If you have gum disease, you're not alone. Many U.S. adults currently have some form of the disease. It ranges from simple gum inflammation, called gingivitis, to serious damage to the tissue and bone supporting the teeth. In the worst cases, you can lose teeth.

In gingivitis, the gums become red and swollen. They can bleed easily. Gingivitis is a mild form of gum disease. You can usually reverse it with daily brushing and flossing and regular cleanings by a dentist or dental hygienist. Untreated gingivitis can lead to periodontitis. If you have periodontitis, the gums pull away from the teeth and form pockets that become infected. If not treated, the bones, gums and connective tissue that support the teeth are destroyed.

The Anatomy of the Gum

The gingiva is the part of the masticatory mucosa that surrounds the teeth and extends to the alveolar mucosa. It is firmly attached to the jaw bone and it has keratinized stratified squamous epithelium. The free gingiva is separated from the tooth by the gingival groove and it it very narrow. Most of the gum is the attached gingiva. The interdental gingiva occupies the cervical embrasures in healthy gums but periodontal disease may cause it to receede. Gingival fibers attach the gums to the neck of the tooth. They also provide structure to the gingiva and connect the free to the attached gingivae.

This chapter is about the gums, which are also called gingivae (singular gingiva). The text will describe the structure of the gingiva and explain its role in periodontal diseases, from gingivitis to abscesses in humans and other mammals.

Structure

The gingiva is part of the masticatory mucosa of the mouth. This mucosa is formed by keratinized stratified squamous epithelium and it covers the dorsum of the tongue and hard palate in addition to forming the gingivae.

The gingivae surround the teeth and provide a seal around each of them. They are tightly bound to the underlying bone. This helps them resist friction against food during mastication. A healthy gingiva is an effective barrier against external threats to deeper tissue. The gingiva interfaces with the alveolar mucosa which is non-keratinized, darker and much looser as a lining of the oral cavity than the masticatory mucosa (Fig. 2). The line of contact between the gingiva and the alveolar mucosa is called mucogingival junction.

Healthy gums range from light pink to tan depending on the person’s skin color. Accumulation of bacterial plague, however, can cause inflammation with increased redness together with swelling and a tendency to bleed. A chronic inflammation of the gingiva can affect the deeper tissue of the periodontium and potentially compromise the tooth.

The gingiva is divided anatomically into three areas called free (marginal), attached and interdental gingivae.

Periodontal (gum) disease is an infection of the tissues that hold your teeth in place. It's typically caused by poor brushing and flossing habits that allow plaque—a sticky film of bacteria—to build up on the teeth and harden. In advanced stages, periodontal disease can lead to sore, bleeding gums; painful chewing problems; and even tooth loss.

Periodontal disease is the result of infections that lead to inflammation and tissue damage in the structures surrounding the teeth. The progression from mild to severe periodontal disease is generally reversible and preventable with good oral hygiene.

Gingivitis

Inflammation of the gums that can lead to irritation and bleeding is called gingivitis. When plaque accumulates on the teeth, bacteria colonize the gingival space. As this space becomes increasingly blocked, the environment becomes anaerobic. This allows a wide variety of microbes to colonize, including Porphyromonas, Streptococcus, and Actinomyces. The bacterial products, which include lipopolysaccharide (LPS), proteases, lipoteichoic acids, and others, cause inflammation and gum damage. It is possible that methanogenic archaeans (including Methanobrevibacter oralis and other Methanobrevibacter species) also contribute to disease progression as some species have been identified in patients with periodontal disease, but this has proven difficult to study. Gingivitis is diagnosed by visual inspection, including measuring pockets in the gums, and X-rays, and is usually treated using good dental hygiene and professional dental cleaning, with antibiotics reserved for severe cases.

Periodontitis

Over time, chronic gingivitis can develop into the more serious condition of periodontitis. When this happens, the gums recede and expose parts of the tooth below the crown. This newly exposed area is relatively unprotected, so bacteria can grow on it and spread underneath the enamel of the crown and cause cavities. Bacteria in the gingival space can also erode the cementum, which helps to hold the teeth in place. If not treated, erosion of cementum can lead to the movement or loss of teeth. The bones of the jaw can even erode if the infection spreads. This condition can be associated with bleeding and halitosis (bad breath). Cleaning and appropriate dental hygiene may be sufficient to treat periodontitis. However, in cases of severe periodontitis, an antibiotic may be given. Antibiotics may be given in pill form or applied directly to the gum (local treatment). Antibiotics given can include tetracycline, doxycycline, macrolides or β-lactams. Because periodontitis can be caused by a mix of microbes, a combination of antibiotics may be given.

