Questions for Eleanor Fleming, Ph.D., D.D.S., M.P.H., Dental Epidemiologist and Lead Author of “Prevalence of Total and Untreated Dental Caries Among Youth: United States, 2015–2016”
Q: What made you decide to focus on the prevalence of dental cavities in young children for this study, versus other dental conditions like gum disease or tooth grinding – or some other critical public health concerns today for America’s youth?
EF: Our intent in conducting this study was to provide up-to-date prevalence estimates for dental caries in children. We decided that our study would focus on dental caries because of the serious and negative impact untreated caries can have on children. By the way, dental “caries” is the scientific term for tooth decay or cavities. Dental caries are the most common chronic disease among youth aged 6-19 years. Untreated caries cause pain and infection. Children miss days from school and have their overall quality of life effected by untreated dental caries. This is an important public health concern for America’s youth. While dental conditions like gum disease or tooth grinding are important, the National Health and Nutrition Examination Survey (NHANES) Oral Health Component does not currently collect data on these dental conditions. The component focuses on collecting data on tooth loss, dental caries, and dental sealants.
Q: In your new report, you examine differences in the prevalence of tooth cavities by income level; what is the motivation to look at income, since many children’s dental care might be paid by either public or private health insurance?
EF: We examined family income in this study for a few reasons. One is that income is a significant social determinant of health. For our study, we decided to include family income in addition to age, race and Hispanic origin. We were curious about the differences in untreated and total caries (tooth decay) by family income level. For both total and untreated caries, prevalence decreased as family income level increased. There is also concern among the public health community that children who may have access to Medicaid dental benefits are not receiving the care that they need. The examination of income levels in our new report might offer some needed insight to this concern.
The prevalence of total dental caries decreased as family income levels increased, from 51.8% for youth from families living below the federal poverty level to 34.2% for youth from families with income levels greater than 300% of the federal poverty level.
The prevalence of untreated dental caries decreased from 18.6% for youth from families living below the federal poverty level to 7.0% for youth from families with incomes greater than 300% of the federal poverty level.
Q: Was there a result in your study that you hadn’t expected and that really surprised you?
EF: Because our motivation for this study was to provide updated national estimates on untreated and total caries (tooth decay) for 2015-2016, all of the results were very interesting in one way or another — and surprising. National estimates for age, race and Hispanic origin, and income are results that we need to understand for public health surveillance purposes. For me though, the overall estimates for youth by age were especially interesting.
While the untreated dental caries prevalence overall for youth is 13.0%, there were age differences that caught my eye. The low prevalence for 2-5 year-olds is an important and encouraging finding. While we don’t know if it is from prevention efforts, access to care, or other factors, the fact that our youngest youth have the lowest untreated and total caries prevalence shows they’re starting off their young lives with healthy teeth.
The prevalence was lowest in youth aged 2-5 years (8.8%) compared with youth aged 6-11 years (15.3%) and 12-19 years (13.4%). The prevalence of the 6-11 and 12-19 years-olds was significantly different from the prevalence of 2-5 year-olds.
The total caries experience was also lowest for youth aged 2-5 years (17.4%) compared to youth aged 6-11 years (45.2%) and 12-19 years (53.5%). As age increased, the total caries prevalence increased.
Q: What, if any, is the difference between the two terms you use in your report – primary teeth and permanent teeth?
EF: Primary teeth are baby teeth, or the first teeth that erupt, or come in, which are later shed and replaced by permanent teeth. Primary teeth erupt from around 6 months to age 2 or 3 years. The permanent teeth replace the primary teeth. These teeth start coming in around the age of 6 years and continue until the third molars, or wisdom teeth come in, somewhere between the ages of 17 to 21 years. In our analysis, we combined the two types of teeth in order to focus on dental caries (tooth decay) regardless of tooth type.
Q: In your report, are untreated dental cavities a subset of the number of total cavities, and therefore included in the total cavity statistics?
EF: Yes, untreated dental caries (tooth decay) are included in the total number of dental caries. When we describe total dental caries, we are focused on both untreated and treated dental caries. Essentially, the total of dental caries take into account any tooth decay experience that someone has had. Untreated dental caries represent tooth decay that has not been treated. Untreated dental caries are also known as cavities. What we capture in the untreated caries measure is the active disease of youth.
Q: What differences or similarities did you see among race and ethnic groups, and various demographics, in this analysis?
EF: We noted a number of differences among youth by race and Hispanic origin in this analysis. Non-Hispanic black youth had the highest prevalence of untreated caries (tooth decay) (17.1%) compared to other race and Hispanic-origin groups. The prevalence for non-Hispanic black youth was significantly different from non-Hispanic whites (11.7%) and non-Hispanic Asians (10.5%). The prevalence of untreated dental caries in Hispanic youth was 13.5%.
Hispanic youth had the highest prevalence of total caries (52.0%) compared to other race and Hispanic-origin groups. The prevalence was also significantly different from non-Hispanic whites (39.0%) and non-Hispanic Asians (42.6%). The prevalence of total caries for non-Hispanic black youth was 44.3%.
Q: What sort of trend data do you have on this topic so we can see how prevalence has evolved over time?
EF: With six years of data, we can look at the trend in prevalence over time. Because dental caries (tooth decay) is the most common condition of childhood, we thought it was important to include trend analysis in our report.
The results show a significant linear decrease in total caries. From 2011-2012 to 2015-2016, the total caries prevalence decreased from 50.0% to 43.1%. The results show a different pattern for untreated dental caries. The prevalence of untreated dental caries increased from 2011-2012 (16.1%) to 2013-2014 (18.0%), and then decreased in 2015-2016 (13.05). There is significant quadratic trend – a single bend either upward or downward — in untreated dental caries from 2011-2012 to 2015-2016.
Q: What is the take-home message of this report?
EF: The take-home message from this report is that there are differences in untreated and total caries (tooth decay) by age group, race and Hispanic origin, and income. The trend analysis shows that the prevalence of untreated and total caries are decreasing. However, there are still disparities that exist. Because monitoring prevalence of untreated and total caries is key to preventing and controlling oral diseases, these disparities are important.
The prevalence of untreated dental caries in America’s youth is 13.0%. The prevalence decreased as family income increased, with youth with family incomes less than 100% of the federal poverty level having the highest prevalence. Disparities in untreated dental caries exist along race and Hispanic origin. Non-Hispanic black youth have the highest prevalence compared to Hispanic, non-Hispanic white, and non-Hispanic Asian youth.