1001 Uses For Dental Floss # 62- A Woman Scribe Got The Blues


A Woman Scribe Got The Blues

You may recall the name–Dr. Christina Warinner, who is an anthropologist, last mentioned in these pages (1001 Uses #4) because she discovered that ancient humans used one type of grass to floss their teeth. Well, here she is again, this time with colleague Anna Radini of the University of York in England, still studying dental calculus, AKA tartar, but on the teeth of a medieval woman’s skeleton. 

What is special about this woman and this skeleton, and these teeth? Well, this anonymous woman’s remains were disinterred from the graveyard of a monastery of a small religious community at Dalheim, Germany. And what they did at this monastery was create illuminated manuscripts. 

Monastery–monks, right? Wrong, sort of. It turns out that this woman was somehow involved with creating these illuminated manuscripts. You know the ones, those beautifully illustrated hand-written biblical texts displaying fanciful brightly multicoloured drawings of saints and demons and dragons along their margins and decorated with real gold foil. 

That’s not done anymore, not since Johannes Gutenberg put an end to all that when he invented the printing press and inaugurated the Age of the Book (I made that title up, but he did do that.) Anyway, I digress. Back to the blue dye.

Anyway, what does that have to do with anything? It turns out that this woman’s teeth had tartar (there were no dental hygienists around in those years to scrape it off–that’s why they called them the Dark Ages- no, not really) on them. And no one flossed, as far as I know. 

These researchers found that the tartar had a striking blue coloration which turned out to be lapis lazuli, a mineral which was ground to a powder and used in these illuminations.

Well, okay, so what? Well, not only that, but the coloration was unevenly distributed on her teeth, so it’s not like she was inhaling the powder while grinding it or from kissing the Bible at the monastery. There was more of the blue tint on her front teeth than in the back, and this suggests that she was probably using a brush, and licked it to make a fine point of the bristles, and in the process picked up some of the lapis lazuli on her teeth.And this means that she was one of the artists creating these illustrations. 

The only question I have is, why weren’t there any other dyes on her teeth, since other coloured minerals were also used? I don’t have the answer to that question, except maybe this woman specialized in applying this particular colour (like in an assembly line, an innovation supposedly invented by Henry Ford in the early 1900s.) 

Maybe further testing will find other dyes on other skeleton’s teeth in that cemetery. We’ll just have to wait with bated breath for the answer to this question.

In the meantime, floss regularly. And visit your dental hygienist at least twice a year. You don’t want some future archeologist checking out your teeth one day in the far future. I’m sure you have secrets you’d rather no one knew anything about.


1001 Uses For Dental Floss #61- Fluoride Toothpaste and Young Children

We’re back after a hiatus of a couple of years. Us smiling up at the top? No, that’s a mild form of dental fluorosis.


A recent report from the Centre for Disease Control and Prevention on the use of toothpaste and tooth-brushing patterns among children and adolescents (https://www.cdc.gov/mmwr/volumes/68/wr/mm6804a3.htm)suggests that young children are using and swallowing too much fluoridated toothpaste when brushing their teeth. They recommend that children under the age of 2 should use a non-fluoride toothpaste and those aged 3-6 should only use a pea-sized portion on their brushes.

Let’s dissect this advice down into its parts, or as they say these days, let’s unpack it. The prime idea here should be to do what is necessary, what is practical, and to not make compliance so difficult or complicated that it would turn some of us off from doing the right thing.

First of all, brushing is important. It should be done as soon as the teeth come into the mouth (about 6 months of age and later), preferably after each time a child eats (or drinks from the mom’s breast or a bottle), but since this is maybe impractical in some cases, like the middle of the night where mom is exhausted, do it at least once or twice a day. (Do it in the middle of the night too, if you can.) That way, bacteria won’t build up a layer thick enough to start retaining acid (from sugar breakdown by these germs) which will start to leach calcium from the tooth surface (and so cause tooth decay.)

Second, fluoride at proper levels has been shown over many years to be beneficial to tooth health, by changing the crystal structure of enamel so that the enamel is more resistant to acid. Fluoride has therefore been added to the water supply of many cities as a public health measure. Almost 200 million people in the U.S. and 300 million world-wide have fluoride added to their water supply.

Third, fluoride can enter tooth enamel in 2 ways, either when the teeth are still under the gums, and after they are already visible in the mouth. Before teeth come into the mouth, the enamel may still be forming and fluoride present in the bloodstream bathing these teeth increases the fluoride content as enamel is laid down as the outside layer of the teeth. After the teeth are already in the mouth, fluoride applied to the teeth strengthens the outer layer of enamel. Fluoride that moves from the blood into the saliva in the salivary glands also can contribute to this beneficial process.

