The problem

Oral Diseases

Oral health is fundamental to general health and well-being. Poor oral health affects quality of life as a result of pain or discomfort, tooth loss, impaired oral functioning, disfigurement, missing school time, loss of work hours and sometimes even death.

Oral diseases are among the highest prevalent health conditions in the world.
The 2017 Global Burden of Disease Study estimated that all oral diseases and conditions (untreated tooth decay, severe periodontitis, and total tooth loss and other oral health conditions) affect 3.46 billion people worldwide. Unmet demand for dental services reached approximately 3.5 billion cases in 2017.2

In 2017 Year lived with disability (YLDs), year of “healthy life” lost due to diseases or injuries, for oral conditions increased by 8% from 16.9 to 18.3 million between 2015 to 2017.2

The WHO has declared oral disease as a critical public-health problem (alongside alcohol, health and nutrition of children, food safety, tobacco use).

Oral disease is the fourth most expensive of all diseases to treat.3

Tooth Decay

Tooth decay (also called dental caries or cavities), is considered to be the most widespread of all health conditions. Nearly 100% of adults, and 60-90% of school children, have cavities.4

Untreated caries in deciduous teeth – The overall prevelance of tooth decay in deciduous teeth was almost 8% in 2017 and it reflects an overall decrease in prevelance of tooth decay by 8% from 1990 to 2017.2

In 2017, the lowest numbers of prevalent cases of tooth decay in deciduous teeth (41 million cases) were observed in high income countries and the highest in lower-middle-income countries (265 billion cases).2
Untreated caries in permanent teeth – The overall prevelance of tooth decay in permanent teeth was almost 30%in 2017 (2.3 billion cases). In 2017, the lowest number of prevalent cases were found in low-and high- income countries (1.98 billion cases, 3.86 billion cases respectively), while the highest were found in lower and upper middle-income countries (9.43 billion, 7.68 billion respectively).2

Tooth decay is the result of our diets changing faster than the evolution of our bodies and microbiome to adjust for the dietary transformation.

Free sugars are the crucial dietary factor in the development of dental caries – dental caries does not occur in the absence of dietary sugars.
 Dental caries develops when bacteria in the mouth metabolize sugars to produce acid that demineralizes the hard tissues of the teeth. 
Free sugars include all monosaccharides and disaccharides added to foods and drinks by the manufacturer, cook or consumer, and sugars naturally present in honey, syrups, fruit juices and fruit juice.
 Confectionery, cakes, biscuits, sweetened cereals, sweet desserts, sucrose, honey, syrups and preserves are common sources of free sugars. 
In many countries, sugar-sweetened beverages, including fruit-based and milk-based sweetened drinks and 100% fruit juices, are a primary source of free sugars. Unlike whole fresh fruits, fruit juices contain free sugars and also contain more calories. Importantly, chewing whole fresh fruit stimulates salivary flow that protects against demineralization of tooth substance.5

Dental caries can be prevented by avoiding dietary free sugars. Moreover, dental caries is largely preventable through simple and cost-effective population-wide and individual interventions. On the other hand, restorative treatment is costly, and is often unavailable in low- and middle-income countries. In low-income countries, the majority of dental caries goes untreated. Teeth affected by caries are often extracted (pulled out) when they cause pain or discomfort.5

Severe dental caries can impair quality of life. For example, dental caries may cause difficulties in eating and sleeping, and in its advanced stages (abscesses), it may result in pain, swelling and chronic systemic infection. Dental caries is also associated with adverse growth patterns. Further, tooth decay is a frequent cause of absence from school or work.5

Other Oral Conditions

Other preventable oral conditions (apart from tooth decay) that we address include:

Severe periodontitis – The overall prevalence of severe periodontitis was 9.8% (7.96 billion cases) in 2017. There was an overall 6% increase in the prevelance of severe periodontitis from 1990 -2017. In 2017, the lowest numbers of prevalent cases were observed in low-income countries (40 million cases) and the highest in lower-middle-income countries (3.28 billion cases). However, between 1990 and 2017, a trend was seen in the percentage change in the number of prevalent cases with the largest increase in low-income countries.2

Noma – a gangrenous lesion that affects young children living in extreme poverty primarily in Africa and Asia. Lesions are severe gingival disease followed by necrosis (premature death of cells in living tissue) of lips and chin. Many children affected by noma suffer from other infections such as measles and HIV. Without any treatment, about 90% of these children die.4

Tooth loss – The overall prevalence of tooth loss was 3.3% in 2017 (2.67 billion cases) There was an overall 10% decrease in tooth loss between 1990-2017. In 2017, the lowest numbers of prevalent cases were observed in low-income countries (8 million cases) and the highest in upper-middle-income countries (1.20 billion cases). Between 1990-2017, the percent change in age-standardized prevalence showed a decrease in tooth loss in high- and upper-middle-income countries, while an increase was observed in lower-middle- and low-income countries.4

Oral cancer – the incidence of oral cancer ranges from 1 to 10 cases per 100 000 people in most countries. The prevalence of oral cancer is relatively higher in men, older people, and among people of low education and low income. Tobacco and alcohol are major causal factors.4

Oro-dental trauma – across the world, 16-40% of children in the age range 6 to 12 years are affected by dental trauma due to unsafe playgrounds, unsafe schools, road accidents, or violence.4

India, China, Indonesia, Brazil, and United States were in the top 10 countries with the highest normative treatment need associated with all 4 dental conditions (untreated caries in deciduous teeth, permanent teeth, severe periodontitis and tooth loss).2

Other Diseases

Oral diseases have many of the same social and behavioural risk factors as other non-communicable diseases (NCDs).

