Comprehensive Notes – Public & Community Dentistry, Epidemiology and Biostatistics

Concepts & Definitions

  • Health (WHO): “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”
  • Four Key Concepts of Health
    • Ecological Concept – dynamic equilibrium between people and their environment
    • Biomedical Concept – health = absence of disease (germ theory focus)
    • Psychosocial Concept – incorporates social, psychological, economic & cultural factors
    • Holistic Concept – synthesis of ecological, biomedical & psychosocial views
  • WHO (World Health Organization)
    • Sets global health goals, policies & decisions
    • “Key worker” for health-related matters
    • April 7 = World Health Day

Public Health & Community Dentistry

  • Public Health = organized action to improve population’s health status
    • Main functions: treatment of indigents, oral-health surveys, public oral-health education
    • Key activities
    • Health Education – positively influence behaviour via education
    • Health Promotion – educational, economic & behavioural incentives for QoL change
    • Health Programs – time-series service activities using physical, human & financial resources
  • Community Dentistry = science & art of preventing / controlling dental diseases & promoting dental health through community efforts
    • Functions: program administration; preventive/diagnostic/corrective services; promotion & consultative services; PH training & teaching; dental-health education & information; research & studies

Milestones in the Philippines

  • RA 1082 (Rural Health Law) – June 15 1954, Pres. Magsaysay: strengthens rural health & dental services
  • Corazon Aquino (Nov 9 1986 speech, 7th World Dental Congress) – first to introduce & stress Dental Public Health importance
  • Proclamation 559 – Feb 24 2004, Pres. Arroyo: February = National Dental Health Month
  • RA 3626 – June 22 1963, Pres. Macapagal: appropriations for national water-supply fluoridation

Administration & Management Basics

  • Administration = determined action toward a conscious purpose
    • Requires systematic ordering, calculated use of resources, goal-orientation
    • 3 Ms of organization: Manpower, Materials, Money (plus Facilities & Finances)
  • Divisions of Administrative Work → Organization
    • Types: Undefined, Well-defined, Over-defined
    • Levels: Policy Maker → Board → Members
  • Principles of Organization
    1. Unity of Objective
    2. Efficiency (minimum unsought cost)
    3. Span of Control
    4. Scalar Principle (stepwise hierarchy)
    5. Delegation (adequate authority)
    6. Unity of Command (single superior)
    7. Absoluteness of Responsibility (no escape)
    8. Parity of Authority & Responsibility (Authority=ResponsibilityAuthority = Responsibility)
  • Management (“executive control”)
    • Functions: Planning, Staffing, Directing, Coordinating, Reporting, Budgeting, Evaluating
    • Evaluation types: Summative, Process, Progress, Impact

Private vs Public Dental Care

AspectPrivatePublic
Dentist rolePractitionerPlanner
DiagnosisIndividual patientCommunity
PlanTreatment planProgram plan
ConsentPatientCommunity approval
ManpowerAppropriate labourAppropriate labour
EvaluationTreatment evaluationProgram evaluation

Health-Care System Components

  • Managerial Subsystem – coordination/control
  • Production Subsystem – service provision
    • Public-health services, Hospitals, Professional practice, Self-help groups
  • Maintenance Subsystem – training & rewarding personnel (PDA, finance orgs, professional education)
  • Adaptive Subsystem – monitors external changes (health services, biomedical research)
  • Department of Health (DOH-PH)
    • Roles: planning, policy, program mobilization, licensing, research, disaster management
    • Headed by Secretary; OIC (2023): Dr. Maria Rosario S. Vergeire, MPH, CESO II

Business Side – 3 Parties in Payment

  1. First Party – patient / family / community
  2. Second Party – health-care provider (charges professional fee)
  3. Third Party – assumes financial burden
    • Government (PhilHealth: National Health Insurance Program)
      • Premium-based contract; goal = healthy subsidize sick
    • Private insurers
      • Gate keeper approval, accredited providers
      • Payment models: Post-payment, Capitation (fixed /person/month), Discounted fees, UCR fee (Usual–Customary–Reasonable), Fee schedules, Fee-for-service

Health Insurance & Managed Care

  • Health Insurance = eligibility via periodic contribution (voluntary/compulsory)
    • Types: Micro-insurance (low-income), International/Expatriate, Managed Care Orgs (MCOs)
  • Managed Care Organization (MCO)
    • Monthly fee, network of providers
    • Key terms
    • PCP (gate keeper), Fee schedule, Out-of-network, Out-of-pocket (Deductible, Co-insurance, Co-payment)
    • Plan types: HMO, PPO, EPO, POS

