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
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 = 1
F = Filled = 1
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
1. The Debri score
2. 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
0 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
0 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
0 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 andor 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
0 • 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
0 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)
