Lecture 12: Epidemiology of Oral and Dental Diseases (PDF)

Epidemiology of oral and dental diseases 29-12-2024 First semester 2024-2025 Dr.Lama Rafieh,DDS,MPH Week 12 Introduction: Oral diseases are among the most prevalent diseases globally and have serious health and economic burdens, greatly re...

Epidemiology of oral and dental diseases 29-12-2024 First semester 2024-2025 Dr.Lama Rafieh,DDS,MPH Week 12 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. Clinical Overview of oral diseases: The key clinical conditions that are considered to be global public health priorities include dental caries, periodontal disease, and oral cancers. Dental Caries: The caries process is dynamic, with alternating periods of demineralization and remineralization of the tooth structure related to fluctuations in the pH of the plaque biofilm. 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.  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. The most commonly used dental caries index is the Decayed, Missing and Filled Teeth (DMFT) index, which counts the number of decayed, missing, and filled teeth resulting from dental caries (with lowercase letters representing primary dentition and capital letters representing permanent dentition). 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 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.  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. 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 In older adults, periodontal disease has been causally linked with aspiration pneumonia, which often results in serious morbidity and mortality. Periodontitis can ultimately lead to tooth loss and negatively affects chewing function, aesthetics, and quality of life. Oral cancers More than 90% of the oral cancers are oral squamous cell carcinoma. Oral cancer may present as an innocuous white/red patch, a small ulcerated lesion with or without pain, a large fungating ulcer that may include a super-added infection, and as indurated lesions of various sizes.  Squamous cell carcinoma is the most common type of oral cancer. The major risk factors for oral cancers are tobacco use, alcohol consumption, and areca nut (betel quid) chewing In many high-income countries (HICs), human papilloma virus infection is responsible for a steep rise in the incidence of oropharyngeal cancers among young people. The prevalence of oral cancers is greater among 1. Men. 2. Older age groups. 3. Individuals from poorer backgrounds. The important epidemiological characteristics of oral cancer that stand out are oral cancer is mainly a disease of older people and is a public health problem there exists a significant racial/ethnic disparity in oral cancer disease burden and outcomes there occurs a significant delay between its clinical presentation and final Diagnosis : the worldwide 5-year relative survival rate from oral cancer is generally less than 50%, although women tend to have a higher relative survival rate than men.  Oral cavity carcinoma is the sixth most common cancer and is often detected in later stages. Oral squamous cell carcinoma (SCC), the predominant type of cancer found in the oral cavity, is a disfiguring and deadly cancer. 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. 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. Dental Caries: Epidemiological evidence indicates that lifetime prevalence of dental caries has decreased in the past four decades, but this is mainly in HICs In 2010: 1. untreated caries in deciduous teeth was the 10th most prevalent health condition, affecting 9% of the global child population.(Marcenes et al., 2013) 2. Untreated caries in permanent teeth was the most prevalent health condition affecting 35% of the global population, or 2·4 billion people worldwide. Between 1990 and 2010: 1. the global age-standardized prevalence remained stable at around 35%. 2. Prevalence reached 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 2015: 1. The prevalence of untreated caries in deciduous teeth was 7·8%. 2. Untreated caries in deciduous teeth peaked among children aged 1–4 years. 3. Untreated caries in the permanent dentition remained the most common health condition globally (34·1%). 4. The peak prevalence of untreated dental caries in the permanent dentition was seen in the younger age group of 15–19 years.  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). The global distribution and intercountry variations in prevalence changed marginally during this period. 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. 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. Tooth Loss Tooth loss reflects the endpoint of a lifetime of dental disease usually dental caries or periodontal diseases. In 2010: 158 million people, or 2·3% of the global population, were completely edentulous. Prevalence of severe tooth loss reduced between 1990 and 2010, declining from 4·4% to 2·4%. Oral Cancer: Lip and oral cavity cancers are among the top 15 most common cancers worldwide, with 500 550 incident cases in 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). Socioeconomic inequalities in oral health: Some studies from the past few years have highlighted causal relationships between socioeconomic status and oral health. A 2015 systematic review assessed the association between socioeconomic position and caries experience in 155 studies involving a total of 329 798 participants. The association between low educational background and having experienced caries was significantly higher in countries with high Human Development Index scores (>0·8) relative to countries with low index scores. Lower Socioeconomic position was also significantly associated with having untreated caries lesions or any caries experience.  (Costa et al., 2018) identified associations between poor socioeconomic status and severe dental caries among adults in highly developed countries (Klinge and Norlund, 2005) identified that poor 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 (Poulton et al., 2002) 1. With increasing socioeconomic status, the amount of poor oral health indicators decreased. 2. Low adult socioeconomic status had a significant effect on poor adult dental health. 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, which serves as a classic example of a so-called cliff-edge of inequality.