DNA Testing and Dentistry

Over the last decade, DNA testing has really come into its own. This is largely due (in my opinion, anyway) to TV shows like CSI and the million spinoffs it spawned, all of which put an entertaining focus on forensics. And, I have to admit, it's all pretty cool. Whenever I watch an old movie, and somebody murders someone and just washes off the blood on their shirt, I'm thinking: "That wouldn't fly today -- they would still catch you because of the arm hair you left behind and the blood residue still present on your washed arm."

We also know that DNA is being performed on older remains to get the genetic makeup of people passed. Again, very interesting stuff.

Until now, DNA testing has usually been reserved for the dead (both recent and long-dead), and occasionally makes its way into our living rooms via TV, where "let's find my baby's daddy" is standard afternoon TV fare. But increasingly, DNA testing is being used on living people for health reasons, to perhaps give an insight as to what your body may hold for you in the future. And dental DNA testing is leading the way.

So first, let's answer a question as to why "dental DNA" matters so much. Well, the DNA under your tooth enamel is considered some of the best DNA available for DNA testing (1). This is simply due to the fact that your tooth enamel is some seriously hard stuff, and forms a pretty good suit of armor. In fact, your teeth are usually the last of your remains to decompose (sorry if you are reading this over breakfast), making them an ideal source for DNA testing of human remains.

But let's talk about the living, shall we? Today, DNA testing is being used on living people to look for gum disease. Because until now, gum disease was primarily diagnosed through sight -- the visual clues it leaves gives us the first inkling that something is amiss. But now, it's being used as predisposition testing. In other words, let's do this test and see if you are susceptible to gum disease.

Right now, this is taking form of saliva testing. Here's a link from the U.S. National Library of Medicine, National Institutes of Health, where they state:

Genetic presymptomatic testing complements bacterial DNA testing by providing insight into the patient's genetic predisposition to periodontal disease before symptoms appear, or when disease is already present. DNA-PCR testing of saliva can help the clinician provide an earlier and more specific diagnosis of disease based on causation. (2)

I'll continue on this talk about gum disease in a moment, but I want to interject that I personally believe this is just the tip of the iceberg. That in 20, 30, 50 years' time, dental DNA testing will be commonly used to "pre-diagnose" all manner of ailments. The future of medicine is really exciting.

But let's get back to gum disease. Why gum disease? Well, for starters, it's an incredibly common affliction. Most dentists (this NYC cosmetic dentist included) will tell you that somewhere around 75 percent of Americans over the age of 35 have some form of periodontal issue. So again, it's really pervasive. Plus, I am guessing (and this is only a guess) that since it's so pervasive, the predispositions I have are fairly easy to weed out -- basically, I am saying gum disease is probably a good jumping off point for future "DNA health testing" research.

Plus, gum disease is also seen as a precursor to other health problems, such as heart disease and stroke. Now there is some debate on this, which I need to bring up. For years, it was thought that gum disease and heart disease were related, and there are many who still think that. But there have been studies -- there's one "plain English" answer given by Mayo Clinic --that debunk this, and claim there is no link between gum disease and heart disease. (3) Personally, I am not ready to dismiss this. I think more research needs to be done before we come up with any definitive answers. So keep brushing and flossing daily, okay?

Stroke is another affliction that has a gum disease link, as seen here in another U.S. National Library of Medicine National Institutes of Health abstract, where they state "There is evidence that periodontitis is associated with increased risk of stroke." (4) So perhaps this "DNA testing for periodontal issues" has some merit.

Actually, that's a silly statement by me -- of course it has merit. Even if gum disease were not linked to ANY other affliction, you still don't want it (trust me on this one, okay?). So the next time you are at the dentist, ask him or her about DNA testing for gum disease. You might find yourself in the middle of a CSI-type of treatment (in a good way).

Until next time, keep smiling.

1. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3125955/
2. http://www.ncbi.nlm.nih.gov/pubmed/20565019
3. http://www.mayoclinic.com/health/heart-disease-prevention/AN02102
4. http://www.ncbi.nlm.nih.gov/pubmed/22244863

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