Bite Point

New Frontiers in Dental Medicine: X-rays and 3-D Imaging

In a brief series of posts, I offer some predictions for the directions that dentistry will take in the coming decades.  Part one:

Imaging

All imaging will be 3-D and very high resolution.  In our own office, we've already transitioned from those little "analog" X-ray films to 2-D digital.  There are so many advantages to this.  We can manipulate and work with our images to better diagnose our patients.  The images are larger and of better resolution than the analog ones were- and kinder on my eyes, which now have behind them more than a quarter century of making decisions for patients based on varying shades of gray...

At the present time, 2-D digital X-rays are the best way to see decay between teeth.  These cavities can be thought of as "flossing cavities", or perhaps "not-flossing cavities", because they occur under the place where teeth meet, where we can clean best by flossing.  These cavities look like little dark triangles, bitten out of the light gray enamel, just where the teeth touch each other.  The question in early ones always is, "Is this deep enough to require a restoration, or is it just a bit decalcified, and not yet a cavity?"  Here are some of these dark areas that have just crossed over the threshold into being cavities:

 

Then we have challenges that are presented by the overlap between teeth on images that results from crowding and misalignment.  In this next film, we have a hard time reading what, if anything, is going on between the two upper molars.  We also have difficulty determining if there is decay under the old silver amalgam restorations, which are the bright white objects.  (Well, the bright white objects except for the one shaped like the letter "a"...)  Yet the lower teeth in this film show up perfectly well.  If we were to try for an angle that better captures the upper situation, we'd miss something on the lower.  It's a catch-22.

 

While the tooth on the far right in the next image has a cavity that deserves its own Zip Code, we still face decisions of whether such a tooth can be saved with advanced treatment.  Perhaps an extraction and implant ("titanium doesn't decay" being a defensible mantra) would be more appropriate.  Many times in my career I've decided such issues by intervention, meaning anesthetizing my patient, excavating decay, initiating root canal treatment, and deciding if I can save the tooth when I've seen what's left.  While I keep my fees low until the issue is decided and my patient commits to a course of treatment, how much better it would be if we could image the tooth in 3-D and with a voxel size of hundredths of a millimeter.  I could look at the image on the computer with my patient by my side and we'd decide on treatment without any invasive procedure being done.

 

What I look forward to is this: that all of our images will soon be very high resolution 3-D.  We will be able to virtually take teeth out of the arch and spin them around and look at them from all sides.  We will be able to look at cross sections and evaluate whether early lesions are decay or not with an extraordinary degree of certainty, even in situations where there is overlap in the actual patient's mouth.  We will be able to manipulate images and better diagnose and evaluate all oral disease, including root canal infections and periodontal issues.  Planning dental implants will become a matter of precision placement, where injury to critical structures in the jaws is avoided with total certainty.  Post-operative radiographic evaluations of restorative, endodontic, implant and other treatments will be orders of magnitude better than they are now, and will provide superb legal documentation.  The list of benefits is almost endless...

The application of this technology to periodontal (gum) disease diagnosis is also exciting to think about.  We will have a better pre-operative understanding of angular bone defects like these:

 

This process of adopting the innovation of 3-D radiographic imaging in denstistry is already starting.  Our periodontist and oral surgeon friends have iCAT and other scanning devices and our patients benefit tremendously when periodontal and dental implant procedures are planned.  In addition, some endodontists (root canal specialists) are using the Kodak K9000 3-D dental imaging device to diagnose and evaluate their treatments in 3-D.  I've listed the 0.005 - 0.038 mSv radiation exposure in http://rickwilsondmd.typepad.com/rick_wilson_dmds_blog/2010/05/sieverts-they-used-to-be-so-rad.html, which lists the exposures from a large array of common medical diagnostic procedures. 

These are from an iCAT scan of me, by the way, done by my friend Thomas Kohler D.D.S.:

 

 

And yes, "Golden-Jaw" would be a very cool nickname for a dentist...

Perhaps the most serious challenge of all in dentistry is to accurately diagnose bone cancer and bone metabolic disorders like Paget's disease.  Scanning in  3-D at high resolution for very minimal radiation exposure will be a tremendous benefit to our patients.

