Dental Caries DES Simulator

What is the Dental Caries Discrete Event Simulation (DES) Platform?

This application simulates school-based oral health outreach programs using Discrete Event Simulation (DES) based on the Lindley recursion. In public health research and policy design, naive ratio calculations (such as dividing total children by total dentists) frequently produce dangerously over-optimistic forecasts because they ignore the operational realities of delivering care in school settings.

This platform solves that problem by explicitly incorporating four real-world operational mechanisms:

• Patient-Level Stochastic Queuing: Children do not arrive in a steady, frictionless stream. They arrive in morning batches from classrooms, queue outside screening stations, and wait for clinical bays to become available.
• Strict 480-Minute (8-Hour) Shift Limit: School dental camps operate strictly between 09:00 AM and 05:00 PM. Any child whose treatment cannot commence before minute 480 must be cut off and sent back to class unserved.
• Multidisciplinary Task Delegation: Compares solo dentist practice (where the dentist performs every step—screening, fluoride varnish, restorations, and health education—alone) against task delegation (where dental auxiliaries handle fluoride varnish and classroom teachers deliver oral health education), freeing the dentist for operative treatment.
• 10-Month Academic Pool Depletion & Recall Dilution: In months 2–10 of a school year, high-risk children require maintenance/recall visits for repeat fluoride varnish. This simulation subtracts recall visits so that only unique children treated are counted toward population coverage.

Navigational Advice by User Role

1. Purpose & Strategic Scope

The National Overview tab aggregates discrete event simulation outcomes over a full 10-month academic school year across all government school children (Classes 1–10). It models how macroscopic policy choices (such as camp frequency, dentist deployment, and team task-shifting) translate into nationwide cavity treatment, population coverage, and public health workforce requirements.

2. What Users Can Do (Interactive Controls)

• Select Feasibility Tiers (Table 1 Benchmarks): Click any of the 4 policy tier cards to load the predefined operational benchmarks:
  • Status Quo (Current Practice): 2 camps/month per public dentist, 0% task-shifting (solo dentist), 50% participation (φ = 0.5). Represents current baseline delivery in India.
  • Plausible (Recommended Policy): 8 camps/month (2 school days/week), task delegation with 30% more referrals (auxiliaries deliver fluoride varnish, teachers deliver oral health education), 50% participation (φ = 0.5).
  • Stretch (Expanded Outreach): 12 camps/month (3 school days/week), 30% task delegation, 80% public dentist participation (φ = 0.8).
  • Theoretical Maximum: 22 camps/month (daily visits every working day), 30% task delegation, 100% public dentist participation (φ = 1.0). Demonstrates upper physical bound of the current public dental cadre.
• Adjust 5 Synchronized What-If Policy Sliders: Customize any parameter to test non-standard scenarios:
  • Monthly Camps / Dentist (c): Sliders range from 2 to 22 camps/month. Moving this slider directly alters provider camp time and child reach.
  • Task-Shifting / Team Delegation (TS %): 0% means no delegation. At 10%, 20% or 30%, OHE goes to the teacher and fluoride varnish to the auxiliary, with that many more referrals per camp.
  • Public Dentists Participating (φ): Adjust from 10% to 100% of the state's sanctioned dental workforce mobilized for school visits.
  • Follow-Up / Maintenance Visits (ρ): Adjust from 5% to 50% to set the proportion of camp slots in months 2–10 allocated to repeat recall visits for high-risk children.
  • OHE Need Reduction (R): Adjust from 0% to 5% to model a percentage-point reduction in the share of students needing OHE.
• Inspect Metric Explanations: Click the small blue i button on any KPI card to open a detailed modal explaining the clinical definition, mathematical formula, and empirical data sources.
• Analyze Tab 1 Visualizations: Directly view Figure S1 (Coverage Across Feasibility Tiers) and Figure S2 (Age-Specific Reach Distribution across Primary, Upper Primary, and Secondary grades).

