A comprehensive presentation about community dentistry, health , definition, dimensions, different concepts, and indicators of health. Disease, its concepts, iceberg concept of disease. Concepts of control. Infections, stages of infectious process, active immunity and passive immunity, difference between two.

4. Community ??

6.  A community is commonly considered a social
unit (a group of people) who have something in
common, such as norms, values, identity, and often a
sense of place that is situated in a given geographical
area (e.g. a village, town, or neighborhood)

7. Characteristics of community are :
1. The community is a contiguous geographic area
2. It is composed of people living together
3. People cooperate to satisfy their basic needs
4. These are common organizations

8. Community Dentistry ?

9. is a branch of dentistry which deals with :
 Preventing disease
 Prolonging life
 Promoting health and efficiency through organized
community efforts for
1. Sanitation of environment
2. Control of communicable infections
3. The education of individual in personal hygiene
4. The organization of medical and nursing services for

10. early diagnosis and preventive treatment of disease and
6. Development of social machinery to ensure a standard
of living adequate for maintainence of health

13.  Procedures employed in practice of dentistry and
community dental health programmes, which prevent
occurrence of oral disease and oral abnormalities.

15. Health
At the end of the lecture, students will know :
 How to define health ?
 Changing concepts in Health
 Dimensions of health
 Spectrum of health
 Determinants of health

17. Health is a state of complete physical, mental and
social well being and not merely an absence of disease or
infirmity

19. Changing concepts of health
 Biomedical
 Ecological
 Psychosocial
 Holistic

21. Biomedical Concept
 Health is the absence of disease
 Human body is a machine and the disease is the
outcome of the breakdown of the machine
 Doctor’s job is to repair the machine

22. Ecological Concept
 Health is a dynamic equilibrium between man, his
environment and disease. A maladjustment of human
organism to environment.
 Human ecological and cultural adaptations to
determine not only the occurrence of disease but also
the availability of food and the population explosion.

23. Psychosocial Concept
 Health is not only a biomedical phenomenon, but one
which is influenced by :
- Psychological
- Cultural
- Social
- Economic
- Political factors

24. Holistic concept
 “Unified or multidimensional process involving the
well being of a person as a whole in context of his
environment”.
 The emphasis is on the promotion and protection of
the health.

26. Dimensions of Health(major)
Physical Social Mental

27. Cont…… (Minor)
Spiritual Emotional Others

28. Physical Dimension
 A state in which every cell and every organ are
functioning at optimum capacity and in perfect
harmony with the rest of the body

29. Mental Dimension
 A state of balance between the individual and the
surrounding world.
 Mental health is the ability to respond to varied
experiences of life with flexibility and a sense of
purpose.

30.  Also, can be defined as :
“ A state of balance b/w the individual and the
surrounding world, a state of harmony b/w oneself and
others, coexistence b/w realities of the self and that of
other people and that of the environment”

31. Social Dimension
 Means harmony and integration with the individual and
other members of society and between the individual and
the world in which they live
 Defined as :
Quantity and quality of an individual interpersonal
ties and the extent of involvement with the community.

32. Spiritual Dimension
 Part of individual which reaches out and strives for
meaning and purpose in life.
 It includes integrity, principles and ethics, the
purpose in life, commitment to some higher being and
belief in concepts that are not subject to “ state of the
art” explanation.

34. Emotional Dimension
 Emotion means Feeling
 This dimension reflects the emotional aspects of
humanities

35. Other Dimensions
 Vocational
 Philosophical
 Cultural
 Socioeconomic
 Environmental
 Education
 Nutritional

36. Vocational Dimension
 Work often plays a role in promoting both physical and
mental health.
 Physical work is usually associated with an improvement in
physical capacity, while goal achievement and self
realization in work are a source of self contentment and
enhanced self-esteem

38.  A spectrum (plural spectra or spectrums) is a
condition that is not limited to a specific set of values
but can vary infinitely within a continuum.

39.  This concept emphasizes that health of an individual
is a dynamic phenomenon and a process of continuous
change, subject to repeated, fine variations.

43. Determinants Of Health
 Health is influenced by multiple factors that lie both
within the individual and externally.
 Genetic factors and environmental factors interact
and the result may be health promoting or otherwise.