Trench Mouth

When certain bacteria, such as Prevotella intermedia, Fusobacterium species, and Treponema vicentii, are involved and periodontal disease progresses, acute necrotizing ulcerative gingivitis or trench mouth, also called Vincent's disease, can develop. This is severe periodontitis characterized by erosion of the gums, ulcers, substantial pain with chewing, and halitosis that can be diagnosed by visual examination and X-rays. In countries with good medical and dental care, it is most common in individuals with weakened immune systems, such as patients with AIDS. In addition to cleaning and pain medication, patients may be prescribed antibiotics such as amoxicillin, amoxicillin clavulanate, clindamycin, or doxycycline.

What is periodontal disease?

Periodontal diseases are mainly the result of infections and inflammation of the gums and bone that surround and support the teeth. In its early stage, called gingivitis, the gums can become swollen and red, and they may bleed. In its more serious form, called periodontitis, the gums can pull away from the tooth, bone can be lost, and the teeth may loosen or even fall out. Periodontal disease is mostly seen in adults. Periodontal disease and tooth decay are the two biggest threats to dental health.

A recent CDC report provides the following data related to prevalence of periodontitis in the U.S.:

• 47.2% of adults aged 30 years and older have some form of periodontal disease.
• Periodontal disease increases with age, 70.1% of adults 65 years and older have periodontal disease.

This condition is more common in men than women (56.4% vs 38.4%), those living below the federal poverty level (65.4%), those with less than a high school education (66.9%), and current smokers (64.2%)

Causes

Bacteria in the mouth infect tissue surrounding the tooth, causing inflammation around the tooth leading to periodontal disease. When bacteria stay on the teeth long enough, they form a film called plaque, which eventually hardens to tartar, also called calculus. Tartar build-up can spread below the gum line, which makes the teeth harder to clean. Then, only a dental health professional can remove the tartar and stop the periodontal disease process.

Warning signs

The following are warning signs of periodontal disease:

• Bad breath or bad taste that won’t go away
• Red or swollen gums
• Tender or bleeding gums
• Painful chewing
• Loose teeth
• Sensitive teeth
• Gums that have pulled away from your teeth
• Any change in the way your teeth fit together when you bite
• Any change in the fit of partial dentures

Risk factors

Certain factors increase the risk for periodontal disease:

• Smoking
• Diabetes
• Poor oral hygiene
• Stress
• Heredity
• Crooked teeth
• Underlying immuno-deficiencies—e.g., AIDS
• Fillings that have become defective
• Taking medications that cause dry mouth
• Bridges that no longer fit properly
• Female hormonal changes, such as with pregnancy or the use of oral contraceptives

Prevention and treatment

Gingivitis can be controlled and treated with good oral hygiene and regular professional cleaning. More severe forms of periodontal disease can also be treated successfully but may require more extensive treatment. Such treatment might include deep cleaning of the tooth root surfaces below the gums, medications prescribed to take by mouth or placed directly under the gums, and sometimes corrective surgery.

To help prevent or control periodontal diseases, it is important to:

1. Brush and floss every day to remove the bacteria that cause gum disease.
2. See a dentist at least once a year for checkups, or more frequently if you have any of the warning signs or risk factors mentioned above.

If you can’t afford dental care, you may be able to find help through the following sources:

• The Health Resources and Services Administration supports a network of “safety net” clinics for people who qualify for reduced-cost care, and many have a dental clinic (toll free: 1-888-275-4772).
• Most dental schools have a clinic staffed by the professors and students, where care is provided based on your ability to pay.
• Your state dental organization may be able to refer you to dentists in your area who provide care at a reduced rate.

It is the exposure in the roots of the teeth caused by a loss of gum tissue and/or retraction of the gingival margin from the crown of the teeth.

