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Dental X-Rays Linked To Common Brain Tumor
redletterdave writes "A new study suggests people who had certain kinds of dental X-rays in the past may be at an increased risk for meningioma, the most commonly diagnosed brain tumor in the U.S. Dr. Elizabeth Klaus, the study's lead author and a professor at the Yale School of Medicine, discovered that dental X-rays are the most common source of exposure to ionizing radiation — which has been linked to meningiomas in the past — and that those diagnosed with meningiomas were more than twice as likely as a comparison group to report ever having had bitewing images taken. And regardless of the age when the bitewings were taken, those who had them yearly or more frequently were between 40 percent and 90 percent higher risk at all ages to be diagnosed with a brain tumor."
A valid reason to avoid the dentist
My father was a dental technician (he made dental crowns) and he always refused to get x-rays when he went in for his check-ups. My physics professor in undergrad told me the same thing - only get dental x-rays when absolutely necessary. Bone does a good job of scattering x-rays all over the place, and your skull and jaw, believe it or not, are composed of a great deal of dense bone.
I'm a dental student, and I have been taught that - with modern equipment - exposure to radiation from 2 bitewings is about the same as half a day of ski holiday. You really need to take a lot x-rays to expose patients to significant more ionizing radiation than they receive from nature itself.
They give you this big heavy blanket (lined with lead? I dunno) to lay across your body when they do the x-ray. They seem to think it's important to block off the areas they're not actually imaging. So why don't they give you something similar to lay across the top half of your face and head? Obviously it wouldn't stop everything, but you'd think it would help at least a little.
This Space Intentionally Left Blank
Any word on whether there was a decline in this type of tumor when CMOS x-ray imaging started being used in dentistry? Using CMOS rather than film supposedly requires less exposure time or less x-ray intensity in order to obtain an image comparable to film. I see the article does comment on the decreased intensity of x-ray source now as compared to a decade or so ago, but unless they couldn't readily identify this type of tumor back then, then I would expect to have seen a decline in this type of tumor as well.
Mobile phones do not release Ionizing Radiation. They release Radio Waves. These are different things. Really... You can take off your tin foil hat to make calls again.
are sources of non-ionizing radiation.
Well, at least our friends in the UK won't have to worry about this... :P
A computer once beat me at chess, but it was no match for me at kick boxing. Emo Philips
Well, I know that it is uncommon on /. to actually RTFA, but:
>>
The lack of association with full-mouth X-rays led one expert to question the connection.
"They found a small risk (from) a pair of bitewings, but not a full mouth series, which is multiple bitewings. That inconsistency is impossible to understand to me," said Dr. Alan Lurie, president of the American Academy of Oral and Maxillofacial Radiology.
>>
So a small risk (increase from 15/10,000 to 22/10,000) caused by a pair of bitewings disappears when you do more?
I don't think so...
This is a very flawed study that doesn't account for many things including a) It's based on patients "memories" of when they got x-rays and not actual dates b) Doesn't account for the dramatic reduction in amount of rays needed for the images in the last 20-30 years.
Proof? Check this far better article http://articles.boston.com/2012-04-10/metro/31313701_1_x-rays-tumor-risk-radiation-exposure
So what's the point?
Judging from my credit card history, dental x-rays are for around $150.
Doctors aren't the only ones getting paid big bucks for doing so many so-called "defensive" tests.
If I have been able to see further than others, it is because I bought a pair of binoculars.
Supposing this is true, it took this long because everybody thought that dental X-ray was harmless.
(tumor growth in less than 1:4.000.000 images, regardless of the type of tumor.)
Dental X-ray uses less than 0.01 mSv per image.
You absorb 200 times this amount every year, year in, year out. all your life. And if you live in a place with higher background radiation, this number goes up quickly.
So it is hard to prove these tumours are caused by the exams.
Lets wait and see what comes out of this.
Usually these kind of studies have some form of bias thats not adequately corrected for.
Why are other peoples sig's always more witty ???
While we take dentistry for granted, an infection driven by a bad tooth used to be a common cause of death. Bad teeth are still a common driver to the ER for many uninsured. Remember Tom Hanks knocking his bad tooth out with an ice skate and a rock on the island? Not going to the dentist for your lifetime has a greater chance of killing you than a rare cancer from a few low dose x-rays. That said, it never hurts to make sure you dentist is using modern low dose digital equipment and not taking any unnecessary images.
And of course the most important question of them all: do Anonymous Cowards know the difference between amalgamated metals and organometallic compounds?
Only second to the question of how hard can it be to find this stuff?
