Epidemiology: Distribution and Determinants of Health

Epidemiology Basics

• Epidemiology studies the distribution and determinants of health-related states or events in specified populations to control health problems.
• Epidemiology focuses on patterns, causes, and effects of health and disease in defined groups of people.
• The goal of epidemiology is to identify the "who, where, and when" (distribution) and "what and why" (determinants) of diseases.
• Epidemiology is used to help prevent, control, and manage diseases at a public health level.
• Epidemiology identifies disease prevalence, incidence, risk factors, and strategies to reduce impact in periodontal disease.

Prevalence and Incidence

• Prevalence refers to the proportion or percentage of a population with a condition, such as a disease, event, or risk factor.
• Prevalence represents the total number of existing cases (both new and pre-existing) of a disease in a population at a specific time.
• Prevalence is usually expressed as a percentage or proportion of the population.
• Incidence measures probability of occurrence of a condition in a population over a time period.
• Incidence tracks new cases of a disease that develop in a population during a specific timeframe.
• Incidence helps determine how frequently new cases occur, offering insight into disease development risk.

Risk Factors and Case Definitions

• A risk factor is any attribute, characteristic, or exposure which increases the person developing disease probability
• Risk factors can be modifiable such as smoking and poor diet, or non-modifiable like age and genetics.
• Identifying risk factors helps predict and prevent disease onset
• Recognizing periodontal disease risk factors allows for early interventions to reduce impact.
• Case definition is a standardized criteria set, used to classify health conditions for counting cases, comparing trends, and guiding disease surveillance.
• Case definitions should remain simple and also practical

Periodontal Diseases (PD)

• Periodontal diseases are chronic oral infectious and inflammatory diseases affecting teeth-supporting periodontium
• Tissues that PD affects includes the gingiva, periodontal ligament, and alveolar bone
• Periodontal diseases range from reversible gingivitis to irreversible periodontitis conditions like chronic periodontitis.
• Noma, also known as cancrum oris is fast progressing gangrenous disease affecting mainly kids aged 2–6 years old suffering from malnutrition
• Is mostly found in sub-Saharan Africa

Clinical Significance of Periodontitis (PD)

• Periodontitis is common and affects a significant portion of the global population.
• Periodontitis majorly causes tooth loss and affects mastication, esthetics, self-confidence, and also the quality of life
• Periodontitis is connected to diabetes, cardiovascular disease (CVD), and respiratory infections, impacting overall health.
• Recognizing the signs and symptoms of PD can help dental professionals intervene early to prevent tooth loss and chronic health complications.

Periodontal Disease Prevalence

• Severe PD is defined by the World Health Organization (WHO) as having a pocket depth of 6 mm or more.
• The global burden of Severe PD is estimated to be ~1 billion cases
• The global prevalence of Severe PD is around 19% in individuals aged 15 years and older.
• Prevalence varies across WHO regions, ranging from 16% to 23%.
• Higher case numbers are usually found in lower-middle-income countries and lowest in low-income countries due to population sizes.
• Severe PD tends to increase with age
• Severe PD often starts in late adolescence and peaks around age 55.

Implications of PD

• Aging populations and longer life expectancy may increase the future burden of severe PD.
• In 2021, over 1 billion people were affected by severe PD, with a global age-standardized prevalence of 12.5%.
• South Asia had the highest prevalence rate at 17.6% and there were an additional 90 million new cases globally in 2021.
• The edentulism affected 353 million globally and most cases were in Latin America and the Caribbean
• By 2050, over 1.5 billion are projected to have severe PD, increasing the burden on both severe PD and edentulism.
• Severe PD and edentulism are projected to be among the top Level 4 conditions affecting Years Lived with Disability (YLDs) globally by 2050.

Risk Factors

• Having a genetic predisposition can increase the odds of PD by up to 50%.
• Data indicates that there's at least a moderate influence when relating a genetic component to the susceptibility of PD.
• Diet, with micronutrient deficiencies can increase the odds of PD
• Rheumatic diseases increases risk of gingivitis/PD and hormonal changes in females during can increase PD risk.
• Socioeconomic factors like education are individual indicators of PD

Impact of PD on Health

• Systematic reviews link PD to metabolic disorders such as dyslipidemia and CVDs.
• Evidence on PD's impact on diabetes risk is limited.
• Conflicting findings result when relating PD's effects on preterm birth/low birthweight.
• Positive findings may result when relating PD's effect when relating impact on respiratory diseases.

Managing PD and EconomicBurden

• Regular tooth brushing and dental visits reduce PD odds by 34% and 44%
• Data over 30 years reveal with improvements to retain molars, and lower plague/gingival scores
• PD cost causes cause an estimated loss of $154.06B in the US and €158.64B in Europe (20180
• Majority of indirect cost: usually because from edentulism relating to PD and PD
• Treatments, medication and preventatives are "Direct costs", when productivity loss is due to "Indirect Cost"

Current/Projected Stats

• In the US Chronic PD in dentate adults aged 30-79 from 2009-2014 was 42.2%
• In the US Severe PD in dentate adults aged 30-79 from 2009-2014 was estimated at 7.8%
• High ratios of adults who have PD compared to their peridiontists are in areas such as the Northeast, Florida, midwest etc
• Preventive dental care can reduce early PD stages, but less effective for severe PD.
• Severe PD/Edentulism remains a huge public issue and need better methods of improve
• Population growth will increase the cases of those affected PD