Dental Check-Up Revisited

Welcome back. About 11 years ago, I released a blog post that became one of the blog’s most popular. In those years, I wrote mainly about me, and that post chronicled my dental history. (Yes, of course it was humorous, see Dental Check-Up Time.)

Simulated reconstruction of Warren’s dentist at work
(from Dental Check-Up Time and Amazon).

It began when I was young, when one visited the dentist only if something was wrong. The likelihood of there being something wrong was much higher in those pre-fluoride, pre-flossing, pre-periodic cleaning, pre-sugarless gum, pre-soft-toothbrush days. And while there was Novocain, which is no longer the anesthetic of choice, it was used sparingly for the big stuff, like extractions.

I ended that post, noting how dentistry had evolved; the only pain on visiting a dentist nowadays is the bill. I also mentioned my dental epiphany. On my first visit to a new dentist some 25 years ago, I was shown the evil decay-causing micro-creatures that were sloshing around in my mouth. That night, I rushed out to buy an antiseptic mouthwash, and I’ve rinsed twice a day ever since. Evil or good, the micro-critters don’t stand a chance.

I was thrilled to see that my mouthwash made the cut in a recent study as one of the best approaches for dental care.  

That study by researchers affiliated with the University of Buffalo (one is now with the University of Rochester) identified the best, worst and unproven approaches for dental care.

Assessing Dental Care Approaches
The researchers’ ratings followed their search and assessment of published systematic reviews of self-administered interventions to prevent periodontal disease.

Lest the terms be unfamiliar, periodontal disease is mainly the result of infections and inflammation of the gums and bone surrounding and supporting the teeth. In its early stage, called gingivitis, the gums can become swollen and red and may bleed. In its more advanced form, called periodontitis, the gums can pull away from the teeth, bone can be lost and the teeth may loosen and even fall out. 

Periodontal disease progression (from https://medlineplus.gov/ency/imagepages/19942.htm).

Periodontitis is common but largely preventable. It's normally the result of poor oral hygiene.

OK. To speed you on your way, I’ll get right to the researchers’ findings. Be forewarned that relatively few interventions have been proven effective.

What’s Recommended, What’s Not?

Best: toothbrush; interdental brush; water pick; mouthwash containing chlorhexidine gluconate (CHX), cetylpyridinium chloride (CPC) or essential oils (e.g., Listerine).

Regular brushing (with periodic dental hygienist cleaning) controls dental plaque, the sticky, colorless or pale-yellow film of bacteria that forms on and between teeth, both above and below the gum line. Interdental brushes and water picks are effective for reducing gingivitis, as are mouthwashes based on CHS, CPC and essential oils.

Toothpicks, though not effective for gingivitis, are useful for monitoring gum health. Gently prodding gums and monitoring for bleeding can detect signs of gum disease.

Unproven: electric toothbrush, dental floss, probiotics, dietary supplements and many mouthwashes.

They may be easier to use, but electric toothbrushes are no better than properly used manual brushes for reducing plaque and gingivitis. Similarly, while flossing is essential for interdental cleaning (including removal of interdental plaque between tightly spaced teeth), its overall value for reducing plaque and gingivitis has not been shown.

Probiotics are a promising yet unproven strategy to prevent gum disease; but there’s little evidence that dietary supplements improve gum health or that mouthwashes containing tea tree oil, green tea, anti-inflammatory agents, hydrogen peroxide, sodium benzoate, stannous fluoride, hexetidine or delmopinol reduce gingivitis. There’s also insufficient evidence that professional plaque removal with a scraper (scaling) prevents gum disease.

Worst: toothpastes containing triclosan.

I used Colgate Total toothpaste for many years before seeing reports that triclosan, its main ingredient for controlling plaque and gingivitis, was a suspected carcinogen. More years passed before Colgate replaced triclosan with sodium fluoride.

Wrap Up
As forewarned, there are surprisingly few self-administered interventions proven to prevent gingivitis and periodontitis, which makes the researchers’ umbrella review even more valuable. I look forward to future updates and hope you agree.