If that's the case then I'd like to see their sample size for full mouth x-rays. I'd bet it's smaller than the sample size for the partial/single bitwing and that could be the source of the vanishing connection. Basic statistics, if a known correlation exists, and you didn't find it in your particular sample check your sample size first. Throwing out the correlation because the smaller sample doesn't show what the larger sample does sounds a bit foolish, and if done that way would result in no correlation ever being found in anything.
Or the sample size for full mouth was larger and a better representation of the norm. Or both were the same just too small to draw a conclusion from.
Either way Lurie is correct in asserting that this type of inconsistency results in an inconclusive study.
Because it is true. The term "ionizing radiation" is not just causal lingo, it is very specifically defined as radiation that is capable of liberating an electron from an atom thus producing an ion. This is not the case for lower frequency electromagnetic radiation such as that produced by mobile phones. Any potential health effects resulting from mobile phone use would have to be due to an entirely different mechanism.
Account -> Discussions -> Disable Sigs
Modern techniques only use 1/100th the amount of radiation of machines from only a decade ago.
I guess my question is how does the new tech affect people. If the old tech only doubled the tumor rate, reducing the amount of radiation by two magnitudes should lower your risk quite a bit.
Also, the machine at my Dentists doesn't do the whole head, but has a VERY focused output that pressed up against your cheek. You place a digital x-ray sensor between your teeth and it works as a "film".
They're like, "we don't even have to leave the room anymore". They stand right behind the machine.
So, not that huge an increase. Actually 46% is a huge increase.
They never seem to show the error bars. We are looking at a sample of 15. Not knowing anything else, one might assume Poisson statistics in which case the 1 sigma error is 1/sqrt(sample), so about 25%.
This means that 66% of the time, if one were to run the exact same test, one would get results that varied by plus or minus 4 events. The difference between a sample of 15 and a sample of 21 can be expected about half the time.
It really takes the urgency out of - OMG a factor of 46%.
http://en.wikipedia.org/wiki/Poisson_distribution.
According to the EPA (and other places), radio waves are firmly in the non-ionizing range whereas x-rays are definitely in the ionizing range. You'll have to provide some evidence that near field effects increase radio wave energy sufficiently to shift the radiation into the ionizing range with cell phones; I couldn't find any, and it's a strong claim to make. Considering the lack of unambiguous cell phone/cancer links I doubt such evidence exists.
I'm not trying to marginalize your point, but at the same time? It seems to me that dentistry is one of the areas of medicine with the least amount of oversight or "checks and balances" to ensure patients are getting what they pay for.
For example, I went to a dentist as a teenager to have an impacted wisdom tooth extracted. The oral surgeon recommended that I have "all 4 wisdom teeth pulled at the same time, since there was a good chance the others weren't all going to come in properly anyway - and it would be less painful if I only went through one extraction". I went with his recommendation, only to find that a couple years later, I had cavities in the back of a couple of my teeth, where they faced those wisdom teeth. Apparently, their enamel was damaged in the tooth extraction process, causing them to get cavities. So then I had those filled, but I remembered thinking the whole process was a bit questionable at the time, because he had a young dental assistant working with him, who he asked to mix up the amalgam filling material for him. I remember him looking at it and questioning her about whether she mixed something up enough because it didn't look quite right, stirring it around a bit in the container she was holding, and ultimately going ahead and using it on my teeth. Well, fast forward a couple more years, and I start having a bad toothache. I go to a dentist (totally different place!) and I'm informed that tooth has a big hole in the back of it (where the filling material had obviously fallen out) and the tooth isn't even salvageable anymore!
I look at all of this and have to wonder if I would have been better off if I had only opted to have the bare minimum work done in the beginning? Seems like all these dentists did was create more problems for other dentists to correct, at my expense!
And my daughter is further making me question some of these dentists.... When she was 8 years old, the pediatric dentist commented that "he saw something on the x-rays that concerned him" and "she might need some dental work, but we'll see". The next time she came in for a checkup, he wanted to schedule an expensive dental surgery procedure for her because he claimed a tooth wasn't going to come in right, etc. etc. Well, I didn't have the money so I kept putting it off.... I did send her to the next scheduled checkup though, where they declared "She doesn't need that surgery after all!" (Really?! WTF?!)
Oh, and then there's my younger brother, who had all kinds of dental problems after his dentist screwed up a procedure -- but of course, denies any of it was his doing.
The shit got modded +5 because...lo and behold...RF from a mobile phone is non-ionizing radiation. I agree that the term "radio waves" could have been better. But it would take tens of thousands of RF photons simultaneously striking the same exact electron at the same exact time to give it enough energy to break free from the atomic bond it has formed. It only takes one photon from an x-ray to do the same.
