Our mouths are an entire wild ecosystem, populated with living things that play a vital role in our well-being and confidence. Getting to know the creatures that live behind your lips will help you manage your oral health more effectively – plus provide fun facts for you to share when you need to amuse small children or perk up a boring conversation with adults.
Scientists have a fancy name for your mouth’s ecosystem – they call it the “human oral microbiome.” A big part of the microbiome is bacteria. A single mouth can be home to more than 6 billion bacteria, an impressive number when compared to 7.3 billion total human population of earth.
Those billions of oral bacteria live in diverse communities, where they go about the business of life: being born, working, feeding, defecating, mating, and dying – yes, all this is happening right now in your mouth. And like most urban areas, your mouth has safe neighborhoods and scary ones. Some of the communities are comprised of pathogenic bacteria that cause decay, gum inflammation and tooth loss.
The bad guys are Streptococcus mutans, which feeds on sugar and starchy carbs and then produces acids that erode your tooth enamel. Streptococcus mutans is the main cause of tooth decay and other oral diseases. Porphyromonas gingivalis isn’t a regular resident of your mouth, but shows up when gums are diseased (Periodontitis). Left to run amok it will destroy gum tissue and the alveolar bone that supports your teeth.
There are also nice, helpful microbes, too, benign bacteria (probiotics) that can support your overall health as well as oral wellness. Other members of the 700 different strains of bacteria that potentially live in your mouth are neither helpful nor harmful – at least as far as we know.
And then there are your teeth. Just like your mouth’s bacteria, your teeth are alive too; they are born, they grow, they (or, to be more specific, the dentin core of your teeth) have nerves and a blood supply. But compared to the activities of the 700 species of bacteria that potentially reside in your mouth, teeth seem to lead very Zen lives. We don’t know how they spend their time – at best, they just hang out and meditate quietly - but even if they aren’t sentient beings they are undoubtedly alive. And like all living things, if they aren’t cared for properly they will get sick, sad, and possibly die.
While about one baby in every 2,500-3,000 is born with a tooth or two, most children begin teething around six months of age. The official name for “baby teeth” is “deciduous teeth,” because these first teeth fall out, just like leaves drop from deciduous trees in autumn. Children grow 20 baby teeth – 10 on top, 10 on the bottom. These start falling out around age six, and over the next ten or more years, baby teeth are replaced with adult teeth.
Most adults grow 32 teeth - 8 incisors (the center four teeth on both the upper and lower jaws), 4 canines (the pointy ones on either side of the incisors), 8 premolars (between the incisors and the molars), and 12 molars (including 4 wisdom teeth, these are the bigger flat teeth in the back of your mouth).
Some people don’t grow the full set of wisdom teeth – some have only two, or one, or none. Wisdom teeth may not be able to fully erupt through the gum, and may be removed if they are causing pain or other dental issues. Other reasons for having less than the standard number of teeth include extractions for orthodontic treatments – some teeth may need to be removed to shift teeth into the desired new position. Teeth can also be lost to decay, gum disease, injury and medical conditions.
Each tooth is comprised of:
Enamel: The outer covering of the tooth, and the strongest, hardest and most highly mineralized substance in your body. Enamel is the most visible part of teeth, and is a semi-translucent material that ranges in color from light yellow to grayish white. Enamel is a barrier that protects your teeth from the ravages of acids and plaque. Enamel does not contain any living cells, and cannot regenerate itself, so it’s critical to preserve it. Proper oral hygiene – brushing, flossing, regular professional checkups and cleanings – help to keep your enamel from eroding.
Dentin: is a layer of living cells that lies underneath the enamel. Dentin is intended to protect the pulp of your teeth, and has a direct hotline to the nerves of teeth. When dentin is exposed due to loss of enamel you experience that sharp, shooting pain associated with cavities or sensitive teeth. Dentin is also what primarily gives your teeth their color.
Pulp: is the living center of your teeth, filled with blood vessels, connective tissue and nerves. Pulp keeps your teeth nourished and moist. Without pulp, our teeth would resemble dried, bleached bones – just like the turkey wishbone that you leave out for a few days following Thanksgiving to become brittle so you can easily snap it while making a wish.
Teeth are held in place by the Tementum, a layer of connective tissue that grips teeth to the gums and jawbone, and the Periodontal ligament, which helps hold the teeth to the jaw.
You also (hopefully!) have gums, upper and lower jaws, a tongue, salivary glands, an uvula (the dangly ball bit at the back of your mouth), and a frenulum linguae (the tissue under your tongue). All of these structures, except your teeth, are covered by a protective lining called the oral mucosa, similar to the mucous membranes inside your nose and inner ears.
