The tooth fairy, movie-star smiles, toothy grins—teeth have carved out an enviable reputation for themselves, especially considering that their primary function is identical to that of the decidedly unglamorous wood chipper, meat mallet, and garbage disposal. And make no mistake: Teeth adore the limelight. They go to great lengths to bury their bad press—plaque, cavities, and the dreaded root canal, just for starters.
But we're out to expose teeth—the whole mouth, in fact—to the harsh truth. Handy as they are, teeth don't always live up to their PR. Let's start by discussing what teeth are made of and what they do.
Teeth may look like fossils, but they're actually dynamic living structures. The bonelike enamel (crown) that we see on the outside of each tooth conceals an interior chamber filled with dentin—a rigid mesh of mineralized connective tissue. Beneath this layer of dentin, each tooth's core consists of nerves encased in a pulpy sheath. Canals in the center of each tooth root allow nerves to pass through. The tooth is anchored in the jaw by sturdy ligaments and a material called, appropriately, cementum.
The blade-shaped incisors are like a built-in set of Ginsu knives—the similarity to the word "scissors" is not coincidental. The pointy cuspids help you slice, gnash, sever, and slash. The bicuspids (premolars) and molars have broad, blunt surfaces that crush and grind like a mortar and pestle.
Chewing (mastication) is the first step in digestive process. You would have a hard time swallowing, say, a boiled egg without chewing it first. What may be less obvious is that chewing not only makes the egg easy to swallow, but it also multiplies the surface area on which digestive enzymes can act in order to convert food into energy.
Three pairs of salivary glands moisten food to ease its passage through the esophagus, the tube that connects the back of the throat to the stomach. These glands also secrete enzymes that begin to dissolve starches.
Oral Health and General Health are Linked
The stature of dental and oral health has risen in recent years as researchers have discovered a connection between declining oral health and underlying systemic conditions. In other words, a healthy mouth can help you maintain a healthy body. Studies suggest that periodontal disease (advanced gum disease) increases the risk of heart disease, stroke, respiratory problems, and diabetes. In addition, bacteria can spread from the oral cavity to the bloodstream, causing a life-threatening infection of the heart valves. For this reason, your dentist may suggest administration of prophylactic (preventive) antibiotics before performing any dental procedure that could dislodge bacteria in the mouth.
What Can Go Wrong
The oral cavity is a catch basin for all sorts of bacteria, viruses, and fungi. Some of them belong there, making up the normal flora of the mouth. In small quantities, they're either harmless or beneficial and tend to keep each other in check. However, a diet high in sugar creates conditions in which acid-producing bacteria can flourish. This acid dissolves tooth enamel, causing dental cavities—or caries, a Latin word for decay.
Bacteria at and just beneath the gum line thrive in a sticky matrix called plaque. If plaque is not removed regularly by brushing and flossing, it accumulates, hardens, and migrates down the length of the tooth, inflaming the gums and causing a condition known as gingivitis. As the inflammation progresses, the gums (gingival) begin to pull away from the teeth, creating pockets in which pus may eventually collect. This more advanced stage of gum disease is called periodontitis (perio for gums, dont for teeth, and itis for inflammation). If periodontal disease exposes the root canal of a tooth, laying bare the nerve root, therapy to save the tooth may be necessary.
The oral cavity, including the lips and throat, may be the site of abscesses or other infections, disorders, or even cancer. Nearly all adults, for example, have been infected with herpes simplex virus, type 1 [HSV-1], the virus that causes cold sores in the mouth or on the lips. This virus may lie dormant, but it remains in the body and may re-emerge intermittently to cause pustules on the lips and inner mouth.
Keeping Your Teeth & Gums Healthy
Good oral health boils down to common sense. Don't use tobacco products. Brush your teeth with fluoride toothpaste twice a day, and floss daily. (Flossing is the most beneficial activity you can do to prevent disease in the oral cavity.) Have your teeth cleaned by a dental professional every six months. Follow a high-fiber, low-fat, low-sugar diet that includes plenty of fruits and vegetables. Such a diet is naturally high in vitamin D, which helps the body absorb and maintain calcium and phosphorus, minerals found in teeth and bones. Limit sugary snacks and foods with hidden sugars, such as ketchup and barbecue sauce, sliced fruit or applesauce in cans or jars, fruit yogurt, pasta sauce, iced tea, soda, sports drinks, juice or juice blends, granola and cereal bars, and muffins (even ones that sound healthy, such as oatmeal-raisin).
