Measurement of diseases


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Measurement of diseases

  3. 3. INTRODUCTION• To compare the health status of differentpeople and the same people at differenttimes, it is necessary to measure a condition.• However this measurement must be based onstandardized and agreed set of guidelines.• measurement of diseases are done usingINDICES
  4. 4. DEFINITION• What is an INDEX?–An index is a means of converting a clinicaldiagnosis into a comparable statistics
  5. 5. PROPERTIES OF AN IDEAL INDEX• Simple• Objective• Valid• Reliable• Reproducible• Quantifiable– Should provide a measurement on which statisticalanalyses can be undertaken.• Acceptable
  6. 6. DENTAL INDICES• DMFT- CARIES• Oral Hygiene Index (GREEN AND VERMILLION1960)• Oral Hygiene Index Simplified (GREEN ANDVERMILLION 1964)• Plaque Index (QUINGLEY& HEIN 1962)• Gingival Index (LEO &SILNESS 1963)• Periodontal Index (RUSSELL 1956)
  7. 7. COMMON DENTAL INDICES• Periodontal disease index (RAMFJORD 1959)• Periodontal Need System (JOHANSEN ET AL1973)• Community Periodontal Index of TreatmentNeed (AINAMO ET AL 1982)
  8. 8. MEASUREMENT OF DENTAL CARIES• Dental caries can be classified according to themorphology of tooth site as:– Occlusal caries– Smooth surface caries– Approximal caries– Recurrent caries– Root surface caries.• The commonest index for measuring dentalcaries is the DMFT index and its variants.
  9. 9. • The DMFT was first described by klein andpalmer in 1937.• The DMFT applies only for permanent teethwhile dmft is used for deciduous teeth• DMFT record the number of :Decayed, Missingand Filled teeth• Decayed, Missing and Filled Surface (DMFS)INDEX is used when each individual surface ofeach tooth is assessed rather than the toothas a whole• DMFS: check all the surfaces 4 for the anteriorand 5 for the posterior
  10. 10. • Three values can be calculated from the datacollected from the DMF, i.e.1. The treatment index =[(M+F)/DMF]X1002. The care index =(F/DMF)X1003. The restorative index= [F/(D+F)]X100
  11. 11. ADVANTAGES OF DMFT• It is a universal index thereby allowinginternational comparison of data collected.• It is easy to use• It is readily acceptable by the patient
  12. 12. DISADVANTAGES• Relevance of DMF to caries experience assume thatmissing and filled teeth were due to caries neglectingother reasons such as trauma and periodontal• Treatment decisions– Restoration may be placed for preventive purpose,e.g. preventive resin restoration for early lesion asagainst restorative reason• Quality of teeth– DMF assigns equal weight to decayed, missing andfilled teeth so that an individual with 5 decayed orfilled and one with 5 missing will both score 5. Despitethe fact that the implication for their dental health isdifferent, distinction was not made.
  13. 13. DISADVANTAGES• DMF is irreversible, score can only increasewith time, so can not determine if there hasbeen an improvement in an individual’shealth.• Filled teeth have same score and missingteeth, implies no benefit to having a decayedtooth filled.