So, I look forward to the day, which will no doubt be here soon, when 2-D X-ray images are a niche, a thing of the past, with all the quaint 80's-era functionality of the fax machine and cassette-based Walkman.  Back then, you could still send information instantaneously and listen to a personal music library- but we do these things much better today with the digital storage and transfer of information.

Next up: 3-D optical scans as an innovation that replaces physical impressions of teeth.

Dentistry's Cost Model in the Context of Health Care Reform

There are many complex issues that we as consumers and voters have to work out regarding the recently passed health care reform law.  A rational, non-partisan approach to understanding it all will surely bring to light both benefits and drawbacks- which cannot be properly understood in the context of media and political sound bites.

As our health care insurance premiums rise faster than North Korea's arms expenditures, I'd like you to consider the manner in which dentistry has dealt with the cost of care issue...

When I had an acute medical problem last April, I saw when the dust settled that the "raw" cost of two CAT scans was $19,000 before insurance adjustments etc.

Sometimes in preparation for dental implants, a dental-specific CAT scan is desireable.  We refer our patients to several providers of this service, both private practioners and hospital-based.  The cost of a dental CAT scan, as provided by our colleagues, is $300, plus or minus about $50.

So, accounting for the fact that I had two CAT scans, the bottom line is that dentistry provides a roughly equivalent diagnostic service for 3% of the medical model's cost.

 

Yes, I've selected the most dramatic example I can possibly think of.  And yes, I'm making a whole range of assumptions and ignoring certain details.  Most significant among them is that the medical CAT scanner machines surely cost a lot more than the dental ones, which are expensive enough themselves.  (They do scan a lot more patients in hospitals than we do, however!)  Still, with the device called the i-CAT, for example, the purchasing practioner gets a lot for her money:

http://www.henryschein.com/us-en/Dental/Equipment/iCat.aspx

Even as a dentist, I wish that I had a better understanding of the historical and economic reasons for our cost model to be so different than that of much of the rest of medicine.  There are so many factors. We tend to practice as individuals or small groups, whereas medicine corporatized and systematized itself long ago.  We introduce new technology that will benefit our patients only when we can either support the acquisition cost directly in our practice or when we can borrow reasonable levels of capital.  As many as 50% of our patients do not have dental "insurance", which at best is really a supplemental benefit to make care more affordable, as my friend Dr. Marc Rothman pointed out in his astute comments to: http://rickwilsondmd.typepad.com/rick_wilson_dmds_blog/2010/09/dental-insurance-the-determining-transaction.html.  

Our patients also pay us much more directly than in the medical model, in which a third party has the role of paying doctors and hospitals, changing the chain of accountability considerably from most other consumer expenditures.  Finally, in dentistry we are superbly successful with prevention of disease and maintenance of health for any patient who is reasonably compliant with our recommendations.  If only the American publlic really knew how much we've reduced the ravages of periodontal disease in the last 30 years...  In contrast, there is significant debate on the focus of American medicine on "fixing" the things that go wrong with people's bodies, and on the role of self-destructive human behavior in the incidence of many disease processes in the first place.  Preventing disease and maintaing health is not emphasized sufficiently in our system.

Whatever the reasons, the next time you find it necessary to make a significant expenditure on dental care, please consider viewing the glass as half full, rather than half empty.

Three percent is remarkable.

 

What Count Basie Taught Me About Intolerance

When I was 13 years old, Count Basie chatted with me during an entire break between sets at one of his gigs.  Me, just a kid at the time, when he could have spent that time in any way he wanted to!  And as if that wasn't enough, his 2nd alto sax man at the time, Curt Pegler, talked shop with me (an alto player myself) all during the next break!

I was so lucky that my parents took me to see so many of these Big Bands while their original band leaders were alive and well.  Maynard Ferguson, Woody Herman, Benny Goodman; Stan Kenton on the Art Museum steps- little knowing that someday I'd live my dental career just scant yards from there! Sonny Payne with his insanely fancy drumstick maneuverings; I even saw Gene Krupa once!  My Dad is a jazz drummer still, and Krupa was always his favorite.  They had met and talked once and Gene recognized my Dad and called him by name, speaking to us at our table for a few minutes.  Ella Fitzgerald- I saw her in college, and I admit it she made me cry with joy, she was so wonderful. 