The main causes are:

Periodontal disease.

• Overaggressive brushing or flossing.
• Genetic predisposition through fragile or insufficient gingival tissue.
• Dipping tobacco, which weakens the mucous membrane lining in the mouth.

1 Total loss of attachment (clinical attachment loss, CAL)

2 Gingival recession 3 Probing depth

1 = 2 + 3

Gum recession is a common problem in adults over the age of 40, but it may also occur in adolescents or children. It occurs with or without a decrease in crown-to-root ratio, which indicates recession of the alveolar bone. In most cases, the condition progresses gradually over the years and patients tend not to notice the recession. It may remain undetected until severe symptoms start to occur.

Elimination of the cause of gingival recession is frequently enough to resolve it. In advanced cases, however, soft-tissue graft surgery may be used to create more gingiva. Depending on the extent and shape of the gum recession, it can be regenerated with new gum tissue using a variety of grafting procedures. These procedures are typically conducted under local anesthesia. The graft may be a:

• Pedicle graft. Repositioning of adjacent gum tissue to cover the recession.
• Free gingival graft. A thin layer of skin from the palatal gingiva.
• Subepithelial connective tissue graft. Tissue removed deeper in the palate.
• Acellular dermal matrix. Processed skin from a human donor.

Healing from such procedures requires 2-4 weeks. The new tissue may need some adjustment for improved results. Nearly complete coverage of the recession area is achievable, especially in cases that do not involve alveolar bone loss.

Our mouths are full of bacteria. These bacteria, along with mucus and other particles, constantly form a sticky, colorless “plaque” on teeth. Brushing and flossing help get rid of plaque. Plaque that is not removed can harden and form “tartar” that brushing doesn’t clean. Only a professional cleaning by a dentist or dental hygienist can remove tartar.

There are a number of risk factors for gum disease, but smoking is the most significant. Smoking also can make treatment for gum disease less successful. Other risk factors include diabetes; hormonal changes in girls and women; diabetes; medications that lessen the flow of saliva; certain illnesses, such as AIDS, and their medications; and genetic susceptibility.

Do you know what’s in your mouth? It’s home to about 700 species of microbes. These include germs like bacteria, fungus, and more.

“Everybody has these microbes in their mouth,” says Dr. Robert Palmer, an NIH expert on oral microbes.

Some microbes are helpful. Others can cause problems like tooth decay and gum disease. Troubles begin when microbes form a sticky, colorless film called plaque on your teeth.

Brushing and flossing help to keep your mouth clean. But after you brush and floss, germs grow again and more plaque forms. That’s why you need to clean your mouth regularly.

Community Growth

Different microbes grow in different places. Some stick to your teeth. Others prefer your tongue. Some lurk in the tiny pockets between tooth and gum. Once they’ve found their homes, they form diverse communities with the other germs.

Mouth microbes work together to protect themselves with a slimy, sticky material called a matrix. The matrix in plaque makes it harder to remove it.

The communities within the matrix include both helpful and disease-causing microbes. The good microbes help keep the growth of bad microbes in check. Good microbes also help you digest food and can protect against harmful microbes in food.

Certain things you may be doing can help bad microbes grow better than the good ones. Sugary foods and drinks feed some microbes and help them increase in number and spread out.

Some of these sugar-loving microbes can turn sugar into matrix and acid. The acid destroys the surface of your teeth. The more sugar in your diet, the more fuel is available for these microbes to build up plaque and damage teeth.

“It’s more productive to think about the community than it is to think about the single microbe that causes disease,” Palmer explains.

You can’t stop tooth decay by getting rid of just one type of acid-making microbe. There are several different types of microbes in the plaque that make acid.

The good news is that limiting sweets and brushing and flossing regularly can help prevent bad microbes from growing out of control.

Helpful Neighbors

“Many bacteria in our mouths depend on help from other members of their community to survive and prosper,” says Dr. Floyd Dewhirst, a dental expert who studies microbes at the Forsyth Institute.

Because microbes grow in communities, it’s important to understand how both helpful and harmful microbes work. Dewhirst’s team is trying to identify all the different germs living in the mouth and what they do.