Warren’s dental visit freebies--toothbrush, floss, interdental brush.

Thanks for stopping by.

P.S.
Umbrella review of periodontal prevention strategies in Journal of International Academy of Periodontology: www.perioiap.org/publications/57-october-2021/256-proven-primary-prevention-strategies-for-plaque-induced-periodontal-disease-an-umbrella-review
Article on review on EurekAlert! website: www.eurekalert.org/news-releases/930042
Periodontal disease:
www.cdc.gov/oralhealth/conditions/periodontal-disease.html
www.nidcr.nih.gov/health-info/gum-disease/more-info
www.mayoclinic.org/diseases-conditions/periodontitis/symptoms-causes/syc-20354473

Reading Folded Documents

Using an X-ray microtomography scanner and computational algorithms, an international team of researchers read unopened, securely and intricately folded 17th-century letters without unsealing or damaging them in any way.

Computer-generated unfolding sequence of 300-year-old sealed letter (from Unlocking History Research Group, www.eurekalert.org/pub_releases/2021-03/qmuo-sos030121.php).

Welcome back. Before I warm up, I must credit researchers affiliated with MIT, Adobe Research, King’s College London, Queen Mary University of London and The Netherlands’ Utrecht, Leiden and Radboud universities for the fascinating study I’m about to review.

Their research was a twofer for me; maybe for you, too. Though generally familiar with tomography from both geologic seismic surveys and X-ray CT or CAT scans (computer tomography aka computerized axial tomography), I was new to X-ray microtomography. Likewise, I’d come across articles on reconstructing documents but had never heard of letterlocked messages, much less applying X-ray microtomography to reveal their contents. Suppose I jump right in.

X-Ray Microtomography (XMT)
Tomography is a method of producing three-dimensional images of the internal structure of solid objects (e.g., the human body or earth) by recording how that internal structure affects energy waves passing through the object. With CAT scans, the energy waves are imposed X-rays; with geology, the seismic waves may be generated by earthquakes or explosions. 

Schematic of X-ray microtomography (from www.sciencedirect.com/science/article/abs/pii/S1044580310002706).

X-ray microtomography, in use since the early 1980s, is tomography that produces high-resolution images with micrometer-size pixels. Among a wide range of applications (e.g., archaeology, fossils, electronics) is biomedical, including dentistry, where XMT can produce high-quality images from the outer to innermost structure of teeth and surrounding structures. The XMT scanner used to read letterlocked messages for this study was developed for dental research.

Letterlocking
The Letterlocking Dictionary and Wikipedia help me define letterlocking as folding and securing a written message, whether on paper or another material, to serve as its own envelope or sending device.

Dating to the 13th century in Western history, letterlocking fastens a letter with slits, tabs or holes, various folding techniques and the possible addition of sealing wax or string. It’s all to prevent the “letterpacket” from being read without breaking the securing features or leaving other signs of tampering. Although letterlocking might involve intricate folding with artistic elements that suggest a sender of elite status, the procedure was used by all social classes before the proliferation of mass-produced envelopes.

Letterlocking categories based on manipulations and assigned security score; filled category numbers indicate historic originals exist; unfilled numbers indicate hypothetical categories; letterlocking formats show up to 12 edges with indicative examples (www.nature.com/articles/s41467-021-21326-w).

The study examined four letters from the Brienne Collection, a postmaster’s trunk of undelivered letters sent from all over Europe to The Hague, the Netherlands, between 1689 and 1706. The trunk contains 3,148 items, including 1,706 opened or partially opened letterpackets and 577 unopened letterpackets, which may themselves contain additional items. One of the four tested letterpackets was opened.

One of four tested letterpackets (DB-1627) from Brienne Collection: (a) outside front and back, (b) transparent view through volumetric XMT data, (c) crease pattern visible if fully opened, (d) proposed step-by-step letterlocking process to make packet from a flat piece of paper based on virtual unfolding results, (e) letterlocking category and format (www.nature.com/articles/s41467-021-21326-w).

