1. MEASUREMENT OF DISEASES
SOYEBO O.A.
Den/2005/075

2. OUTLINE
• INTRODUCTION
• DEFINITION
• PROPERTIES OF AN IDEAL INDEX
• COMMON DENTAL INDICES
• MEASUREMENT OF DENTAL CARIES
• MEASUREMENT OF PERIODONTAL DISEASE
• CONCLUSION

3. INTRODUCTION
• To compare the health status of different
people and the same people at different
times, it is necessary to measure a condition.
• However this measurement must be based on
standardized and agreed set of guidelines.
• measurement of diseases are done using
INDICES

4. DEFINITION
• What is an INDEX?
–An index is a means of converting a clinical
diagnosis into a comparable statistics

5. PROPERTIES OF AN IDEAL INDEX
• Simple
• Objective
• Valid
• Reliable
• Reproducible
• Quantifiable
– Should provide a measurement on which statistical
analyses can be undertaken.
• Acceptable

6. DENTAL INDICES
• DMFT- CARIES
• Oral Hygiene Index (GREEN AND VERMILLION
1960)
• Oral Hygiene Index Simplified (GREEN AND
VERMILLION 1964)
• Plaque Index (QUINGLEY& HEIN 1962)
• Gingival Index (LEO &SILNESS 1963)
• Periodontal Index (RUSSELL 1956)

7. COMMON DENTAL INDICES
• Periodontal disease index (RAMFJORD 1959)
• Periodontal Need System (JOHANSEN ET AL
1973)
• Community Periodontal Index of Treatment
Need (AINAMO ET AL 1982)

8. MEASUREMENT OF DENTAL CARIES
• Dental caries can be classified according to the
morphology of tooth site as:
– Occlusal caries
– Smooth surface caries
– Approximal caries
– Recurrent caries
– Root surface caries.
• The commonest index for measuring dental
caries is the DMFT index and its variants.

9. • The DMFT was first described by klein and
palmer in 1937.
• The DMFT applies only for permanent teeth
while dmft is used for deciduous teeth
• DMFT record the number of :Decayed, Missing
and Filled teeth
• Decayed, Missing and Filled Surface (DMFS)
INDEX is used when each individual surface of
each tooth is assessed rather than the tooth
as a whole
• DMFS: check all the surfaces 4 for the anterior
and 5 for the posterior

10. • Three values can be calculated from the data
collected from the DMF, i.e.
1. The treatment index =[(M+F)/DMF]X100
2. The care index =(F/DMF)X100
3. The restorative index= [F/(D+F)]X100

11. ADVANTAGES OF DMFT
• It is a universal index thereby allowing
international comparison of data collected.
• It is easy to use
• It is readily acceptable by the patient

12. DISADVANTAGES
• Relevance of DMF to caries experience assume that
missing and filled teeth were due to caries neglecting
other reasons such as trauma and periodontal
• Treatment decisions
– Restoration may be placed for preventive purpose,
e.g. preventive resin restoration for early lesion as
against restorative reason
• Quality of teeth
– DMF assigns equal weight to decayed, missing and
filled teeth so that an individual with 5 decayed or
filled and one with 5 missing will both score 5. Despite
the fact that the implication for their dental health is
different, distinction was not made.

13. DISADVANTAGES
• DMF is irreversible, score can only increase
with time, so can not determine if there has
been an improvement in an individual’s
health.
• Filled teeth have same score and missing
teeth, implies no benefit to having a decayed
tooth filled.

14. MEASUREMENT OF PERIODONTAL
DISEASE
• Oral hygiene index (Green & Vermillion 1960)
• Oral hygiene index simplified (Green &
Vermillion 1964)
• Plaque index (Quingley &Hein 1962)
• gingival index (Leo &silness 1963)
• Community periodontal index of treatment
needs(CPITN) (Ainamo et al 1982

15. Community Periodontal Index of
Treatment Needs (CPITN)
• Presently, it is the internationally established
method of estimating levels of periodontal
conditions in populations
• Assessment of treatment need not the
amount or activity of periodontal disease

16. CPITN
• For periodontal treatment Needs
• Relevant for planning and disease control
• Measures consequences of plaque namely:
– Gingival inflammation
– Pocket formation

17. • 3 indicators are used for this assessment.
– Presence or absence of gingival bleeding
– Supra or sub-gingival calculus
– Periodontal pockets

