🏛️ Act 4 · The Referee — Risk & Classification
Slide 1 / 4

🏛️ E1 · The Referee

Risk Modifiers — The Referee Enters

Risk Modifiers
The Referee

In the war between the Villain (dysbiotic microbiome) and the Victim (host periodontium), the Referee decides who wins — and by how much. Risk modifiers do not cause disease directly; they tilt the balance, amplifying host susceptibility or microbial virulence, ultimately governing disease expression and severity.

🧬 Genetic Factors

  • IL-1 gene polymorphism
  • TNF-α variants
  • Fcγ receptor
  • HLA types

🚬 Behavioural Factors

  • Tobacco smoking
  • Smokeless tobacco
  • Alcohol use
  • Poor oral hygiene

🩺 Systemic Conditions

  • Diabetes mellitus
  • HIV/AIDS
  • Osteoporosis
  • Leukaemia

💊 Local & Environmental

  • Calculus & plaque retention
  • Overhanging restorations
  • Stress & psychosocial
  • Medications (cyclosporin)

🏛️ E2 · The Referee — Classification

1999 AAP Classification of Periodontal Diseases

1999
International Workshop

Convened by the American Academy of Periodontology. Replaced earlier 1989 classification. Introduced Chronic vs Aggressive distinction and formalised gingival disease as a separate category. Remained the standard for nearly two decades.

↙ Click any category to expand details

I Gingival Diseases
  • Dental plaque-induced gingival diseases
  • Non-plaque-induced gingival lesions
  • Gingival diseases modified by systemic factors (puberty, pregnancy, diabetes)
  • Gingival diseases modified by medications (drug-influenced enlargements)
  • Gingival diseases modified by malnutrition (ascorbic acid deficiency)
II Chronic Periodontitis
  • Localised (<30% sites affected)
  • Generalised (≥30% sites affected)
  • Severity: Slight (1–2 mm CAL), Moderate (3–4 mm), Severe (≥5 mm)
  • Associated with local predisposing factors
III Aggressive Periodontitis
  • Localised Aggressive Periodontitis (LAP) — circumpubertal onset, first molars & incisors
  • Generalised Aggressive Periodontitis (GAP) — <30 years, widespread bone loss
  • Strong familial aggregation; A. actinomycetemcomitans a key pathogen
IV Periodontitis as Manifestation of Systemic Disease
  • Associated with haematological disorders (leukaemia, neutropenia)
  • Associated with genetic disorders (Down syndrome, Papillon–Lefèvre, Chédiak–Higashi)
  • Not otherwise specified (NOS)
V Necrotising Periodontal Diseases
  • Necrotising Ulcerative Gingivitis (NUG)
  • Necrotising Ulcerative Periodontitis (NUP)
VI–VIII Abscesses · Implants · Developmental Conditions
  • VI — Abscesses of the periodontium (gingival, periodontal, pericoronal)
  • VII — Periodontitis associated with endodontic lesions
  • VIII — Developmental or acquired deformities & conditions

🏛️ E3 · The Referee — New Rules of the Game

2017 World Workshop — Staging & Grading

Jointly convened by the AAP and EFP, the 2017 World Workshop fundamentally restructured how periodontal disease is classified — shifting from descriptive categories to a multidimensional Staging & Grading framework that better reflects disease complexity, risk, and treatment planning.

1999 AAP System — Retired

Basis

Descriptive categories (Chronic, Aggressive, Systemic) based on clinical presentation alone

Severity

Slight / Moderate / Severe — based on CAL in mm

Limits

Poor correlation with actual complexity; "Chronic" vs "Aggressive" distinction not evidence-supported

Systemic Link

Addressed only as separate category; bidirectional link not emphasised

2017 World Workshop — Current Standard

Basis

Multidimensional framework addressing severity, complexity, and risk simultaneously

Staging (I–IV)

Reflects severity & complexity of management

Stage I Stage II Stage III Stage IV

Grading (A–C)

Reflects rate of progression & systemic risk modifiers

Grade A — Slow Grade B — Moderate Grade C — Rapid

New Categories Added

Peri-implant diseases (peri-implant mucositis, peri-implantitis); Periodontal Health formally defined

🏛️ E4 · The Referee — Systemic Arena

Periodontal Disease & Systemic Health

The Bidirectional Relationship (Offenbacher 1996)

Periodontitis is not an isolated oral disease. Systemic conditions worsen periodontal status, and in turn, periodontal infection exacerbates systemic diseases via bacteraemia, cytokine spillover (IL-1β, TNF-α, PGE₂), and inflammatory mediator cascades reaching distant organs.

🩸

Diabetes Mellitus

Periodontal → Systemic: Inflammatory mediators impair insulin signalling; bacteraemia raises HbA1c.

Systemic → Periodontal: Hyperglycaemia promotes AGE formation, impairs PMN function, and increases susceptibility to infection. Diabetics are 3× more likely to develop periodontitis.

True Bidirectional

❤️

Cardiovascular Disease

Proposed mechanisms: Periodontal pathogens (especially P. gingivalis) invade vascular endothelium, promote foam cell formation, and trigger atherogenesis. Elevated CRP and fibrinogen levels link both conditions.

Evidence shows periodontitis patients have ~2× increased risk of atherosclerotic CVD.

Periodontal → CVD Link

🤰

Adverse Pregnancy Outcomes

Mechanism: Periodontal bacteria and their LPS reach the foetoplacental unit via haematogenous spread. PGE₂ and IL-1β can trigger labour induction.

Offenbacher (1996) reported periodontal disease as an independent risk factor for preterm low birth weight (PLBW) — up to 7× increased risk in severe cases.

Offenbacher 1996