Virtually Unfolding Letterlocked Messages
The computational algorithms used to unfold the four XMT-scanned letterpackets built upon earlier work that extracted text from historical documents--primarily scrolls, books and once or twice folded artifacts, particularly highly damaged documents that could not be physically opened and read.

Given that the letterpackets were largely undamaged homogenous paper material, the focus was to automate and extend computational flattening frameworks to address more intricately folded documents than had previously been considered. The general steps were as follows:

- XMT scanning produces a volumetric dataset representing material density in 3D space.
- Segmentation identifies and separates layers of writing substrate.
- Flattening computes a distortion-minimizing, 2D embedding of the segmentation result, corresponding to the document’s unfolded state.
- Hybrid mesh propagation repairs discontinuities on the folded and flattened embeddings and automatically merges flattened connected components into a common reference frame.
- Texturing produces a 2D image of the virtually unfolded letter by mapping voxels (essentially 3D pixels) from the volumetric scan to their corresponding flattened destination.

Wrap Up
Virtual unfolding produced nearly complete reconstructions of all four letterpackets. Each had a distinct folding sequence, including inner folds angled diagonally to their outer silhouette. For two with a separate paper lock, unfolding reconstructed the primary writing substrate and the paper lock as two pieces.

The results demonstrated the applicability of the approach for letterlocked messages and likely for many other types of historical texts (letters, scrolls and books).

So, was it a twofer for you? At least a one? Thanks for stopping by.

P.S.
Study of virtual unfolding of sealed documents in Nature Communications journal: www.nature.com/articles/s41467-021-21326-w
Letterpackets from study: brienne.org/unfolding
Article on study on EurekAlert! website: www.eurekalert.org/pub_releases/2021-03/qmuo-sos030121.php
X-ray microtomography background: en.wikipedia.org/wiki/X-ray_microtomography
Letterlocking:
letterlocking.org/dictionary
en.wikipedia.org/wiki/Letterlocking
letterlocking.org/imaging-locked-letter-collections
www.youtube.com/channel/UCNPZ-f_IWDLz2S1hO027hRQ
www.atlasobscura.com/articles/what-did-people-do-before-envelopes-letterlocking

If you're interested in letterlocking, here are two rather involved (very cool) techniques:

Letterlocking with a spiral lock (photo from 5:29 minute video www.youtube.com/watch?v=1ZRA8KZrNTQ).

Letterlocking with dagger-trap pleated letter (photo from 12:11 minute video www.youtube.com/watch?v=16GAIaYN_Gk).

Skip Mouthwash After Exercise

Welcome back. You might recall my blog post Salt in Mind. Though I wrote about my dislike of salty food, the takeaway was salt’s link with increased risk of dementia and diseases of the brain and blood vessels, at least in mice.

Salt was being blamed because a study found: [E]xcess salt suppressed functioning of cells lining blood vessels to the brain (endothelial cells). This caused a reduction of nitric oxide, a gas the cells produce to relax the blood vessels and increase blood flow.
 

Reading blood pressure (from
www.cdc.gov/features/blood-pressure-tips/index.html).

OK, so what has this got to do with mouthwash and exercise, the subject of this post? I’m going to tell you. Just don’t forget that nitric oxide relaxes blood vessels and increases blood flow. In other words, it affects blood pressure. 

Post-Exercise Hypotension
International collaborators led by an investigator from the UK’s University of Plymouth conducted a study that demonstrated the importance of oral bacteria in cardiovascular health.

Their work built upon earlier research that showed exercise reduces blood pressure. How? Exercise produces nitric oxide, which (as you know) dilates blood vessels (“vasodilation”), increasing blood flow to active muscles.

The question addressed by the recent study was how blood circulation stays higher after exercise--how does exercise cause a blood-pressure lowering response known as post-exercise hypotension?

Nitric Oxide, Nitrate, Nitrite, Nitric Oxide
To answer the question, the investigators focused on nitric oxide and a compound that nitric oxide degrades to, nitrate.

