Ok, let's talk about this controversial dental x-ray study...

Since I appear to be on a roll with a number of issues these days, including dental xrays, I might as well add the latest (and very controversial) study to come out about the "links" between dental xrays and some form of brain tumor. It simply must be addressed, as I've been asked my opinion on this a lot recently. As usual, I conduct my own research on the research reportings, plus the fine print (of course!), before presenting the facts. THEN, and only THEN, do I give my opinion. So, here goes...here's what I found....and hold on to your hats, 'cuz this is going to be one heck of a bumpy ride...just sayin'..(shaking my head)...

First thing to state here is that there is a significant difference in the way this study was reported by three sources. Significant is an understatement. I have to wonder if I'm looking at the same study results here. I've looked at four articles "reporting" the study results. I have not viewed the actual study itself as it is not yet accessible to me through the journal Cancer, that published it. I can assure you, though, that I WILL read that study and report back on it, as soon as I can access it. So, consider this Round One (ding! ding!) of this controversial study.

Here are the links to those articles:
1. The Washington Post
 http://www.washingtonpost.com/blogs/the-checkup/post/study-links-dental-x-rays-to-brain-tumor-risk/2012/04/09/gIQALz8k6S_blog.html
2. WebMd
 http://www.webmd.com/brain/news/20120410/dental-x-rays-linked-brain-tumors
3. Yahoo Health
http://health.yahoo.net/news/s/nm/dental-x-rays-linked-to-common-brain-tumor
4. Reuters
http://www.reuters.com/article/2012/04/10/us-dental-x-rays-idUSBRE8390GM20120410

After reading all four articles, all I can say is Holy Biased Study Reporting, Batman! Facts, assumptions, and correlations swing wildly between the four articles. Limitations and potential issues with the study, also swing wildly. This is such a classic case of playing "telephone" with a study. However, we, as the readers and consumers of dental services, have a right to know exactly what the deal is here. Having and knowing the facts can GREATLY impact decisions regarding dental care here. Yowza...while the facts from this study are fascinating; how they are written, in what tone, and with what "spin" they include, will fuel consumers and feed their preconceived notions.  Time to put our "pseudo surgeon's gloves" on and dissect this mystery...

Facts stated:
1. Two groups of subjects were studied; one group with meningioma brain tumors (benign, as in not cancerous), and one group without meningioma brain tumors. Good. A comparison group is good to use. I like it so far.

2. Ages of study participants ranged from 20 to 79. That is a significant variation in age and could be considered a study limitation right off the bat. It would be very difficult to "control" or rule out, other potentially influential factors here with this wide span of "adults".

3. The sample size (# of study participants) was similar for both groups and was fairly large: 1,433 people with tumors, and 1,350 people without the tumors. Apparently, the study participants in both groups were of similar age (?) and from similar states/cities (Conn., Ma., NC., Houston and San Francisco areas). I'm not sure why they chose broad states and two cities as study sites, but my guess is that there were numerous researchers involved in the study and they lived in these areas listed above. However, the 3 states and 2 cities are a strange choice overall. Again, it would be hard to rule out other impacting geographical factors arising from these locations alone, and I'm not sure if locations were even taken into consideration, but this is what I have to work with until I can read the actual study itself.

4. The study participants were asked to remember their xray usage, type, and frequency, dating back to the 1960's. (RED FLAG HERE!!!) Huh? How many of us remember what we had for breakfast in 1968 let alone how many xrays we had taken at the dentist 50 years ago??? This is a SELF REPORTED study. It is not based on gathering actual FACTS from physical DATA, from, say, DENTAL OFFICES. They are relying on people's MEMORIES here. They are basing a HUGE conclusion linking xrays to BRAIN TUMORS on people's recollections!?! That's a huge step and conclusion to make with unreliable data, from decades ago.

Ok, as a researcher myself, I have to step back and gain my breath. (Breathe, Annelise, breathe...inhale, exhale, inhale, exhale..). I am now officially skeptical (understatement of the century). Remember here, that many study participants were in their 60's and 70's when this study was conducted. The age ranges of participants were up to 79. 79, for pete's sake!!!!! You mean, these researchers interviewed senior citizens about when, type and number of xrays they had dating back to the 1960's??? Is that what they are basing these IMPORTANT conclusions & results on????? If so, I might as well stop here and tell you in my most humble and professional opinion, that this study is flawed, if this is the methodology used. I don't mean slightly flawed, I mean, "are you people seriously KIDDING ME?" kind of flawed. I believe the british term here is "bullocks", but I'm not positive. There was NO conclusive, confirmed, credible DATA to back those "guestimates" up. None. Ok, granted back in the 60's, 70's and even into the 80's dental offices used paper, not digital charts and computers, but dental charts were not studied at all here. They relied on people's memories alone. It would be near IMPOSSIBLE to verify ANY of these "guestimates" since most of those dental practices are GONE by now. Not to mention, how mentally and cognitively healthy were those senior citizens interviewed for this study??