3. Key Performance Indicators (KPIs) & Results Interpretation

Every KPI card displays national aggregates updated dynamically as policy sliders change:

1. Purpose & Micro-Level Simulation Mechanics

While Tab 1 analyzes national 10-month outcomes, Tab 2 models the ground-level operational reality of an 8-hour (480-minute) school dental camp running from 09:00 AM to 05:00 PM. It simulates individual student arrivals, waiting line build-up, triage decisions, workstation procedure times, and the 480-minute shift cut-off.

2. What Users Can Do (Interactive Controls)

• Adjust Camp Operational Sliders: Located directly above the playback controls, you can adjust parameters without switching tabs:
  • Task-Shifting (TS%): 0% (Solo Dentist) vs 30% (Team Delegation with Auxiliary & Teacher).
  • Monthly Camps / Dentist: 2 to 22 camps.
  • Cohort Batch Size Scale: Scale student arrival volume from 0.5x to 2.0x.
  • OHE need reduction (R): 0 to 5 percentage points.
  • Dentist Participation (φ): Share of dentists participating.
• Playback Control Bar:
  • Start Animation / Pause: Starts or freezes the camp clock, advancing time in steps of 2 simulation minutes.
  • Step (+2 min): Manually advance simulation time by one step to inspect individual transitions.
  • Reset: Clears the facility and samples a fresh stochastic batch of students with realistic ages, cavity severities, and arrival times.
  • Instant Run: Instantly executes the entire 480-minute camp day in milliseconds, displaying final metrics and Gantt charts.
  • Speed Chips: Toggle simulation speed between 0.5x (slow-motion observation), 1x (normal), 2x (fast), and 5x (turbo).
• Dynamic Bottleneck Alert: Real-time banner evaluating clinical flow:
  • Amber Bottleneck: Active when Task-Shifting = 0% (Solo Dentist). The dentist must perform triage, fluoride varnish, and fillings alone. A queue of 8+ children forms outside Chair 3A while other stations remain vacant.
  • Green Optimal Flow: Active when Task-Shifting is above 0%. Dental auxiliaries handle fluoride varnish and teachers deliver oral health education, leaving Chair 3A for clinical procedures.
• Interactive 2D Clinic Floorplan:
  • Waiting Hall / Reception: Displays arriving students. Click ANY student chip (e.g. #4 (Age 9-11)) to open their Detailed Patient Clinical Chart Modal displaying individual tooth status, assigned provider, procedure start/end times, and wait duration.
  • Bay 2: Auxiliary Triage Desk: Dental auxiliary admits each student in FIFO order (Uniform 0.5 to 1.5 minutes) and routes them based on diagnosed condition.
  • Bay 3A: Dentist Operatory Chair: Dental surgeon performing restorative care (ART, GIC, pulpectomy, extractions). Features a live progress bar indicating % completion of the active procedure.
  • Bay 3B: Preventive Fluoride Bay: Dental auxiliary applying fluoride varnish.
  • Bay 3C: Teacher Oral Health Room: Classroom teacher delivering oral health education.
  • Bay 4: Discharge Lounge: Displays successfully treated children as they finish care.
• 4-Track Multi-Provider Gantt Scheduling Timeline: Displays 4 horizontal tracks: Dentist Chair, Auxiliary Triage, Auxiliary Fluoride, and Teacher Room. Each procedure block is color-coded by treatment type (Screening, Fluoride Varnish, ART Restoration, Pulpectomy, Extraction). Hover over any block to inspect exact minute timestamps.
• Live Simulation Event Log: Scrollable live terminal feed logging student admissions, workstation transfers, procedure completions, and 480-minute cut-offs.

3. Single-Camp KPIs & Operational Results Interpretation

1. Purpose

This tab provides interactive Chart.js versions of the 9 manuscript figures (Figures 1–4 and Supplementary Figures S1–S5). It allows clinicians, reviewers, and researchers to explore underlying data points, inspect exact values, and export publication-ready high-definition graphics.

