epidemiology (periodontics)

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Al-Rafidain University College
Dentistry Department
Periodontics
Epidemiology of periodontal disease
Ghadeer abdulbasit fat'hi
Grade five
Group A3

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INRODUCTION
Epidemiology is the study of health and disease in populations and of how
these states are influenced by biology, heredity, and physical and social
environment, as well as personal behavior. Advances in research over recent
years have led to a fundamental change in our understanding of the
periodontal diseases. As recently as the mid-1960s, the prevailing model for
the epidemiology of periodontal diseases included the following precepts:
(1) all individuals were considered more or less equally susceptible to severe
periodontitis; (2) gingivitis usually progressed to periodontitis with
consequent loss of bone support and eventually loss of teeth; (3)
susceptibility to periodontitis increased with age and was the main cause of
tooth loss after age 35–55. Since the development of this paradigm,
advances in the understanding of periodontal diseases have led this disease
model to be reevaluated. Current knowledge has shown that periodontitis
does not present a linear progression and is not age dependent. Moreover, its
distribution and severity are strongly influenced by host susceptibility and
risk factors. Several epidemiological studies evaluating destructive
periodontal diseases have been pursuing associations in the incessant
identification of risk factors for these diseases. Analytical epidemiology
seeks to identify the risk factors associated with a disease, to quantify the
strength of those associations and to estimate whether an association is
causal. An understanding of risk factors can lead to theories of causation and
then to treatment protocols for clinicians to use in their daily practice. The
essential features of epidemiology as a method of research, when compared
to clinical research and case studies, are that (1) groups rather than
individuals are the focus of study; (2) persons with and without a particular
disease (e.g., periodontal diseases) and with and without the exposure of
interest are included, rather than just patients. The study of population
groups rather than individuals is to allow for valid estimates while
accounting for normal biological variation (e.g., some individuals form
dental biofilm readily; others do not). Broadening a study to include those
with and without a disease can provide a reference point against which a risk
is quantified.
Epidemiology: the study of distribution and determinant of disease in
human .
Uses of epidemiology in study of periodontal diseases
1.To study historically rise and fall of disease.
2.To diagnose community problems of health and disease by study and
analysis of incidence, prevalence and morbidity.

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3.To estimate individuals risk and chances of developing disease.
4.To help complete the clinical picture and natural history of disease by
group analysis.
5. To identify clinical syndromes by observation of group behavior.
6.To evaluate need and effectiveness of health services.
7.To search for causes of disease and of health by observation of group
habits, customs and models of life.
Some Definitions used :
Prevalence : Prevalence is the proportion of persons in a population who
have the disease of interest at a given point in or period of time. It is
calculated by dividing the number of persons in the population who have the
disease, by the number of persons in the population.
Incidence :(also referred as risk or cumulative incidence) It is the average
percentage of unaffected persons who will develop the disease of interest
during a given period of time. Incidence can be viewed as the risk or
probability that a person will become a case. It is calculated by dividing the
number of new cases of disease by the number of persons in the population
who are at risk for the disease.
Probing Pocket Depth :Distance from the gingival margin to the location of the tip
of a periodontal probe inserted in the pocket with moderate probing force .
Probing Attachment Level (PAL)OrClinical Attachment Level
(CAL):The distance from the Cemento - Enamel Junction (CEJ) to the
location of the inserted probe tip is known as Probing Attachment Level
(PAL) or Clinical Attachment Level (CAL)
Epidemiological triad include :
1.host. 2. Environment. 3.agent.
Periodontal disease include:
Gingivitis: It is the inflammation of the Gingiva in which the junctional
epithelium remains attached to the tooth at its original level.
Periodontitis : It is the inflammatory process which involves the Gingiva
and the periodontium & loss of periodontal attachment has occurred.

