You may not think of your toothbrush as a powerful disease-fighting tool, but oral health has a significant impact on health and quality of life. It affects the ability to speak, eat, and smile, and it influences social interactions, work, and school performance. Poor oral health is also linked to numerous diseases, including diabetes, cardiovascular disease, some cancers, and adverse pregnancy outcomes.

Unfortunately, millions of Americans experience pain and disability from cavities, gum disease, and other conditions. Some 34 million school hours are lost each year because of emergency dental care, and over $45 billion in U.S. productivity is lost annually due to untreated dental disease, according to the Centers for Disease Control and Prevention (CDC).

While dentistry and public health are traditionally viewed as separate fields, they often intersect in support of oral health. Community water fluoridation, reduction of tobacco and alcohol use, improved nutrition, and cancer screenings are some of the many ways that public health and dental health work together. Several investigators in the College of Public Health conduct research on oral health topics such as access to care, cancer prevention, and children’s dental health.

Dental Health and Schooling

Cavities are the most common chronic disease of childhood in the United States. Research shows that children from low-income families are twice as likely to have cavities as children from higher-income households, and young children with public insurance also have higher rates of dental problems and unmet dental needs than those with private insurance.

George Wehby, professor and John W. Colloton Chair of Health Management and Policy, conducted a study that examined the association between oral health during the first five years of life and subsequent academic achievement for low-income children in Iowa. The study used a unique population-based linkage between Medicaid claims data, birth certificates, and standardized test scores from grades 2-11.

The results showed that children who received comprehensive dental exams and minor dental treatments (such as fillings) during the first five years of life had higher reading and math scores, while children who received major dental treatments (such as a crown or tooth extraction) had lower reading and math scores.

These results suggest that “minor treatments prevented dental issues from deteriorating into more severe problems later in life, and that comprehensive dental exams were also beneficial,” Wehby explains. In contrast, the major treatments serve as markers for more severe dental problems that may disrupt children’s attention, sleep, and learning.

The findings support the importance of addressing barriers to dental care and promoting oral health in early childhood and suggest that the disproportionally high rates of unmet oral health needs among low-income children are associated with income gaps in academic achievement.

Barriers to Care

Barriers to accessing dental care include lack of time, information, and transportation, but the two primary barriers are affordability and insurance, Wehby says.

More than 84 million Americans with limited income rely on Medicaid for health coverage. With the passage of the 2010 Affordable Care Act (ACA), many people became newly eligible for medical and dental coverage in states that adopted Medicaid expansions.

But Medicaid is complicated: States are required to provide dental benefits to children covered by Medicaid and the Children’s Health Insurance Program. However, the federal government does not require Medicaid plans to cover adult dental services.

“It’s really up to states, and states vary dramatically in what dental services they cover under Medicaid for adults,” Wehby notes. Some states offer extensive benefits, others offer limited benefits, and others offer emergency-only or no benefits for adults.

Another difficulty is “finding dentists who accept Medicaid coverage and are willing to provide services,” Wehby says. “There are also geographic barriers—there are shortage areas for access and availability of dental care.”

Shortage areas are not exclusively a rural issue, he adds. “Even in urban areas, finding a dentist that accepts Medicaid patients might not be as easy as one would think.”

Reducing Disparities

Racial and ethnic inequities in accessing dental care have persisted for decades. Wehby and his colleagues Wei Lyu and Dan Shane conducted a study to see if recent ACA Medicaid expansions that included coverage of dental services for adults affected racial and ethnic disparities in dental services use.

While no decline in disparities was seen in states with less generous dental benefits, “We found that Medicaid expansion with extensive adult dental benefits has increased dental services use, particularly for Hispanic adults and non-Hispanic Black adults, and reduced racial and ethnic disparities in use,” the authors noted in their paper published in Health Affairs

However, the researchers found that utilization rates remained low across all groups during the study period, regardless of expansion status or the generosity of dental benefits.

“Even with improvements in coverage and narrowing of disparities in accessing care, more actions are needed to further reduce access barriers for all,” the authors concluded.

Cancer Prevention

Oral health involves more than teeth and gums. “It means being free of chronic oral-facial pain conditions, oral and pharyngeal (throat) cancers, oral soft tissue lesions, birth defects such as cleft lip and palate, and scores of other diseases and disorders that affect the oral, dental, and craniofacial tissues,” notes the 2000 Surgeon General’s Report on Oral Health in America.

Cancers in the back of the throat (oropharynx) traditionally have been caused by tobacco and alcohol, but recent studies show that human papillomavirus (HPV)-associated oropharyngeal cancer rates are increasing. Up to 70% of oropharyngeal cancers may be caused by HPV, according to the CDC.

The HPV vaccine, recommended for children at ages 11-12, is safe and effective in protecting against HPV and the cancers it causes. However, HPV vaccination rates remain below the Healthy People 2030 goal of 80% coverage.

Natoshia Askelson, associate professor of community and behavioral health, is part of a research team that conducted a study showing that dental providers are willing to be partners in HPV vaccine promotion. The team used data from the study to develop a series of continuing education trainings for dental providers. The training covers HPV basics, the vaccine and its connection to oral health, and how to recommend the vaccine.

“The goal of the intervention is to train dentists and dental hygienists so that they can make a strong recommendation for the HPV vaccine to the parents of the [adolescent] patients that they see,” says Askelson. “We know a recommendation is more effective when coming from a health care provider.”

Working with colleagues from the University of Iowa College of Dentistry, the team has delivered the training to dental providers at Federally Qualified Health Centers in Iowa and to an oral health coalition in western Iowa.

The team plans to pilot the training in a study to see whether dental providers ultimately make strong recommendations for the HPV vaccine and if parents follow through and get their kids vaccinated.

The investigators are also working on a similar project with ENT (ear, nose, and throat) specialists.

“We hope to develop an intervention that would help ENTs in the community know how best they can support the uptake of the HPV vaccine,” says Askelson.

Understanding Orofacial Clefts

Cleft lip and cleft palate are among the most common birth defects globally. They occur when facial structures that are developing in an unborn baby don’t close completely and are thought to be caused by an interaction of genetic and environmental factors.

“Orofacial clefts cause significant medical, psychological, educational, and financial problems,” says Azeez Alade, a PhD student in epidemiology whose research focuses on identifying the genetic and genomic causes of orofacial clefts. “There is a critical need to identify effective interventions, which will require more in-depth knowledge of the underlying genetics. The knowledge gained from our study will facilitate risk prediction, genetic counseling, and, ultimately, prevention.”

Tabitha Peter, a PhD student in biostatistics, is also applying her skills to better understand orofacial clefts. “For my dissertation, I’m studying families and how genetic markers impact physical traits for people in those families,” she says. “My work includes collaborating with other students from my department in writing code for a computing tool. This tool (an R package) is designed to analyze associations between multiple genetic markers and a physical trait. A novel feature of this tool is in its method for analyzing data from studies of related individuals. A specific application of this tool will be to a data set that describes families impacted by cleft lip/cleft palate.”

Supporting good oral health requires a multidisciplinary approach, and public health has a wide array of expertise to tackle policy, disparities, genetics, disease, and more. As former U.S. Surgeon General David Satcher said more than 20 years ago, “You cannot be healthy without oral health.”

This story originally appeared in the spring 2023 issue of InSight magazine