Basie was always my favorite though, and I saw him twice.  The first time I was younger, maybe 11, and my signature memory besides the gorgeous and fascinating music was smoke in my eyes.  Not the sultry old standard "Smoke Gets in my Eyes", but the real, airway-burning, eye-ripping carcinogenic effluent from too many cigarettes in a crowded room.  The second time, my Dad and I caught him at, I believe, the old Covered Wagon Inn.  All these years later I recall the room precisely and can hark back and picture Curt and I chatting at the corner of the bar.   (Were they more lax about kids, accompanied by their parents, being in proximity with alcohol in those days?  I dunno.)

http://www.youtube.com/watch?v=GQi4jglT0Vo

Basie taught me so much.  First, the man had incredible "chops"- the basic set of musical skills a musician possesses, particularly in jazz.  He could shed arpeggios with blinding speed.  I've heard him do it, it's amazing.  And yet he often started a piece or took a solo with just a few spare notes.  Why did he forego musical density for minimalism so often?  I'm not sure what was in his mind, but I have my theory.  He may have only played a few notes, but they were excellent notes.  They mattered.  Basie also understood that the spaces between the notes were just as important, if not more so, than the notes themselves.  There's a lesson in human communication!  He also left us wanting more.  That was part of why he was so successful for his entire career; in short, he was always cool.  Never jumped the shark... 

Imagine my elation when I got to Muhlenberg College and found that our band director, Barry Kolman, was also into Basie.  Every concert contained at least one chart, sometimes two.  In fact I can quote Dr. Kolman precisely: "If you can understand Basie, you can understand the rest ot jazz."  And it was true.

My most important and valuable lessons learned from Basie are not about music, however, but concern intolerance.  The thing is, William "Count" Basie was born in 1904, a time of open and raw intolerance in this country.  I wish at age 13 I could have had the understanding to ask him about his response to the intolerance he saw around him, but I believe that I know the essence of it.  Faced with something monstrous that he could not control, he chose to influence it- and also to control his own reactions to it.  What I mean is, in his gentle and yet relentlessly consistent way, he broke down barriers long before the more famous musicians and athletes of a later generation.  Basie was an outlier- in Malcolm Gladwell's definition from the book of the same name.  Outliers are defined by Gladwell as people who do not fit into our normal understanding of achievement; exceptional people, especially those who are smart, rich, and successful, and those who operate at the extreme outer edge of what is statistically possible.

What I want to say to a later generation of listeners who may not be familiar with Count Basie's music is this: you can hear in the music itself that the man is an outlier.  You can hear that he was remarkable and interested in doing things the way he felt, not the way that someone told him to.  And, most importantly, you can hear Basie's essential optimism.  It runs through every note.  That irrepressible mid-20th Century American optimism that may be gone now.  A recognition that things may not be perfect, but that they for darn sure are going to keep getting better, and this man's job is to contribute something positive to that goal with his music and his actions and his life.

And, in a classic and memorable example of doing just that, one person at a time: by talking to a 13 year old kid and signing a photograph to him: "To Rick, Basie '74".

     
 

The Flawed Corporate-Interchangeable Model

 

Regarding the dehumanized, corporate-interchangeable model of customers and employees: Fear is at its core. Fear of us, the customer. Fear of their bosses coming down on them for not following the manual. Fear of making a decision, fear of being proactive, fear of emotional labor, fear of bringing the delight of a meaningful human encounter to their fellow man. It's fear of success, not fear of failure!

 
 

 
 

 

(see Anne McCrossan's www.visceralbusiness.com for superb ideas on how to fight this model in your organization)

Green Dots and Red Dots- Susceptibility to Periodontitis

One of the best lecturers in my profession on the subject of periodontal disease is Dr. Sam Low. 

http://www.perio.org/consumer/bio_low2009.htm

One of the brilliant things that he does is to break down all the thousands of studies that look into the germs that cause gum disease, the genetic susceptibilites that we inherit, the oral hygiene and patient motivational factors- all of it- and then to come up with an astonishingly simple lens through which to view the situation:

Green Dots and Red Dots.

