DNA & Teeth
Each year, we celebrate National DNA Day on April 25. It’s a day that Congress and the National Human Research Institute set aside to:
- Celebrate the anniversary of the Human Genome Project
- Share the latest advances in genomic research with the public, and
- Let people see how these can improve their daily lives
DNA From a Tooth
Some may not realize that teeth are one of the most durable and revealing sources of DNA available. Lodged in the jaw bone, teeth are somewhat protected. Also, dental pulp and dentin—key genetic repositories—lie safely covered in enamel.
In addition, plaque and saliva play a role. Notably, these offer valuable data for decoding many of life’s greatest mysteries.
In difficult criminal or legal investigations, forensic teeth specialists may be the only ones able to identify someone’s remains. Especially in cases where many people are involved—like plane crashes or disasters—teeth are often one of the most reliable sources of genetic data.
In the past, personal identification relied on:
- Dental records
- Postmortem reconstruction
- Dental profiling
However, dental material is far more accurate in establishing identity. As long, that is, as a pre-death sample is available for comparison.
Researchers have found that both the dentin within teeth as well as the plaques that form on them can be rich sources of genetic data. One study was published in the American Journal of Physical Anthropology. The researchers looked specifically at tooth calculus—plaque—on the remains of six Native Americans in Illinois. Surprisingly, the calculus:
- Yielded DNA for all six individuals—even for three whose bones held no genetic material
- Contained “DNA not only from the human but also the microbiome and the diet”
In fact, “[n]o other material in the archaeological record contain[ed] so much DNA.” Who would have thought that plaque would allow researchers to “trace the history of the human species and provide glimpses at population movements” across the globe?
Today, science is even more focused on using genetics to do the following:
- Learn why dental health varies so widely among people
- Identify the causes of dental problems and diseases
- Create effective ways of treating or preventing them
Interestingly, saliva is proving helpful. It contains both human DNA and that of bacteria that live in the mouth. Researchers are examining dental heredity and genetic predisposition to diseases like periodontitis. In addition, they’re looking at the effects of certain pathogens that cause oral health problems.
National DNA Day
Genetic material is indeed the language of life. The Human Genome Project proved this in 2003. Since then, every day brings still more discoveries. That’s because the applications for dental materials extend from forensics and archaeology to dentistry, medicine and beyond.
National DNA Day reminds us of our shared humanity. In addition, it reminds us that the answers to so many of science’s questions lie within us.