Community DentistryYears I - IV

Dr David LockerRoom 521 (ext 4490)

Year I: Term IYear I: Term I

• Epidemiological methods

• Epidemiology of oral diseases

• Determinants of health and disease

Year I: Term IIYear I: Term II

• Current issues in dental health care

• Current issues in dental health care

Year II: Term IYear II: Term I

• Clinical epidemiology and critical appraisal

• Clinical epidemiology and critical appraisal

Year II: Term IIYear II: Term II

• Evidence-based care: small groups learning

• Evidence-based care: small groups learning

Years III and IVYears III and IV• Communication in dental

practice

• Psychological and behavioural issues in dental practice

• Ethics in dentistry

• Jurisprudence

Years I and IIProviding clinical care to patients

Years I and IIProviding clinical care to patients

• What is the evidence re:

benefit?

• Is the evidence high quality?

• Is the evidence relevant?

Year 1: Fall Term

Lecture 1

Year 1: Fall Term

Lecture 1

Introduction to EpidemiologyIntroduction to Epidemiology

• Nature and scope of

epidemiology

• Contribution to dentistry

and dental practice

OBJECTIVES:OBJECTIVES:

Two Types of Health CareTwo Types of Health Care

1. Treats individuals

2. With physical and psychological disorders

3. Aims to RESTORE HEALTH

Clinical Practice:

1. “Treats” communities and populations

2. Currently healthy

3. Aims to PREVENT DISEASE and MAINTAIN HEALTH

Population (Public) Health Practice:

• Scientific study of the

frequency, distribution and

determinants of health and

disease in human populations

• Scientific study of the

frequency, distribution and

determinants of health and

disease in human populations

EXPOSURES

INTERVENTIONS

EXPOSURES

INTERVENTIONS

OUTCOMESOUTCOMES

CausationCausation

All decisions that health professionals make health professionals make involve assumptions about causal mechanisms

Aetiology: Risk factors Disease

Therapy: Treatment Improvementin patientscondition

Health service Health services Improved delivery: community

health

Aetiology: Risk factors Disease

Therapy: Treatment Improvementin patientscondition

Health service Health services Improved delivery: community

health

Causal Relationships in Health CareCausal Relationships in Health Care

• Comprehensive understanding of

oral health and disease

• Understanding of scientific methods

Causes of oral disease Evaluation of interventions

• Role in decisions re: diagnosis and

treatment for the individual patient

SCIENTIFIC METHODS

CRITICAL APPRAISAL

EVIDENCE BASED CARE

Characteristics of Epidemiology

Characteristics of Epidemiology

1. Science

2. Populations and population sub-groups

3. Prevalence, incidence and risk

ScienceScience

A systematic set of methods

for producing knowledge

about events and their

relationships which eliminates

chance, bias and error.

A systematic set of methods

for producing knowledge

about events and their

relationships which eliminates

chance, bias and error.

Power of EpidemiologyPower of Epidemiology

1854 London cholera epidemic

1940 Fluoride and dental caries

1970 US toxic shock syndrome

epidemic

London cholera epidemics1848-1854

Table 1: Results of Snow’s InvestigationTable 1: Results of Snow’s Investigation

61

Known to

have drunk

pump water

61

Known to

have drunk

pump water

6

Believed not to

have drunk

pump water

6

Believed not to

have drunk

pump water

6

No info

6

No info

5

In families

sending to

Broad St.

pump for

water

5

In families

sending to

Broad St.

pump for

water

3

Children

attending

school near

pump

3

Children

attending

school near

pump

2

No info

2

No info

73 living near Broad St. pump 10 not living near pump73 living near Broad St. pump 10 not living near pump

83 Deaths*83 Deaths*

* Out of 83 individuals who had died of the disease, 69 were known definitely or could be assumed to have drunk the pump water, 6 were believed not to have drunk it, and for 8 there was no information

* Out of 83 individuals who had died of the disease, 69 were known definitely or could be assumed to have drunk the pump water, 6 were believed not to have drunk it, and for 8 there was no information

Fluoride and dental caries

(see attachment)

Mechanisms by which fluoride considered to inhibit

dental decay

1. Pre-eruptive

- reduce enamel solubility

Mechanisms by which fluoride considered to inhibit

dental decay

2. Post-eruptive

- promote remineralization

- inhibit bacterial acids

Fluoride mechanisms

Better understanding of mechanisms

Debate re: modes of delivery

Toxic shock syndrome

1. Epidemiology is a logical discipline which

proceeds by way of sequence of reasoning

2. It is a comparative discipline in which causes

of disease are identified by comparing its

frequency in different groups

3. Epidemiological investigations can lead to

reductions in the frequency of disease even

though biological mechanisms are not known

Two Approaches to Explaining and Controlling Disease

Two Approaches to Explaining and Controlling Disease

Environmental:

Mechanistic:

• Focus on environmental, behavioural,

lifestyle causes of disease

• Focus on biological and pathological

mechanisms which cause disease

• Focus on biological and pathological

mechanisms which cause disease

LUNG CANCERLUNG CANCER

CARCINOGENESIS

SMOKINGSMOKING

Disease Preventive measure

Agent

Scurvy 1753 1928

Smallpox 1798 1958

Oral cancer 1915 1974

Sequence of epidemiological reasoning

Observation

Suspicion

Hypothesis

Epidemiological study

Statistical association

Causal inference

Prevention

Types of EpidemiologyTypes of Epidemiology

Classical:

Modern:

• Field epidemiology

• Descriptive epidemiology

• Analytic epidemiology

• Experimental epidemiology

• Clinical epidemiology

• Molecular epidemiology

1. Identifying a new syndrome and its cause

2. Assessing risks of exposures to harmful agents

3. Identification of high risk groups

4. Effectiveness of treatment and preventive technologies

5. Needs for and trends in use of health services

6. Variations in diagnosis and treatment planning among practitioners

Current Applications of Epidemiology

Current Applications of Epidemiology

What is the oral health status of Ontario’s elderly?

Is there an association between smoking and the onset and course of periodontal disease?

Does community water fluoridation increase the risk of hip fracture in the elderly?

Does the use of dental services by adolescents decline after school dental programs cease?

How does chronic facial pain affect the quality of life? Is this improved following consultation and treatment at a specialist pain clinic?

How much variation is there in dentists’ diagnoses of caries based on radiographs?

What proportion of the population avoid dental treatment because of fear and anxiety, and how is this changing over time?

Does oral infection (periodontal

disease) increase the risk of

major systemic disorders such as

heart disease, stroke and low

birth weight?

Does oral infection (periodontal

disease) increase the risk of

major systemic disorders such as

heart disease, stroke and low

birth weight?