Epidemiology of
periodontal diseases
Dr. Mona Nagy
Lecturer of Pediatric Dentistry,
Minia University
Indices used for assessment of
gingival and periodontal diseases :
• 1- P.M.A. Index.
• 2- The Gingival Index (GI).
• 3- The Periodontal Index (PI).
• 4- The Oral Hygiene Index (OHI) and the Oral
Hygiene Index Simplified (OHI-S).
• 5- Community Periodontal Index of Treatment Need
(CPITN).
Criteria • Mild : If 1to 4 papillae are affected and 0 to 2
margins are affected
• Moderate: : If 4to 8 papillae are affected and 2 to 4
margins are affected
• Sever : If more than 8 papillae are affected and
more than 4 margins are affected or involvement of
attached gingiva
Scoring • The no. of affected PMA units are counted and
considered as separate estimates for the individual.
• PMA= no. of affected gingival units
no. of cases in the study
• All the present teeth are examined
2- The Gingival Index (GI).
the severity of the gingival condition is
indicated on a scale running from 0-3.
Criteria • 0 Normal gingiva
• 1 Mild inflammation: slight change in color and slight
edema. No bleeding on probing.
• 2 Moderate inflammation: redness, edema, and
glazing. running along soft tissue wall of gingival crevice.
• 3 Severe inflammation: marked redness and edema.
Ulceration, Tendency toward spontaneous bleeding.
• For each of the six teeth , mesial , distal , buccal
and lingual gingival units are scored independently.
• The tooth scores are summed and divided by 4
which gives the gingival index of the tooth.
• The scores of the 6 teeth are summed and divided
by their number which gives the GI of the individual.
3- The Periodontal Index (PI).
• All the teeth are examined in this index.
• Russell chose the scoring values as 0,1,2,4,6,8 in
order to relate the stage of the disease in an
epidemiological survey to the clinical conditions
observed.
Criteria
• 0 Negative. There is neither overt inflammation in the
investing tissues nor loss of function due to destruction of
supporting tissue.
• 1 Mild gingivitis. There is an overt area of inflammation in
the free gingivae which does not circumscribe the tooth.
• 2 Gingivitis. Inflammation completely circumscribes the
tooth, but there is no apparent break in the epithelial
attachment.
• 6 Gingivitis with pocket formation. The epithelial
attachment has been broken and there is a pocket (not
merely a deepened gingival crevice due to swelling in
the free gingivae). There is no interference with normal
masticatory function, the tooth is firm in its socket, and
has not drifted.
• 8 Advanced destruction with loss of masticatory
function. The tooth may be loose; may have drifted; may
sound dull on percussion with a metallic instrument; may
be depressible in its socket.
Modification
• It was modified by using a partial recording system
to be easier with large surveys . The teeth used are:
7 14
41 7 • He used the 7 instead of 6 in case of loss due to
caries
4- The Oral Hygiene Index (OHI) and the
Oral Hygiene Index Simplified (OHI-S).
RULES OF ORAL HYGIENE INDEX
1. Only fully erupted permanent teeth are scored.
2. Third molars are not included
3. The buccal & lingual calculus scores are both taken
on the tooth in a segment having the greatest surface
area covered by supra and subgingival calculus.
4. The worst tooth in each segment is taken as
representative of the segment.
DEBRIS INDEX CRITERIA
0 – No debris or stain present
1 – Soft debris covering not more than 1/3rd the tooth
surface, or presence of extrinsic stains without other
debris regardless of the area covered.
2 – Soft debris covering more than 1/3rd but not more
than 2/3rd of the exposed tooth surface.
3 – Soft debris covering more than 2/3rd of the
exposed tooth surface.
CALCULUS INDEX CRITERIA
0 No calculus present
1 Supragingival calculus covering not more than 1/3rd of the
exposed tooth surface
2 Supragingival calculus covering more than 1/3rd but not more
than 2/3rd the exposed tooth surface or presence of individual
flecks of subgingival calculus around the cervical portion of the
tooth or both
3 Supragingival calculus covering more than 2/3rd the exposed
tooth surface or a continuous heavy band of subgingival calculus
around the cervical portion of tooth or both
Calculation • Debris Index (DI) =
( Buccal Score+ Lingual Score) / NO. OF SEG
• Calculus Index (CI) =
( Buccal Score+ Lingual Score) / NO. OF SEG
• OHI=D.I+C.I
• DI and CI range from 0-6
• Maximum score for all segments can be 36 for
debris or calculus
• OHI range from 0-12
• Higher the OHI, poorer is the oral hygiene of patient
SIMPLIFIED ORAL HYGIENE INDEX
• Only fully erupted permanent teeth are scored.
• Natural teeth with full crown restorations and
surfaces reduced in height by caries or trauma are
not scored
INTERPRETATION
DI –S and CI-S
1. Good -0.0-0.6
2. Fair – 0.7-1.8
3. Poor – 1.9 -3.0
OHI-S
1. Good - 0.0-1.2
2. Fair – 1.3- 3.0
3. Poor – 3.0 -6.0