Dental X-Rays Linked To Common Brain Tumor 248
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."
Finally (Score:3)
Re:Finally (Score:4, Funny)
A valid reason to avoid the dentist
Here is a better reason [youtube.com].
not sure (Score:2, Interesting)
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.
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Along these lines, my dentist once told me that the lead apron they have you wear is more for patients peace of mind then necessity.
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Ya, and that's why they leave the room when taking the x-ray.
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That actually seems reasonable enough to me. I mean, one x-ray every 9 months.. probably not bad. Being in the same room with dozens of x-rays a day .. that might cause problems.
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Usually the machine you think of as the "decades-old X-ray machine" isn't discarded and isn't insanely expensive; a new X-ray can be had in the $1.2 - 2.5K range. The magic sauce is the film, the people in the study, as old as 79 were likely X-rayed with the very old and slow C speed film, new film E and F speed is much faster alowing reduced exposure; changing to a faster film is trivial. Next comes the Phosphor storage screen, used like film, but laser scanned and digitalized, way faster than film but co
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Re:not sure (Score:5, Insightful)
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.
These comparisons are always misleading, because they ignore the density of the radiation received. Radiation from half a day of ski holiday is diffused over your entire body. The radiation from bite wing X-rays is concentrated on your teeth and skull. The concentration matters.
Let's use a better analogy. The energy at the focal point of a magnifying glass might be one-hundredth the amount of energy you get from standing out in the sunshine. But because that energy is concentrated into a small point, it will burn your skin.
We survive nature not because it isn't powerful, but because its power is spread out. That power gets dangerous when mankind focuses and purifies it.
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Point is, it's as likely that the film you bite down on and the plastic it's covered in turns out to be carcinogenic. We're talking a very small amount of radiation here.
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The concentration matters.
Not really. It's still well below the acute-effect threshold. Cancer, as far as we can tell, is a long-term, low-probability effect that is linear in the total amount of exposure. Being concentrated in one place over another may well influence what body parts have a higher probability of getting cancer, but in terms of total probability, concentrating the radiation in time (short exposure) or space (concentrated area) has no effect. Linear relationship means that only total dose matters.
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But it cannot be a linear effect. The ionizing events may be linear, but the body's ability to deal with damage will be non-linear -- approximating to linear only over a small enough number of events. It is also now known that the probability of mutation events in DNA differs substantially along its length - two or three orders of magnitude isn't unusual. Some areas of DNA are unimportant, others more so. Approximating everything to linear relationships doesn't work.
Also, the vast majority of what we know a
Re:not sure (Score:5, Informative)
>> 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.
>These comparisons are always misleading, because they ignore the density of the radiation received. Radiation from half a day of ski holiday is diffused over your entire body. The radiation from bite wing X-rays is concentrated on your teeth and skull. The concentration matters. Let's use a better analogy. The energy at the focal point of a magnifying glass might be one-hundredth the amount of energy you get from standing out in the sunshine. But because that energy is concentrated into a small point, it will burn your skin.
Unsurprisingly, the dental student's professor knows more about this than you do. The professor's analogy is the correct one. Yours is the incorrect one.
When x-rays cause cancer, it's a statistical process. Each x-ray photon has some small probability P of damaging a cell's DNA in such a way as to make it cancerous.
When you go skiing in the mountains, you're exposing yourself to more cosmic rays than you get at sea level. These are high-energy charged particles, not x-ray photons, but the statistical nature of the process is the same.
When you burn your skin with a magnifying glass, there is nothing statistical about the process. The outcome is deterministic. You're simply transporting x amount of energy into a certain piece of your flesh, raising its temperature by y degrees.
In case it matters, I have a PhD in physics, my field is nuclear physics, and I have worked with ionizing radiation a lot.
The only thing I would add to the correct information that the GP related from his/her professor is that in addition to the possibility of causing cancer, radiation can also make you healthier, via a well-documented effect called radiation hormesis. The usual interpretation (which is hard to test empirically) is that the radiation stimulates your cells' damage-control mechanisms. At the very low doses we're talking about, the evidence from controlled animal studies is that the net effect on your health is positive, because the hormesis effect is orders of magnitude stronger than the negative effects of the radiation.
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You are correct, although the repair mechanism is not all that good and ONLY exists in nucleic DNA (there is no repair mechanism in mitochondrial DNA).