Nitrate was of interest because research has shown it can be absorbed in the salivary glands and excreted with saliva in the mouth. Some species of oral bacteria can use the nitrate and convert it into nitrite.

If it seems we’re going in circles, we are. When the nitrite in saliva is swallowed, it’s partly absorbed into the circulation and reduced to nitric oxide, which could be responsible for post-exercise hypotension.

Testing the Importance of Oral Bacteria
How could the researchers prove this? By interfering with the oral bacteria. If those critters don’t convert nitrate to nitrite, blood circulation won’t stay higher and blood pressure lower after exercising.

In two separate sessions, the researchers had 23 healthy adults run on a treadmill for 30 minutes, then be monitored at rest for two hours. Only water was allowed during exercise and recovery.

Blood pressure was measured before exercise and at 1 hour and 2 hours after exercise. To analyze nitrate and nitrite concentrations and oral bacteria, other testing included blood and salivary samples taken before and 2 hours after exercise. 

Mouthwash and exercise,
here with my stationary bike
rather than a treadmill.

To gauge the importance of oral bacteria, the runners rinsed their mouths periodically during the recovery with either an antibacterial mouthwash (0.2% chlorhexidine) or a placebo of mint-flavored water.

The Mouthwash Effect
The study found that rinsing with antibacterial mouthwash after exercise reduced the  blood-pressure lowering effect by 61% at 1 hour into the recovery period and completely by 2 hours.

In contrast, the average blood pressure of participants that rinsed with the placebo remained lower than the baseline throughout the 2-hour recovery period.

Supporting the researchers’ expectation, the measured levels of circulatory nitrite at 2 hours after exercise increased for participants that rinsed with the placebo and remained constant for those that rinsed with the antibacterial mouthwash.
 
Wrap Up
The researchers concluded that nitrite synthesis by oral bacteria is a key mechanism to induce the vascular response to exercise over the first period of recovery thereby promoting lower blood pressure and greater muscle oxygenation.

Though I stand by my earlier comments on the virtues of antibacterial mouthwash to control the evil tooth decay-causing micro-creatures that slosh around in your mouth (Dental Check-Up Time), you may want to adjust the timing of your rinse. Thanks for stopping by.

P.S.
Study of mouthwash and post-exercise hypotension in Free Radical Biology and Medicine journal: www.sciencedirect.com/science/article/abs/pii/S0891584919307610
Example articles on study:
www.eurekalert.org/pub_releases/2019-09/uop-muc090319.php
www.sciencealert.com/a-strange-thing-happens-if-you-use-mouthwash-after-you-exercise

Posts You May Like

Welcome back. Although I’m now blogging on a different website, Warren’s Notice (www.warrensnotice.com), this website offers some 550 posts and is still quite active. Should you wish to look around, the lengthy Blog Post Topics column on the right can help you find posts of interest. (If you’re not on the website, it’s at www.retired--nowwhat.com.) That said, I’ll highlight a handful of posts.

Most-Viewed Blog Posts
Here are the five most-viewed posts with their links; just click on the post title:

Mehgan Murphy’s exceptional photographs made the 2013 post Anteater Photo Addendum very special. (Photo from www.flickr.com/search/?w=26357527@N05&q=anteater)

I was surprised how much interest the 2014 post Stroboscopic Training elicited, especially because it didn’t really catch on until months after the post was released. (Nike advertisement for stroboscopic eyewear.)

Interest in the 2013 post Fish Eyespots, which also began months after the post’s release, caused me to wonder if I should be writing more about tropical fish. (Photo from www.ibrc-bali.org/)

The 2015 post Facial Expressions Addendum reviewed the Facial Action Coding System developed and modified by Paul Ekman and colleagues. (Photos of Tim Roth, lead actor in the TV show Lie to Me, are from multiple websites.)