Your gums protect your teeth and hold them in place.
The salvia produced by your salivary glands is a self-cleansing system for your mouth, and also helps to break down food, and neutralize acids that can damage teeth.
Your tongue lets you taste, moves food from your mouth to your digestive system, and helps you speak.
The uvula – well, science is stumped about its purpose, but the current consensus it that it might help moisturize your mouth and/or prevent food/liquids from entering your nasal cavity. It may also be something humans developed to help us speak.
The frenulum linguae connects your tongue to the base of your mouth.
Your jaws enable you to chew, speak and provide a nice scaffold for your face.
The health of all these structures are directly related to the health of your teeth. Your mouth is a holistic system, and if one part of it is not well, other parts also suffer.
Thankfully, teeth and your entire mouth can typically be kept healthy and happy with minimal effort. Sometimes you do have to work a little harder – pregnancy can cause dental issues, as can medical conditions such as diabetes. Ask your dentist for advice on managing your own personal mouth. In general, though, dentists advise:
Skip or limit your intake of simple carbohydrates (like foods made with white flour, and sugar). Those bacteria that live in your mouth love to snack on sweets and carbs. Carb-fueled bacteria multiply super-fast and cling to each other, creating a “biofilm” that’s commonly referred to as plaque. Bacterial plaque is the primary cause of 90% of all dental disease because bacteria secrete acidic waste products. This creates an acidic environment in your mouth that weakens teeth and leads to decay.
You’ll also want to limit acidic foods (citrus fruits, vinegary pickles, etc.) and beverages, such as soda, citrus juices, energy and sports drinks and wine. Sugar-laden acidic drinks such as citrus juice and citrus-flavored sodas can cause double the dental damage, so be especially vigilant about how often you indulge in them.
Try to rinse your mouth with water after drinking acidy liquids. Acidic foods and drinks can cause dental erosion, a softening of the enamel on your teeth, which can progress to the dentin, and cause decay. Hold off on brushing for about an hour after eating acidic foods, to avoid damaging enamel.
Here’s a little more info about your dental enamel – it is comprised of tiny, tightly-packed rods of minerals. You have about 5 million rods in the lower lateral incisor and up to 12 million in the upper first molar. Brushing your teeth with a side-to-side motion goes against the orientation of the enamel rods in your teeth, which can cause the rods to weaken and break. Instead, position your toothbrush’s bristles at a 45-degree angle to the surface of the teeth and brush gently in small circles.
Dental hygienists advise brushing for three minutes, with a soft brush. Replace the brush every three months – or sooner if the bristles are worn, bent or frayed. Also, replace your toothbrush if you’ve just recovered from a cold, the flu or another ailment. Germs like to lurk in your brushes bristles.
You may want to talk to your dentist or dental hygienist about electronic toothbrushes or the newer brushes that use ultrasound to destroy bad bacteria and debris.
Flossing has recently come under fire – there’s no scientific proof of its effectiveness. But that doesn’t necessarily mean that it is ineffective – it just indicates that no one has spent the money and time necessary to do an in-depth research study on flossing. Logic seems to indicate that flossing is a very effective way to remove food debris from between the teeth.
Dry mouth also puts teeth at increased risk for erosion, as a healthy saliva flow helps protect teeth from exposure to acid. Drink water, and if you’re still feeling parched try rinsing your mouth with a product designed for dry mouth care, and chewing sugarless gum.
No matter how devoted you are to at home care, regular exams and professional teeth cleanings are critical. Checkups involve more than a quick peek at your teeth – your dentist will screen you for oral cancer, tooth decay and gum disease. Caught early, these conditions are far easier to manage.
Even people who are super-dedicated to good oral hygiene will inevitably miss a bit of plaque here and there, which can harden into tartar. Removing tartar is not something that you can do at home, without risking the chance that you’ll cause more dental damage with abrasive toothpastes, scraping and whatever other weird DIY dentist trick YouTube may be recommending today. Your hygienist will safely clean hardened dental plaque that’s impossible to remove at home, and any trapped debris.
Your dental care team is the absolute best source of information on oral hygiene practices and addressing your oral health concerns. Don’t wait until a problem arises to check in with your dentist!If you’ve been skipping regular checkups and cleanings due to budget concerns and no dental insurance, consider getting a dental savings plan. These plans are an affordable alternative to dental insurance, providing plan members with discounts of 10-60% on the majority of dental procedures.
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