44. 1. Biological determinant
2. Behavioral and sociocultural conditions
3. Environmental factors
4. Socioeconomic conditions
5. Health services
6. Aging of population
7. Gender
8. Other factors

45. Biological Determinants
 Physical and mental traits of every human being are
to some extent determined by nature of genes at the
moment of conception.
 The state of health therefore depends partly to the
genetic constitution of man and his relationship with
his environment– an environment that transforms
genetic potentialities into phenotypic realities.

48. Indicator
 A sign that shows how the situation is changing
 As per WHO guidelines, indicators are variables that
help to measure changes.
1. Health indicators
2. Economic indicators

49. Characteristics of Indicators
 Valid : should measure what they are supposed to measure
 Reliable : Should be the same when measured by different people in
similar circumstances
 Sensitive : Should be sensitive to minor changes
 Specific : Should reflect changes only in situation concerned
 Feasible : Should have the ability to obtain the data needed
 Relevant : Should contribute to the understanding of phenomenon of
interest.

51. Health indicators (Functions)
 Required to measure the health status of a community
 To compare the health status of one community with other
 Assessment of health care needs
 Monitoring and evaluation of the health services, activities
and programs

52. Classification of Health Indicators
 Mortality
 Morbidity
 Disability rates
 Nutritional status
 Health care delivery
 Utilization rates
 Indicators for social and mental health

53. Cont……
 Environmental indicators
 Socioeconomic indicators
 Health policy indicators
 Indicators of Quality of life
 Others

55. Mortality
 Definition?

56.  Mortality rate is a measure of the number of deaths (in
general, or due to a specific cause) in a population, scaled
to the size of that population, per unit of time. Mortality
rate is typically expressed in units of deaths per 1000
individuals per year;

57. Mortality Indicators
1. Crude death rate
2. Life expectancy at birth
3. Infant mortality rate
4. Child mortality rate
5. Under 5 proportionate Mortality rate
6. Maternal Mortality rate
7. Disease Specific Mortality rate
8. Proportionate Mortality rate

58. Crude Death rates
 Indicates the number of deaths per 1000 population
per year in a given community.
 So, a decrease in death rate provides a good tool for
assessing the overall health improvement in a
population.

59. Life expectancy/ Expectation Of
Life
 Average no of years that will be lived by those who
were born alive in a population if the current age
specific mortality rate persists

60. Infant mortality rate
 Ratio of deaths under 1 year of age in a given year to the
total number of live births in the same year, usually
expressed as a rate per 1000 live births.
 It is one of the most universally accepted indicators of
health status not only of infants, but also of whole
population and of socioeconomic conditions under
which they live.

61. Child mortality rate
 No of deaths between age 1-4 in a given year per 1000
children in that age group at the mid point of the year
concerned.
 It is related to in sufficient nutrition, low coverage by
immunization, adverse environmental exposure and
other exogenous agents.

62. Under 5 Propotionate Mortality
Rate
 It is the proportion of total deaths occurring in the
under 5 age group.
 This ratio can be used to reflect both infant and child
mortality rates.

63. Maternal (puerperal) Mortality
Rate
 Maternal mortality accounts to the greatest
proportion of deaths among women of reproductive
age.
 Number of maternal deaths per 1000 women of
reproductive age in a population (15 – 44)age

64. Disease Specific Mortality Rate
 Mortality rates can be computed for specific diseases.

65. Proportional Mortality Rate
 This estimates the burden of disease in the
community.

66. Health Indicators of Pakistan
Under 5 mortality rank 42
Under 5 mortality rate 89/1000
Infant mortality rate 72
Neonatal mortality rate(2004) 53
Annual no of births 5337000
Annual no of under 5 deaths 465000
Life expectancy at birth 67
% of infants with low birth weight 32
% of under 5 with under weight 38
Estimated no of people with HIV 96/1000
Crude death rate 7/1000
% of hepatitis affected persons 10 %

68.  Morbidity (from Latin morbidus, meaning "sick,
unhealthy") is a diseased state, disability, or poor
health due to any cause. The term may be used to refer
to the existence of any form of disease, or to the degree
that the health condition affects the patient..

