Epidemiology of Gingival & Periodontal Diseases.pptx

Epidemiology of Gingival and Periodontal Diseases Dr. Nawal Khalifa Babiker. DEFINITION OF EPIDEMIOLOGY John M. Last (1988) defined epidemiology as “the study of the distribution and determinants of health related states or events in specified populations and the application of this...

Epidemiology of Gingival and Periodontal Diseases Dr. Nawal Khalifa Babiker. DEFINITION OF EPIDEMIOLOGY John M. Last (1988) defined epidemiology as “the study of the distribution and determinants of health related states or events in specified populations and the application of this study to the control of health problems”. AIMS OF EPIDEMIOLOGY The International Epidemiological Association has listed three main aims of epidemiology, which were put forward by Lowe and Kost Rzewski in 1973 as follows: 1. To describe the size and distribution of the disease problems in human populations. 2. To provide the data essential for the planning, implementation and evaluation of health services for the prevention, control and treatment of diseases. 3. To identify etiological factors in the pathogenesis of disease. USES OF EPIDEMIOLOGY Morris has identified seven distinct uses of epidemiology: 1. To study historically, the rise and fall of disease in the population. 2. Community diagnosis. 3. Planning and evaluation. 4. Evaluation of individuals risks and chances. 5. Syndrome identification. 6. Completing the natural history of disease. 7. Searching for causes and risk factors. EPIDEMIOLOGICAL METHODS Epidemiology as a science is organized into 3 distinct divisions as: 1. Descriptive Epidemiology: Descriptive studies are used to observe and document the occurrence, progression and distribution of a disease or condition in population in relation to host, environmental and agent factors. Descriptive studies are usually the first phase of any epidemiological investigation. 2. Analytical Epidemiology: Analytical studies are used to investigate hypothesis derived from descriptive epidemiologic studies or other data sources. 3. Experimental Epidemiology: Experimental epidemiology is used to test hypothesis further by introducing A preventive or therapeutic agent and comparing the outcome in test subjects with concurrent observations In control groups. Descriptive and analytical studies are also called as observational studies. INDICES According to AL Russell an index has been defined as a numerical value describing the relative status of a population on a graduated scale with definite upper and lower limits, which are designed to permit and facilitate comparison with other populations classified by the same criteria and methods”. Methods which express clinical observations in numerical values are known as indices. There are many indices for recording and quantifying periodontal and gingival conditions which can be used with reproducible accuracy. Indices may allow a more straight forward approach to gather and interpret data. Indices Classification: Indices may be classified as: I. According to reversibility of the index:  Irreversible index: Index that measures conditions that will not change. e.g an index that measures dental caries.  Reversible index: Index that measures conditions that can be changed. e.g Gingival index. II. According to extent of area measured:  Full mouth indices: Index that measures the patients entire dentition or periodontium e. g Russel’s periodontal index.  Simplified Indices: Index that measures only a representative sample of the dental apparatus. III. According to entity which they measure:  Disease index – The D (decay) portion of the DMF index.  Treatment index – The F (filled) portion of the DMF index.  Symptom index – The Gingival or sulcular bleeding index. 1. Gingival Indices. 2. Bleeding Indices. 3. Plaque Indices. 4. Calculus Indices. 5. Periodontal Diseases Indices. GINGIVAL INDEX Criteria for Gingival index: It was developed by H Loe and J Silness in 1963. Score 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. Bleeding on probing. 3 Severe inflammation: Marked redness, edema and ulceration. Tendency towards spontaneous bleeding. Plaque index (PI): This index assesses only the thickness of plaque at the gingival area of the tooth. Method: The evaluation or scoring is done on the entire dentition or on selected teeth. The surfaces examined are the four gingival areas of the tooth i.e. distofacial, facial, mesiofacial and lingual surfaces. Mouth mirror, light source, dental explorer and air drying of the teeth and gingiva are used in the scoring of this index.  Was develped by by Silness & Loe 1964 Scoring Criteria Score Criteria 0 No plaque in the gingival area 1 A film of plaque adhering to the free gingival margin and adjacent area of the tooth. The plaque may be recognized only by running a probe across the tooth surface. 2 Moderate accumulation of soft deposits within the gingival pocket and on the gingival margin and/or adjacent tooth surface that can be seen by the naked eye. 3 Abundance of soft matter within the gingival pocket and/or on the gingival margin and adjacent tooth surface. Any Questions? The End.