(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. Mean number of decayed teeth among male adults aged 16–65 years in England, Wales, and Northern Ireland in 2009 Effects of oral diseases on individuals, families and society: Economic burden of oral diseases: Dental diseases impose a substantial economic burden on society Worldwide in 2015, dental diseases accounted for USD 356·80 billion in direct costs (treatment expenditures), and US$187·61 billion in indirect costs (productivity losses due to absence from work and school). Dental diseases might also exacerbate the burden of other diseases and thereby contribute to the economic burden of these conditions. For example, periodontal disease has been linked to poor glycemic control among diabetes patients. For such patients, periodontal treatment has been shown to reduce total and diabetes related health-care costs Children: The prevalence of dental pain ranged from 5% to 33%, and increased with child age, caries severity, and decreasing socioeconomic status. Dental problems can result in lost time from school and have a negative effect on school performance, possibly exacerbating social inequalities. Dental caries and associated oral problems substantially decrease quality of life for the child and their caregivers. For young children with extensive dental caries, treatment under general anesthesia is often the only realistic approach. Such care is expensive varied between over USD 5500 (in 2008) and USD7303 (in 2012) per child, and usually only viable in HICs. Adults: Many adults have poor access to dental care, which means they also have to cope with acute and chronic dental pain and diminished quality of life.  In many countries, access to dental care for adults is often challenging, as the financing and care delivery models are often more restricted. The result is that many patients wait until their dental problems become painful, or serious infections develop, which then drives them into hospital emergency departments for urgent care. In the USA, a 16% increase in emergency department visits for dental conditions occurred between 2006 and 2009, with nearly 1 million patient visits in 2009. Unfortunately, emergency departments are usually not equipped to address oral problems other than orofacial trauma, and thus services are limited to palliative measures  A nationwide study done in Canada found that dental-related issues resulted in an average of 3·5 hours of lost working time per person per year, adding to a national total of 40 million lost work hours, which they estimated led to a productivity loss of over CAN$1 billion. A nationally representative study of employed adults in Australia found that 9% of employed people missed one or more half days in a year due to dental problems, with lost productivity costs of AUS$660 million. In a regional survey of working adults in Brazil, reported that orofacial pain led to 15% of respondents being absent from work in the 6 months prior to the survey. Older Adults: Adults in many HICs are retaining more of their natural dentition as they age. Although this outcome is desirable, many o the teeth now being retained into older age (over 65 years) have longstanding dental restorations and, in most older adults, have some degree of advanced periodontal disease. This rise in tooth retention into older age has led to an increased need for more complex restorative care for a growing number of older adults.  Reduced mobility and transportation difficulties associated with older age are adding to the challenge of accessing oral health care. The result tends to be lower dental service use among older people, leading to an accumulation of untreated dental conditions or a late stage disease diagnosis and, thus, a poor prognosis. Poor oral health in later life has also been shown to affect social relationships and loneliness leading to poor nutrition. Social and commercial determinants of oral diseases: The WHO conceptual framework for action on the social determinants of health highlights how structural determinants, such as economic, social, and welfare policies, can generate social hierarchies and influence the socioeconomic status of individuals within societies. Socioeconomic status can then influence health through the circumstances in which people live, work, and age, and their risks for disease. These intermediate determinants include housing and working conditions, social capital, psychosocial factors such as stress and social support, and access to health care.  Dental policy makers tend to rely on simplistic downstream interventions; in part, because of the dominance of a clinical interventionist philosophy, and because of the challenges of generating evidence of efficacy for the more complex upstream interventions. Globally, a steady overall increase has occurred in the production of sucrose, the most widely available sweetener since the 1980s. As a consequence, in many LMICs, prevalence of dental caries is increasing at the same time as reported marked increases in the consumption of sugars. Economic development in many LMICs has moved millions out of poverty, resulting in a rapid demographic and nutritional transition characterized by some adverse changes in diet, physical activity, and health. The increased availability of unhealthy consumer goods, including high-sugar foods and drinks, is shifting behaviors and contributing to the increase in NCDs.  “We cannot treat our way out of the NCD epidemic.” We agree with their view that a radically different approach is needed. Oral health in the wider context of sustainable development (Watt et al., 2019) Conclusion: Oral diseases are a major global public health problem, having both high prevalence and major negative impacts on individuals, communities, and society. Globally, over 3·5 billion people have oral diseases that are chronic and progressive in nature, starting in early childhood and progressing throughout adolescence and adulthood and into later life. Oral diseases disproportionally affect poorer and marginalized groups in society, being very closely linked to socioeconomic status and broader social and commercial determinants. Increasing consumption of free sugars particularly in LMICs is causing an increase in dental caries, as well as other NCDs such as obesity and diabetes. Therefore, dental treatment alone cannot solve this problem. A radically different approach is now needed to tackle this global health challenge.  Achieving such a convergence of efforts needs bold leadership, solid evidence of intervention effectiveness, innovative policies, and openness to an agenda of global change on all levels. As the world intensifies efforts to reach the Sustainable Development Goals within the coming decade, oral health can no longer be left behind and requires urgent and decisive action. Thank you