methods of measuring oral diseases

8/17/2019 Methods of Measuring Oral Diseases

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Methods of Measuring Oral

Diseases


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Counts

Number of cases of disease occurrence.

Most useful with unusual condition of lowprevalence.

Less useful as prevalence increases.


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Proportions

By adding a denominator to count

!ample "

Prevalence # count of caries of population grp.

divided by the total group pop$n

e.g. %& cases of aged %& to '&

%&& total age group

# (& or (& )


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*ates

+ proportion using standardi,ed denominator and includesa time dimension.

-e.g. infant mortality rate crude birth rate /

Little use in oral disease measure "

0 in caries incidence over a period of time

in clinical trials 0 annual rate of loss of periodontal attachment in

longitudinal studies


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1ndices

+ graduated numerical scale having upper and lower limits with scoreson the scale corresponding to speci2c criteria.

(. Ordinal scale 3 lists of conditions in some order of severity without

attempting to de2ne any mathematical relation between categories.

4. Nominal scale 3 simply gives names to di5erent conditions.

6. Interval or ratio scale 3 one in which the number used in themeasuring

scale have a mathematical relation to each other.


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1ndices

!ample " 1f ( is used to describe a degree of gingivitis

7hen 4 is twice as bad

6 is three times as bad

8ntil the upper limit of the scale is reached.

Note " Di5erence between 1nterval and *atio 9cales

*atio 3 has true ,ero point -e.g. height and weight /

1nterval 3 no ,ero point -e.g. :ahrenheit Celsius /


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Properties of 1ndices

Clarity 3 simplicity and ob;ectivity for ease of

application and memori,ation.


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Properties of 1ndices

=uanti2ability 3 must be amenable to statisticalanalysis so that the status of the group can be

e!pressed by a distribution - e.g. mean median orother statistical measures.

9ensitivity 3 should be able to detect reasonablysmall shifts in either direction in the condition.

+cceptability

*eversible > 1rreversible


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Measuring Dental Caries

DMF 3 D decayed

M missing due to caries

F 2lled

def 0 d0 decayed

e0 indicated for e!traction

f 0 2lled


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Measuring PeriodontalDiseases

Gingivitis

0 PM+ - Papillary Marginal +ttached /

0 ?1 - ?ingival 1nde!/

0 9B1 - 9ulcus 3 Bleeding inde!/

0 1B1 - astman 1nterdental Bleeding1nde!/

0 M?1 - Modi2ed ?ingival 1nde! /


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Periodontitis

0 P1 - Periodontal 1nde! / described by

*ussell - (@%'/ scored both gingivitis

and periodontitis

0 PD1 - Periodontal Disease 1nde! /

suggested by *amf;ord - (@%@/ an indirect

method of measuring loss of periodontal

attatchment.


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GPI 3 ?ingival Periodontal 1nde! an adaptation of PD1- O$Leary / both gingivitis and pocAet depth .

The Periodontal Treatment Need System (PTNS)

0 gave rise to CP17N presently being used by

O - (@4/ surveys.

0 categori,ed patients into levels of treatment need

and assigned times for type of treatment reEuired.


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PlaEue and Calculus

OHIS - 9impli2ed Oral ygiene 1nde!/ scorescalculus and plaEue together both supra andsubgingivally .

PHPI - Patient ygiene Performance 1nde! / isintended for monitoring of oral health performanceby patients . 1t reEuires a disclosing stain.


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PlaEue and Calculus

PlI -PlaEue 1nde!/ suggested by 9ilness and Loe-(@'F/ is designed to be used along with ?1.

!MI -

methods of measuring oral diseases

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