Oral diseases are among the most prevalent diseases globally and have serious health and economic burdens, depriving people of health, wellbeing, and the ability to achieve their full potential. By virtue of their high prevalence, the most consequential oral diseases affecting global health are: dental caries, periodontal disease, tooth loss, and cancers of the lips and oral cavity. In this first of two papers, we describe the scope of the global oral disease epidemic, describe its origins in social and commercial determinants, and its costs in terms of human suffering and societal impact. Even though oral diseases are largely preventable, they persist with high prevalence as a reflection of pervasive social and economic inequalities, along with inadequate funding for prevention and treatment, particularly in low and middleincome countries (LMIC). As with most non-communicable diseases (NCDs), oral conditions are chronic and strongly socially patterned. Poor children, socially marginalised groups, and older people suffer the most from oral diseases and have more limited access to dental care. In many LMIC oral diseases remain largely untreated as the treatment costs exceed available resources. The personal consequences of chronic untreated oral diseases are often severe and include unremitting pain, sepsis, reduced quality of life, lost school days, family disruption, and decreased work productivity. The societal costs of treating oral diseases are a very high economic burden to families and the health care system. Oral diseases are truly a global public health problem with particular concern over rising prevalence in many LMIC linked to wider social, economic and commercial changes. By describing the extent and consequences of oral diseases, their roots in social and commercial determinants, and their ongoing neglect in global health policy, we aim to highlight the urgency of addressing oral diseases as a global health and NCD priority. 4 Key messages  Oral health is an integral element of overall health and wellbeing enabling individuals to perform essential daily functions.  Oral diseases include a range of chronic clinical conditions that affect the teeth and mouth including dental caries (tooth decay), periodontal (gum) disease and oral cancers.  Despite being largely preventable, oral diseases are highly prevalent conditions affecting over 3.5 billion people around the world, with dental caries being the most common disease globally with increasing prevalence in many low and middle-income countries (LMIC)  Oral diseases disproportionally affect poorer and marginalised groups in society being very closely linked to socioeconomic status and the broader social determinants of health.  Oral diseases have a significant impact causing pain, sepsis, reduced quality of life, lost school days, family disruption, decreased work productivity, and the costs of dental treatment can be considerable for both individuals, and the wider health care system.  Oral conditions share common risks with other non-communicabl...

75Oral diseases are a major global public health problem affecting over 3.5 billion people. 76Dentistry however has failed to tackle this problem. A fundamentally different approach is 77 now needed. In this second paper on oral health, we present a critique of dentistry 78 highlighting its key limitations and the urgent need for system reform. In high-income 79 countries (HIC) the current treatment-dominated, increasingly high-tech, interventionist and 80 specialised approach, is failing to tackle the underlying causes of disease and is not 81 addressing oral health inequalities. In low-and middle-income countries (LMIC) the 82 limitations of "westernised" dentistry are most acutedentistry is often unavailable, 83 unaffordable and inappropriate to the majority of these populations, but particularly the rural 84 poor. Rather than being isolated and separated from the mainstream health care system, 85 dentistry needs to be more integrated with primary care services in particular. The global 86 drive for universal health coverage (UHC) provides an ideal opportunity for this. Dental care 87 systems should focus more on promoting and maintaining oral health and achieving greater 88 oral health equity, rather than the interventionist treatment approach that currently dominates. 89Sugar, alcohol and tobacco use and their driving social and commercial determinants are the 90 underlying causes of oral diseases, common risks shared with a range of other non-91 communicable diseases (NCDs). Coherent and comprehensive regulation and legislation is 92 needed to tackle these shared risk factors. In this paper we focus on the need to reduce sugars 93 consumption through the adoption of a range of upstream policies designed to combat the 94 corporate strategies used by the global sugar industry to promote sugar consumption and 95 profits. At present the sugar industry is influencing dental research, oral health policy and 96 professional organisations through its well-developed corporate strategies. There is a pressing 97 need to develop clearer and more transparent conflict of interest policies and procedures to 98 limit and clarify the influence of the sugar industry on research, policy and practice. 99

Oral health inequalities associated with socioeconomic status are widely observed but may depend on the way that both oral health and socioeconomic status are measured. Our aim was to investigate inequalities using diverse indicators of oral health and 4 socioeconomic determinants, in the context of age and cohort. Multiple linear or logistic regressions were estimated for 7 oral health measures representing very different outcomes (2 caries prevalence measures, decayed/missing/filled teeth, 6-mm pockets, number of teeth, anterior spaces, and excellent oral health) against 4 socioeconomic measures (income, education, Index of Multiple Deprivation, and occupational social class) for adults aged ≥21 y in the 2009 UK Adult Dental Health Survey data set. Confounders were adjusted and marginal effects calculated. The results showed highly variable relationships for the different combinations of variables and that age group was critical, with different relationships at different ages. There were significant income inequalities in caries prevalence in the youngest age group, marginal effects of 0.10 to 0.18, representing a 10- to 18-percentage point increase in the probability of caries between the wealthiest and every other quintile, but there was not a clear gradient across the quintiles. With number of teeth as an outcome, there were significant income gradients after adjustment in older groups, up to 4.5 teeth (95% confidence interval, 2.2-6.8) between richest and poorest but none for the younger groups. For periodontal disease, income inequalities were mediated by other socioeconomic variables and smoking, while for anterior spaces, the relationships were age dependent and complex. In conclusion, oral health inequalities manifest in different ways in different age groups, representing age and cohort effects. Income sometimes has an independent relationship, but education and area of residence are also contributory. Appropriate choices of measures in relation to age are fundamental if we are to understand and address inequalities.

Objective To assess the effects of dental health on school performance and psychosocial well-being in a nationally representative sample of children in the US. Study design We analyzed data from the 2007 National Survey of Children’s Health for 40,752– 41,988 children. The effects of dental problems and maternal-rated dental health on school performance and psychosocial well-being outcomes were evaluated using regression models adjusting for demographic, socioeconomic, and health characteristics. Results Dental problems were significantly associated with reductions in school performance and psychosocial well-being. Children with dental problems were more likely to have problems at school (OR=1.52; 95% CI: 1.37–1.72) and to miss school (OR=1.42; 95% CI: 1.23–1.64) and were less likely to do all required homework (OR=0.76; 95% CI: 0.68–0.85). Dental problems were associated with shyness, unhappiness, feeling of worthlessness, and reduced friendliness. The effects of dental problems on unhappiness and feeling of worthlessness were largest for adolescents between 15 and 17 years. Conclusion Preventing and treating dental problems and improving dental health may benefit child academic achievement and cognitive and psychosocial development.