Go ahead. Do the math. Look up the energy it takes to ionize an atomic bond. Calculate the energy in an RF photon at 2.4 GHz. Calculate the energy in a photon of an dental x-ray (not sure what frequency they use). And then marvel at the four orders of magnitude between the two. I did this once, and maybe I should have saved a copy of the results so that I could paste it into the discussion every time some tin foil hatter thinks that 2.4 GHz "radiation" will give you cancer.
The primary mode of action for RF energy on biological tissue is in the form of heating. Just like your microwave. The electric field causes the dipole water molecules to rattle around, and the increased friction results in heat.
In fact, if you get an MRI, they make sure that for example your thighs are not touching each other. Because if they are, your flesh forms a loop antenna that can pick up the RF energy in the magnet room...which will cause localized heating and burns.
http://www.mrisafety.com/safety_article.asp?subject=17
"-Prepare the patient for the MR procedure by using insulation material (i.e., appropriate padding) to prevent skin-to-skin contact points and the formation of “closed-loops” from touching body parts."
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That's a total lie. They use exactly half. Source: I'm a certified dental x-ray technician.
'New' digital sensors require the same amount of X-Ray radiation, but for half the amount of time (for bitewings, that's about 100ms instead of 200ms), but since they're so quick to scan in (i.e. the Dentist doesn't have to wait for them to develop), if they aren't exactly perfect, dentists will often ask for re-takes. The average was 5 or 6 images on each patient. I was pretty good and usually only had a re-take every 3rd patient or so, but the other x-ray technician I worked with would often take 4 or 5 re-takes on a single patient. All-in-all, that means they got more radiation than if they had just gotten the traditional x-rays.
I should point out, though, that the Dentist told every patient (and told us to tell them, as well) that they only get 1/100th of the radiation. It's just a party lie.
As far as the 'pointed beam' you're talking about, that hasn't been improved, ever. The cone is just as large as it's always been. If the technician stands in the room (as my co-worker often did), they're just stupid. In fact, according to ADA recommendations, X-Ray techs are supposed to wear dosimeters. Most dentists are too cheap to buy them, though.
The 'Bitewing' x-rays that this article is about are exactly the kind that are close to your cheek. There are 3 types of dental x-rays: Bitewings, which shoot the radiation between your molars and premolars, and are used to diagnose cavities between yoru teeth. PA's, which are used to view your entire tooth, including the entire root and an area of bone beyond it. These are useful for diagnosing a toothache, because if the toothache is caused by an infection at the apex of your root, it will be visible. That, in turn, means a root canal. The third is a Panoramic, which is the kind that wraps around your entire head, and shows all of your teeth in one shot. These are beneficial for things like getting an 'aerial view'; they don't show a lot of detail (not enough to diagnose a cavity), but will show things like impacted wisdom teeth, and are useful for Orthodontists.
Yeah ironic isn't it, the type of dental radiographs that people who are paranoid of radiation exposure are most likely to insist on, is shown in a Cohort Study, which are infamous for finding false associations, to be the one more likely to cause brain cancer! Yet a FMX, Full Mouth X-ray which includes at least two Bitewings doesn't. My Magic Eight Ball says "People who show up at the Dentist's office with an acute symptomatic tooth that is leaking bacterial toxins into their blood streams are also;
More likely to get Menigiomas,
More likely to need an exquisitely painful root canal,
More likely to have a heart attack,
More likely to get type 2 diabetes,
Than people how receive routine dental care.
Apocalypse Cancelled, Sorry, No Ticket Refunds
Firstly, where did they find their sample of people who have never had bitewings taken? If you've EVER received a dental exam, the dentist almost certainly took a set of bitewings, and probably a panorex.
If you've actually never had bitewings takne, you probably aren't receiving dental care at all. And if you aren't receiving dental care, it's a safe bet that you are more likely (though not certain) to not be receiving quality medical either. Meaning you could have a menengioma and die without it ever being diagnosed.
And please, please, note that even the study stated these results were based on far older radiation levels. Today's x-rays don't need nearly as much.
Given that dental abscesses can be fatal if untreated, (in addition to poor dental health being linked to stuff far more common and deadly than brain tumors), don't refuse dental x-rays based on this report.
I think you will find that people died of brain tumours even before the mobile phone was invented. What was your point?
Quidnam Latine loqui modo coepi?
Modern x-rays (digital) use about 1/3 of the radiation of older "E-speed" (high radiation, high definition) film so your estimate of 1/100 is an exaggeration.