Though included to supplement a post on research sponsor bias, the 2014 post Sugary Beverage Addendum presented different campaigns against sugary beverages and attracted its own audience. (The Rethink Your Drink poster is from Hawaii’s eatrighthawaii.org/2013/11/14/rethink-your-drink-campaign/)

Humorous Posts
The early posts were well received though the blog had yet to attain a ranking on Google that would allow them to be found by chance. Many of those posts tended to be humorous, such as these three:

In the 2011 post Time for Lawn and Garden, I described the rites of spring but somehow pulled the wrong photos. For example, this photo's caption was "Neighbors’ kids helping out in Warren’s garden."

The 2012 post Dental Check-Up Time was an abridged memoir of my dental experiences. Pictured here from the post is the drill used by a local dentist I visited in the Philippines. (Photo of Fuller drill from Amazon)

Pet posts were all well received, particularly those about cats. Nevertheless, my choice for the top pet post is the 2011 Time for Non-Furry Pets, at least the part about my wife’s tropical fish, Godzilla. (Photos provided by badmanstropicalfish.com/)

Noteworthy Firsts

Being a romantic, I’ve always had a special place in my heart for my first Valentine’s Day post, the 2012 Happy Valentine’s Day! Familiarity with the Trogg’s love song "Wild Thing" will enhance your admiration for the rose I presented to my wife.

I occasionally ventured into the world of fantasy, most often knowingly. The first such post was the 2012 Predawn Jogging Mystery.

Although I began including travel photos with my first post, the first travelogue was the 2011 Time to Visit the Arecibo Observatory, which described my 1965 introduction to Puerto Rico and first day on the job at what was then the world’s largest radar-radio astronomy telescope.

Research Reviews
A sea change in blog topics came with my shift from personal experiences to research reviews, which eventually led me to move to Warren’s Notice.

The first research review was the 2012 post Memories and Doors, which addressed how walking through doorways caused forgetting. I had questions about the test participants and if doorways affected cats.

There was a gap of four months between the first and second research review, the 2012 post Snail Power, which described how snails can be used to generate electricity. I proposed a scheme for powering houses with snails in the basement. (Photo of Giant East African snails by Roberta Zimmerman, USDA APHIS.)

Wrap Up

One of the earliest Retired--Now What? Blog headers.

It’s difficult for me to pick and choose. Like Time for Non-Furry Pets, listed above, it’s often parts of a post rather than the entire post that I wish I could read to you. I do hope you’ll look around, and then please join me at www.warrensnotice.com. Thanks for stopping by.

Taking a Break

Welcome back. I’m going to take a couple of weeks off to play and seek out new blog topics. I hope you won’t mind, and I sincerely hope you’ll miss me.

In the absence of new Retired—Now What? Blog posts, may I suggest that you review some of the older posts? I’ve released nearly 400 posts since April 2011, and the lengthy Blog Post Topics column of links on the right of the blog website can help you find possible posts of interest. (If you’re not on the website, it’s at www.retired--nowwhat.com)

Most-Viewed Blog Posts

If you’d like to sample the most-viewed posts, here are links to the top five, listed from first to fifth. Six posts are listed because the last two were tied.

Mehgan Murphy’s exceptional photographs made the Anteater Photo Addendum very special. (Photo from www.flickr.com/search/?w=26357527@N05&q=anteater)

I was surprised at the interest that Stroboscopic Training elicited, especially because it didn’t really catch on until months after the post was released. (Nike advertisement for stroboscopic eyewear.)

The interest in Fish Eyespots, which also began months after the post’s release, caused me to wonder if I should be writing more about tropical fish. (Photo from www.ibrc-bali.org/)

Like most of my research reviews, The Ecuadorian Bat mixed research reporting and personal experience, with a dose of humor. That wasn’t too difficult when writing about a bat whose tongue is roughly one and a half times longer than its body.