Genetic susceptibility is very important to consider.  It turns out that 65% of the population are fairly resistant to periodontal disease.  This does not mean that we should be complacent!  If the system is overloaded, so to speak, with vast amounts of plaque and tartar and the mouth is not clean, then gum disease will still occur. It just takes some time.  Then there are 35% of the population that are susceptible to periodontal disease, 15% being highly susceptible.  Dr. Low classifies patients as "Green Dots" and "Red Dots", referring to the stickers that they place on the outside of patient charts at the University of Florida.  Bottom line: if you're a "Red Dot", you are disease-prone and keeping up with your home care, the way that you clean your teeth daily on your own, is extremely critical.  So are regular visits to your general dentist and, perhaps, periodontist.  In susceptible individuals it's considered best to have a professional cleaning four times per year rather than the more commonly scheduled two. 

If you're a "Green Dot", then the same level of home care will still keep you free of disease, and will also help prevent cavities, ensure that food tastes better, and improve your breath.  These techniques are healthful for everyone; it's just that "Red Dots" have to be hypervigilant and will run downhill very very quickly if they go off the wagon.

Let's look at some X-rays that demonstrate this concept.  The tartar, or calculus, that forms on our teeth consists of lots and lots of germs and looks like little triangular wings on X-rays whenever it is large enough to be seen in this way.

 
In this film, we are seeing bone loss- the bone should be much higher up on these teeth.  Still, there is a lot of calculus present, and it took a very long time for this bone loss to occur.  Years and years, as a matter of fact.  What happens is that the calculus and all the germs act as an irritant, like a splinter, and as the immune system reacts to the irritant, inflammation results.  Damage is done.  Bone runs away...  Yet runs away from the irritation in a sort of predictable wave, just keeping ahead of the obvious calculus and plaque.  So we see in this example that the bone loss is in a horizontal pattern, like a water level dropping.  (Remember that Jerry Lewis romp, "Don't Raise the Bridge- Lower the River"?)  Treatment is necessary here, and it's not easy; also, prevention would have been far easier. 

What is far more dangerous is to be a Red Dot and not take care of your teeth for a time.  Even over short time periods, a few years or even months, this kind of thing can happen:

 

There is no calculus visible on the X-ray, and not in the mouth either.  This patient's mouth generally looks clean.  Yet the specific germs in his mouth, and his immune system's response to them, are a dangerous combination that rapidly, very rapidly, has wiped out much of the bone on this tooth.  And it's a more vertical and angular bone loss than in the last case; it's more random and deep.  Often we see one tooth become loose and devastated with loss of bone while its neighbors are almost left alone.

Oh, and even what with all the damage to teeth and jaws that this calculus can cause, I'm still more afraid of this kind of calculus:

 

I'm sorry, but this kind of thing just freaks me out!

One of my patients was in the journalism biz before retiring, and as such he has a gift for flavorful, descriptive phrases.  He uses the term "actuarial crapshoot" to describe the process of cost and risk assessment that we all do when faced with medical treatment decisions in the face of random factors that are out of our personal control.  (In his case, he's weighing the cost of various dental restorative treatments against his own guesstimate of how much longer he will live.  I always tease him that he's gonna be the guy that keeps going to 107...)

When it comes to periodontal disease, it's really best to just assume that we are all Red Dots and then maintain our mouths accordingly.  No rolling dice in an actuarial crapshoot.  Because: maintenence is far less costly than treatment, in terms of financial cost, and also in loss of function and esthetics in our mouths if teeth are lost or advanced treatments are necessary.

Nanotubes are a Girl's Best Friend...

This post has nothing to do with dentistry, except perhaps for some vague ideas about new antibiotics.  I have to post it though because this stuff is just so very cool...