Fourth, too much fluoride can cause white spots (see photo above) or lines on developing teeth (termed “fluorosis”), which are teeth which haven’t yet broken through the gums and entered the mouth. By the way, this growth of teeth from below the gums into the mouth is called “eruption”, sort of like a volcano erupts lava from underground onto the earth’s surface. I know, it’s a weird comparison but the term has been around for a long time, so what can you do?

If the concentration of fluoride your child is exposed to is significantly higher than 1.2 parts per million (ppm), fluorosis can result. If it is higher than that (the upper limit here is not well-defined), the enamel can be disrupted enough that surface defects, staining, and weakening of the enamel’s strength can happen. It’s therefore important that the fluoride concentration stays in the “Mama bear” zone (thanks, Goldilocks, for giving us this concept of just-rightness.) The two permanent upper front teeth, which are the most esthetically important teeth when we smile, have generally completed enamel formation between 15 to 24 months for boys, and between 21 and 30 months for girls, so fluorosis can happen to these teeth during this period.  Also, because we drink more when it’s hot, people living in a hot climate should probably have less fluoride added to their water, since they’ll drink more and absorb more fluoride, possibly producing fluorosis more easily.

Fifth, it’s clear that young children, if unsupervised, will not follow dental association guidelines (or listen to you, either.) Toothpaste, especially the fruit-flavoured children’s toothpastes, appeals to kids’ natural affinity for sweet flavours, so watch out.

Sixth, below the age of 6, children haven’t developed enough control over the swallowing reflex and the ability to spit to prevent swallowing of toothpaste. Some, if not most, will be swallowed. So, obviously, preparing the toothbrush with the right amount of fluoride toothpaste by a parent or supervising adult is very important. As for the right amount to put on the toothbrush, a very thin smear of toothpaste for kids below the age of 3, and a pea-sized blob, not more, is recommended after 3. The parent actively doing the brushing is really the best way to go.

So, finally, use of a non-fluoride toothpaste below the age of 3 is probably a good idea, and using a children’s fluoridated toothpaste, which has half the adult concentration of fluoride, from 3 to 6 years of age, is also recommended. And a parent should always be watching and helping young children brush their teeth. I hope all this is clear and convincing.

And don’t forget the dental floss (again, done by the parent), especially once the teeth next to each other are touching.

1001 Uses For Dental Floss #57- The Dental Nurse Who Became An Alligator Catcher- A Story With Teeth.

Image copyright by Christy Kroboth, 2017. One of her catches (on a golf course).

Not exactly dental floss-related, but a fun story anyway. I came across this story of a dental assistant who decided to give up her career to become a full-time alligator catcher. Alligators of course have a lot more teeth than your (or my) average dental patient, and they’re a lot sharper and dangerous, so there’s part of the challenge. When Christy Kroboth started training as an alligator catcher she was the only woman in her class, but – she’s apretty tough and determined woman. She wanted to show that she could jump on an animal much bigger than her, and tape its jaws tightly shut before it had a chance to do her any damage.

She first started to catch alligators as a side employment to her main job, which was as a dental assistant, but her reputation grew to the point that demand made her take this on as full-time work. She’s a real animal lover, and remembers how she got to be that way- her mom used to stop the car at the side of the road to help ducks and turtles cross, and took in stray cats, dogs, and any other animal that needed a home.

In southern Texas, where Christy lives, there are a lot of communities where large man-made lakes and ponds are a sure attraction for alligators who live in the region to move in, but surprisingly, only one person has been killed by an alligator in the last 100 years. (So she claims, anyway.) People are of course afraid that their children and pets will be attacked and eaten,but she pooh-poohs this just a “superstition”, that they’re not the monsters they’re made out to be.

Alligators, being reptiles, have been around for millions of years, and have become an important part of the ecosystem, maintaining the fine balance of aquatic life. Apparently, they’re quite shy (when have you ever seen an alligator on a celebrity reality show?) and are fairly benign.

With a special licence and a permit, having taken a course which includes both a theoretical and a practical part (in other words, catching the beast with your bare hands).
She was the only girl in the class and also the youngest. The trainer told them: “OK, you’ve all passed the paperwork, now let’s go do this hands-on.”
Having never even touched an alligator before, for a split second she thought, “I can’t do this.” She called my mom, who said, as most loving moms would,”Come home right now, don’t do it!”
But this yound lady had something to prove, to herself, her mother, and especially to the “big ol’ country boys”. In her words, she ran out to the pond, got the alligator, taped him up and ended up passing the test. It was one of the happiest moments of her life and that adrenaline rush lasted the whole day.

