📐 Important Diagrams for Theory Examination - Aggressive Periodontitis

🔴 TIER 1 - Highest Probability (Almost Certainly Asked)

1. Arc-Shaped / Angular Bone Loss Pattern in LAP

• Panoramic or periapical schematic showing the mandible/maxilla
• Arc-shaped (vertical/angular) bone loss on the mesial and distal surfaces of first molars
• Bone loss on incisors (upper and lower)
• Show "mirror image" symmetrical pattern bilaterally
• Label: alveolar crest, arc-shaped defect, CEJ, teeth involved (16, 26, 36, 46 + incisors)

"The most characteristic finding of LAP is arc-shaped bone loss on the mesial and distal surfaces of first molars - a classic radiographic mirror-image pattern." - Carranza 10th ed., Ch. 33

2. Flowchart: Classification / Nomenclature Evolution of Aggressive Periodontitis (Historical Timeline)

1923 → Gottlieb: "Diffuse atrophy of alveolar bone"
1928 → Gottlieb: "Deep cementopathia"
1938 → Wannenmacher: "Parodontitis marginalis progressiva"
1942 → Orban & Weinmann: "Periodontosis" (3 stages)
1966 → AAP: Periodontosis retained
1989 → AAP: "Early-onset periodontitis" → LJP / GJP / RPP / PPP
1999 → AAP/EFP: "Aggressive Periodontitis" → LAP / GAP
2017 → New Classification: Merged into "Periodontitis" (Grade C)

3. Virulence Factors of Aggregatibacter actinomycetemcomitans (A.a.)

• Leukotoxin - destroys PMNs and monocytes
• Collagenase - destroys connective tissue
• Endotoxin (LPS) - bone resorption
• Epitheliotoxin - damages epithelial cells
• Fibroblast inhibition factor - inhibits fibroblast proliferation
• Bone resorption-inducing factors
• Fc receptor I & II - inhibits phagocytosis
• Invasion of host cells - intracellular survival
• Chemotaxis inhibition - impairs neutrophil migration

4. PMN (Neutrophil) Chemotaxis Defect Diagram

• Normal PMN: shows directed migration toward bacterial stimulus (C5a, FMLP, LTB4)
• Defective PMN in LAP: random migration, no directed movement
• Label: GP110 glycoprotein deficiency on neutrophil surface (~40% deficient)
• Note: ~75% of LAP patients have this defect
• Show: intact opsonization/phagocytosis (secondary functions preserved) vs. defective chemotaxis (primary defect)

5. Diagrammatic Representation of LAP (Localized Aggressive Periodontitis) Tooth Distribution

• Full dental arch diagram (upper + lower)
• Shade/mark: 6 anterior teeth (incisors + canines) and 4 first molars (16, 26, 36, 46)
• Show periodontal pocket/attachment loss only at these sites
• Label: "No more than 2 teeth other than first molars and incisors affected"
• Contrast with GAP where all teeth are generalized

6. Pathogenesis of Aggressive Periodontitis - Flow Diagram

Bacterial challenge (A.a. / P. gingivalis)
        ↓
PMN dysfunction (Chemotaxis defect)
        ↓
Inadequate bacterial clearance
        ↓
Bacterial invasion of connective tissue
        ↓
Leukotoxin → kills PMNs + monocytes
        ↓
Hyperresponsive monocyte phenotype
        ↓
Elevated PGE2, IL-1α, IL-1β, TNF-α
        ↓
Osteoclast activation → Bone resorption
        ↓
Rapid Attachment and Bone Loss

🟠 TIER 2 - Very Likely to Be Asked

7. Stages in Development of AgP (Orban and Weinmann, 1942)

• Stage 1: Degeneration of principal fibers of PDL (no pocket yet)
• Stage 2: Progressive degeneration, early pocket formation
• Stage 3: Deep pocket, bone loss, advanced destruction

8. Familial Aggregation / Genetic Transmission Pattern

• Family pedigree diagram
• Autosomal dominant or X-linked pattern (note: debated, but familial clustering shown)
• Show affected family members (shaded circles/squares) clustered
• Arrow showing parent-to-child transmission of A.a.
• Label: "Familial aggregation - primary feature of AgP"

9. Comparison Diagram: LAP vs. GAP vs. Chronic Periodontitis

10. Radiographic Bone Loss Pattern - Horizontal vs. Arc-Shaped vs. Vertical

• Chronic Periodontitis: Horizontal bone loss pattern
• LAP: Arc-shaped (angular) vertical bone loss at first molars/incisors
• GAP: Generalized severe bone loss, variable pattern
• Label CEJ, alveolar crest, depth of destruction

11. Antibody Response Diagram: LAP vs. GAP

• LAP: High IgG2 serum antibody titer (protective - explains localization/"burnout")
• GAP: Low/poor antibody response (explains spread and severity)
• Show IgG2 = specific to A.a. antigens
• Label: "Burnout phenomenon" in LAP due to antibody surge

12. Treatment Protocol Flowchart for Aggressive Periodontitis

Step 1: Supragingival plaque control (<25% plaque sites)
        ↓
Step 2: Subgingival scaling & root planing (completed within 24-48 hrs)
        ↓
Step 3: Systemic antibiotics - Metronidazole 500mg TID + Amoxicillin 500mg TID × 7 days
        ↓
Step 4: Chlorhexidine rinses
        ↓
Step 5: Re-evaluation at 6-8 weeks
        ↓
Surgical intervention if needed (Modified Widman Flap / Osseous surgery)
        ↓
Maintenance / Supportive Periodontal Therapy

🟡 TIER 3 - Moderately Important

13. Role of Cytokines in AgP Tissue Destruction

• Monocyte/macrophage in center
• Arrows showing release of: PGE2, IL-1α, IL-1β, TNF-α
• These cytokines activating osteoclasts → bone resorption
• Note: "Hyper-responsive monocyte/macrophage phenotype"

14. Cementum Pathology in LAP (Hypoplastic/Aplastic Cementum)

• Cross-section of tooth root
• Normal tooth: intact cementum layer
• LAP tooth: thin/absent cementum (hypoplastic) especially at cervical region
• Arrow showing bacterial colonization facilitated by cementum defect
• Label: "Lindskog & Blomlöf finding"

15. "Burnout" / Self-Arresting Mechanism in LAP

A.a. colonizes first molar/incisor
→ Host immune response activated
→ IgG2 opsonic antibodies produced (robust)
→ Antibodies control bacterial spread
→ Burnout/self-arresting of lesion
→ No further sites colonized
(3 proposed mechanisms: opsonic Ab, antagonistic bacteria, loss of leukotoxin production)

📋 Quick Summary Table for Revision