When I was in college- sometime in the Late Mesozoic Era, I believe it was- the element carbon was known to exist in precisely two forms: diamonds and graphite.  The one: beautiful, lustrous, valuable beyond compare.  The other: highly useful in a pencilly way at times, but a sort of bland dull gray.  Graphite Gray, in fact.

Yet we found in our chemistry classes that graphite was more stable over very long periods of time than carbon.  Yep.  Place a diamond and a lump of graphite in a perfectly sealed container and let a few billion years pass and when you open up your container you will find: two lumps of graphite.  My friend Mark famously tried to convince his soon-to-be-fiancee Karen that a graphite engagement ring was a more valued expression of his love than some rusty old diamond could ever be.

It was a short conversation.

Here is what the diamond crystal lattice looks like:

The carbon-to-carbon bonds are so strong in this arrangement that diamonds are the hardest known mineral that occurs in nature.  And as we know the crystal lattice is clear- almost, and it's that almost that makes each diamond unique and special.

Graphite is the most stable carbon structure.  It is made up of many carbon ring (graphene) layers stacked together.  Graphite is opaque gray, is soft and slippery, and conducts heat and electricity very well.  Graphite looks like this:

 

 

Diamond and graphite were thought to be the only ways in which pure carbon atoms arranged themselves.  Some years ago, however, scientists discovered buckyballs, the slang name for buckminsterfullerene.  This substance was named for engineer Buckminster Fuller, because it resembles his geodesic domes.  Buckyballs are 60-carbon spheres that look like little tiny soccer balls, although without any manufacturer or sponsor logos.  Yet.

 

There is a whole family of molecules now called fullerenes, which are any molecule composed entirely of carbon.  They come in spheres, ellipsoids, and tubes.  Buckyballs and other fullerenes are being investigated for use in heat resistance, superconductivity, lubrication, and even in medicine as possible antibiotic components.

Another exciting form of carbon is the nanotube.  These are made of a single layer of graphene which is rolled into a hollow tube:

 

The unique molecular structure of carbon nanotubes results in extraordinary large-scale properties, including high tensile strength, high electrical conductivity, high ductility, high heat conductivity, and relative chemical inactivity.  Carbon nanotubes are among the strongest materials yet discovered in terms of tensile strength, the stiffest in terms of elastic modulus, and the hardest, beating out the diamond by about 20%.  They also have some wild electrical properties.  It may be possible to manufacture a practical carbon nanotube supercapacitor which would make every battery design on the planet obsolete overnight.  No more heavy metals getting into the environment from our endless use of batteries!  And imagine a laptop that could run for a week or two on a charge...

 The fifth form of carbon is the most recently discovered.  This is graphene:

 

Graphene takes the prize for weirdness in its properties.  It is a one atom thick layer of hexagonal carbon rings.  It is the strongest substance known to man, on a strength to weight basis.  Potential uses of graphene range from super-strong structural members to antimicrobial medicines; it seems to be particularly good at killing E. coli.  Graphene has the ideal properties to be an excellent component of integrated circuits.  So we may see it someday in places as diverse as inside our computers and in our food packaging. 

It is interesting to note that the 2010 Nobel Prize in Physics was won by Andre Geim and Konstantin Novoselov "for groundbreaking experiments regarding the two-dimensional material graphene".  This stuff may be thin, but it's pretty hot right now too.

Perhaps the weirdest thing of all about graphene is that, although it's only one atom thick, you can actually see it in transmitted light with your own eyes, because it absorbs 2.3% of white light:

 

The problem with that fact is, it completely dashes my plans to make super-strong graphene bar stools that are so clear that you can't see them at all- even when cold sober.  Oh well...

Just Four Ingredients

Gunpowder = sulfur + charcoal + potassium nitrate + graphite

Beer = water + barley + hops + yeast

Chocolate = cocoa beans + sugar + milk + vanilla

Solar Panel = copper + silicon + cadmium + tellurium

In each case, just four ingredients were combined to make something world-changing.  And yet how different they all are- different in form, different in function, different in meaning.

If you were to combine just a few simple ingredients (especially considering ideas as ingredients) to make something spectacular, how would you want it to turn out?  What would you want it to accomplish?