In addition, the "very focused" radiation beam can be a problem since even a small amount of radiation is delivered to a small area.
Standing behind the machine is probably safe. I would hope they would shield the back of the machine. However, the patient is in front of the machine and is the target of the radiation.
Radiation is bad in any amount and it doesn't do any good to deny this fact. Instead, we should all look for ways to avoid or minimize radiation exposure.
I don't read your sig. Why are you reading mine?
Since the reports of "dental x-rays" were based on patient's memory and not on actual dental records, it is likely that there is some error here. Many people probably don't remember or don't know the difference between bitewings and full mouth x-rays. They probably only remember that they had some dental x-rays. I wouldn't put too much emphasis on the difference between the two.
I don't read your sig. Why are you reading mine?
Here is the study itself. Ignore the media, they're obviously idiots.
http://onlinelibrary.wiley.com/doi/10.1002/cncr.26625/abstract
There are too many variables left untouched. The only reason this is getting attention is because it's from an Ivy.
Are these digital radiographs (formal term for "x-ray")? Are these older film radiographs? What other sources of radiation are these people exposed to? What were their settings for each capture? Is it confirmed and documented? Are they travelers?
Obviously exposure to ionizing radiation is bad. No one is arguing that. However, in terms of damage, you just threw a pebble at a canoe in the water.
A radiograph from a general dentist, be it bite-wing or periapical is about 1/2 the daily background radiation exposure per shot.
Panorex (the thing you bite down and another thing goes around your head... most common when you see an oral surgeon to get third molars removed or an ortho / perio / prostho) is obviously more radiation exposure. While it is a fairly centralized beam, there still is scatter as it moves around your head.
Then if you see an orthodontist, you'll probably get something called a lateral cephalogram which is even more with a larger exposure target (includes brain).
In the dental community, there is a LOT of skepticism and unanswered questions.
Oh since this is /. here is a obligatory XKCD - http://xkcd.com/radiation/
Given the chart I linked and it's relative accuracy, these people would probably blame a Sinal CT on Kennedy getting shot.
That is called a digital intraoral sensor.
The thing where it's directly against your cheek is called a periapical radiograph. (from above the tooth to root structure).
The thing where you bite down on is called a bite-wing (go figure).
Digitals are such low doses. However you should always get a lead shield on you and the practitioner should leave the room. You might get it once every 6 months, but I do it 10 to 15 times a day. Deduced from this article, all dentists by the age of 50 should be similar to The Toxic Avenger.
Now I know why the dentist next door goes through so many dental hygienists...
All your post states is that you don't understand radiation.
You certification means you can operate the q\equipment with minimal safety guidelines, and that's it.
You are not an expert, scientists, or specialist. Please leave the science to actual experts and stop waving your certificate around like it some how adds validation to anything outside the operation of you job.
I hate it when people get a piece of paper in one things and then think that makes them an expert on everything.
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The Kruger Dunning explains most post on
Looking at your article, I'm left wondering, if the H and E fields are so capable of ionization, why aren't MRIs giving everyone cancer? I mean, an MRI has up to seven Teslas of magnetism. Around ten Teslas you can make frogs levitate. Ten Teslas is way fucking bigger than any H field you will see in the near field, I don't care if you're just one angstrom away from the antenna.
As far as glow discharge, the glowing is not caused by the electric field ionizing the atoms. Rather, the electric field accelerates the electrons, and when the accelerated electron slams into an atom, *that* causes the ionization. Those glowing tubes that you mentioned earlier? Did you know that sometimes they put in a trace of radioactive gas to help seed electrons in the tube? You only need a few to start, and once they get moving they cause more, kinda like a nuclear chain reaction.
It sounds like you should do some more research on dielectrics and breakdown voltage. You seem to think that dielectric breakdown causes ionization, when the reverse is actually more true; ionization reduces the dielectric constant for the path that has been ionized.
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With dentists, just like doctors, they're not all equal. Some are downright incompetent. Plus, just like with surgeons, dentistry is a very hands-on profession, making it a real art. Not everyone is gifted with great dexterity and the ability to do extremely fine work. If the dentist you're seeing is saying things that bother you, you should go visit a different dentist for a second opinion.
+5 Informative? Really? Basically, you said We are looking at a sample of 15 - after that your math is worthless. They said 15 out of 10,000, and if you RTFA, the sample size is stated at 1350.
You can re-do your math for partial credit, but my point still stands - 15 to 21 IS a huge increase, even if 15/10000 vs 21/10000 is not a very big number.
Jerk (he says, ironically belittling his own point).
This issue is a bit more complicated than you think.