69.  Among severely ill patients, the level of morbidity is
often measured by ICU scoring systems.
 Comorbidity is the simultaneous presence of two or
more medical conditions, such as schizophrenia and
substance abuse

70. Morbidity indicators
 Incidence & prevalence
 Attendance rates at OPDs
 Admissions, readmissions and discharge rates
 Duration of stay in hospitals
 Absence from work or schools due to sickness

71. Incidence
 Number of new cases in a defined population during a
specified period of time

72. Prevalence
 All current cases (old & new) existing at a given point
in time in a given population

74. Sullivan’s index
 Calculated by subtracting from the life expectancy, the
probable duration of bed disability and inability to
perform major activities OR
 Life expectancy – (probable duration of bed
disability & inability to perform major functions)

76. Nutritional status indicators
 They are :
1. Anthropometric measurements of pre school
children
2. Height of children at school entry
3. Prevalence of low birth weight

77. Health care Delivery Indicators
 Doctor population ratio
 Doctor nurse ratio
 Population bed ratio
 Population per health/ subcentre
 Population per traditional birth attendent

78. Define Indicator ?

79.  Dynamic equilibrium between man and his
environment and disease – a maladjustment of human
organism to environment is _________________
a. Biomedical concept
b. Holistic concept
c. Physical dimension
d. Vocational dimension

80.  Preventing disease, prolonging life and promoting
health and efficiency through organized community
efforts is referred to as _________________

81.  Number of deaths per 1000 population per year in a
given population is
a. Morbidity rate
b. Child mortality rate
c. Life expectancy rate
d. Disease specific mortality rate
e. Crude death rate

82.  Basic tools for examination are :
I. Mouth mirror
II. Explorer
III. Tweezer
IV. Probe
V. All of the above excluding 2
VI. All of the above excluding 4

83.  Importance of taking medical history ?

86. At the end of lecture, the students shall be able to
understand :
 Concepts of causation
 Natural history of disease
 Concepts of control

87. Definition
 Any deviation from normal functioning or state of
complete physical, social or mental well being
OR
 A condition in which body’s health is impaired, a
departure from a state of health, an alteration of
human body interrupting the performance of vital
functions

88. Concept of Causation of Disease
 Supernatural theory
 Germ theory of disease
 Epidemiological triad
 Multifactorial causation
 Web of causation

89. Supernatural theory of disease
 Disease and human sufferings and calamities were
attributed to the wrath of gods
 Influence of evil spirits, planets and stars

90. Germ theory
 One to one relationship
Disease agent Man Disease

92. Epidemiological Triad
AGENT
HOST ENVIRONMENT

94. cont……
 Today, public health has introduced the concept of Epidemiological
tetrad
Environment
Host
(tooth)
Time period
(time required
for pH
Level)
Agent
(micro-organism)
Multifactorial
Theory – a
disease is rarely
caused by
a single agent

95. Agent
 A substance, living or non living, or a force, tangible
or intangible, the excessive presence or relative lack of
which may initiate or perpetuate a disease process

96. Cont……
 Biological agents
 Nutritional agents
 Physical agents
 Chemical agents
 Mechanical agents
 Social agents

98. 2: Host factors
 A person or other animal that affords subsistence or
lodgement to an infectious agent under natural
conditions

99. Cont……
 Demographic factors
 Biological factors
 Socio economic factors
 Life style factors

100. 3: Environmental factors
 Everything surrounding us is environment
- physical environment
- biological environment
- psychosocial environment

102. Cont……
 Suggested by Mac mahon & Pugh
 Used for the study of chronic disease where the disease
agent is not known

103. Web of Causation
Modernization of lifestyle
Sedentary life
Smoking & drinking
Pan, tobacco chewing Hypertension/diabetes
Leucoplakia Poor oral hygiene endoarteritis
Sub-mucous Fibrosis endoneuritis
Oral cancer Anaerobic infection
Oral manifestations
Periodontal disease
 Disease is the result of interaction of multiple factors with multiple outcomes

106. Cont……
 Describes the whole course of disease
i e Prepathogenesis to termination
 Two phases;
- Prepathogenesis
- Pathogenesis
 Apart from these we will be discussing :
 Risk factors
 Risk groups
 Spectrum of disease
 Iceberg of disease

107. Prepathogenesis Phase
 Period preliminary to the onset of disease
 In this phase the disease agent has not yet entered
man, but the factors that favour its interaction with
the human host already exist in the environment.

