epidemiology of oral diseases

epidemiology of oral diseases

1. Epidemiology of Oral Diseases Dr. Hala Ben Ghasheer DrDPH , MCOH, MDSc , BDS

2. Introduction : Oral diseases are among the most prevalent diseases globally and have serious health and economic burdens , greatly reducing quality of life for those affected. The most prevalent and consequential oral diseases globally are dental caries , periodontal disease , tooth loss , and cancers of the lips and oral cavity. Although oral diseases are largely preventable , they persist with high prevalence , reflecting widespread social and economic inequalities and inadequate funding for prevention and treatment, particularly in low-income and middle-income countries (LMICs) In other words oral conditions are chronic and strongly socially patterned since in many LMICs, oral diseases remain largely untreated because the treatment costs exceed available resources.

3. Global epidemiological overview of oral diseases: According to the Global Burden of Disease (GBD) 2015 study, around 3·5 billion people worldwide live with dental conditions, predominantly untreated dental caries in the deciduous and permanent dentitions, severe periodontal disease, edentulism (complete tooth loss), and severe tooth loss. ( Kassebaum et al. , 2017) According to the International Agency for Research on Cancer, lip and oral cavity cancers were among the top 15 most common cancers in the world in 2018. (Bray et al. , 2018)

4. 1. Dental Caries Agent: Microorganisms. 2 . Host: Personal and tooth risk factors . 3 . Environment: Dietary, and oral hygiene related risk factors . In addition, a 4th factor time , must be considered . It is a multifactorial disease in which the following risk factors play role in its causation process:

5. Agent Environment Host 1-Streptococcus mutans. 2- Lactobacilli . 3- Actinomyces. 1-Flouride . 2-Diet. 3-Social factors. 1-Age. 2- Gender. 3- Race . 4- Genetic & familial. 5- Role of saliva . 6-Systemic diseases and drugs. 7-Nutrition.

6. If the pH in the biofilm falls below a critical threshold for a sustained period following the consumption of free sugars, the result is progressive demineralization and sustained loss of calcium and phosphate from the mineral substance of the tooth. In the very early (subclinical) stages, and even once sufficient mineral is lost for the lesion to appear clinically as a white spot on the tooth surface, caries can be reversed or arrested , especially with exposure to fluoride (Pitts et al. , 2017 ). If caries progresses and leads to cavitation , it is the usual criterion for caries detection in most epidemiological studies worldwide. In this condition considerable pain and discomfort may be resulted and if it spreads to the dental pulp, can also cause infection, and ultimately sepsis and tooth loss.

7. High prevalence in developed countries & higher socioeconomic group. Current global distribution: During most of the 20th century, dental caries pattern was: Low prevalence in developing countries with less economic development. “Caries was referred to as a disease of civilization."

8. 2. Diet low in fermentable carbohydrates in developing countries surviving on farming & hunting. Explanation of this pattern is : 1. High level of consumption of refined carbohydrates in developed countries.

9. 1- Sharp rising in caries prevalence and severity in most developing countries especially urban areas. By the late 20th century, caries pattern changing in two ways: 2- Marked reduction among children & young adults in developed countries.

10. The decline of caries is attributed to : 1. Use of fluoridated tooth paste and fluoridation of water supplies . 2. The use of fissure sealants. 3. Implementation of preventive programs. 4. Better access to health care. 5. Better living conditions. 6. Change of sugar consumption.

11. Between 1990 and 2010: the global age-standardized prevalence remained stable at around 35%. Prevalence peaked in 1990 and 2010; the largest peak was at age 25 years and a smaller peak occurred at around age 70 years, probably explained by increased root caries . In 2010: Untreated caries in deciduous teeth was the 10 th most prevalent health condition, affecting 9% of the global child population .( Marcenes et al. , 2013) Untreated caries in permanent teeth was the most prevalent health condition affecting 35% of the global population , or 2·4 billion people worldwide.

12. In 2015: The prevalence of untreated caries in deciduous teeth was 7·8%. Untreated caries in deciduous teeth peaked among children aged 1–4 years. Untreated caries in the permanent dentition remained the most common health condition globally (34·1%). The peak prevalence of untreated dental caries in the permanent dentition was seen in the younger age group of 15–19 years.

13. In 2017: Only a 4% decrease in the number of prevalent cases of untreated dental caries occurred globally from 1990 (31 407 cases per 100 000) to 2017 (30 129 cases per 100 000). Overall, the global burden of untreated dental caries for primary and permanent dentition has remained relatively unchanged over the past 30 years , challenging the conventional view that the burden of dental caries has generally improved.

14. Demographic risk factor : An attribute or exposure that increase probability of disease occurrence that can not be modified . Age Gender Race and ethnicity Socio-economic status Familial and genetic distribution

15. Age : Previously caries was considered " essentially a disease of childhood ". With the advent of better preventive measures like use of fluorides, maintenance of oral hygiene, etc , more and more younger people are reaching adulthood with many caries free surfaces, and hence caries is becoming a   life time disease . The mean DMFT scores increase with age. Children → restoration Adult → missing

16. Gender : Many studies have shown higher caries experience in girls than boys. (DMFT in females higher than males) Increased susceptibility may be due to : Early eruption of teeth in females. Increased fondness towards sweets among girls due to hormonal changes. Root caries is more prevalent in males

17. Race and Ethnicity : Certain races enjoy high degree of resistance to caries . Non-European races such as African and Asian enjoyed freedom from caries than Europeans . These beliefs have faded as evidence suggests that these differences are more due to environmental factors than inherent racial  attributes. Moreover , certain groups, once thought to be resistant to caries became susceptible when they moved area with different cultural and dietary pattern.