Dosage over time is important, which is why the maximum safe dose is given as a dose per unit of time. However, in the better tables, the maximum safe dose per year is NOT 365.25x the maximum safe dose per day. The calculations are not simple ones and are constantly under revision. I imagine that with this new data on dental X-Rays that the safe dosage calcul
Re:not sure (Score:5, Interesting)
In case it matters, I have a PhD in physics, my field is nuclear physics, and I have worked with ionizing radiation a lot.
Masters' in physics here with a similar background to yours.
My point is that the statistical likelihood of damage due to radiation depends upon its flux. For the same amount of incident energy, the flux you receive across your entire body is lower than if the same energy were collimated and aimed at your skull. The same number of photons in a smaller area increases the risk in that area. So saying that a dental X-ray has the same energy as a full-body soak in low-level radiation is deceptive. The dental X-ray is over a much smaller area, has a higher incident flux, and therefore has a larger chance to cause damage in that specific region.
The only thing I would add to the correct information that the GP related from his/her professor is that in addition to the possibility of causing cancer, radiation can also make you healthier, via a well-documented effect called radiation hormesis. The usual interpretation (which is hard to test empirically) is that the radiation stimulates your cells' damage-control mechanisms. At the very low doses we're talking about, the evidence from controlled animal studies is that the net effect on your health is positive, because the hormesis effect is orders of magnitude stronger than the negative effects of the radiation.
And this makes me suspicious of your credentials, because hormesis is an effect usually only talked about by snake oil salesmen. It's not a reliable effect, and there's a good bit of argument against it existing at all. Even if it does exist it is not something you want to play with, as a very small change of dose can drive your exposure from 'beneficial' to 'really dangerous'. If you're relying on hormesis to keep you safe then you are begging for disaster.
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The article sort of touches on this:
Lurie also echoed Claus' caution that radiation levels from dental X-rays when some of the participants were younger was much greater than is used now.
The result may be different if everyone had used today's equipment the whole time.
I've often wondered... (Score:4, Interesting)
Re:I've often wondered... (Score:4, Informative)
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Lead doesn't reflect radiation, it absorbs it. But that's irrelevant because "bouncing off your teeth and jaw" is equally flawed. X-Rays and other forms of ionizing radiation don't "bounce off" surfaces, it will either pass through, be absorbed, or trigger another particle to be emitted. There are 3 types of radiation that may be emitted, alpha, beta, and gamma. Alpha and beta will only penetrate a few millimeters of solid/liquid matter such as skin, muscle, etc so those won't make it back out of the body.
Re:I've often wondered... (Score:5, Insightful)
X-Rays and other forms of ionizing radiation don't "bounce off" surfaces, it will either pass through, be absorbed, or trigger another particle to be emitted.
I assure you that all kinds of ionizing radiation can reflect. X-rays can reflect -- they make X-ray mirrors, usually out of highly-polished beryllium. It's more effective at small reflection angles (glancing reflection). You can even make X-ray fiber optics (glass light pipes), which is a decent way of focusing an X-ray beam. These again are only really effective for glancing reflections. Alpha particles and electrons also reflect.
Triggering another particle to be emitted is actually a subset of "be absorbed", although this isn't obvious. Photons aborbed by atoms regularly kick an electron into an excited state (or ionize it, the highest-energy excited state, in a sense). Electrons falling back into their ground states cause the emission of new photons with well-defined energies. I suppose you could also have a photon kick an electron into motion, producing a beta ray, but I don't think that occurs much in nonconductive bulk materials. (Usually you go the other way: electron beam to X-ray beam through brehmsstralung.)
There are 3 types of radiation that may be emitted, alpha, beta, and gamma.
Sort of. From nuclear sources. There are actually many more particles that can be emitted from particle decays, but those are the most common. More to the point, though, radiation sources used for X-rays generally don't emit alpha or beta particles. In fact, the term "X-ray" refers to a particular part of the electromagnetic spectrum. Gamma rays are electromagnetic radiation. (They conventionally referred to electromagnetic radiation within the energy range commonly emitted by radioactive materials. It's really preferable these days to call all such things "photons" regardless of their energy.) So, X-rays and gamma radiation are the same thing. Alpha and beta radiation are in no way relevant here.
However, putting a shield over the patient's head would only protect other people in the room, not the patient, because any such radiation would coming OUT of the patient's head.
That's only really true if the X-rays are well-collimated. Since they point the X-ray beam so that it goes horizontally through your head (more or less) and then give you a lead shield for your chest, it stands to reason that either the X-ray beam is not well-collimated or the lead shield isn't there to serve a functional purpose.