108.  It may be said that everyone is in the period of pre
pathogenesis of many different diseases because
diseases are present in the environment where we live

109. Pathogenesis Phase
 Begins with the entry of the disease agent into the
susceptible host
 Following events occur in case of the infectious
disease ;
- Entry of agent in host
- Multiplication of agent
- Incubation
- Tissue changes/ body response
- Final outcome

111. Definition
 Any attribute or exposure that is significantly
associated with the development of disease OR
 A determinant that can be modified by intervention,
thus reducing the possibility of occurrence of disease

112.  Combination of risk factors in the same individual
may be purely additive or synergistic.
 Risk factors may be causative as in smoking for lung
cancer or they may be merely contributory to
undesired outcome such as lack of physical exercise is
a contributory factor for coronary heart disease

113. Spectrum Of Disease
 Graphic representation of variation in the
manifestation of the disease.
 At one end of the disease spectrum are sub-clinical
infections, which are not ordinarily identified and at
the other end are fatal illnesses.

114. Iceberg Of Disease

115.  Iceberg of disease emphasis that for virtually every
health problem the number of cases ascertained
(those of disease ascertained (those visible) is
outweighed by visible) outweighed by those not
discovered.

116.  This leads to what has been called the inaccurate view
of the nature and causes of a disease and results from
studying the minority of cases of the disease.

117.  The visible part of the iceberg denotes the clinically
apparent cases of disease in the community
 The submerged portion represents the hidden masses
of the disease.

119. Concepts Of Control
 Disease Control
 Disease Elimination
 Disease Eradication

121.  Disease Control :
Describes operations aims at reducing :
a. Incidence of disease
b. The duration of disease and consequently the risk of
transmission

122.  In ‘ Disease Control’ the disease agent is permitted to
persist in the community at a level where it ceases to
be a public health problem according to tolerance of
the total population

123. Disease Elimination
 The term ‘ Elimination’ is used to describe
interruption of transmission of disease, e.g
elimination of polio, diphtheria and measles from
major geographic areas

124. Disease Eradication
 Eradication of disease implies termination of all
transmission of infection by extermination of
infectious agent.
 Example : small pox

125. Screening For Oral Diseases
Defined as :
“The search for unrecognized disease or defect by
means of rapidly applied tests, examinations or other
procedures in apparently healthy individuals.

126. Objectives Of Screening
 To sort out from a large group of apparently healthy
persons those likely to have the disease or at increased
risk of disease understudy, to bring those who are
“Apparently abnormal” under medical supervision and
treatment.

127. S.No Screening Test Diagnostic Test
1. Done on apparently healthy Done on those with indications or sick
2. Applied to groups Applied to single patients, all diseases
are considered.
3. Test results are arbitrary and
final
Diagnosis is not final but modified in
light of new evidence, diagnosis is the
sum of all evidence.
4. Based on one criterion or cut off
point
Based on evaluation of a number of
symptoms, signs and laboratory
findings
5. Less accurate More accurate
6. Less expensive More expensive
7. Not a basis for treatment Used as a basis for treatment
8. The initiative comes from
investigator or agency providing
care
The initiative comes from a patient
with a complaint

128. Criteria For Screening
 The criteria for screening are based on two
considerations :
1. The Disease to be Screened.
2. The test to be Applied.

129. Disease
 The disease to be screened should fulfill the following
criteria:
1. The condition sought should be an important
health problem.
2. There should be a recognizable latent or early
asymptomatic stage.
3. Facilities should be available.
4. There is an effective treatment.
5. Expected benefits.

130. Screening Test
The test must satisfy the criteria of :
 Acceptability
 Repeatability
 Validity

131. Screening Test Result By
Diagnosis
Screening Test Result Diagnosis
Diseased Not Diseased
Total
Positive a (True b ( False
Positive) Positive)
a+b
Negative C (False d (True
Negative Negative)
c+d
Total a+c b+d a+b+c+d

132. Sensitivity
 The term is used as a statistical index of diagnostic
accuracy.
 It is defined as the ability of a test to identify correctly
all those who have the disease, i-e true positive.

