Chewing tobacco and other types of smokeless tobacco use have had less attention from the global health community than smoked tobacco use. However, the practice is popular in many parts of the world and has been linked to several adverse health outcomes. Understanding trends in prevalence with age, over time, and by location and sex is important for policy setting and in relation to monitoring and assessing commitment to the WHO Framework Convention on Tobacco Control. We estimated prevalence of chewing tobacco use as part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 using a modelling strategy that used information on multiple types of smokeless tobacco products. We generated a time series of prevalence of chewing tobacco use among individuals aged 15 years and older from 1990 to 2019 in 204 countries and territories, including age-sex specific estimates. We also compared these trends to those of smoked tobacco over the same time period. In 2019, 273·9 million (95% uncertainty interval 258·5 to 290·9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4·72% (4·46 to 5·01). 228·2 million (213·6 to 244·7; 83·29% [82·15 to 84·42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global age-standardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1·21% [-1·26 to -1·16]), similar progress was not observed for chewing tobacco (0·46% [0·13 to 0·79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0·94% [-1·72 to -0·14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Bloomberg Philanthropies and the Bill & Melinda Gates Foundation.

In the present study, silver nanoparticles (AgNPs) were synthesized in situ on orthodontic elastomeric modules (OEM) using silver nitrate salts as metal-ion precursors and extract of the plant Hetheroteca inuloides (H. inuloides) as bioreductant via a simple and eco-friendly method. The synthesized AgNPs were characterized by UV-visible spectroscopy; scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). The surface plasmon resonance peak found at 472 nm confirmed the formation of AgNPs. SEM and TEM images reveal that the particles are quasi-spherical. The EDS analysis of the AgNPs confirmed the presence of elemental silver. The antibacterial properties of OEM with AgNPs were evaluated against the clinical isolates Streptococcus mutans, Lactobacillus casei, Staphylococcus aureus and Escherichia coli using agar diffusion tests. The physical properties were evaluated by a universal testing machine. OEM with AgNPs had shown inhibition halos for all microorganisms in comparison with OEM control. Physical properties increased with respect to the control group. The results suggest the potential of the material to combat dental biofilm and in turn decrease the incidence of demineralization in dental enamel, ensuring their performance in patients with orthodontic treatment.

The objectives of the present study were to establish dental caries prevalence (percentage with caries) and experience in the primary and permanent dentition (dmft and DMFT) of 6 to 13-year-old schoolchildren in Campeche, Mexico, and to estimate the contributing roles of the likely risk indicators. A cross-sectional study was carried out in 1,644 children aged 6–13 years. Self-administered questionnaires obtained information on social, economic, behavioral, and demographic variables. The primary dentition of 1,309 children and the permanent dentition of 1,640 children were evaluated in the oral examinations. The main outcome measures were DMFT, dmft, and SiC indices. Data were modeled using logistic regression analysis. The overall caries prevalence was 77.4%, 73.6% in the primary dentition (61.6% in 6-year-olds), and 49.4% in the permanent dentition. The dmft and DMFT indices were 2.85±2.73 and 1.44±2.05, respectively (DMFT=3.11±2.62 in 12-year-olds). The SiC index was 6.05 at 12 years of age. Associated variables to dental caries in both dentitions were presence of enamel defects, presence of dental plaque, low socio-economic status, female sex, and older age. Mother's schooling was negatively associated (OR=0.95) with caries in primary dentition. Caries experience in the primary dentition (OR=6.02) was positively associated with caries in the permanent dentition. Dental caries status in these Mexican children was closer to the goals proposed by the WHO/FDI for 2000 than previous studies. This study has identified clinical, socio-economic, and behavioral determinants for dental caries in primary and permanent dentition on Mexican schoolchildren.

Tobacco use is associated with diseases worldwide, including cancer. This is one of the major public health problems globally, causing more than 19 million new cases in 2020. Lip and oral cavity cancer (LOCC) is neoplastic growth in the tongue, gums, and lips. The objective of this ecological study was to quantify the strength of the association between incidence and mortality of LOCC, with tobacco use and with the Human Development Index (HDI). Incidence and mortality data on LOCC were obtained for 172 countries in 2020, from the Global Cancer Observatory (GLOBOCAN). The prevalence of tobacco smoking and chewing was obtained from reports conducted in 2019. The inequality in human development was estimated using the HDI from the United Nations Development Program, Human Development Report (2019). Statistically significant correlations were observed between the incidence of LOCC and tobacco smoking and chewing prevalence, except for negative correlations between the prevalence of tobacco smoking LOCC mortality in women, just as in the case of the HDI. No statistically significant differences were found between the prevalence of tobacco chewing only and the incidence of LOCC overall and by sex. A higher LOCC incidence overall and by sex was associated with higher HDI. In conclusion, the present study found positive correlations for various HDI socioeconomic indicators and tobacco use with the incidence and mortality of LOCC, but also a few inverse correlations.

We used National Performance Evaluation Survey data to estimate the prevalence and associated factors of edentulism among noninstitutionalized adults aged 35 years and older in Mexico. Statistically, the variables positively associated with edentulism were older age (odds ratio [OR]=1.08) and female gender (OR=1.79). Nonsmoking status (OR=0.70) and having a higher wealth index score (OR=0.72) were negatively associated. This information constitutes the first large-scale evaluation in Mexico for one of the World Health Organization’s priority oral health problems.