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I assure you that all kinds of ionizing radiation can reflect. X-rays can reflect -- they make X-ray mirrors, usually out of highly-polished beryllium. It's more effective at small reflection angles (glancing reflection). You can even make X-ray fiber optics (glass light pipes), which is a decent way of focusing an X-ray beam. These again are only really effective for glancing reflections.
Which simply affirms my statement. Yes, some small portion can be deflected, but as you noted, it's "only really effective for glancing reflections".
Gamma rays are electromagnetic radiation. (They conventionally referred to electromagnetic radiation within the energy range commonly emitted by radioactive materials. It's really preferable these days to call all such things "photons" regardless of their energy.) So, X-rays and gamma radiation are the same thing.
Actually, gamma [wikipedia.org] has two different uses, the older/historical definition is based upon the wavelength/energy of the radiation. That definition is now only used in astronomy (because the source of the emission can't be determined). The accepted usage in cases where the source can be determined is that gamma ray/radiation is produced in the nucleus, x-rays are pro
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"Keep it in" only happens if the material reflects X-rays. Most materials don't reflect X-rays; it's a pain to make an X-ray mirror. They use lead, which absorbs X-rays. A lead apron (or hat) always "keeps it in" in the sense that the X-rays are converted into heat inside the lead apron.
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My dentist once told me that the apron is more for patient peace of mind then any practical purpose these days. Given the nature of how the x-rays are delivered, it would seem a useless measure (hint: they point the thing at your head...).
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I'm pretty if sure most people were told to put on this lead mask they would tell their dentist to f-off and forget about the xray.
CMOS imaging? (Score:3, Interesting)
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.
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Although the sensitivies for film and sensors have been improving, dental head CTs (which are much higher dose) have become increasingly common. While dental CTs are intended for special situations involving complex procedures, I've head of them being used in routine care as well, and it'd be interesting to know if it off-sets doage reductions elsewhere.
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What was considered "routine care" for the CT?
I can't think of anything in bread and butter dentistry that a CT would actually help with to any practical extent.
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That another area where the study seems nonsensical, it assumes that every exposure is equivalent, the newer films are almost as fast as the original sensors, and some of the subjects, being as old as 79, could easily been exposed be equipment a century old containing rotary telephone exchange technology of counting pulses with mechanical relays.
Well at least... (Score:3)
Well, at least our friends in the UK won't have to worry about this... :P
Flawed Study (Score:5, Informative)
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 [boston.com]
A newspaper report. (Score:2)
Sorry, but my main objection to both the claim and counter-claim is that this is journalism, not science. Can't someone provide links to PLoS One papers? Arxiv? Cancer research group websites? I'd ask my uncle, who was a statistician specializing in cancer research, but he's retired and won't be on the cutting edge any more. This needs to be answered by researchers who have that up-to-the-microsecond knowledge.
However, I'd also point out that the "dramatic reduction" you speak of is questionable. I've seen
This is bizzare (Score:3)
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.
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Oops! (Score:2)
I've been having problems with frequent headaches recently and I was worried that I might have a brain tumor or something. I've been to a neurologist who had me get an MRI to eliminate that possibility (which BTW it did, phew!). I've had enough dental xrays over the years, but rarely a full mouth set. Most of the time the dentist would only take views of any teeth that looked problematic visually, or if I was complaining of pain and nothing was visual in that area. I also had localized views taken befor
Ok but.... (Score:2)
Here is the study itself. Ignore the media, they're obviously idiots.
http://onlinelibrary.wiley.com/doi/10.1002/cncr.26625/abstract [wiley.com]
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 exp
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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.
Re:Cancer... (Score:5, Insightful)
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.
Re:Cancer... (Score:5, Informative)
'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.
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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.
Is there ANY truth to this? Where does the 1/100 come from? It's hard for me to believe it's just a complete lie, especially considering you're talking about being off by a factor of 50.
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Very, very early x-ray machines used considerably more radiation. Over a thousand times as much, according to some.
http://abcnews.go.com/Health/Wellness/century-ray-machine-shows-radiation-risks-yore/story?id=13140857#.T4R5CtXe4tY [go.com]
I would imagine that it is possible to find a band of time over which radiation has decreased by 100, but how useful is it as a measure? Does it really matter that an x-ray machine emits 100x less over the course of a lifetime, or even a decade? If the dosage was so great a decade
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So, basically, the GP is totally, utterly debunked in every aspect and every statement.
so that's why the dentist goes through so many.... (Score:3)
Now I know why the dentist next door goes through so many dental hygienists...