133. Specificity
 It is defined as the ability of test to identify correctly
those who do not have the disease, that is True
negative

134. Predictive Value Of Positive Test
 Is the probability that a person actually has the
disease given that he or she test positive.
 It is the probability that the disease is present when
the test result is positive

135. Predictive Value Of Negative
Test
 Is the probability that an individual is truly disease
free given that he or she tests negative.

136. Evaluation Of Screening Test
The following measures are used to evaluate a screening
test:
1. Sensitivity : a/(a+c)×100
2. Specificity : d/(b+d)×100
3. Predictive Value of a Positive Test a/(a+b)×100
4. Predictive Value of a Negative Test : d/(c+d)×100

137. Screening Test Result By
Diagnosis
Screening Test Result Diagnosis
Diseased Not Diseased
Total
Positive 40(a) 20(b) 60 (a+b)
Negative 100(c) 9840(d) 9940(c+d)
Total 140(a+c) 9860 (b+d) 10,000 (a+b+c+d)

138.  Sensitivity(True Positive)
= (40/140)× 100 = 28.57%
 Specificity (True Negative)
=(9840/9860 × 100 = 99.7%
 Predictive Value = (9840/9940)× 100 =
98.9% of a negative test.

139. Uses Of Screening
 Case Detection
 Control Of Disease
 Research Purpose
 Educational Opportunities

144. Definition
“ The entry & development or multiplication of an
infectious agent in the body of man or animals.”

145. Dynamics Of Disease
Transmission
The three main links in the transmission are :
 The Reservoir
 Modes Of Transmission
 Susceptible Host

146. Sources & Reservoir
 The starting point for the occurrence of a
communicable disease is the existence of a reservoir or
source of infection.
 Source of Infection is defined as :
“ The person, animal, object or substance from
which an infectious agent passes or is disseminated to
the host.”

147. Reservoir is defined as :
“ Any person, animal, arthropod, plant or substance or (
combination of these) in which an infectious agent
lives and multiplies, on which it depends primarily on
survival, and where it reproduces itself in such a
manner that it can be transmitted to susceptible host.”

148. Reservoir may be of three types :
 Human Reservoir
 Animal Reservoir
 Reservoir in non- living things

149. Human Reservoir :
The most important source or reservoir of infection for
humans is man itself. He may be a case or carrier.

150.  Case :
A person in a population or study group identified as
having the particular disease, health disorder or condition
under investigation.
 Carriers :
An infected person or animal that harbors a specific
infectious agent in the absence of discernible clinical
disease & serves as a potential source of infection for
others.

151. The elements in the carrier state are :
 The presence in the body of the disease agent.
 The absence of recognizable symptoms & signs of
disease.
 The shedding of the disease agent in the
discharges or excretions, thus acting as a source of
infection for other persons.

152. Animal Reservoir
 The disease & infection that are transmissable to man
through vertebrates are called as Zoonoses.
 These are over 100 zoonotic diseases which may be
conveyed to man from animals & birds. Examples
include Rabies, Yellow Fever, Influenza.

153. Reservoir In Non- Living Things
 Soil or inanimate matter can also act as a reservoirs of
infection.

154. Modes Of Transmission
(A). Direct Transmission
1. Direct Contact
2. Droplet Infection
3. Contact with soil
4. Inoculation into skin or mucosa
5. Transplacental ( Vertical )

155. (B) Indirect Transmission
1. Vehicle– Borne
2. Vector– Borne
a. Mechanical
b. Biological
3. Air– Borne
a. Droplet Infection
b. Dust
4. Fomite– borne
5. Unclean hands & Fingers

156. Direct Transmission
1. Direct Contact :
Transmitted through skin, mucosa.
Examples include : STD, AIDS, Leprosy.
2. Droplet Infection :
Direct projection of spray of droplets of saliva, or
nasopharyngeal secretions during coughing, sneezing etc.
Examples Include : Common cold, whooping cough,
tuberculosis.