 But this is too important to simply state the early limitations of this study that I have found. There is more so let's keep going here...

5. The study looked at 3 different types of xrays that people "recalled" having taken on them. Bitewing xrays (4 films of your back/posterior teeth; 2 of the upper back, and 2 of the lower back), a full mouth series of xrays (FMX) which total 18 xrays of all teeth and INCLUDES a set of 4 bitewings in this series of xrays (remember that), and a pano xray that is taken from further away from the face, circles the face, and gets a wider image of all teeth, bone, sinus cavities, etc. Ok, that said, here is what they found. Ready? This is going to blow you away. Honest. You need to sit down for this level of contradictory reporting. The study found that those study participants who had bitewings and a pano were much more likely to develop this benign brain tumor; 40%-90% more likely, is what they are saying. HOWEVER, (here it comes), those that had an FMX series of xrays (which INCLUDES bitewings, you will recall) are NOT more likely to develop meningioma brain tumors. Huh?? What?? Back up a sec. How is it possible that bitewings by themselves are linked to higher likelihood of developing brain tumors but FMX which INCLUDES bitewings, are NOT linked to developing brain tumors? I'm raising a hale and hearty RED FLAG here. Umm. Pardon me, but that makes NO sense whatsoever. None. Zero. Zip. Nada. No Way, Jose. A flat out Oh HELL NO....you just did NOT say that, did you? Ugh...wow. Ok, well, in the best interest of everyone getting all the "facts" straight, let's continue...I did warn you...this is about to get even bumpier...strap yourself in.

6. The study reported, based on the highly scientific "findings" (oye vey..were the surveys filled out with red crayon too, or burnt sienna, by chance?) that those study participants who were more likely to develop these brain tumors  received a more frequent number of xrays back in the 1960's, because the ionizing radiation from the OLD xray systems was HIGHER then, so THOSE people who REMEMBER that they had lots of bitewings every year at the dentist back in the 1960's were 40-90% more likely to develop brain tumors! Yes, you heard me right!! This HIGHLY "scientific study" linking dental xrays with BRAIN TUMOR development, is basing its conclusions on self-reporting, and on xrays that have not been used in 50 years! Guys, this is like saying that not washing your hands back in 1912 led to a kabillion percent increase in risk of infection! Really? No WAY! I'm FLOORED!....I kid you not. I am beyond floored. The more I read, the more doubtful I became.....but THIS??? Dear Lord, save us all.....from this level of skewed, flawed, and flat out DANGEROUSLY overstated reporting...please...I beg of you...because, Lord, if you don't....people will HONESTLY think that getting xrays at the dentist TODAY will give them brain tumors TOMORROW!

Yes, I am continuing...against my better judgement here...but nonetheless...

7. Direct quote from the lead researcher, Dr. Elizabeth Claus "It's likely that the exposure association we're seeing here is past exposure, and past exposure levels were much higher", end quote. I'm very tempted to quote my adorable grandson, Gage, here when I say something silly and he looks at me and says "Double Duh, Grammalise"! But I won't. What I will say is this: you will receive higher levels of radiation walking out your front door than you will from getting a dental xray taken today. In fact, and I will back this up with REAL facts, dental clinical staff do not even have to WEAR xray badges, like hospital staff or medical staff who take xrays do. Why, you ask? Well, because the miniscule levels of radiation from today's wonderful digital xrays are not even a concern to the health department that REGULATES xray radiation exposure levels!! That's right! Anyone else in ANY medical facility that takes xrays MUST wear a radiation badge around their neck and have it tested for exposure levels throughout the year to avoid staff overexposure to radiation, EXCEPT dental staff. This can be found in Florida's Administrative Code 64E-5.314, and here it is:

64E-5.313 Compliance with Dose Limits for Individual Members of the Public.
(1) The licensee or registrant shall make or cause to be made surveys of radiation
levels in unrestricted areas and radioactive materials in effluents released to
unrestricted areas to demonstrate compliance with the dose limits for individual
members of the public in 64E-5.312.
(2) A licensee or registrant shall show compliance with the annual dose limit in
64E-5.312 by:
(a) Demonstrating by measurement or calculation that the total effective dose
equivalent to the individual who is likely to receive the highest dose from
the licensed or registered operation does not exceed the annual dose
limit; or
(b) Demonstrating that:
1. The annual average concentrations of radioactive material released
in gaseous and liquid effluents at the boundary of the unrestricted
area do not exceed the values specified in State of Florida Bureau
of Radiation Control ALIs, DACs and Effluent Concentrations, July
1993, Table II; and
2. The dose from external sources would not exceed 0.002 rem
(0.02 millisievert) in an hour and 0.05 rem (0.5 millisievert) in a year
if an individual were continually present in an unrestricted area.
64E-5 Florida Administrative Code 64E-5.314
III - 12
(3) Upon approval from the department, the licensee can adjust the effluent
concentration values in State of Florida Bureau of Radiation Control ALIs, DACs,
and Effluent Concentrations, July 1993, for members of the public to take into
account the actual physical and chemical characteristics of the effluents, such as
aerosol size distribution, solubility, density, radioactive decay equilibrium, and
chemical form.
(4) Dental and podiatry registrants are exempt from (1), (2), and (3), above.(Here it is)
(5) Each licensee or registrant shall maintain records sufficient to demonstrate
compliance with the dose limit for individual members of the public until the
department terminates each pertinent license or registration requiring the record.