Health Planning & Program Planning

  • Steps
    1. Define community health problems
    2. Establish goals & objectives
    3. Set priorities
    4. Identify needs & resources
    5. Decide administrative actions
  • Program Plan = blueprint for guided action
    • Situational Analysis (backbone)
    • Priority Determination (values & judgements imposed on data)

Epidemiology Fundamentals

  • Definition: study of distribution & determinants of health-related states/events in specified populations
    • Distribution: frequency & pattern
    • Determinants: causes & risk factors
  • John Snow – Father of Modern Epidemiology
  • Two Factors in Distribution
    1. Frequency (number of disease occurrences)
    2. Pattern (person–place–time)
  • Major Study Types
    1. Descriptive (5 Ws)
    2. Analytical
    • Experimental (Randomized Clinical Trial, Field Trial; single vs double-blinded)
    • Observational (Ecological, Cross-sectional, Case-control, Cohort)

Dental & Periodontal Indices

  • Purpose: standardization & baseline data
  • Ideal qualities: Clarity, Simplicity, Objectivity, Validity, Reliability, Acceptability, Sensitivity (true +), Specificity (true –)
  • Direction of fluctuation
    • Reversible (e.g., CPITN)
    • Irreversible (e.g., DMFT)
  • Coverage: Full-mouth vs Simplified
  • Entity: Disease / Symptom / Treatment
  • Special: Simple vs Cumulative
  • Key Indices
    1. DMFT (Decayed-Missing-Filled Teeth) – H. Klein et al.
    • \text{Mean DMFT} \le 3 considered healthy (WHO)
    • Exclude 3rd molars, unerupted, congenitally missing, supernumerary, non-caries extractions/restorations
    • No tooth counted more than once; deciduous teeth use “def” index
    • Score range: 0 \text{ – } 28;DMFSsurfaces; DMFS surfaces0 \text{ – } 128
    1. CPITN – Cutress & Ainamo (WHO/FDI 1979)
    2. Root Caries Index
    3. PHP Index (Podshadley & Haley)
    4. OHI-S (Greene & Vermillion) – debris + calculus on 6 specific surfaces
    5. Gingival Index (Löe & Silness variant, NIDR bleeding-only)
    6. Periodontal Index (Russell)
    7. Plaque Index (Silness & Löe) – brushing/gum pre-test lowers value

Levels of Prevention

  1. Primordial – remove risk factors (e.g., safe water, routine rinsing)
  2. Primary – prevent onset
    • Health promotion & specific protection (fluoride, sealants, education)
  3. Secondary – early diagnosis & prompt treatment (screening, simple restorations)
  4. Tertiary – disability limitation & rehabilitation (RCT, prosthodontics, ortho)

Natural History of Disease

  • Epidemiologic Triad: Host–Agent–Environment; Tetrad adds Time
  • Phases
    • Pre-pathogenesis (interaction of risk factors)
    • Pathogenesis (agent–host interaction)
    1. Incubation
    2. Early (adhesion + multiplication)
    3. Late (damage & evasion)
    4. Final (recovery, disability, death)
  • Clinical phase = manifestation

Biostatistics & Demography

  • Biostatistics: application of stats in biomedicine
    • Uses: relate conditions to causes, collect & display morbidity/mortality, test hypotheses
  • Demography: study of human population phenomena
    • Human phenomena: Size, Composition, Distribution in space
    • Dynamic processes: Natality, Migration, Mortality
    • Uses: assess health status, plan & evaluate programs, set priorities, allocate resources
    • Sources: Census, Event registration, Morbidity records
    • Data collection: Primary (interviews, surveys), Secondary (gov’t), Tertiary (books)

Statistical Concepts & Tools

  • Descriptive vs Inferential statistics
  • Sampling Terminology
    • Population, Target population, Sampling population, Elementary units, Sampling units, Sampling frame
  • Sampling Methods
    • Non-probability: Convenience, Judgement, Snowball (hidden), Quota
    • Probability: Simple random, Systematic, Cluster, Stratified
  • Central Tendency
    • Mean, Median, Mode
  • Variation
    • Standard Deviation (SD)
    • SD \downarrowassamplesizeas sample sizen \uparrow, and vice-versa
    • Variance = SD^2
  • Distributions
    • Normal (depends on mean & SD)
    • Skewed (left/right)
  • Other terms: Frequency, Range, Standard Error, Test of Significance
    • Standard Error of Proportion = \sqrt{PQ/n}
  • Scales of Measurement: Nominal, Ordinal, Interval, Ratio
  • Statistical Tests
    • Correlation: Pearson (continuous), Spearman (ordinal), \chi^2 (related variables)
    • T-tests: Paired, Independent, Student (vs standard value)
    • ANOVA: One-way, Two-way
  • Data Organization
    • Array, Frequency distribution (≥5 classes; \text{class width}=\frac{\text{highest}-\text{lowest}}{\text{# classes}}), Cumulative frequency
  • Graphical Presentation
    • Qualitative: Bar, Pie
    • Quantitative: Histogram, Scatter, Line graph, Frequency polygon
    • Geographic: Cartogram
  • Test Interpretation
    • True +/–, False +/–
    • Sensitivity (true + detection) & Specificity (true –); high values → strong test