157. 3. Contact With Soil :
By direct exposure of susceptible tissue to the disease
agent in soil.
Example include : tetanus, mycosis etc
4. Inoculation into skin or mucosa :
Disease agent may be directly inoculated into skin or
mucosa.
Examples include : Rabies virus via dog bite, Hep. B

158. 5. Transplacental / Vertical Transmission :
Disease agent can be transmited transplacentally.
Examples Include : TORCH

159.  TORCH :
1. Toxoplasmosis
2. Other ( syphilis )
3. Rubella
4. CMV
5. HSV

160. Indirect Transmission
 Include traditional 5 F’S :
Flies, Fingers, fomites, food & fluid.
 In indirect transmission the agent responsible should
be capable enough to survive outside the human host
in external environment.

161. 1. Vehicle – borne :
Implies transmission of infectious agent
through agency of water, food ( including raw
vegetables, fruits, milk products)
Examples Include : acute diarrhoea, typhoid
fever, cholera.
2. Vector – borne :
An arthropod or any living carrier.

162. 3. Fomite Borne :
Fomites are inanimate articles or substances other than
water contaminated by infectious discharges from a patient
and capable of harboring and transferring the infectious
agent to healthy person.
Fomites include : soiled clothes, towels. Linen,
handkerchief etc.

163. Stages
Incubation
period
Prodromal
stage
Period of
Fastigium
Period of
Defervescence
Period of
Convalescence

164. Stages of Infectious Disease
All infectious diseases pass through five stages.
1. Incubation Period :
Defined as :
“ The time interval between invasion by an
infectious agent & appearance of first sign or
symptom of the disease in question.”

165. 2. The Onset or Prodormal Stage :
Commences when first symptom appear.
3. The period of advance or Fastigium :
All the symptoms are now increasing in severity
untill climax reached.

166. 4. Period of Defervescence :
All symptoms are now decreasing.
5. Period of Convalescence :
The patient has overcome completely the
invaders or toxins.

167. Specific Defenses
Include :
 Active Immunity:
1. Humoral Immunity
2. Cellular Immunity
3. Combination of the above
 Passive Immunity :
1. Normal Human Ig
2. Specific Human Ig
3. Animal intoxins or antisera

168. Active Immunity
 It is the immunity which an individual develops as a
result of an infection or by specific immunization and
is usually associated with the presence of antibodies or
cells having a specific action or microorganism
concerned with a particular infectious disease or on its
toxic.

169. Active Immunity can be acquired in following ways :
 Following clinical infection e.g Chicken pox, rubella,
measles.
 Following subclinical or inapparent infection e.g
polio, diptheria
 Following immunization with an antigen which may
be a killed vaccine, a live attenuated vaccine or toxoid.

170. Humoral Immunity
 Humoral immunity comes from B cells ( bone marrow
derived B lymphocytes) which proliferates and
manufacture specific antibodies after antigen
presentation by macrophages.
 They act directly by neutralizing microbes or its
toxins.

171. Cellular Immunity
 It is mediated by T- lymphocytes which differentiate
into sub populations able to help B – lymphocytes. The
T cells do not secrete antigen but are responsible for
recognition of antigen.

172. Passive Immunity
 When antibodies produce in one body are transferred
to another to induce protection against disease, it is
known as passive immunity.

173. Passive Immunity may be induced by :
 By administration of an antibody– containing
preparation.
 By transfer of maternal antibodies across the placenta.
 By transfer of lymphocytes, to induce passive cellular
immunity

174. Passive Immunity differs from active immunity in the
following aspects :
 Immunity is rapidly established.
 Immunity produced is only temporary till the
antibody is eliminated from body.
 There is no education of reticulo endothelial system.

175.  Active immunity takes time to develop. It is superior to
Passive immunity because,
1. The duration of protection, like that of natural
infection is frequently long lasting.
2. With few exceptions, severe infections are rare.

176. 3. The protective efficacy of active immunization exceeds
that of passive immunization and in some instances,
approaches 100 %
4. Active immunization is less expensive than passive
immunization. Vaccines are cheaper to produce than
are antisera.

177. Herd Immunity
 Herd refers to group of animal or people that move in a
group
 Herd immunity ( Community immunity ) describes a type
of immunity that occurs when the vaccination of portion of
population ( or herd ) provides protection to unprotected
individuals

178.  Herd immunity theory proposes that in diseases
passed from individual to individual, it is difficult to
maintain a chain of infection when large numbers of a
population are immune.
 The higher the number of immune individuals, the
lower the likelihood that a susceptible person will
come in contact with an infectious agent.