18. CPITN probe

19. • The mouth is divided into sextant by teeth number.
Note: a sextant should only be examined if there are 2 or
more teeth present and not indicated for extraction.
• When only one tooth remains, it should be added to
adjacent sextant.
18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28
48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38

20. • Index teeth: for adults aged 20years and
above, the teeth to be examined are:
• The 2 molars in each posterior sextants are
paired for recording.
• If no index teeth is present in a sextant, all the
remaining teeth in the sextant are examined.
17 16 11 26 27
47 46 31 36 37

21. Range: 0 – 4, X
Assessed Index Teeth :
Up to age 19: Six Teeth
Age 20 and greater: Ten teeth.
Tools: Mirror, CPITN Probe
Scores: 0-4, X

22. CPITN Scores/Codes
Code “X”= 1 tooth or no tooth in sextant
Code “4”= deep Pocket >5.5mm
Code 3= Pocket of 3.5-5.5mm
Code 2= Supragingival / subgingival calculus
Code 1= Gingival bleeding on gentle probing
Code 0 = Healthy

23. Code 0 : No treatment needed
Code 1: TN 1= OHI, Scaling and polishing
Code 2: TN 2= OHI, Scaling and polishing
Code 3: TN 3= OHI, Scaling and polishing+ RP
Code 4: OHI, Scaling and polishing+ complex
periodontal treatment

24. Advantages of CPITN
• It is a universal index thereby allowing
international comparison of data collected.
• It is easy to use
• It is useful for describing the prevalence of
needs for different treatment
• It is readily acceptable by the patient

25. Disadvantages of CPITN
• Measures several parameters(e.g. gingival
bleeding, calculus, periodontal pocket) using
the same index
• Measures treatment needs and not diseases
• Does not measure the effectiveness of
treatment
• Recession and mobility excluded

26. Oral hygiene index simplified
• The OHI has 2 components, the debris index
and calculus index.
• Each of these indices is based on numerical
determination representing the amount of
calculus and debris found on the tooth
surfaces.

27. • The 6 surfaces examined for the OHI are
selected from 4 posterior teeth and 2 anterior
teeth.
• In absence of these anterior teeth, the central
incisors on the opposite side of the midline is
substituted.
6 1 6
6 1 6

28. • Criteria for classifying debris
Scores Criteria
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-third of the exposed tooth surface.
3 Soft debris covering more than two-third of the exposed
tooth surface.

29. • Criteria for classifying calculus
Scores criteria
0 No Calculus present
1 Supra-gingival calculus covering not more than third of
the exposed tooth surface.
2 Supra-gingival calculus covering more than one third but
not more than two-third of the exposed tooth surface or
the presence of individual flecks of sub-gingival calculus
around the cervical portion of the tooth or both.
3 Supra-gingival calculus covering more than two-third of
the exposed tooth surface or a continuous heavy band
of sub-gingival calculus around the cervical portion of
tooth or both

31. Right molar Anterior Left molar Total
Buccal lingual Labial Labial Buccal lingual Buccal lingual
Upper 3 - 2 - 3 - 8 -
lower - 2 - 1 - 2 1 4
Debris index=buccal scores+lingual scores
total number of examined surfaces.
Debris index= (9+4)/6=2.2
Debris

32. • Calculus
Right molar Anterior Left molar Total
Buccal lingual Labial Labial Buccal lingual Buccal lingual
Upper 1 - 0 - 1 - 2 -
lower - 1 - 2 - 2 2 3
Calculus index= (4+3)/6=1.2

33. Oral hygiene index =
Debris index+ calculus index
2.2+1.3=3.4
0-1.2= Good
1.3-3.0= fair
3.1 and above is poor

34. Other commonly used index
Index Uses
DDE modified Enamel defect Clarkson and O’Mullen
1989
TF index Fluorosis Thystrup and fejerskov
1978
Dean’s index Fluorosis Dean 1934
Horowitz index Fluorosis Horowitz 1986
IOTN and PAR Orthodontic treatment need and
assessment of patient of
treatment need
Shaw et al 1991
Trauma index Trauma O’Brien 1994
Erosion index Erosion Walker et al 2000

35. LIMITATIONS OF INDICES
• They measure disease and not health
• Fail to measure the impact of the disease.

36. CONCLUSION
• indices should be made to measure
effectiveness of therapy, not in terms of
clinical outcomes but in terms of
improvement to the quality of life.