The blog has had writing contests, and I was thrilled when Josefina Wopatova's entry, Goal Setting--Second Winning Blog, made the most-viewed list. (Rock concert photo from multiple websites)

How rewarding that the research review Curse Tablets--a topic I found fascinating--did so well! (Photo of 5th century BC curse tablet from www.schoyencollection.com/greekbkscr.html)

Examples of Older Humorous Posts

Some of the oldest posts were very well received though the blog had yet to attain a ranking on Google that would allow it to be found by chance. Many of those posts tended to be humorous, such as these three:

In the post Time for Lawn and Garden, I described the rites of spring at our former house but somehow twisted my photos and captions. For example, this photo was labeled "Neighbors’ kids helping out in Warren’s garden."

The post Dental Check-Up Time was an abridged memoir of my dental experiences from youth to present day. Pictured here from the post is the drill used by the local dentist I visited in the Philippines. (Photo of Fuller drill from Amazon)

The pet posts were all well received, particularly those about cats. Nevertheless, my choice for the top pet post would be Time for Non-Furry Pets, at least the part about my wife’s tropical fish, Godzilla. (Photos provided by badmanstropicalfish.com/)

Noteworthy Firsts

Being a romantic, I’ve always had a special place in my heart and archive for my first Valentine’s Day post Happy Valentine’s Day!. Familiarity with the Trogg’s love song "Wild Thing" will enhance your admiration for the rose I presented to my wife.

I occasionally venture into the world of fantasy, most often knowingly. The first such post was Predawn Jogging Mystery.

Although I began including travel photos with my first blog post, the first travelogue was Time to Visit the Arecibo Observatory, which documented my introduction in 1965 to Puerto Rico and the world’s largest radar-radio astronomy telescope.

Research Reviews
 
A sea change in blog topics came with my shift from personal experiences to research reviews. While that didn’t please every regular reader, it certainly attracted a much larger audience. 

The first research review was the post Memories and Doors, which addressed how walking through doorways caused forgetting. I had questions about the student test participants and if doorways would affect cats.

Most of my blog posts are now research reviews; however, there was a gap of four months between the first and this second research review, Snail Power, in which I proposed powering your house with snails in the basement. (Photo of Giant East African snails by Roberta Zimmerman, USDA APHIS.)

Wrap Up

That’s probably more than enough. If there’s a blog post you would like to see but can’t find, email me at retirednw@gmail.com. I’ll try to find it.

Thank you for stopping by; your visits are always greatly appreciated. Happy Holidays and Best Wishes for 2015! -warren

One of the earliest Retired--Now What? Blog mastheads.

Tooth Sleuths

Welcome back. As much as I admire and respect each and every dentist, I am convinced that the ADA (American Dental Association) is in cahoots with popcorn producers. I chipped another tooth on an unpopped kernel. Actually, it might be the same tooth I chipped when I described the ordeals of having teeth before fluoride, floss and present-day dentistry in Dental Check-Up Time.

Knowing this day would come, I’ve been saving accounts of dental-related research. I’ll highlight three studies to give you something to chew on while I’m at my dentist. All fall under the archaeological umbrella.

Modern man and Neanderthal skull props.
(www.bjwinslow.com/gallery/skulls)

I’ve been tuned into dental anthropology since I was a grad student with a neighbor who was finishing his doctorate in anthropology. His major professor and sometimes my neighbor traveled the world to perform assessments of teeth--sort of an ADA-produced version of the TV show, Bones. Stay alert and you may see why I chose these three studies.

Neanderthals and Toothpicks

I’ve written about the shocking Georgia Toothpick Theft, when 374,400 plastic toothpicks were stolen from a toothpick manufacturer, but this toothpick news didn’t make the front page.

Researchers from Spain’s Universitat Rovira i Virgili, Universitat Autònoma de Barcelona and two other institutions examined three, upper jaw, Neanderthal teeth found at the archaeological site of Cova Foradà in Valencia, Spain.

Grooves between the teeth showed signs of pulling a hard, narrow object, such as a toothpick, between adjacent teeth. Cool! I thought, but I was applauding a concert at the wrong moment. It turns out the use of toothpicks has been documented from the beginning of the genus Homo. Interproximal grooves on Neanderthal teeth are common.

