Dental Detectives: What Fossil Teeth Reveal About Ancestral Human Diets

When scientists want to know what our ancient ancestors ate, they can look at a few things: fossilized animal bones with marks from tools used to butcher and cut them; fossilized poop; and teeth. The first two can tell us a lot, but they're hard to come by in the fossil record. Thankfully, there are a lot of teeth to fill in the gaps.
"They preserve really well," explains Debbie Guatelli-Steinberg, a dental anthropologist at Ohio State University. "It's kind of convenient because teeth hold so much information."
The structure of a tooth and even the amount of enamel, for example, hint at what the teeth are adapted to eat.
Look at molars: Thick enamel on a molar is good for crushing foods. It suggests an animal used its teeth to grind seeds or crush the marrow out of bones. Thin enamel on a molar, while delicate, causes sharp edges — perfect for slicing and tearing foods like leaves and fruits.
However, these are just clues to some of the things the animal could have been eating, not what it ate every day, says Peter Ungar, an anthropologist at the University of Arkansas.

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"If you eat Jell-O almost every day of the year, but sometimes you need to eat rocks ... you want teeth that can eat rocks," he explains. So, teeth are usually adapted for the toughest component of an animal's diet, not what it eats on a daily basis.
To see what an animal was actually eating, Ungar studies something called dental microwear, the marks left behind by food on teeth. As we chew on say, a celery stick, hard particles — either bits of silica from the plants' cells or sand and grit from the surrounding environment — are dragged across and pressed into our teeth. When we chomp down on something hard, like a nut, the crushing force leaves microscopic pits behind. When we tear through tough grasses — which may not sound appetizing now, but it's likely some of our ancestors did eat them — by moving our teeth side-to-side, the teeth get tiny, microscopic scratches.
"I call it a foodprint," Ungar says.
These foodprints can paint a pretty good picture of what an animal ate in the weeks leading up to its death — a sort of last meal. A study of such microwear revealed that Australopithecus afarensis, our 4 million-year-old ancestor best known by the famous fossil of Lucy, probably ate tough grasses and leaves. And it looks like early members of our genus, Homo — like Homo habilis, which lived 2.4 million years ago or Homo erectus, which even overlapped with humans about 100,000 years ago — were omnivores like us. They ate a variety of foods like meat, plants, fruits, "Anything they wanted!" says Ungar.
So we can tell what an animal was adapted to eat and what it ate shortly before it died. But to know what it ate for longer periods, scientists have to look deeper — to just below the surface of a tooth — for certain molecular signatures left behind from daily meals.
As our teeth grow in early childhood and adolescence, they incorporate certain molecules from the food we eat. The same was true for our ancestors. Paleoanthropologists studying ancient diets are especially interested in carbon molecules in our ancestors' teeth, because they come from plants and stick around for a long time.
Some groups of plants use mostly one form, or isotope, of carbon. Plants with C3 isotopes are usually found in fruits and leaves — things that grow in forests. Plants with C4 isotopes, like grasses and sedges, grow in savannas.
Data from isotopes confirmed that Lucy's species switched from forest foods to savanna foods about 3.5 million years ago. That transition from forests to grasslands may have played a key role in human evolution, explains Matt Sponheimer, a paleoanthropologist at the University of Colorado, Boulder. Some researchers even think that adding more grass to our diets gave our ancestors more foods to eat and places to live as the early climate changed causing Africa's forests to shrink.
Our understanding of what our ancestors ate has become more complex and richer with time, as scientists have applied newer, more advanced techniques to study teeth. When Mary Leakey dug the 2 million-year-old human ancestor Paranthropus boisei out of Olduvai Gorge in Tanzania in 1959 year, she noticed the fossil's wide, thick molars. The skull had huge cheekbones to accommodate strong chewing muscles and powerful jaws, suggesting the species was well-suited for crushing nuts. So, Paranthropus boisei was nicknamed Nutcracker Man.
But when Peter Ungar and others examined Nutcracker Man's teeth, they barely found any foodprints, so they decided he likely ate soft foods like fruits.

An analysis of Nutcracker Man's tooth isotopes revealed C4 carbon, which comes from savannas, not fruit-filled forests.
Today, researchers think that Paranthropus boisei ate a varied diet with lots of different foods, but he mostly ate tough grasses and sedges.