Considering the the average alligator weighs almost 800 pounds (360 kilgrams) and is over 13 feet (4 meters) long, you can imagine the guts it takes to do this work. And she loves her job. She didn’t say, though, if she ever tried to floss an alligator’s teeth, and if she would ever try to use floss to tie one up. Somehow, I think, the answer to both these questions would be “no”.

This story was first reported by BBC Magazine. You will find the original article at: http://www.bbc.com/news/magazine-38641709

1001 Uses For Dental Floss #54- Can Good Oral Hygiene Damage Your Body? Really?

Probably not.
Years ago, when I was a beginner dentist, I didn’t know much, but then a lot of others were in the same boat. At one time, the teeth were considered a focus of infection, a place which harboured bacteria just waiting to set forth and infect the rest of the body. Boy, did dentists feel maligned, something like weathermen who were blamed for every storm and cold font, tornado, and drought, just for being around.
There was then an orthodoxy surrounding dental treatment for patients who had various sorts of heart defects, such as damaged or defective heart valves, a history of heart valve replacement, a history of rheumatic fever, or other heart-related problems. All such individuals were given penicillin (or, if they were allergic to that, another antibiotic) for two days before treatment and then for a day after the procedure, because it was felt that bacteria such as Streptococcus mutans or Streptococcus viridans lodged in the gums and around teeth would get pushed into the blood and then travel to and colonize these damaged, sensitive surfaces of the heart. A few years later, the regimen (developed by the American Heart Foundation) got simpler and involved just a single dose of penicillin (or other as above) an hour before the dental treatment started.
More recently, realizing that people with these problems could seed their hearts with bacteria just by brushing (and flossing), it became clear that it was a fool’s errand to try to prevent these effects except where there were powerful reasons to try to do so: recent heart valve surgery (within the last year) or certain serious and complex developmental defects involving the heart, or a heart transplant. Unfortunately, it was not a good idea to have these patients on a continuous dose of antibiotics either. The free and easy way in which antibiotics were being used was becoming a danger in itself, because strains of antibiotic-resistant bacteria were arising due to their overuse.
So, at the time, there was also a concern that certain artificial implants, such as latex tubes placed to drain excess fluid from the brain, or artificial hip joints, might offer internal surfaces that could be colonized by mouth bacteria, and antibiotics might be useful against this possibility too. And then antibiotics for these cases fell out of fashion, too.
That was then. Here, now, we’re up against the same situation again. Recently, a woman with an artificial knee joint arrived in hospital with a painful infection in that site. Puzzled doctors opened up the knee and discovered that the infection was by another type of bacteria, this time Streptococcus gordonii, commonly found in the mouth, and decided that because the woman had recently started vigorous flossing, that must have pushed them into the blood, and the infection of the knee followed.

Of course it did. Obviously.

Same old story, blaming the teeth again.To which I say, maybe. And if history is any sort of guide any more, probably not.

Keep flossing.

1001 Uses For Dental Floss #44- Voices In My Head

No, you’re not – I know it’s not politically correct to use this term – crazy. Not really.

We’ve all heard stories of people claiming to hear the radio signal inside their head because of a new filling in a tooth, sometimes causing them distress. So far, this phenomenon is pretty-much discounted; it’s all in their heads, as they say. Well, now someone has gone out and developed a tooth implant, a small wireless radio receiver, with a linked micro-vibrator, which can be placed inside an opening (an artificially created cavity) in a tooth, something like a filling is. A dentist makes a space in the tooth for it, and covers it with a white dental filling to seal it up.

Two researchers at the MIT Media Lab Europe, Jimmy Loizeau and James Auger, designed this object, and it was exhibited a few years ago in a collaboration between the Science Museum and the Royal College of Art in London.

The device retransmits digital radio signals from a local cell phone (within a short distance.) This electromagnetic signal is translated into low-level sound vibrations by a micro-vibrator, which then travel through the jawbone by bone resonance to the ear, where it is heard. No one outside the mouth hears it, so it can remain secret. Need an alarm clock to wake you up at a time when your bed buddy would rather not be disturbed? Want to hear the latest news or a secret message? Want someone to coach you through an exam?

Want to know what it’s like to feel like you have voices in your head? Now you can. And how to turn it off? There’s an app for that, which can remotely activate it or shut it down.

Now if only your tooth would stop ringing while you’re having that deeply romantic moment. It could get you into trouble.

1001 Uses For Dental Floss #43- Archeology, Dental Evidence, and Child Sacrifice

Today’s post is a mixture of history, archeology, religion, conjecture and controversy. Not much to do with floss, but hang in for the surprises.

