[Study1] Oral Health and General Health - What are the connections?

General idea

Oral health is associated with general health especially

• Periodontitis & systemic inflammation

Association ≠ Causation

Association

• People with A are more likely to have B

Causation

• A directly causes B

Father of medicine

Hippocrates

• Extraction of tooth and cure of arthritis — Earliest link between oral and systemic condition

William Hunter

Developed theory of focal infection (20th century)

• Suggests that oral infections (teeth) can cause systemic diseases elsewhere in the body (arthritis, gastro-intestinal problems etc)

• Resulted in wholesale removal of teeth in an attempt to treat various coditions

  • 71% people 55+ were edentulous (lacking teeth)

• No clinical studies supported the theory → abeyance (state of suspension)

• Improved understanding of periodontal disease → linked to cardiovascular, diabetes etc made theory fall out of favor

Periodontitis

Inflammatory disease — by bacteria causes tooth loss, masticatory dysfunction

• Association between periodontitis & systemic conditions (common factor = inflammation)

Evidence of periodontal disease and systemic conditions

Plausibility

• Biological factor

• Periodontitis increases inflammation

  • Bacteria enters circulation during speech, eating, brushing

  • Activates acute-phase response (defense) and stimulates neutrophils — generates oxidative stress

  • Bacteria is not problem — inflammation is the problem

Epidemiological data

• Researchers look at populations and determine whether 2 conditions occur together more frequently

• Does not prove causation tho

Intervention studies

• Researchers try to intervene/ treat 1 condition and see if the other condition improves

Periodontitis and diabetes

Plausibility

• Bacteria enters blood stream — cause systemic infection

• Damages pacreatic beta cells, apoptosis, and increase insulin resistance

Epidemiological data

• Severe periodontitis → greater problem with glycemic control

• Raises blood sugar levels in non diabetic

Intervention studies

• Periodontal therapy = moderate reduction in HbA1c at 3 months (blood sugar levels)

• BUT non-surgical periodontal treatment - didn’t improve glyemic control in type 2 diabetes with chronic periodontitis

Periodontitis and Cardiovascular disease

Plausibility

• Oral bacteria triggers infllamatory immune response that promote artery plaque build up (atheroma formation)

Epidemiological data

• Periodontitis increase risk for future cardiovascular diseases

Intervention studies

• Periodontal treatment

  • Reduced C reactive proteins (CRP)

  • Oxidative stress

Periodontitis and pregnancy

Plausibility

• Bacteria enter bloodstream

• Reach fetal environment

• Triggers inflammation/ immune response

• Affect fetoplacental unit

Epidemiological data

• Looked at periodontitis w/ low birth weight, preterm birth, preeclampsia

• No association for some

Intervention studies

• Periodontal treatment

  • During pregnancy did not significantly improve pregnancy outcomes (preterm birth, low birth weight)

  • Other factors: Study type, timing, patient selected

Periodontitis and other diseases

Periodontitis may be associated with COPD, kidney disease, RA, obesity, cognitive impairment, cancer

• Associate ≠ causation

BUT

• Evidence of oral biofilm = reservoir for respiratory pathogens

• Result = Nosocomial pneumonia (hospital acquired pneumonia)

Caries and other diseases

Caries - also disease can produce inflammation (apical periodontitis)

Summary

Topic	What to remember
Main theme	Oral health is connected to general health
Main disease discussed	Periodontitis
Central mechanism	Inflammation
Periodontitis	Chronic, multifactorial inflammatory disease initiated by bacteria
Focal infection theory	Old theory linking oral infection to systemic disease; ultimately discredited
Scientific evidence	Plausibility → epidemiology → intervention studies
Diabetes	Periodontitis associated with poorer glycemic control and diabetes complications
HbA1c	Some studies show improvement after periodontal treatment; a large RCT did not show improved glycemic control
Cardiovascular disease	Periodontitis associated with increased cardiovascular risk; inflammation is an important mechanism
CRP	Periodontal treatment has moderate evidence for reducing systemic inflammation/CRP
Pregnancy	Periodontitis associated with preterm birth, low birth weight, preeclampsia
Pregnancy treatment	Treatment has not consistently been shown to prevent adverse pregnancy outcomes
Other associations	COPD, CKD, rheumatoid arthritis, cognitive impairment, obesity, metabolic syndrome, some cancers
Nosocomial pneumonia	Oral biofilm can serve as a reservoir for respiratory pathogens in high-risk hospital patients
Caries	Can cause apical periodontitis and potentially serious acute systemic complications
Ludwig's angina	Associated with periapical infection from dental caries
Main clinical message	Prevent, diagnose early, and effectively treat periodontal disease