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).

1- P.M.A. Index • Recording gingival condition

• P: papillary

• M: marginal

• A: attached gingival

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.

Scoring

• It is a partial recording system , six teeth are

selected for the examination

62 4

4 26

• 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.

Scoring

• PI score per person = Sum of individual scores

No of teeth present

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

SURFACES TO BE EXAMINED

CALCULATION

• DI –S/CI-S = Total score/No of surfaces

• OHI -S= DI-S+ CI-S

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