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