Although the investigators’ morphological analyses found no evidence of dental caries or calculus (tartar), abscesses or bone perforation related to a cyst, there were indications of periodontal (gum) disease. They had documented the oldest case of using toothpicks to ease the pain caused by dental disease.

Strontium Measure of Migration

Not far from St. Louis, Missouri, is a UNESCO World Heritage site: the Cahokia Mounds State Historic Site, the largest and earliest pre-Columbian settlement north of Mexico. The site, over 6 square miles, dates from the Mississippian period (800-1350), has some 120 mounds, and is estimated to have had a peak population of 10,000 to 20,000.

Mound at Cahokia Mounds State Historic Site.
(townplannerstl.com/Attractions/place/cahokia-mounds-state-historic-site/)

To better understand the settlement’s regional and cultural interactions and population history and diversity, researchers from the University of Illinois analyzed strontium isotope ratios of teeth.

Different isotopes of the chemical element strontium are found in most rocks, and the ratio of two of those isotopes, strontium-87 to strontium-86, varies with the geology. By consuming plants and water, humans and animals absorb strontium, thus collecting a signature of the local rock.

Because the strontium ratios found in teeth and bones reflect absorption at different life stages--tooth enamel ratios from infancy and childhood and bone ratios from the most recent 7 to 10 years--the different ratios are often compared in archaeological investigations.

For the Cahokia investigation, however, the researchers measured ratios from the teeth of individuals buried at different locations within the settlement, and compared those to ratios from the teeth of small animals found at the site, the assumption being that the animals had never left the site.

The analysis estimates that at least one third of the Cahokia’s residents came to the settlement from multiple places outside of the area.

Plaque Window to the Past

The last study illustrates how your teeth can become the center of attention. Don’t care for them and don’t visit your friendly dental hygienist to remove plaque, the biofilm that sticks to your teeth and causes decay and periodontal disease. Let that soft plaque build and harden to dental calculus (tartar), mentioned above.

After, say, 1000 years, the calculus on any teeth left in your skeleton may be selected for analysis, such as that led by the University of Zurich, Switzerland, and Denmark’s University of Copenhagen.

Plaque is loaded with microorganisms; the fossilized dental calculus preserves the microbiome. The study’s large group of collaborators (over 25 from 21 institutions in 4 countries!) applied genetic and protein-assessing (proteonomic) technologies to determine the DNA and proteins in ancient dental calculus.

They characterized the microbiome in a diseased state, opportunistic pathogens, ancient antibiotic-resistance genes, a genome reconstruction of a periodontal pathogen, numerous bacterial and human proteins, and DNA sequences matching dietary sources.

The analysis and those to follow permit the investigation of pathogen activity, host immunity and diet, and thereby extend direct investigation of common diseases into the human evolutionary past.

Wrap Up

And there you have it. Three studies that employed different approaches: morphological analyses, strontium determinations, and the latest genetic and protein-assessing technologies. All sought to gain insight into our past and perhaps our future. Thanks for stopping by.

P.S.

-Toothpick paper in PLOS One:
www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0076852
-Article on toothpick paper on Science Daily website:
www.sciencedaily.com/releases/2013/10/131017080300.htm

-Cahokia Mounds paper in Journal of Archaeological Science:
www.sciencedirect.com/science/article/pii/S0305440314000302
- National Geographic article on Cahokia Mounds research:
news.nationalgeographic.com/news/2014/03/140307-cahokia-native-american-archaeology-mississippian/
-Cahokia Mounds State Historic Site website: cahokiamounds.org/
-World Heritage Site description of Cahokia Mounds site: whc.unesco.org/en/list/198
-Handbook of Environmental Isotope Geochemistry (Chap 35: Applications of Sr Isotopes in Archaeology):  www.springer.com/978-3-642-10636-1

-Plaque analysis paper in Nature Genetics, Feb 2014:
www.nature.com/ng/journal/vaop/ncurrent/full/ng.2906.html
-The Times of India article on plaque analysis paper:
timesofindia.indiatimes.com/home/science/1000-years-old-microbial-Pompeii-unlocked/articleshow/30957394.cms
-Video presentation (5:31 min) of plaque work by lead author at March 2012 TED: www.youtube.com/watch?v=4ZB29iq_Zd8#t=78

Dental Check-Up Time

Welcome back. I just got back from my dentist’s. He did a superb job of loading me up with Novocain and replacing an ancient filling that finally caved to popcorn kernels. (I eat a lot of air-popped popcorn.)