2. What Users Can Do (Interactive Controls)

• Select Any of the 9 Figures: Click the figure toggle buttons at the top of the tab:
  • Figure 1: Queuing Flowchart & Architecture: Visual architecture of the Lindley recursion queuing logic, triage routing, workstation parallel processing, and the 480-minute shift cut-off.
  • Figure 2: Provider Resource Utilization: Comparison of dentist, dental auxiliary, and classroom teacher busy time across operational camp frequencies.
  • Figure 3: Subnational State Coverage Rankings: Complete horizontal bar chart ranking all 35 Indian States and Union Territories by achieved coverage.
  • Figure 4: Structural Disparities Scatter Plot: Students per government dental surgeon against achieved coverage, by state.
  • Figure S1: Feasibility Tiers National Reach: National coverage and unique population reach across the 4 policy tiers.
  • Figure S2: Age-Specific Reach: Disaggregated reach across Primary (Classes 1–5, ages 6–8), Upper Primary (Classes 6–8, ages 9–11), and Secondary (Classes 9–10, ages 12–15).
  • Figure S3: Population-Level DMFT Reduction: DMFT reduction by age group across the scenario grid.
  • Figure S4: National Scenario Heatmap: Full 44-cell matrix showing national coverage across 11 camp frequencies and 4 task-shifting levels.
  • Figure S5: PSA Tornado Diagram: Ranks input parameters by their contribution to variance in national reach.
• Hover for Interactive Data Inspection: Hover over any bar, line vertex, scatter point, or heatmap cell to view exact numerical figures, sample sizes, and confidence bounds.
• Download HD Image Snapshots: Click the Download HD Image button on any active figure to instantly download a 300+ DPI equivalent PNG file suitable for manuscripts, slide decks, and policy briefs.

3. Figure-by-Figure Results & Scientific Takeaways

1. Understanding the 200-Fold Interstate Disparity

National averages conceal extreme subnational inequalities. In India, public dental surgeon availability varies by more than 200-fold across states: from 1 public dentist per 1,500 children in small Union Territories (such as DNH&DD and Lakshadweep) to 1 dentist per 300,000+ children in populous rural states (such as Uttar Pradesh, Madhya Pradesh, and Bihar).

2. What Users Can Do (Interactive Controls)

• Instant Name Search Filter: Type any state or UT name (e.g. "Kerala", "Assam", "Maharashtra", "Rajasthan") in the search box to filter the table and charts immediately.
• Administrative Zonal Filter: Select a geographical zone from the dropdown (North, South, East, West, Central, North-East, or Union Territories) to isolate regional performance.
• Synchronized State Charts: The horizontal state ranking bar chart and structural scatter plot re-render automatically to display only the states matching your active filters.
• Sortable State Data Table: Inspect detailed empirical variables for each of the 35 jurisdictions.

3. Table Variables & Results Interpretation

1. Purpose & Analytical Foundations

Health policy operates under parameter uncertainty. Tab 5 addresses this through two advanced analytical modules: an exhaustive 44-Cell Scenario Grid Matrix and a live in-browser Monte Carlo Probabilistic Sensitivity Analysis (PSA) engine.

2. What Users Can Do (Interactive Controls)

• Inspect the 44-Cell Scenario Matrix:
  • Examines 11 camp frequency levels (from 2 camps/mo up to 22 daily camps/mo) across 4 task-shifting intensities: 0% (no delegation) and 10%, 20% or 30% (delegation with that many more referrals per camp).
  • Hover over any cell to see the exact national coverage percentage, total unique children treated, and remaining child deficit.
  • Color ramp visualizes performance from dark slate (2.4% reach) to deep navy (51.2% reach).
• Configure & Run the Live Monte Carlo PSA Engine:
  • Select Draw Count: Choose the number of Monte Carlo iterations using the number input box, the range slider, or click one of the quick chips: 25, 50, 100, or 200 draws (capped at 200 for responsive browser execution).
  • Click "Run Monte Carlo PSA": Draws the shared assumptions jointly from uniform ranges: dentist availability (φ), repeat visit share (ρ), referrals, process times, effectiveness, disability weights, durations of effect, prevalence anchor and the regional gradient.
  • Analyze Empirical PSA Results: View the live frequency histogram, mean coverage, standard deviation, and 95% Uncertainty Intervals.