18. S ocio-Economic Status (SES ) : SES is inversely related to the status of many diseases . Low SES have higher values of Decayed and Missing but low values of Filled teeth. Fluoride reduce disparities.

19. Familial and Genetic Distribution: “GOOD OR BAD TEETH RUN IN THE FAMILY“ Family studies have shown that offspring have the same score as parents and this happens due to transmission of dietary and oral hygiene habits through family . Studies suggest that genetically determined factors such as tooth morphology and occlusion, may play a significant role in determining  caries rate. Bacterial transmission.

20. Periodontal Diseases: Periodontal diseases are chronic inflammatory conditions that affect the tissues surrounding and supporting the teeth. Initially, periodontal disease presents as gingivitis, a reversible inflammation of the periodontal soft tissues resulting in gingival bleeding and swelling. In susceptible individuals with a compromised immune response, gingivitis might lead to periodontitis, which progressively destroys the periodontal tissue support, including the bone surrounding the teeth (Chapple, 2014). It is characterized by this loss of periodontal tissue support, manifesting as clinical attachment loss, the presence of periodontal pocketing, gingival bleeding, and radiographically assessed alveolar bone loss.

21. The main cause of periodontal disease is poor oral hygiene leading to an accumulation of pathogenic microbial biofilm ( plaque ) at and below the gingival margin Tonetti et al. , 2017) Tobacco use is also an important independent risk factor for periodontal disease. Through the sharing of a common inflammatory pathway, periodontal disease is associated with other chronic diseases including diabetes, cardiovascular diseases, and dementia (Lockhart et al. , 2012; Daly et al. , 2017) Periodontitis can ultimately lead to tooth loss and negatively affects chewing function, aesthetics, and quality of life.

22. Periodontal Diseases: Case definition of periodontal disease in epidemiological studies is a challenge, but is generally based on measures of probing periodontal pocket depth and clinical attachment loss. In 2010: Severe periodontitis was the sixth-most prevalent health condition, affecting 10·8% of people, or 743 million, worldwide. The global age-standardized prevalence and incidence have remained stable since 1990 prevalence was at 11·2 %. According to the Global Burden of Disease Study (2016), severe periodontal disease was the 11th most prevalent condition in the world with a prevalence ranging from 20% to 50 %.

23. Current model of periodontal disease : Age relationship: a more pronounced inflammatory response to the same plaque challenge has been reported in older than younger people . Smokers also appear to be at higher risk than nonsmokers of making the transition from gingiva that do not bleed on probing . Stress has also been associated with increasing IL-1 β levels . Oral contraceptive: risk factor for gingival bleeding but modern O.C. may not affect the inflammatory response of gingiva to dental plaque.

24. Squamous cell carcinoma is the most common type of oral cancer. The major risk factors for oral cancers are tobacco use, alcohol consumption, and betel quid chewing (Winn et al. , 2015) In many high-income countries (HICs), human papilloma virus ( HPV ) infection is responsible for a steep rise in the incidence of oropharyngeal cancers among young people ( Mehanna et al. , 2013) The prevalence of oral cancers is greater among Men. Older age groups. Individuals from poorer backgrounds. (Conway et al. , 2015) Oral Cancers

25. Lip and oral cavity cancers are among the top 15 most common cancers worldwide, with 500 550 incident cases in 2018. (Bray et al. , 2018). The total number of deaths due to cancer of the lip and oral cavity was 177 384 in 2018 ( 67% of deaths in males ). Data from 2018 show that oral cancer has the highest incidence among all cancers in south Asia among males, and is the leading cause of cancer-related mortality among males in India and Sri Lanka(Bray et al. , 2018 ).

26. Distribution of oral cancer lesions by Arab country.

27. Distribution of risk factors associated with oral cancer by Arab country.

28. Distribution of oral cancer histological stage at the time of diagnosis by Arab country.

29. Socioeconomic inequalities in oral health: Some studies from the past few years have highlighted causal relationships between socioeconomic status and oral health. (Matsuyama et al. , 2017). A 2015 systematic review assessed the association between socioeconomic position and caries experience in 155 studies involving a total of 329 798 participants. Lower Socioeconomic position was also significantly associated with having untreated caries lesions.( Schwendicke et al. , 2015)

30. (Costa et al. (2018 ) identified associations between poor socioeconomic status and severe dental caries among adults in highly developed countries; an increase in one unit of socioeconomic status level was associated with an increase in 10·35 DMFT score units. Klinge and Norlund (2005 ) identified that disadvantagde socioeconomic circumstances were associated with poor periodontal health, even after controlling for smoking, a well known risk factor for periodontal disease. Conway et al. (2008 ) showed a consistent association between low socioeconomic status and oral cancer in both LMICs and HICs, even after adjustment for behavioral confounders. Poulton et al . ,(2002): With increasing socioeconomic status, the amount of poor oral health indicators decreased. Low adult socioeconomic status had a significant effect on poor adult dental health.

31. Marginalized groups and disability: Extreme oral health inequalities exist for the most marginalized and socially excluded groups in societies, such as homeless people, prisoners, those with long term disabilities, refugees, and indigenous groups (Aldridge et al. , 2018) Homeless people living in HICs have more untreated dental caries, more severe tooth loss, and are more likely to experience toothache than the general population. Prisoners also have very poor oral health. The situation for homeless people and prisoners in low-income countries is less documented.