Fluoride Essentials

  • First isolated by Moissan
  • Daily intake recommendations
    • 0.01\text{–}0.7\,\text{mg} (birth–3 yr)
    • 1\,\text{mg} (4–8 yr)
    • 2\,\text{mg} (9–13 yr)
    • 3\,\text{mg} (14–18 yr, pregnant, lactating)
    • 4\,\text{mg} (>19 yr)
  • Lethal Dose
    • \approx 500\,\text{mg} small children
    • 5\text{–}10\,\text{g} \; (32\text{–}64\,\text{mg/kg}) adults
    • Antidotes: Milk of Magnesia, Syrup of Ipecac
  • High-fluoride foods: Salmon/Sardines > Tea > Cheese
  • Fluoridation vs Fluoridization
    • Community water: 0.7\text{–}1.2\,\text{ppm}→→50\text{–}65\% caries ↓
    • School water: 3\text{–}4\,\text{ppm}→→35\text{–}40\% caries ↓
    • Topical programs: 30\text{–}40\% caries ↓
  • Professional Topicals
    • APF 1.23% (Brudevold) – most common gel
    • NaF 2% (Knutson) – also in water; NaF 0.05% rinse → 20\% reduction
    • SnF₂ 8–10% (Muhler) – stains
    • SDF 38% (Nishino): 44 800 ppm F, 253 870 ppm Ag; for cavitated dentin
  • Varnish application frequency: High-risk every 3 mo; Low-risk every 6 mo
  • Dentifrice F concentration
    • 1000 ppm – non-spitters; 1500 ppm – can spit; active = Na monofluorophosphate
  • Multiple Utilization = best to raise surface F
  • Mouth rinses best for 6–12 yr high-risk children
  • Fluorosis
    • Colorado Stain (McKay & Black)
    • Index by Dean; endemic areas: Bacoor (Cavite), Agno (Pangasinan)
    • Affects permanent > primary; maxillary teeth (order: Central Incisors > Premolars > 2nd Molars)

WHO Index Age Groups

  • 5\,\text{yr} – deciduous
  • 12\,\text{yr} – mixed/permanent baseline
  • 15\,\text{yr} – adolescent
  • 35\text{–}44\,\text{yr} – adult
  • 65\text{–}74\,\text{yr}$$ – elderly

Disease Occurrence Levels

  • Endemic – baseline/community
    • Sporadic (irregular), Hyperendemic (persistently high)
  • Epidemic – rise above expected
    • Outbreak (limited area), Cluster (cases grouped by place/time)
  • Pandemic – worldwide (e.g., Dental caries classified as pandemic)

Dental Caries Highlights

  • Multifactorial etiology: Agent, Host, Environment, Time
  • Salivary antibacterial: Lactoperoxidase (oxidises thiocyanate → hypothiocyanite)
  • Caries Susceptibility (CS) / Activity (CA) tests
    • Salivary pH test = CS
    • Snyder test = CS + CA
    • Lactobacillus count = CS + CA
    • Disclosing dye = CA only

Oral Cancer Snapshot

  • Risk factors: UV (lips), Smoking, Family history
  • Can occur at any age; risk ↑ with age

COVID-19 Key Points

  • SARS-CoV-2; probable animal origin
  • Timeline
    • Dec 31 2019 – Wuhan pneumonia cluster
    • Jan 21 2020 – first PH case
    • Mar 11 2020 – WHO pandemic declaration
  • Transmission: Airborne/aerosol, fomite surfaces
  • Affects anyone; severe in immunocompromised
  • No specific treatment; prevention via vaccines
    • Viral vector: AstraZeneca, Sputnik, Janssen
    • mRNA: Pfizer, Moderna
    • Whole virus: Sinovac, Sinopharm
    • Protein subunit: Novavax, Covishield

Review & Motivational Note

  • "Things will get better – the last THREE letters after your name are within reach!"