Teeth from more recent fossils reveal more because they have more isotopes preserved in them. For example, the nitrogen in the teeth of Neanderthals can reveal whether the protein they ate came from plants or animals. It's one of many reasons researchers think Neanderthals hunted large mammals, though scientists have also found fossilized plants stuck in Neanderthal teeth.
Researchers were even able to use isotopes to find out when one Neanderthal started weaning her baby. As teeth grow, they lay down layers of enamel. And barium, a molecule children get from breast feeding mothers, builds up in baby teeth until the mother stops nursing. By comparing barium in a Neanderthal tooth with levels in donated present day baby teeth, the scientists were able to find out that the Neanderthal baby had been weaned at about seven months.
We can even use teeth to tell if someone moved between places with dramatically different foods or soils. Since wisdom teeth are the last adult teeth to come in, comparing them to an early emerging canine tooth can give scientists a dietary snapshot across time. Say someone was born in Africa and moved to a new continent as a preteen, while wisdom teeth were still growing. A comparison of the isotopes in the teeth would reveal the story of that migration.
There's still a lot to learn from teeth, and a lot of fossil teeth still being discovered, says Sponheimer. And as the tools to study them get more sophisticated, teeth are providing a richer picture of "who we are and how we came to be," he says.

By: Erin Ross, NPR
http://www.npr.org/sections/thesalt/2016/10/25/497094756/dental-detectives-what-fossil-teeth-reveal-about-ancestral-human-diets

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North Austin on Hymeadow Drive: (512) 250-5012
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Should You Get A Tongue-Scraper?

A tongue scraper is an oral hygiene product that removes bacteria, food debris, fungi, toxins, and dead cells from the surface of the tongue.

When we sleep, our digestive system remains awake, removing toxins from our body by depositing them onto the surface of our tongue. If we do not scrape away these toxins, they get reabsorbed by the body and can lead to respiratory difficulties, digestive problems, and a compromised immune system.

Dental research has concluded that a tongue scraper is more effective at removing toxins and bacteria from the tongue than a toothbrush. Although brushing and flossing will loosen and move debris around, they do not actually remove the bacteria. Almost half of our oral bacteria live on and in the deep crevices of our tongue; the scraping action of a tongue scraper collects these toxic tongue coatings (which can range in color from clear, white, yellow, or green) and removes them from the body. However, still remain strict on continuing with the rest of your dental care routine, The bacteria that causes tartar to build up still remains your teeth and under your gums. Left untreated, this can lead to gum disease, receding gums, and loose teeth that can ultimately fall out.

What is a tongue scraper?
It is a long, thin, flat piece of metal that is bent in a "U" shape 

How to use a tongue-scraper
You should use a tongue-scraper on a regular basis, in the morning and on an empty stomach. 
1. Stand in front of a mirror
2. Hold the two ends of the scraper in both hands
3. Stick out your tongue
4. Place the scraper as far back on your tongue as possible
5. With firm but gentle pressure, scrape the surface of your tongue in one long stroke
6. Rinse the scraper and repeat until your tongue feels clean and is free of coating (usually 5 to 10 times) 

Why do I need one?
1. Lessen halitosis
Bad breath can have a negative impact on a person's life, relationships, and self-esteem. Given that most bad breath comes from the bacteria at the back of the tongue (an area that's difficult to reach with a toothbrush), clinical studies have shown that tongue scraping significantly reduces and removes oral bacteria from the crevices of all areas on the tongue.

2. Experience the flavors of your food
Proper digestion begins with taste and salivation. If you do not take steps to remove toxic mucus on the tongue, your taste buds can become blocked. This may lead to false cravings or an inability to recognize the taste of food. Removing build-up from the surface of your tongue will open up its pores and better expose your taste buds, allow for greater enjoyment of food flavors, and help your body digest and assimilate food.

3. Boost your immunity
The tongue is part of the first line of defense in your immune system. Scraping your tongue prevents toxins from being reabsorbed into your body and boosts overall immune function.

4. Improve your dental health
This oral hygiene product promotes general tooth and gum health and removes bacteria and toxins responsible for periodontal problems, plaque build-up, tooth decay, loss of teeth, gum infections, and gum recession.

5. Improve your digestive health
Given that digestion begins with taste, it is important to remove any toxins that may obstruct optimal functioning. Scraping also activates saliva production and promotes agni (the body's digestive fire) to help with digestion throughout the day.

Where do I buy one?
Tongue scrapers and inexpensive and can be found at most health food stores as well as online. Choose a stainless steel scraper because they are easier to clean. Another dental tip, the side of a metal spoon can also be effective.

http://www.mindbodygreen.com/0-12028/5-reasons-why-everyone-needs-a-tongue-scraper.html

A Beginner's Basics to Braces

How can orthodontics help you?
If your teeth are in poor alignment, you could be facing a functional or cosmetic problem. Orthodontics (braces) can eliminate that problem for you. One of the first things people notice about you is your smile and how your teeth look. You don't have to be a dentist to notice poorly positioned, crooked teeth. In today's culture, crooked teeth are not regarded as attractive or desirable. Most people, when asked, say that they would like to have straight teeth. Straight, white teeth are the cosmetic dental improvements patients most request.

Braces may also be suggested to correct a specific dental problem that only affects one or several teeth. This is not a cosmetic tooth repositioning, but rather a functional tooth movement. Occasionally, in order to properly finish an orthodontic case, the orthodontist may ask the dentist to adjust the enamel of some teeth or bond a resin to some teeth to improve the occlusion (bite alignment) or to enhance cosmetics. This will be discussed with you as soon as it becomes apparent.

