iDentistry The Journal identistry_may_aug2019 | Page 14

The Journal
Negative predictive value is the proportion of
persons with a negative test who are disease
free.
Risk factors and risk indicators
Chronic inflammatory periodontal diseases
have several etiological factors for which a
possible biological model of effect exists.
Microorganisms in dental plaque biofilms are
etiological factors essential for the initiation of
the inflammatory process locally at the infection
site, and in the absence of these, the
inflammatory response does not take place.
Oral hygiene level
The role of dental plaque as the principal
etiological factor in the development of
periodontal diseases has been shown by Löe &
Silness in 1960s. In 1971–1974, the first
National Health and Nutrition Examination
Survey (NHANES I)3 was conducted in the
United States and included a very large sample
representative of 194 million non
institutionalized American civilians. In this
study, the status of oral hygiene was assessed
by the Simplified Oral Hygiene Index on six
teeth per person, and the periodontal status
was assessed by the Periodontal Index on all
teeth present. Although the Russell’s
Periodontal Index has considerable
shortcomings in assessing disease prevalence
and severity, it has value in the identification of
risk indicators for advanced disease. The
NHANES I survey also showed that the level of
oral hygiene differs significantly by race and
gender with poorer oral hygiene found in blacks
than in whites, and in males than in females.
The level of oral hygiene is an important risk
factor for periodontal diseases in population
studies, this parameter shows a much weaker
value as a predictor of the future occurrence of
periodontal tissue loss when assessed on the
3
person level.
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Smoking
There is a very strong association between
various types and intensity of smoking habits on
gingival tissue status, periodontal tissue loss,
and severity of periodontitis.
Diabetes mellitus
Odds ratio of developing bone loss over time
was 2.2 in the better controlled diabetics
compared to nondiabetics, and 5.3 in the poorly
controlled diabetics compared to the better
controlled diabetics.4 Young persons with
insulin- dependent diabetes, particularly those
with poor glycemic control, have poorer
periodontal health than nondiabetics
Age
Large epidemiological studies, including the
NIDR3 National Survey of Employed Adults and
Seniors, and the third National Health and
Nutrition Examination Survey (NHANES III),
have clearly demonstrated an increase in the
prevalence (percentage of persons), extent
(percentage of teeth per person), and severity
of periodontal attachment loss with increasing
age.
Gender
In the first National Health and Nutrition
Examination Survey NHANES I3 survey
conducted in 1971–1974 in the U.S. population,
a better periodontal status was reported for
females than males in all age groups (21). Also
a higher prevalence of probing depth of 4mm in
males than in females have been shown across
the different age groups in the NIDR survey of
adults and seniors.
Race-ethnicity
An important finding of the NHANES I survey
was its finding of a much higher occurrence of
Vol. 15
No. 2
May-Aug 2019