculus felt during probing but all the black area of the visible 1
Bleeding observed, directly or by using mouth mirror, after sensing
Healthy

28. FURTHER READING
Norman O. Harris ; Arden G. Christen Chapter 13 – Periodontal Disease – Risk Assessment and Evaluation in ‘Primary preventive dentistry’ 4th edition.
World health Organisation; Extracts of Oral Health Methods and Indices (copies provided)

29. END