Simulated reconstruction of 

Warren’s dentist at work

 
Are you afraid to go to the dentist? The thought of going to a dentist spooked a former colleague so much, he kept putting it off. His minor case of nerves was nothing like the sheer terror I used to experience when I was young. Unlike today, fear used to be warranted.

Growing Up with the Dentist 
 
Dentists hated kids when I grew up. Maybe not every dentist, but even if our dentist didn’t hate me, he enjoyed torturing me. And my parents paid him for it, too, I think. So there might be more to it.
 
Our dentist’s nurse was very nice. (They were “nurses” or “assistants” then, not “hygienists.”) For the most part she was there to make sympathetic faces and go “Ohhh” each time I screamed, which I usually did as soon as I saw the dentist.
 
In those days, you went to the dentist when something was wrong, not periodically for a cleaning and check up. I would do anything…no, everything to avoid going to the dentist. If my tooth ached so much I squinted, I’d keep that to myself. If I chipped or cracked a tooth, I’d keep that to myself. If I had a gum abscess, I’d…you know. 
 
And teeth and gums were much more prone to hurting in those pre-fluoride, pre-flossing, pre-periodic cleaning, pre-sugarless gum, pre-soft-toothbrush days. Oh, and while there was Novocain, it was used sparingly for the big stuff, like extractions.

One of several tools

used for extractions when

Warren was young.

And the non-disposable needles were blunter with barbs.

Enlarged view of tip of needles

used when Warren was young.

Philippine Dental Appointments

By the time I was in college, I was tough; I could take it. Go ahead, torture me. Take Novocain for a filling? Ha! No way.

I don’t remember why I had to see a local dentist when I was in the Philippines, but she was so impressed by my courage and she charged so little, I had her update any questionable filling. She worked alone in her Spartan office with equipment I hadn’t seen in years.

Examples of tools used by local Philippine dentist.

Before I returned to the U.S., someone suggested that I visit a dentist in Manila, where dental care was top-notch and the cost was much lower than back home. Wow! I entered a space-age examination room, with ergonomic chair, speed drill, dentist and staff in color-coordinated uniforms, the whole shebang. 

Simulated reconstruction of

Manila dental exam room.

Female simulations of Manila

dentist (standing) and Warren (sitting).

The dentist gently probed as his nurse--"hygienist"?--stood close by, ready to serve. After careful study, he concluded that the work I had had done locally, though far from cosmetically pleasing, would hold together.

Simulated reconstructions

of what Manila dentist

encountered in Warren’s mouth

U.S. Dental Appointments

Back in the States, my dental life evolved over the years with 6-month cleanings and check-ups, flossing, fluoride, equipment and techniques that advanced with each visit, and Novocain for everything...I don’t need it…You do…No, I don’t; I’m tough…You’ll flinch; I don’t allow that when I’m working…

About 15 years ago I had a dental epiphany. On a first visit to a new dental office, I was shown the evil decay-causing micro-creatures that were sloshing around in my mouth. Ugh!
 
That night, I rushed out to buy an antiseptic mouthwash, and I’ve rinsed at least twice a day since. Evil or good, the micro-critters don’t stand a chance.
 
Wrap Up
 
What a pleasure to go to the dentist nowadays! They try so hard to save each tooth and to do it painlessly. About the only part that always hurts is the bill. I’m exploring dental tourism. The Philippines is kind of distant but I’ve never been to Mexico or Costa Rica.
 
Thanks for stopping by. I’ll write again in about a week.