3. PSA Outputs & Statistical Interpretation

1. Global Adaptation Capability

The discrete event simulation logic is universal and can be adapted to any country, subnational province, or school health district worldwide. Tab 6 allows researchers and public health ministries to configure a custom health system, upload regional provinces, and simulate school outreach capacity.

2. What Users Can Do (Step-by-Step Instructions)

1. Enter National Parameters:
   • Country Name: Enter the jurisdiction name (e.g. "Indonesia", "Nigeria", "Brazil", "Kenya").
   • Government School Enrolment (Classes 1–10): Total eligible public student population.
   • Public Dentists: Total dental surgeons employed in government clinics and hospitals.
   • Untreated Caries Prevalence (%): Estimated proportion of school children with active cavities.
2. Apply WHO Archetype Quick Presets: Click any preset button to prefill calibrated parameters:
   • Low-Income (High Caries): 65% caries prevalence, severe dentist scarcity (1:50,000 child-to-dentist ratio).
   • Middle-Income (Transition): 52% caries prevalence, moderate dentist availability (1:15,000 ratio).
   • High-Density Urban: Clustered school demographics, higher dentist density (1:5,000 ratio).
3. Add / Edit Subnational Provinces:
   • Click "Add Province / State" to add regional rows with local province names, enrollments, and public dentist counts.
   • Delete individual rows or edit values inline.
4. Save & Apply Custom Country: Click "Save & Apply Custom Country". The entire simulation platform (Tab 1, Tab 2, Tab 3, Tab 4, Tab 5) immediately recalculates using your custom country data!
5. Import / Export JSON Configuration: Click "Export JSON" to save your customized country model to a file, or click "Import JSON" to restore a previously saved model.

3. Results & Policy Application for Custom Jurisdictions

Once applied, the custom country profile updates all 4 feasibility tiers, calculating the exact annual child reach, national coverage, unserved children, and dedicated school dentists required to eliminate cavities in that nation.

1. Purpose & Reproducibility

Tab 7 provides full mathematical transparency, documenting every formula, recursion, probability distribution, and data citation. It proves mathematically why discrete event simulation is superior to static ratio approximations.

2. Key Equations & Scientific Explanations

• Lindley Queuing Recursion: Models patient event queues at each workstation:
  Start[j] = max(Ready[j], Free_Time[r]),   Served if Start[j] < 480 min
  Guarantees that a child cannot begin service before either they finish triage or the designated provider becomes free, and strictly enforces the 480-minute shift cut-off.
• Multi-Month Pool Depletion & Recall Adjustment: In months 2–10 of a school year, recall visits consume camp slots:
  Rep[g] = min(ρ × S[g], U[g]),   New[g] = min(S[g] - Rep[g], P[g] - U[g])
  Ensures that only unique, previously unreached children count toward annual population coverage.
• Duration-Adjusted YLDs (Years Lived with Disability): Incorporates multi-year biological duration with a standard 3% annual social discount rate:
  YLD_dur = ∑ Eff_New[g, i] × DW[i] × [ (1 - e^(-0.03 × dur[i])) / 0.03 ]
  Accounts for the fact that an ART/GIC restoration preserves tooth integrity for 3–5 years, providing prolonged disability prevention.
• Dedicated Workforce Gap Capacity:
  Dedicated_Dentists_Needed = Unmet_Need / 1,889
  Based on the empirical throughput of 1 dedicated school dental surgeon conducting 16 camps/month for 10 months with team delegation, treating ~1,889 unique children per year.

3. Primary Empirical Data Sources

• School Demographics: Unified District Information System for Education (UDISE+ 2024-25, Department of School Education and Literacy, Ministry of Education, Government of India).
• Public Dental Workforce: National Health Profile (NHP 2022, Central Bureau of Health Intelligence, Directorate General of Health Services, MoHFW, Government of India).
• Epidemiological Burden: National Oral Health Survey and GBD 2019 Oral Disorders Collaborators.

Data Management Tools in the Top Navigation Header

The two-row header contains four dedicated data tools designed for seamless interoperability with institutional databases, spreadsheets, and academic software: