Once they fall out, baby teeth are usually discarded or gathered by the tooth fairy. But Manish Arora has found a different use: extracting information from them to search other biological samples for early signs of disease.
Arora, the Edith J. Baerwald Professor of Environmental Medicine and Public Health at the Icahn School of Medicine at Mount Sinai, has found that abnormalities in teeth correspond to conditions such as autism, attention-deficit/hyperactivity disorder, cancer, and Lou Gehrig’s disease or ALS.
“Teeth are biological hard drives,” Arora says. “We can build a history of someone’s exposures to chemicals through their teeth.”
Teeth—particularly the baby teeth that Arora focuses on—have rings that can be mapped to track age and development. With lasers one-tenth the width of a hair, Arora has been mapping them to find biological markers that signal disease. Those markers could prompt early disease detection and intervention, leading to improvements in patient care, new treatment or cures.
In one study, Arora, who is also Director of Exposure Biology at Mount Sinai’s Senator Frank R. Lautenberg Environmental Health Sciences Laboratory, discovered that children with autism exhibit an inability to process certain elements before they are even born. The distinction is visible in a fetus’s third trimester. And while he doesn’t know why it happens, Arora said the signature could be used to predict which children will develop autism so they’re treated as early as possible. While an infant’s teeth can’t be examined until they fall out, the information about biochemical pathways gleaned from studying them has indicated what to look for in other samples, such as blood and urine, which can be collected at birth.
“We can’t change genes but we can change the environment,” he says.
Arora’s fascination with environmental health started at an early age. As a boy living in Zambia during the 1970s, he watched trucks spray the controversial insecticide DDT to kill malaria-carrying mosquitos. He also practiced dentistry, a family tradition, in a northern region of his native India amid ever-increasing levels of air pollution and infectious disease epidemics.
That interest ultimately led him away from dentistry to pursue a doctorate in public health at the University of Sydney in Australia. There, a colleague gave Arora a study which examined lead levels in pulverized baby teeth and found a correlation between high amounts and children with low IQs. His interest piqued, Arora started working with the physics department to develop methods using lasers and nuclear beams to study the chemical architecture of whole teeth, rather than ground, as was common practice at that time. (Because baby teeth are shed naturally, they are easier to study than adult teeth.)
Arora was recruited to the Icahn School of Medicine five years ago and is continuing a tradition of out-of-the-box environmental public health research that stretches back to the school’s inception. At the school’s dedication, four Nobel laureates spoke, including the renowned chemist Linus Pauling. Like Arora, Pauling had been involved with studies that examined metals in children’s teeth—research that set him on a path to opposition to nuclear weapons, work that won him a Nobel Peace Prize in 1962, eight years after he won the Nobel for chemistry.
Since then, the Icahn School of Medicine has continued to innovate in the area of public and occupational health. The Selikoff Centers for Occupational Health is one of the country’s first hospital departments of environmental medicine. It’s named for Irving J. Selikoff, a Mount Sinai researcher who established a link between the inhalation of asbestos particles and lung-related ailments in the 1960s.
Last year, the school was named the world’s 10th most influential research institution in the Nature Index Innovation 2017. The index, which is compiled by the publisher of the journal Nature, a sister publication to Scientific American, ranks universities and research organizations based on their contributions to published research that is later cited in other organizations’ patents.
Arora’s work furthers that reputation. In 2014, he received the New Innovator Award from the National Institutes of Health, a distinction bestowed on those conducting particularly novel research and that comes with a $1.5 million grant, and last year he won the Presidential Early Career Awards for Scientists and Engineers, the highest civilian honor bestowed by the U.S. government on outstanding scientists and engineers beginning their independent careers.
As teeth continue to arrive from medical centers around the world for Arora to examine, his research is set to deepen. He says he even plans to make his own contribution—as soon as his five-year-old triplets shed their baby teeth.
To learn more about how scientists are translating research into life-changing treatments, visit the New Heights in Medicine.