How common are oral diseases?

Oral diseases collectively affect approximately 3.5 billion people — more than any other health condition globally. Untreated dental caries in permanent teeth affects 2.5 billion people; severe periodontitis affects approximately 1 billion; untreated caries in primary (baby) teeth affects 530 million children. Oral diseases cause enormous suffering, lost productivity and high out-of-pocket costs, yet remain severely under-resourced in public health systems.

What causes dental caries (tooth decay)?

Dental caries is caused by acid produced when bacteria (primarily Streptococcus mutans) in the mouth ferment dietary sugars. The acid demineralises tooth enamel and dentine, creating cavities. Free sugars — sucrose, glucose, fructose — are the primary substrate. Frequency of sugar consumption matters more than total amount. Prevention: fluoride toothpaste, reduced sugar intake, regular brushing, dental sealants and professional fluoride applications.

How does fluoride prevent tooth decay?

Fluoride is incorporated into enamel during tooth formation (systemic fluoride) and promotes remineralisation after acid attack (topical fluoride from toothpaste and water). It also inhibits the enzymes used by cariogenic bacteria. Water fluoridation (0.5-1.0 mg/L) reduces caries by 20-40% at a population level. Fluoride toothpaste (1,000+ ppm) is the most cost-effective preventive intervention; universal availability at affordable prices is a global oral health priority.

What is periodontitis and how is it linked to general health?

Periodontitis is an inflammatory disease of the tissues supporting the teeth, caused by bacterial biofilm (dental plaque). It causes gum recession, bone loss and eventually tooth loss. Severe periodontitis affects approximately 1 billion people. The link with systemic health is now well-established: diabetes and periodontitis are bidirectionally linked — each worsens the other. Periodontitis is also independently associated with cardiovascular disease (possibly through bacteraemia and systemic inflammation), adverse pregnancy outcomes and respiratory disease.

What is oral cancer and what causes it?

Oral cancer includes malignancies of the lip, tongue, gum, floor of mouth, palate and cheek (oral cavity cancers) and the oropharynx. Over 380,000 new cases occur per year. Tobacco (all forms) and alcohol are the dominant risk factors for oral cavity cancers, acting synergistically. HPV (particularly HPV-16) is now the leading cause of oropharyngeal cancers (tonsil, base of tongue) in high-income countries — and HPV vaccination of adolescents is reducing their incidence. Late diagnosis is common because early oral cancers are often painless.

Why is dentistry excluded from most health systems?

Historically, dentistry developed separately from medicine — with different professional training, regulation and financing. In most countries, dental care is financed out-of-pocket or through voluntary insurance, not through public health systems. This exclusion reflects a false distinction between oral health and general health. The result is that dental treatment is the most common unmet healthcare need in many high-income countries, and tooth decay is the most prevalent untreated disease globally. WHO's Global Oral Health Action Plan 2023-2030 specifically calls for integration of oral health into UHC.

What is the WHO Global Oral Health Action Plan 2023-2030?

Endorsed by WHA75 in 2022, the WHO Global Oral Health Action Plan 2023-2030 sets out the international framework for transforming oral health. Key targets: 100% of countries with a national oral health plan; coverage of essential oral health services for at least 80% of population; all countries with oral health integrated into UHC schemes. Priorities include oral health promotion, primary prevention, integrating oral health into NCD and other health programmes, and the oral health workforce.

How does sugar reduction improve oral health?

Free sugars (sucrose, glucose, fructose, honey, syrups) are the primary substrate for cariogenic bacteria. WHO recommends reducing free sugar intake to less than 10% of total energy intake, and ideally below 5%. Countries that have implemented sugar taxes and marketing restrictions on sugary drinks and foods have seen measurable improvements in dental caries rates, particularly in children. School-based interventions limiting sugar availability and promoting water consumption are evidence-based strategies.

What is early childhood caries?

Early childhood caries (ECC) — formerly called "bottle caries" or "nursing caries" — is dental decay in children below age 6, defined as one or more decayed, missing or filled primary teeth. It is one of the most common chronic childhood diseases globally. It is caused by frequent exposure to fermentable carbohydrates (formula with sugar, juice, sweetened drinks) particularly during sleep, combined with poor oral hygiene and inadequate fluoride exposure. ECC causes pain, infection, sleep disruption, poor nutrition and school absenteeism.

Can oral health affect pregnancy?

Yes — periodontitis during pregnancy is associated with preterm birth and low birth weight, though causality is complex. Hormonal changes in pregnancy can worsen periodontitis. Additionally, cariogenic bacteria can be transmitted from mother to child through shared utensils or kissing, establishing early S. mutans colonisation in infants. Oral health care during pregnancy — including dental scaling and treatment of active disease — is safe and recommended.

What is the role of HPV vaccination in oral cancer prevention?

HPV (particularly HPV-16) is now the leading cause of oropharyngeal cancers — cancers of the back of the throat, tonsils and base of the tongue — in high-income countries. These cancers are increasing rapidly, particularly in younger men. The HPV vaccine (Gardasil 9) is highly effective at preventing HPV-16 infection and its associated cancers, including oropharyngeal cancers. WHO's cervical cancer elimination strategy (90-70-90) — while targeting cervical cancer — will also reduce HPV-related oropharyngeal, vulvar, penile and anal cancers.

