The document discusses the ideal requisites of dental indices like DMFT. It states that indices are used to determine the incidence, prevalence and severity of dental diseases. Some key requisites discussed are simplicity, objectivity, validity, reliability and acceptability. It then describes the DMFT index which measures decayed, missing and filled teeth. It was developed in 1938 and is widely used. The document outlines the criteria for classifying a tooth as decayed, missing or filled according to the DMFT index.

1. IDEAL REQUISITES OF
INDICES AND DMFT
PRESENTED BY-
NAVEEN KUMAR
3RD YEAR (2013 BATCH)
UNDER THE GUIDANCE OF
Dr. GEETIKA ARORA [HOD]

2. Dental index or indices are devices to
find out the incidence, prevalence and
severity of the disease ,based on which
preventive programs can be adopted.

3.  ‘ A numerical value describing the
relative status of a population on a
graduated scale with definite upper and
lower limits, which is designed to permit
and facilitate comparison with other
populations classified by the same
criteria and methods. ’
- Rusell A.L

4. Simplicity:
 Should be easy to apply so that there is
no undue time lost during field
examinations.
 No expensive equipment should be
needed.
Objectivity:
 Criteria for the index should be clear and
unambiguous, with mutually exclusive
categories.

5.  Validity:
Must measure what it is intended to measure, so it
should correspond with the clinical stages of the
disease under study at each point.
o SENSITIVITY: should be able to detect reasonable
small shift, in either direction in the group
condition.

6. Reliability:
 Should measure consistently at different
times and under a variety of conditions.
 2 components-
Inter examiner reliability: different examiners
record the same result.
Intra examiner reliability: same examiner records
the same result at repeated attempts.

7. Acceptability
 Safe and not demeaning to the subject.
Quantifiability
 The index should be amenable to statistical
analysis and interpretable.

8.  Developed by Henry T Klein,Carrole E.
Palmer and Knutson J W in 1938.
 To determine prevalence of coronal caries.
 Advantages:
 Simple
 Rapid
 Versatile
 Universally accepted

9.  DMFT applied only to permanent teeth.
 3 components:
D – decayed teeth
M – missing teeth due to caries
F - filled teeth
 Instruments : mouth mirror , explorer.
 Teeth not included :
 3rd molars
 Unerupted teeth
 Congenitally missing & Supernumerary teeth
 Teeth removed & restored for reasons other than caries

10. 1. No tooth counted more than once , its either
decayed/missing/filled/sound.
2. Tooth having several restorations also counted as
one.
3. Deciduous teeth not included in DMFT.
4. Tooth considered present even though crown is
destroyed and only roots are left.

11.  The lesion is clinically visible and obvious.
 The explorer tip can penetrate deep into soft
yielding material.
 There is discoloration or loss of translucency
typical of undermined or demineralized
enamel.

12.  Maximum DMFT score for an individual is 28 or
32.
A. Individual DMFT:
 Eg:DMFT score of 3+2+5=10;3 teeth decayed,2
missing and 5 filled.
 Also 28-10=18 teeth are sound.
D+M+F=DMF

13. B. Group average:
Average DMFT= Total DMF
Total no:of subjects examined.

14.  DMFT values are not related to the number
of teeth at risk.
 DMFT index can be invalid in older adults
because teeth can become lost for reasons
other than caries.
 DMFT index is of little use in studies of root
caries.

15. 1. All third molars included.
2. Temporary restorations considered as ‘D’
3. Only carious cavities considered as ‘D’.
Initial lesions not considered as ‘D’.
4. Only teeth missing due to caries are
included in its M-component.

16. According to the criteria by the WHO only
teeth missing due to caries were introduced
for its M-component. However,in1997, WHO
has stated that for individual 30 yr and older,
the M-component should compromise teeth
missing due to caries or for any other
reasons. But for subjects under 30yr old
age,the M-component should only include
teeth missing due to caries. The instrumens
used to record denatl caries are a mouth
mirror and the WHO periodontal probe.
According to the criteria by the WHO only
teeth missing due to caries were introduced
for its M-component. However,in1997, WHO
has stated that for individual 30 yr and older,
the M-component should compromise teeth
missing due to caries or for any other reasons.
But for subjects under 30yr old age,the M-
component should only include teeth missing
due to caries. The instrumens used to record
denatl caries are a mouth mirror and the WHO
periodontal probe.

17.  SOBEN PETER ( Textbook for public health
dentistry )
 https://www.google.co.in/search?q=background+pi
ctures+for+ppt&biw=1366&bih=662&source=lnms&
tbm=isch&sa=X&ved=0ahUKEwjgzOeH5K7PAhWJ
v48KHYywDvUQ_AU
 https://en.wikipedia.org/wiki/Sampling_(statistics)
 http://www.socialresearchmethods.net/kb/sampling.
php
 http://www.investopedia.com/terms/s/sampling.asp