First, a little history. Carthage was once a city in what is now Tunisia. You may remember Carthage, a city and an empire which clashed with Rome and lost. Hannibal, famous for crossing the Alps into Italy with his elephants, engaged the Romans in war and won most of the battles, except for the last one, which is of course the most important one. That’s why the languages many of us speak are descended from variants of Latin instead of variants of Aramaic, which is what the Carthaginians spoke.

Aramaic happens to be the language spoken in the eastern Mediterranean lands before the Romans and Greeks came along, and was the language used by Jesus. It was spoken by the Phoenicians, who were the close cousins, if not the same crew, as the Carthaginians. They were also known as the Canaanites, who worshipped the God Baal.

So it happens, if you remember any of the Old Testament part of the Bible from your youth, that these Baalists carried out all sorts of atrocities in their religious rites, including child sacrifice, and this practice, and therefore Phoenician/ Canaanite culture (and thus also Carthaginian culture) were abhorred by the Israelites, and later by the Greeks and Romans.

Human sacrifice was vigorously condemned in the Old Testament by the prophet Elijah, who promoted the destruction of the Baalists by the Israelites for this reason, among others.

So, did these peoples really sacrifice children in their temples? Now here the evidence starts to stir up controversy. This all hangs on evidence related to something called the “neonatal line” in baby teeth. What is termed the “neonatal line” is a noticeable change in layers of enamel evenly laid down before birth, something like the rings in a tree. This mechanism is briefly disrupted during a week or more following birth because birth process is so traumatic to the newborn, and this line can be seen when these teeth are viewed by a number of different analytical methods.

Still with me?

In a children’s cemetery recently examined in the ruins of Carthage, young children’s remains included both ones who died shortly after birth, but also many who were the results of miscarriages, because their teeth bore no signs of the neonatal line and so died before birth. It is known that the survival of newborns past their first year or two was only about 50% at best.

What this implies is that these fetuses were buried with reverence in the cemetery and suggests, from the inscriptions on grave markers there, that the other children died a natural death and were not given by their parents to be sacrificed, but their lives rather were highly valued.

Read this as you will, but this could imply that the whole notion of child sacrifice in Canaanite culture could be wrong and written in the Old Testament to justify the destruction of these people by the abhorrence of God for this practice. The evidence could be flimsy or it could be robust, depending on where your sympathies lie, but experts in the field (historians and archeologists) are strongly divided on whether this is real evidence and if it means anything when compared to the historical record that was written by the Jews, the Greeks, and the Romans, who were of course the enemies of this people. Historical revisionism by the victor, after all, has been around for a long, long time. But at this point, the verdict seems to hinge on evidence from teeth.

To which I say: I don’t know, but remember to floss.

For both takes on this story, see:



1001 Uses For Dental Floss #38- Our Friends The Animals

This story isn’t about floss. Not this time. It’s about the unusual variations of teeth in the animal world

I have to credit pediatric anesthetist Dr. Karen Brown for asking me one day, while we were working together in the O.R., if I knew which mammal had the largest number of sets of teeth. I failed the test because I didn’t know the answer. So Dr. Brown told me.

As most of us know, humans have 2 sets of teeth, but that’s not true for some of our friends, the animals. Not always.

It turns out that elephants grow up to 6 sets of teeth in a lifetime (the record), and that can be a long time, something like 70 years or so. It’s not like our teeth, where the permanent teeth form under the baby teeth and grow into the mouth to replace the baby teeth as they are shed. In elephants, as well as in dugongs, kangaroos (nor strictly mammals, but marsupials) and a certain type of African rodent, all have the teeth slide forward in the jaw, and as the frontmost of 3 molars are shed, new ones grow in behind them, something like a tooth assembly line. This type of dentition is called polyphyodont.

Of course, that’s not so for the elephant’s tusks, which are actually a specialized type of tooth. They’re the ones that the poachers are after, with the result that elephants are rapidly going extinct. Tusks keep on growing longer throughout the elephant’s lifespan. They’re not shed.

Now you know.

1001 Uses For Dental Floss #2– Radium Toothpaste

http-inlinethumb23.webshots.com-43798-2706452680102347975S600x600Q85During World War II, a German company, Auergesellschaft of Berlin, marketed a radioactive toothpaste, Doramad. On the back of the toothpaste tube it was stated that, ‘radioactive radiation increases the defenses of teeth and gums… cells are loaded with new life energy, the destroying effect of bacteria is hindered… it gently polishes the dental enamel and turns it white and shiny.’ The description failed to mention that the radiation could cause mutations and cancer in the mouths of the users and, when swallowed, many other organs of the body. The popularity of this toothpaste is unknown, likely because Germans were more concerned with surviving the war and “following orders” at the time.