Epidemiology of Oral Cancer in Asia in the Past Decade- An Update (2000-2012) Oral cancer;epidemiology;incidence;mortality;socioeconomic conditions;risk factor; The prevalence of oral cancers (OC) is high in Asian countries, especially in South and Southeast Asia. Asian distinct cultural practices such as betel-quid chewing, and varying patterns of tobacco and alcohol use are important risk factors that predispose to cancer of the oral cavity. The aim of this review is to provide an update on epidemiology of OC between 2000 and 2012. A literature search for this review was conducted on Medline for articles on OC from Asian countries. Some of the articles were also hand searched using Google. High incidence rates were reported from developing nations like India, Pakistan, Bangladesh, Taiwan and Sri Lanka. While an increasing trend has been observed in Pakistan, Taiwan and Thailand, a decreasing trend is seen in Philippines and Sri Lanka. The mean age of occurrence of cancer in different parts of oral cavity is usually between 51-55 years in most countries. The tongue is the leading site among oral cancers in India. The next most common sites in Asian countries include the buccal mucosa and gingiva. The 5 year survival rate has been low for OC, despite improvements in diagnosis and treatment. Tobacco chewing, smoking and alcohol are the main reasons for the increasing incidence rates. Low socioeconomic status and diet low in nutritional value lacking vegetables and fruits contribute towards the risk. In addition, viral infections, such as HPV and poor oral hygiene, are other important risk factors. Hence, it is important to control OC by screening for early diagnosis and controlling tobacco and alcohol use. It is also necessary to have cancer surveillance at the national-level to collect and utilise data for cancer prevention and control programs.

With clinical oral examinations not always possible in health surveys, researchers may instead be invited to add questions to a wider health survey. In such situations, an item is needed which adequately represents both clinical and self-reported oral health. This study investigated the clinical validity of Locker’s global self-reported oral health item among young middle-aged adults in populations in New Zealand and Australia. Clinical examination and self-report data (including the OHIP-14) were obtained from recent national dental surveys in NZ and Australia, and from age-38 assessments in the Dunedin Multidisciplinary Health and Development Study. National dataset analyses involved 35- to 44-year-olds. Caries and tooth-loss experience showed mostly consistent, statistically significant gradients across the Locker item responses; those responding ‘Excellent’ had the lowest scores, and those responding ‘Poor’ the highest. Periodontitis experience gradients in the NZ national sample were mainly as hypothesized; those rating their oral health as ‘Poor’ had the highest disease experience. OHIP-14 gradients across the Locker item responses were consistent and as hypothesized. The proportion of disease in the population borne by those ‘Fair’ or ‘Poor’ ranged from 26% to 72%. These findings provide preliminary support for the measure’s validity as a global self-reported oral health measure in young middle-aged adults.

Socioeconomic inequalities are associated with oral health status, either subjectively (self-rated oral health) or objectively (clinically-diagnosed dental diseases). The aim of this study is to compare the magnitude of socioeconomic inequality in oral health and dental disease among adults in Australia, Canada, New Zealand and the United States (US). Nationally-representative survey examination data were used to calculate adjusted absolute differences (AD) in prevalence of untreated decay and fair/poor self-rated oral health (SROH) in income and education. We pooled age- and gender-adjusted inequality estimates using random effects meta-analysis. New Zealand demonstrated the highest adjusted estimate for untreated decay; the US showed the highest adjusted prevalence of fair/poor SROH. The meta-analysis showed little heterogeneity across countries for the prevalence of decayed teeth; the pooled ADs were 19.7 (95% CI = 16.7–22.7) and 12.0 (95% CI = 8.4–15.7) between highest and lowest education and income groups, respectively. There was heterogeneity in the mean number of decayed teeth and in fair/poor SROH. New Zealand had the widest inequality in decay (education AD = 0.8; 95% CI = 0.4–1.2; income AD = 1.0; 95% CI = 0.5–1.5) and the US the widest inequality in fair/poor SROH (education AD = 40.4; 95% CI = 35.2–45.5; income AD = 20.5; 95% CI = 13.0–27.9). The differences in estimates, and variation in the magnitude of inequality, suggest the need for further examining socio-cultural and contextual determinants of oral health and dental disease in both the included and other countries.

This study aimed to (1) describe social gradients in dental caries in a population-level survey and (2) examine whether inequalities are greater in disease experience or in its treatment. Using data from Australia’s National Survey of Adult Oral Health 2004-2006, we examined absolute and relative income inequalities for DMFT and its separate components (DT, MT, FT) using adjusted proportions, means, and health disparity indices [Slope Index of Inequality (SII) and Relative Index of Inequality (RII)]. Approximately 90% of Australian adults had experienced caries, with prevalence ranging from 89.7% in the highest to 96.6% in the lowest income group. Social gradients in caries were evident across all components of DMFT, but particularly notable in Missing (SII = −15.5, RII = −0.3) and untreated Decay (SII = −23.7, RII = −0.9). Analysis of age- and gender-adjusted data indicated less variation in levels of disease experienced (DMFT) than in the health outcomes of its management (missing teeth). The findings indicate that social gradients for dental caries have a greater effect on how the disease was treated than on lifetime disease experience.

The objective was to compare absolute differences in the prevalence of Indigenous-related inequalities in dental disease experience and self-rated oral health in Australia, Canada, and New Zealand. Data were sourced from national oral health surveys in Australia (2004 to 2006), Canada (2007 to 2009), and New Zealand (2009). Participants were aged ≥18 y. The authors measured age- and sex-adjusted inequalities by estimating absolute prevalence differences and their corresponding 95% confidence intervals (95% CIs). Clinical measures included the prevalence of untreated decayed teeth, missing teeth, and filled teeth; self-reported measures included the prevalence of “fair” or “poor” self-rated oral health. The overall pattern of Indigenous disadvantage was similar across all countries. The summary estimates for the adjusted prevalence differences were as follows: 16.5 (95% CI: 11.1 to 21.9) for decayed teeth (all countries combined), 18.2 (95% CI: 12.5 to 24.0) for missing teeth, 0.8 (95% CI: –1.9 to 3.5) for filled teeth, and 17.5 (95% CI: 11.3 to 23.6) for fair/poor self-rated oral health. The I²estimates were small for each outcome: 0.0% for decayed, missing, and filled teeth and 11.6% for fair/poor self-rated oral health. Irrespective of country, when compared with their non-Indigenous counterparts, Indigenous persons had more untreated dental caries and missing teeth, fewer teeth that had been restored (with the exception of Canada), and a higher proportion reporting fair/poor self-rated oral health. There were no discernible differences among the 3 countries.