How does GMJ News cover oral health?

GMJ News covers WHO Global Oral Health Action Plan developments, periodontitis-systemic disease research, oral cancer epidemiology, fluoride evidence and sugar reduction policy. Oral health integration into UHC is directly relevant to PHIG's health system and accreditation work. The Georgian Medical Journal covers oral health in Georgia — where dental caries and periodontitis remain significant public health burdens with inadequate public coverage.

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Oral Health

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Oral diseases are the most widespread noncommunicable diseases on the planet, affecting an estimated 3.5 billion people — nearly half of humanity — led by untreated dental caries, severe periodontal disease and tooth loss (WHO Global Oral Health Status Report 2022). Three-quarters of those affected live in low- and middle-income countries, where care is often unavailable or unaffordable; oral cancers add hundreds of thousands of cases a year, strongly linked to tobacco, alcohol and areca nut. The WHO Global Strategy and Action Plan on Oral Health 2023–2030 aims to integrate oral care into universal health coverage — moving a field long left to private markets back into public health.

Primary sources: WHO fact sheet — Oral health · WHO Global Oral Health Status Report 2022

Key messages

Most prevalent condition

Oral diseases affect approximately 3.5 billion people globally — making them collectively the most prevalent health conditions in the world. Untreated dental caries (tooth decay) in permanent teeth is the most prevalent condition in the GBD study.

Neglected public health issue

Oral health has been described by WHO as a "neglected epidemic." Despite the universal nature of oral diseases, dentistry is often excluded from national health insurance schemes, and oral health receives less than 1% of development aid for health.

General health link

Oral health is profoundly linked to general health. Periodontitis (gum disease) is associated with diabetes (bidirectional), cardiovascular disease, adverse pregnancy outcomes and respiratory infections. Oral bacteria can enter the bloodstream and affect distant organs.

Prevention is possible

The main oral diseases — caries, periodontitis and oral cancer — are largely preventable. Fluoride (water fluoridation, fluoride toothpaste), dietary sugar reduction, smoking cessation and early HPV vaccination substantially reduce the burden.

WHO 2030 Strategy

The WHO Global Oral Health Action Plan 2023-2030, endorsed by WHA75, provides the international framework — targeting 100% of countries with national oral health plans, integration of oral health into universal health coverage, and a global commitment to tackle the neglected epidemic.

Oral cancer

Oral cancer — cancers of the lip, tongue, gum, floor of mouth, palate and oropharynx — causes over 380,000 new cases and 190,000 deaths per year. HPV (particularly HPV-16) is the leading cause of oropharyngeal cancers in high-income countries. Tobacco and alcohol are the main risk factors for oral cavity cancers.

Key statistics

3.5B

people affected by oral diseases

WHO 2023

2.5B

with untreated caries in permanent teeth

GBD 2019

with severe periodontitis

GBD 2019

380K

new oral cancer cases/year

IARC 2022

<1%

of health development aid goes to oral health

WHO

2023-2030

WHO Global Oral Health Action Plan period

WHA75

Global burden of oral diseases by condition — GBD 2019 (millions affected)

Source: Global Burden of Disease 2019. Oral diseases collectively affect more people than any other health condition.

Glossary of key terms

Dental caries
WHO/FDIThe most prevalent non-communicable disease globally — caused by acid produced by bacteria (Streptococcus mutans) that ferment dietary sugars, demineralising tooth enamel and dentine. Prevention: fluoride, sugar reduction, oral hygiene.

Periodontitis
WHO/EFPInflammatory disease of the supporting structures of the teeth (periodontal ligament, alveolar bone) — caused by bacterial biofilm (plaque). Severe periodontitis affects approximately 1 billion people and is independently associated with diabetes, CVD and adverse pregnancy outcomes.

Fluoride
WHOThe most evidence-based preventive agent for dental caries. Water fluoridation (0.5-1.0 mg/L), fluoride toothpaste (1,000-1,500 ppm) and professional fluoride varnish applications all substantially reduce caries incidence. Safe at recommended levels.

Oral cancer
IARC/WHOMalignant tumours of the lip, tongue, gum, floor of mouth, palate, cheek and oropharynx. Risk factors: tobacco (all forms), alcohol, areca nut (betel), HPV (oropharyngeal cancers). Over 380,000 new cases and 190,000 deaths per year.

Early childhood caries (ECC)
WHO/AAPDThe presence of one or more decayed, missing or filled teeth in any primary tooth in a child below 6 years of age. One of the most common chronic diseases of childhood. Caused by frequent sugar-sweetened beverage consumption and inadequate oral hygiene.

Universal dental coverage
WHOAccess to essential oral health services — preventive and curative — without financial hardship, as part of universal health coverage. Most countries currently exclude dentistry from public insurance, making dental treatment the most common unmet health need in many high-income countries.