See? I told you so. AND, if you still need further proof that the radiation exposure in dental offices TODAY is SO LOW that dental personnel who take dozens of xrays EVERY DAY, don't even have to wear an exposure capture badge, you should call my buddies at the Department of Health; they are awesome peeps!
Bureau of Radiation Control
Radiation Machine Section
Suite 300
705 Wells Road,
Orange Park, FL 32073
Telephone: (904) 278-5730 Fax: (904) 278-5737

So, getting back to this study. First, if researchers wish to study whether xray exposure is really linked to brain tumors, they should seriously study dental personnel. They're in the xray trenches everyday for years on end. To date, I have known no one in dental clinic settings, to have developed any form of cancer, let alone, brain tumors. That's not to say they haven't; I just have not heard of any, and believe me, I get around (in a professional way only).

The four articles were extremely selective in what they reported on this study. One article, from WebMd, no less, omitted the most important limitations of this study. By doing so, they have, unfortunately, and in my HUMBLE opinion, done an injustice and disservice to themselves. Based on this important, and omitted, information, I now have my serious doubts as to the credibility of information presented by WebMd. In fact, it states that "Neurosurgeon Michael Schulder, MD agrees that the published findings make a good case for limiting the frequency of dental xrays whenever possible". Wow. Michael...did you even READ this study? Did you READ the methodology? Did you READ the self-reported instrument used? Did you READ the time frame the "link"s were referring to? And, lastly, Michael, did you READ the age groups that self-reported???? Wow... Wow.... And Wow....How incredible to make such broad statements on such flawed and skewed presentation of information. Wow. Unless I am 100% wrong, and the actual study itself states something very different than the articles reporting on them, I'm floored still.

Here's my last word...and it's strong. The only other studies conducted on ionizing radiation and its effects were conducted on atomic bomb survivors or radiation treatment patients. Studies were inconclusive. This study does NOT show cause and effect. The findings CANNOT prove that radiation from imaging caused tumors. This is clearly stated in the articles. I have been reviewing study manuscripts for many peer-reviewed journals and had I received a manuscript of this study to review, with these limitations & biases, I would have rejected it from being published. It is misleading the public dangerously, into believing that dental xrays CAUSE brain tumors, and they don't, according to the current body of knowledge.

With 66% of our population overweight or obese, one can safely say, that those extra pounds didn't come from overeating on salads. The 50% of children who have their first cavity by age 5 did not get them from eating lettuce. Diabetes, heart disease, high blood pressure, certain cancers, and many other current chronic conditions that the majority of Americans suffer from, can be traced back to poor eating habits. Those poor eating habits include the MOUTH as the receptacle for the poor food choices and the MOUTH as the ENTRANCE to the rest of the body. What do you think the oral health status is of this vast majority of Americans? Is it healthy? Not likely. Is it cavity free? Again, not likely. If you ask any of the 88 million Floridians who went to the Emergency Room in 2009 with severe tooth abscesses (NY Times, 4/9/2012), I'm fairly sure they will agree here. Should we wait to take xrays until someone has a symptom, like INTENSE PAIN? Or do we take a more proactive approach in those people who are at a higher risk of tooth decay by taking needed xrays to avoid  waiting 2 years (thanks for that suggestion, Dr. Neurosurgeon) until that little cavity turns into a full blown abscess with more than $2000.00 in needed treatment to save a tooth that a $20 xray and a $100 filling could have taken care of??? Well, I suppose so, bit it certainly is not optimal, now is it.

Instead of worrying about a questionable study, stating that taking those xrays (taken in 1960) could give you a benign brain tumor in 50 years, why don't we address the xray needed to ensure that the abscess doesn't travel to the brain and kill someone THIS YEAR. Just a thought. That's all I'm saying...

Whew! That was a workout. Hopefully, I burned calories over this one. It certainly was draining, wasn't it? Well, that's it for me today. Thanks for stopping by. And, remember, you only have to brush and floss the teeth that you ABSOLUTELY, POSITIVELY, want to keep. That's it. Nothing more.

Dr. Driscoll