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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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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
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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
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Deduced from this article, all dentists by the age of 50 should be similar to The Toxic Avenger.
Why? the patient is being subjected to radiaiton; my dentist leaves the room.
Re:And it took this long to "make the connection"? (Score:5, Informative)
Re:And it took this long to "make the connection"? (Score:5, Insightful)
Re:And it took this long to "make the connection"? (Score:4, Informative)
According to the EPA [epa.gov] (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.
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A 4W handheld CB at 27MHz will light up a neon tube when you bring the antenna close to the bulb.
Cell phones star at 800mhz and most in the US are at 1800-1900mhz. That means touching the tube.
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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 [youtube.com]. 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 accele
Re:And it took this long to "make the connection"? (Score:5, Insightful)
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 [mrisafety.com]
"-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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Don't forget cell phones operate below 2.4GHz, so it's an even bigger difference between RF and ionizing radiation
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Don't have time to post it all out, put it's easy to compare energies of photons at various frequencies at Wolfram-Alpha. Very instructive exercise left to the student.
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The higher the frequency, the higher the energy. You can throw as many low-energy photons at something as you want (let's disregard extreme cases like MW lasers firing at something), but you won't ionize anything. You'll just heat it up.
Quantum physics 101.
Re:And it took this long to "make the connection"? (Score:4, Informative)
Re:And it took this long to "make the connection"? (Score:5, Interesting)
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...
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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.
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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.
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Exactly. These sorts of 'memory recall' studies usually never pan out. I don't remember what x-rays I got 10 years ago. I can't even remember the details of my last series (did we do a bite wing? an apical? was that the time I was dealing with the root canal?).
But now you've got enough data to go and scrounge for money for a prospective study. This is all well and good, I can't come up with a better way to do science in our current environment. But don't stop the presses just yet.
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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 [wikipedia.org], 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;
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Hey look, a stupid, panicky post made in repsonse to "brain tumor" and "radiation" with not a shred of accuracy.
But that doesn't make it obvious that a dental x-ray would be a source of such mutations. Like all x-rays they are carefully dosed and focused on a narrow region.
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Actually 46% is a huge increase.
Re:And it took this long to "make the connection"? (Score:5, Informative)
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 [wikipedia.org].
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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).
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But that doesn't make it obvious that a dental x-ray would be a source of such mutations. Like all x-rays they are carefully dosed and focused on a narrow region.
I've had a couple of dental X-rays. Both times I was asked if I'd had any kind of head X-ray within the last year. The last one was almost a decade ago, and even then they were very hesitant to X-ray anyone more than once every few years. Saying that there is an increased risk for people who have 'one or more' dental X-rays per year is repeating something that dentists have apparently known for a very long time. Quantifying that risk may be news, but the existence of it certainly isn't.
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IMO That's because it takes a few decades for the "new adopters" of a technology to get old enough to provide enough data for how damaging these things are to us. We've already studied and solved things that harm us in the short term, but things like whether something causes a higher incidence of cancer requires you to
a) Get cancer
b) Lots of other people from your generation to get cancer (both those who used the technology heavily or none/a little)
Then you can look at cancer types, where they start, how
New vs Old tech (Score:2)
So, you're proposing we only use 'old technology'.
That means Film X-rays [eavesdental.com] vs digital ones [rdhmag.com] that reduce radiation exposure 50-90%
Rather than using digital cell phones transmitting 1/4 watt, we'd be using analog ones that transmitted at 4 watts.
Rather than using wifi, we'd just stick with old portable phones - 2.4Ghz, right next to your head, at like 10X the output.
The list goes on. As mentioned in other threads here, there's a big difference between ionizing and non-ionizing radiation.
Heck, you list Asbestos
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I think you missed my point, not that there wasn't more danger back then. Just that back then we didn't know how dangerous everything was. People back then probably thought they were really safe and advanced, compared to a few generations before them (nerds with a well rounded understanding of technology excepted).
As for asbestos, I was referring to its use for fire protection in houses/buildings, which was going on before the war AFAIK, at least in Europe.
Take lead piping as another example, I think that
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Before you indirectly attack Wi-Fi (even if that wasn't your intention), please try and find a biological, chemical or physical mechanism for cancer to develop due to microwave radiation.
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I was using it as an example of "unknown" that some people go nuts about. The worst I got from wifi was headaches when near a transmitter (back when they first came out, it became an excellent way of telling if there was a wifi network nearby I could use without having to take out and boot up my laptop), or a very long migrane after I stuck my head in-between a very powerful point to point microwave link (it was not supposed to be running at the time).