When should you see an orthodontist?
The need for orthodontics is best discovered when you are young. A dentist will have a good indication of whether or not your teeth will be straight when he sees you as a child 6 to 8 years of age. Most treatment would not begin until a patient is 8 years old, although in some cases, orthodontics can be started earlier.

It is easier to direct the movement of teeth in a child. Early tooth guidance is a very important phase of orthodontic care, which can take place even though all the permanent teeth are not yet in place. Certain problems are much easier to correct at this stage of a "mixed dentition" of baby and permanent teeth. An average case can last from 18 to 24 months.

While orthodontic therapy is admittedly easier in the child patient, you are never too old to begin orthodontics. The number of adults seeking orthodontic treatment has risen dramatically during the past decade. As long as you have healthy bone support for your teeth, you can have orthodontic therapy. Most adult cases take 18 to 24 months to complete.
What are retainers?
Once braces are removed, it is usually necessary to wear a retainer. After your braces come off, your orthodontist will make a mold of your mouth and produce a set of retainers. This retainer will maintain the new tooth alignment until the teeth have had a chance to become firmly set in their new positions. This retainer may be either removable or fixed in place. Aside from a permanent bonded retainer, there are two other types that most people get.

A Hawley Retainer is made of acrylic and metal. The acrylic goes behind your teeth and up against your upper palate; the metal is in front of your teeth. This is the most reliable refinements that still need to be done to your teeth.

Orthodontic Toothbrush

An Essix Retainer is clear plastic and looks like an Invisalign aligner tray. Many people want this type of retainer, but it has its disadvantages. Many orthodontists feel that because it covers the biting surface of your teeth, they do not "settle" properly after treatment. For this reason, sometimes orthodontists give a patient both types of retainers: an Essix Retainer to wear during the day when they are people-facing, and a Hawley Retainer to wear at night when they are home sleeping.

No matter what type of retainer you get, the most important thing is to wear it exactly as the orthodontist tells you. Most people need to wear their retainers 24/7 for at least 6 months, then switch to wearing it only at night when sleeping. 

How do I keep clean teeth with braces on?
While orthodontic treatment is in the active phase, that is, while the braces are on your teeth, you must be very diligent about keeping your teeth clean. This will be more difficult than and somewhat different from cleaning your teeth without braces. You will be instructed in the use of any cleaning aids needed. These may include dental floss threaders, orthodontic toothbrushes, an oral irrigator to flush out debris, proper brushing habits, fluoride mouth-rinses, and periodontal aids. You must follow your proper oral self-care routine each night to prevent decay, decalcification of the teeth, and gum disease. You also should not use a whitening toothpaste when you have braces. It could cause you to have "two tone" teeth after the brackets are removed. Another thing to remember is that although a device like a Waterpik is great for gum stimulation and dislodging food, it is not a substitute for flossing. You still need to floss daily.

Give Yourself A 60-Second Dental Check-Up

Regular visits to your dentists are absolutely essential to prevent serious dental problems. But it is also important to give yourself an oral check-up from time to time. This simple process just takes a minute, but it can yield valuable clues to the health of your mouth, teeth, and gums.

Stand before a well-lit mirror and open your mouth wide.

1. Check your gum line and the lines between your teeth
Good: There should be no brown lines here
Bad: If you see brown lines, that is a sign of tartar build-up
What to do: Time to go to the dentist. Once the brown lines are cleaned up at the clinic, regular flossing will keep tartar away.

2. Stick out your tongue. What does the surface look like? 
Good: A healthy tongue should be pink
Bad: If it is coated with white, it can be an indication of poor digestion. This coating also results in bad breath.
What to do: Use a stainless steel scraper to clean your tongue every morning. 

3. Are there ridges along your tongue? 
Bad: This is often a sign of tooth grinding. People may not be aware they grind their teeth, but it can happen when they are stressed. 
What to do: If you wake up with an aching jaw, you should see a dentist.

4. Take a look at the inside of your cheeks. 
Bad: Do you see white patches? These can occur if you chew the inside of your mouth when you bite and chew your food. 
What to do: These should be checked by your dentist because a wound inside the cheek can not only get infected, but may also be a sign of pre-cancerous changes, especially in smokers. An ulcer that does not heal within three weeks should also be investigated.

5. How do your gums look?
Good: If they are pink and rosy, your gums are in good health. 
Bad: But if they are red, it is a signal that gingivitis or gum inflammation has turned into gum disease. Another clue: gums that bleed when you brush your teeth. 
What to do: Your dentist can help you with a course of antibiotics and dental hygiene guidance on how to rebuild gum health. 

Bad: Pale gums can indicate iron deficiency - a warning sign of anemia. 
What to do: Up your intake of green vegetables, tofu, chickpeas, lentils, and dried fruits such as raisins and prunes.