Unhealthy diets are associated with coronary heart disease, type 2 diabetes, strokes, many cancers and dental caries.6

Tobacco use, for example, is linked to periodontal disease, tooth loss, and 90 % of all lung cancers.6

(Our own project in the Kalwa slums of Mumbai revealed a surprising link between tobacco and oral health – the use of chewing-tobacco (gul) to brush their teeth twice a day and as a remedy for toothache, gum infections bad breath).7

In other words, oral disease shares risk factors for the four leading chronic diseases – cardiovascular diseases, cancer, chronic respiratory diseases and diabetes – and oral diseases are often linked to chronic diseases.
The “common risk factor approach” (CRFA) to oral health promotion addresses risk factors shared with NCDs within the broader social and economic environment, while highlighting the importance of the mouth-body connection for overall health and well-being.

Focusing on the common determinants of health, community participation, partnerships with other sectors, healthy public policies and reducing health inequalities and inequities is the way to achieve improvements in oral and overall health.

What problems could poor oral health cause?


Fig 1. General health problems associated with poor oral health


With one billion people on the move or having moved in 20188, migration and global health are both defining issues of our time. In recent decades, people have suffered from conflicts, climate change, urbanization, and economic challenges, to name only a few. Some people decided to flee from these disasters, while others decided to stay. Regardless of their choices, people around the world are facing huge challenges in their lives, particularly regarding their living conditions.

  • 29% of the world’s population does not have access to clean water
  • 11% suffer from malnutrition
  • 50% has no access to basic healthcare


Living in these challenging contexts puts pressures on people especially those that are living in remote areas or that were forced to migrate. Each community has its unique challenges.

Often rural family members are separated in the quest for work in the cities. In some places HIV/AIDS has ravaged family integrity. These pressures affect the health of communities, especially among school-aged children. As a consequence, many of these children find themselves in a downward spiral in their health which began with a poor oral health status.

One of the most promising measures to address health inequities is access to health care through universal health coverage. Universal health coverage (UHC) means that all people and communities can use the promotive, preventive, curative, rehabilitative and palliative health services they need, of sufficient quality to be effective, while also ensuring that the use of these services does not expose the user to financial hardship.9 UHC cuts across all of the health-related Sustainable Development Goals (SDGs) and brings hope of better health and protection for the world’s poorest.


Significant barriers exist to ensuring people receive basic healthcare, and this is especially so with oral healthcare. Amongst these barriers are ignorance, inadequate financial resources and lack of adequate numbers of educated and trained healthcare workers. This, together with insufficient emphasis on primary prevention of oral diseases, poses a considerable challenge for several countries, particularly developing countries and countries with economies and health systems in transition.10

Despite the remarkable advancements in dentistry, millions of people around the world are excluded from scientific and technological developments. This unequal access to basic oral health care and policies is directly reflected in health problems, especially among school-aged children. The greatest burden of oral diseases lies on disadvantaged and poor populations.



Fig 2. Where we work: Unmet needs

Global inequalities in oral health, both between and within different regions and societies, undermine the fabric, productivity and quality of life of many of the worlds’ people.

Humble Smile Foundation takes these global and local challenges as an opportunity to invest in healthy lives. Investing in children and their communities, means positively contributing to a sustainable and healthy world. Furthermore, we believe the dental profession should play a leading role in a global movement to reduce social inequities and optimise health through good oral health “by shifting the focus from (i) a traditionally curative, mostly pathogenic model to a more salutogenic approach, which concentrates on prevention and promotion of good oral health and (ii) from a rather exclusive to a more inclusive approach, which takes into consideration all the stakeholders who can participate in improving the oral health of the public.11

To move forward as Dental Public Health professionals, we must be honest with ourselves and acknowledge three major concerns in the current culture of dental care on a global level:

  1. Inequitable distribution – where there is no money there is no dentistry
  2. Dental care has had little direct impact on disease
  3. Dentistry introspectively develops complex and expensive clinical, technological and restorative practices to address simple oral health issues.

The current pattern of common oral diseases reflects distinct risk profiles across countries related to:

  • living conditions
  • behavioural factors (tobacco, sugar)
  • environmental factors (clean water, sanitation, oral hygiene, fluoride)
  • oral care systems
  • implementation of schemes to prevent oral diseases


This is why Humble Smile has adopted an evidence-based, preventive and holistic approach that is culturally sensitive and politically aligned with each community according to its particular needs.

2. GBD 2017 Oral Disorders Collaborators et al. Global, Regional, and National Levels and Trends in Burden of Oral Conditions from 1990 to 2017: “A Systematic Analysis for the Global Burden of Disease 2017 Study.” Journal of dental research vol. 99,4 (2020): 362-373. doi:10.1177/0022034520908533

3. Executive Board, 120. (‎2007)‎. Oral health: action plan for promotion and integrated disease prevention. World Health Organization.

4. WHO Oral Health Information Sheet, 2012.

5. WHO Guideline on sugars intake for adults and children.

6. Sheiham A, Alexander D, Cohen L, Marinho V, Moyses S, Petersen PE, Spencer J, Watt RG, Weyant R. Global oral health inequalities: task group–implementation and delivery of oral health strategies. Adv Dent Res. 2011;23(2):259-67.

7. Devi A et al. Gabriel Smiles Project Needs Assessment. Internal document, Humble Smile Foundation, August 2018.

8. The UCL–Lancet Commission on Migration and Health: the health of a world on the move. Lancet Dec, 2018; 392: 2606–54

9. WHO What is universal coverage?. June 14, 2018

10. The Challenge of Oral Disease- A call for global action. The Oral Health Atlas. 2nd ed. Geneva: FDI World Dental Federation; 2015.

11. Glick M, Monteiro da Silva O, Seeberger GK, Xu T, et al. FDI Vision 2020: shaping the future of oral health. Int Dent J. 2012 Dec;62(6):278-91.