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depending onthe rate of bone loss may vary,Rate of bone loss :
the type of disease present Loe et al identified the following three
subgroups of patients with periodontal disease based on
interproximal loss of attachment and tooth mortality::
.1.Approx. 8% of persons had rapid progression of periodontal disease,
characterized by a yearly loss of attachment of 0.1 to 1mm..
2.Approximately 81% of individuals had moderately progressive periodontal
disease, with a yearly loss of attachment of 0.05 to 0.5mm.
.3.The remaining 11% of persons had minimal or no progression of
destructive disease (0.05 to 0.09) mm yearly .
An Epidemiologic Survey performed during the 1950s in India, used
assessments of alveolar Bone height to distinguish between gingivitis &
destructive periodontal disease, in a sample involving 1187dentate subject
:Marshall Day et al 1955
1.A 100 % occurrence of destructive periodontitis after the age of 40 yrs has
been seen ..
2.A decrease in the percentage of studies with "Gingival disease without any
Bone involvement" with increasing age concomitant
Study design
experimental Observational
Descriptive Analytical
Case control
Cross
sectional
Cohort
study
1.community
interventional trial .
2.randomised clinical
trials .
3. field trials .

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with an increase in percentage of subjects with "Chronic destructive
periodontal disease".
In a study of un-referred patients to 'Glasgow Dental Hospital United
Kingdom, which included :
1.Number Of Subjects : 74
2.age 50 yrs (30) to age 73 yrs (40) .
3.54% optimum bone height .
4. 5% generalized advanced bone loss.
5. 20% three quarter of teeth with advanced bone loss .
Periodontal indices
1.peroidontal index:
a)periodontal index (by Russel et al 1970)
b)periodontal disease index (by Sigurd P. Ramfjord 1959)
c)gingival periodontal index (o. Leary T.l., Gibson W.A., Shannon
.(I.L., Schuessler C.F. & Nabers C.L. In 1963
d) Extent & Severity Index (J.P. Carlos, M. D. Wolfe & A. Kingman in
1986).
e)community periodontal index (CPI) .
F)Community periodontal index for treatment Needs (CPITN) id Barmes,
George Beagrie, Terry Cutress, Jean Martin & Jennifer Sardo-Infirri in 1982
2.for the assesment of plaque :
1.Oral Hygiene Index (By Vermillion & Greene in 1960)
2.Oral Hygiene Index - Simplified ( Vermillion & Greene in 1964)
3.Turesky - Gilmore - Glickman Modification Of the Quigley Hein Plaque
Index (Titresky & colleagues in 1970).
3.for the assessment of calculus :
a) Calculus Surface Index (By Ennever Sturzenberger P. Radike A.W. 1961)
b)calculus Surface Severity Index (CSSI).
.

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CONCLUSION
*Periodontal diseases are one of the more prevalent oral diseases affecting
more than 50 % of Indian community..
*Untreated chronic periodontitis is responsible for tooth loss in majority of
the cases..
*Constant presence of chronic inflammation and inflammatory mediators
has also been proved to be a significant risk factor of several systemic
diseases e.g. preterm low birth weight babies, coronary artery diseases,
diabetes mellitus etc.
*Foreseeing the bad effects of periodontal diseases on oral as well as general
health,the prevention of these diseases should be included in national
health programme and national oral health survey should be conducted to get
meaningful data for different oral diseases and plan around preventive or
curative measures.

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cesReferen
J Int. Acad Periodontol; PMC 2006 January 25-
*indian Journal of Community Medicine 2005-10-2005-12;30
Indian Journal of Community Medicine 2005-04-2005-06;30:2*
Indian J Dent Res 2003;14(4):289-297*
*J Indian Soc Pedod. Prev. Dent 1997;15(4):114-117
*Fermin A. Carranza ( 10'* Edition)
Journals Of Periodontology, 1999*
Jan Lindhe (4th & 5th Edition)*
*Journals Of Periodontology, 1998; Volume 16; Epidemiology of
periodontal disease ..