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Tuesday, April 10, 2012

Dental X-rays "Tied" to Brain Tumors?

Here we go again. Another "study" warning of the dangers of dental x-rays was featured on a morning news show. I'm sure the other news programs will pick up on it quickly. And, dentists across the country will collectively sigh.

Here's a link to a report about the study.

Strange Science

What's most frustrating is that it's as invalid a "study" as any scientist could dream up. Real science does not rely on anecdote (stories). And, this study relies on interviewing the subjects and asking them to recollect how many dental x-rays they had since childhood. I'm shaking my head as I type this. They could have asked them to recall just about anything, including how many carrots they ate or how much time they spent under fluorescent lighting.

Real scientific studies rely on HARD DATA, not what someone remembers from their childhood. By asking questions that rely on anecdote, I could fashion a "study" to prove just about anything.

Some basic tenets of science are:
  • "Multiple anecdotes are not data."
  • "Correlation does not equal causation."
As mentioned before, anecdotes / stories cannot be considered when creating a study to prove cause and effect.

The second quote above means that because two things are related or happen together, it does not mean one caused the other.  "Correlation does not equal causation."  It bears repeating, because it's true.

Just the FACTS, Ma'am

Unfortunately, this type of "popular science" creates tremendous headaches for dentists and endangers the health of our patients.  Today's dentists have gone to great lengths to reduce radiation exposure while maintaining optimal diagnostic capabilities.  And, dentists order x-rays based on a number of factors including individual patient histories.

The truth is that dental x-rays are the LOWEST source of ionizing radiation from medical AND natural sources.  A series of four check-up bitewings is the same as a 2-hour flight in a passenger jet.  Likewise, the radiation you receive by living inside a concrete block house (most modern houses in Florida) for one year, is about the same as you get from a Full Mouth Series (18 films) of dental x-rays.  A chest CT scan is 700 times the radiation of a dental x-ray.  These are verifiable, measurable facts.

Dosages of radiation from various common sources (measured in "millirems"):

1 dental x-ray: 0.5 mrem

2 hours in an airliner: 2 mrem

1 dental panoramic x-ray: 3 mrem

Living in a concrete house / per year: 7 mrem

A full mouth set of x-rays (18 films): 9 mrem 

Chest x-ray: 10 mrem

1 pack of cigarettes per day / year: 36 mrem

Chest CT scan: 700 mrem

Whole Body CT scan: 1000 mrem

My Hands Are Tied

Ultimately, we cannot... neither ethically nor legally... treat patients without appropriate x-rays as part of an examination that meets the standard of care.  In our current system and environment, patients cannot consent to negligence.  In other words, a patient cannot sign a "waiver" and refuse x-rays.   If a diagnosis is missed, or incorrect treatment is rendered as a result of not having x-rays, the dentist WILL be held liable, regardless of any signed "waiver."  That's reality.

A patient does have the right to refuse TREATMENT.  But, they can't sign away their right to a proper DIAGNOSIS by the doctor.  X-rays are done for diagnostic purposes.  If we miss a diagnosis by not taking the proper x-rays, we will be hung out to dry... every time.  That's our reality.  A patient cannot legally consent to negligence.

But, even more important than that, patients may SUFFER from undiagnosed issues.

Don't Wait Until It Hurts!

I'm surely glad this patient didn't refuse x-rays.  She didn't know or feel this very large cyst that was destroying her jaw bone.  No symptoms.  No pain.  But, it's a very good thing we caught it.


In my opinion, it was grossly irresponsible, if not reckless, for the "Cancer" journal to publish this so-called "study."

Talk With Your Dentist

My suggestion is to have an open dialogue with your dentist.  He or she has your best interests at heart.  Getting medical or dental advice from TV (or even the internet) can be dangerous to your health.  Find a dentist you trust.  Trust is the foundation of the doctor-patient relationship.

One more tenet of science is that a VALID study must be REPEATABLE.  One study... even if it's a good study (this one is not)...  cannot be used to draw solid conclusions.  The study has to be repeated (usually by someone else) and have the same results.

American Cancer Society Responds (to me)

Finally, I have personally been communicating with the American Cancer Society, which publishes the journal, "Cancer."  I expressed my concerns and they have responded.  I won't paste the entire conversation here, but it's VERY puzzling why they would publish this laughable "report," when their Chief Medical Officer, Otis W. Brawley, M.D., said regarding this study, “We need more data before we can even begin to state there is a relationship between dental x-rays and these tumors."  It surely raises the question:  Then WHY did you publish it???

I won't speculate on what agenda(s) may be behind the release of this report.  Dental x-rays shouldn't even be on the "radiation radar" when compared to even natural sources of ionizing radiation.  But, ultimately, you don't want to risk your health based on "factoids" regurgitated by the talking heads on TV.  Ask your dentist questions.  He or she should be able to address them with scientific facts.