I think the "OMG wifi is giving me cancer crowd" are in
look on the bright side (Score:2)
it only affects those people constant babbling loudly in quiet public places about their boyfriend's parents, their kid's rash, or their awesome trip to the city, because they have the cell phone constantly stuck to their ear
a mobile app user like myself, i just keep my cell phone at my waist, so my brain is fine. it only means i'm going to be sterile and leave no offspring
it will be quieter world, whatever type of mobile user you are
Re:And it took this long to "make the connection"? (Score:5, Insightful)
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.
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http://www.youtube.com/watch?v=BOIDFh3wPXY
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Because cancers don't appear immediately after exposure - sometimes it takes decades for the cancers to appear. Then, once cancer does appear, you have to wait until enough of those cancers appear to have a valid statistical base. Then you have to work through all the potential causes to isolate the prime cause... And that's all made more difficult when t
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Alpha particles are He2+ ions (that is, a pair of protons and a pair of neutrons with no electrons) and beta particles are electrons. However, neither of those penetrate matter very effectively, while gamma rays (i.e., photons) do.
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Good. At the rate this society is going we'll have completely cured brain cancer in a decade or so.
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are sources of non-ionizing radiation.
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I think they identify problems below the gumline, or some problems inside the teeth. I presume they could find a cancerous mass in a jaw sooner and save some lives too. Perhaps when smoking/chewing was more prevalent that was a good service, but the odds of a modern nonsmoker getting jaw cancer are likely quite low.
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I presume they could find a cancerous mass in a jaw sooner and save some lives too. Perhaps when smoking/chewing was more prevalent that was a good service, but the odds of a modern nonsmoker getting jaw cancer are likely quite low.
Seems like a nice business plan:
1. Take dental X-rays
2. Which cause jaw cancer
3. Which can only be found using dental X-rays
4. Profit!
5. GOTO 1
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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.
Bunch of reasons: (Score:2)
- Cavities between the teeth that cannot be found via the probe. If they are caught early, they can be easily treated. If you wait until they CAN be found by the probe, you risk a root canal, or worse.
- The dentist is looking for bone recession indicating gum problems
- Abscesses under the gumline.
Re: (Score:2)
Searching for cavities is the only thing dentists do? I bet you can be more imaginative if you try a little bit more.
Re:Between that and Mercury thats "locked" in fill (Score:4)
re: taking dentistry for granted (Score:5, Interesting)
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.
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I have a buddy with this huge gap right in the middle of his upper front teeth. Other than that he has perfect teeth. Years ago he went in to get a small gap closed and the idiot dentist actually spread the gap wider instead. I don't know how he couldn't tell it was going the wrong way while it was happening. After it was done apparently all the rest of his teeth were scooted by it and closing it now is not a simple procedure so he just left it. HUGE GAP for no reason.
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Hate to burst a bubble but pretty much all 'medical' practitioners from acupuncturists to neurosurgeons have limited oversight and do things that, in retrospect, seem batshit insane.
Health care can be a big gamble, some things work, a lot don't. In general, I think we're improving all of the time (Big Pharma being a notable exception) but it's not easy, inexpensive or guaranteed.
McCoy: [McCoy, masked and in surgical garb, passes an elderly woman groaning on a gurney in the hallway] What's the matter with you?
Elderly patient: [weakly] Kidney
[pause]
Elderly patient: dialysis.
McCoy: [geniunely surprised] Dialysis?
[musing to himself]
McCoy: What is this, the Dark Ages?
[He turns back to the patient and hands her a large white pill]
McCoy: Here,
[pause]
McCoy: you swallow that, and if you have any more problems, just call me!
[He pats her cheek and leaves]
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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.
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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? [lsro.org]
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Even if all the mercury leaks out of a filling over the course of a few days it won't harm you. It's not good for you, but you'll be fine.
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Yep. No more mercury poisoning. Now we'll get UV radiation induced skin cancers inside our mouths.
Science marches on!
(Only half kidding.)
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A person might get a dental x-ray every 6 months, but if a person had a serious head injury every 6 months then they've bigger problems than brain cancer.
This matters.
You've also got to consider the radiation involved. Ionizing radiation of different frequencies won't have an equal probability of ionizing, and a higher frequency will only have a higher probability of ionizing SPECIFIC things (an electron cannot jump half an orbit, you cannot have half a quantum leap).
Finally, you declare that there is no ev