  14. 14. MEASUREMENT OF PERIODONTALDISEASE• 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 treatmentneeds(CPITN) (Ainamo et al 1982
  15. 15. Community Periodontal Index ofTreatment Needs (CPITN)• Presently, it is the internationally establishedmethod of estimating levels of periodontalconditions in populations• Assessment of treatment need not theamount or activity of periodontal disease
  16. 16. CPITN• For periodontal treatment Needs• Relevant for planning and disease control• Measures consequences of plaque namely:– Gingival inflammation– Pocket formation
  17. 17. • 3 indicators are used for this assessment.– Presence or absence of gingival bleeding– Supra or sub-gingival calculus– Periodontal pockets
  18. 18. CPITN probe
  19. 19. • The mouth is divided into sextant by teeth number.Note: a sextant should only be examined if there are 2 ormore teeth present and not indicated for extraction.• When only one tooth remains, it should be added toadjacent sextant.18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 2848 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38
  20. 20. • Index teeth: for adults aged 20years andabove, the teeth to be examined are:• The 2 molars in each posterior sextants arepaired for recording.• If no index teeth is present in a sextant, all theremaining teeth in the sextant are examined.17 16 11 26 2747 46 31 36 37
  21. 21. Range: 0 – 4, XAssessed Index Teeth :Up to age 19: Six TeethAge 20 and greater: Ten teeth.Tools: Mirror, CPITN ProbeScores: 0-4, X
  22. 22. CPITN Scores/CodesCode “X”= 1 tooth or no tooth in sextantCode “4”= deep Pocket >5.5mmCode 3= Pocket of 3.5-5.5mmCode 2= Supragingival / subgingival calculusCode 1= Gingival bleeding on gentle probingCode 0 = Healthy
  23. 23. Code 0 : No treatment neededCode 1: TN 1= OHI, Scaling and polishingCode 2: TN 2= OHI, Scaling and polishingCode 3: TN 3= OHI, Scaling and polishing+ RPCode 4: OHI, Scaling and polishing+ complexperiodontal treatment
  24. 24. Advantages of CPITN• It is a universal index thereby allowinginternational comparison of data collected.• It is easy to use• It is useful for describing the prevalence ofneeds for different treatment• It is readily acceptable by the patient
  25. 25. Disadvantages of CPITN• Measures several parameters(e.g. gingivalbleeding, calculus, periodontal pocket) usingthe same index• Measures treatment needs and not diseases• Does not measure the effectiveness oftreatment• Recession and mobility excluded
  26. 26. Oral hygiene index simplified• The OHI has 2 components, the debris indexand calculus index.• Each of these indices is based on numericaldetermination representing the amount ofcalculus and debris found on the toothsurfaces.
  27. 27. • The 6 surfaces examined for the OHI areselected from 4 posterior teeth and 2 anteriorteeth.• In absence of these anterior teeth, the centralincisors on the opposite side of the midline issubstituted.6 1 66 1 6
  28. 28. • Criteria for classifying debrisScores Criteria0 No debris or stain present1 Soft debris covering not more than one-third of the toothsurface, or presence of extrinsic stains without otherdebris regardless of surface area covered.2 Soft debris covering more than one-third, but not morethan two-third of the exposed tooth surface.3 Soft debris covering more than two-third of the exposedtooth surface.
  29. 29. • Criteria for classifying calculusScores criteria0 No Calculus present1 Supra-gingival calculus covering not more than third ofthe exposed tooth surface.2 Supra-gingival calculus covering more than one third butnot more than two-third of the exposed tooth surface orthe presence of individual flecks of sub-gingival calculusaround the cervical portion of the tooth or both.3 Supra-gingival calculus covering more than two-third ofthe exposed tooth surface or a continuous heavy bandof sub-gingival calculus around the cervical portion oftooth or both
  30. 30. Right molar Anterior Left molar TotalBuccal lingual Labial Labial Buccal lingual Buccal lingualUpper 3 - 2 - 3 - 8 -lower - 2 - 1 - 2 1 4Debris index=buccal scores+lingual scorestotal number of examined surfaces.Debris index= (9+4)/6=2.2Debris
  31. 31. • CalculusRight molar Anterior Left molar TotalBuccal lingual Labial Labial Buccal lingual Buccal lingualUpper 1 - 0 - 1 - 2 -lower - 1 - 2 - 2 2 3Calculus index= (4+3)/6=1.2
  32. 32. Oral hygiene index =Debris index+ calculus index2.2+1.3=3.40-1.2= Good1.3-3.0= fair3.1 and above is poor
  33. 33. Other commonly used indexIndex UsesDDE modified Enamel defect Clarkson and O’Mullen1989TF index Fluorosis Thystrup and fejerskov1978Dean’s index Fluorosis Dean 1934Horowitz index Fluorosis Horowitz 1986IOTN and PAR Orthodontic treatment need andassessment of patient oftreatment needShaw et al 1991Trauma index Trauma O’Brien 1994Erosion index Erosion Walker et al 2000
  34. 34. LIMITATIONS OF INDICES• They measure disease and not health• Fail to measure the impact of the disease.
  35. 35. CONCLUSION• indices should be made to measureeffectiveness of therapy, not in terms ofclinical outcomes but in terms ofimprovement to the quality of life.