Before the team can study a microbe, they have to figure out how to grow it. The challenge is that some microbes don’t like to grow anywhere but in your mouth. About 30% of the 700 species haven’t been grown in the lab yet.

Dewhirst’s team is working on growing those microbes in the lab that no one has grown before. They’re using genetic and other information to identify each one and learn more about them.

“The question is,” he says, “once you know who is there and have a quick way of identifying them, what are all of these bacteria doing?”

Dewhirst’s studies have shown that some microbes make certain substances that help their neighbors grow. His team is trying to identify what those substances are.

They also want to find out how these microbes may affect people’s health. Being able to grow microbes in the lab lets scientists run tests to figure out how they’re involved in health and disease. This information could one day help scientists come up with better ways of preventing and treating oral diseases.

Partners in Decay

An important health problem caused by mouth microbes is early childhood tooth decay. “In the U.S., about 23% of our children between the ages of 1 and 5 are affected by this disease,” says Dr. Hyun (Michel) Koo, a dental researcher and oral health expert at the University of Pennsylvania.

Tooth decay can get worse very fast. The microbe matrix and acid from bacteria are thought to be the main cause of tooth decay in young kids.

Koo’s team has found that there’s also fungus in the plaque of kids with rampant tooth decay. The fungus partners with the matrix- and acid-making bacteria to worsen tooth decay.

“Bacteria by itself can cause tooth decay,” Koo explains. “But when fungus is there, it boosts up the entire machinery.”

Koo’s team has shown that some fungus can get energy from sugar that bacteria release while making acid. The fungus then releases substances that feed the bacteria’s growth. This helps the bacteria form an even tougher matrix and make more acid.

Busting Plaque

Koo’s team is looking for new ways to fight plaque buildup and tooth decay. They’ve developed tiny substances, called nanoparticles, that are small enough to get inside and destroy the matrix that protects microbes. The nanoparticles can also kill the acid-making bacteria without harming good bacteria in the mouth.

Koo’s team has shown that these tiny substances can reduce acid damage to the tooth surface. The researchers hope to test the approach in people in the future.

Nanoparticles are just one approach now being studied to prevent or treat mouth diseases.

Future technologies may help keep our mouths healthier. But there are many things you can do to keep bad mouth microbes in check now. See the Wise Choices box for some tips. You can’t have a healthy body without a healthy mouth.

Keep Mouth Microbes in Check

These tips can help prevent tooth decay and mouth infections:

• Brush your teeth with a toothpaste that contains fluoride.
• Floss away the plaque between your teeth.
• Don’t forget to brush your tongue.
• Limit sugary foods and drinks.
• Drink fluoridated water. Learn about fluoride levels in your water (CDC).
• Get regular dental exams and professional cleanings.

Symptoms of gum disease include:

• Bad breath that won’t go away
• Red or swollen gums
• Tender or bleeding gums
• Painful chewing
• Loose teeth
• Sensitive teeth
• Receding gums or longer appearing teeth

At a dental visit, a dentist or dental hygienist will:

• Examine your gums and note any signs of inflammation.
• Use a tiny ruler called a “probe” to check for and measure any pockets around the teeth. In a healthy mouth, the depth of these pockets is usually between 1 and 3 millimeters. This test for pocket depth is usually painless.
• Ask about your medical history to identify conditions or risk factors (such as smoking or diabetes) that may contribute to gum disease.

The dental professional may also:

• Take an x-ray to see whether there is any bone loss.
• Refer you to a periodontist. Periodontists are experts in the diagnosis and treatment of gum disease and may provide you with treatment options that are not offered by your dentist.

The main goal of treatment is to control the infection. The number and types of treatment will vary, depending on the extent of the gum disease. Any type of treatment requires that the patient keep up good daily care at home. The dentist may also suggest changing certain behaviors, such as quitting smoking, as a way to improve your treatment results.

Progression

As dental plaque accumulates on the tooth near and below the gums, its microbial composition changes from a dominance by Streptococcus to a dominance by Actinomyces. The gingiva becomes irritated and inflamed, a condition called gingivitis. A person can have gingivitis for years and the condition may not progress. When the microorganisms in plaque start attacking the periodontal ligament, the condition changes to periodontitis. The gingiva tends to bleed and a predominantly gram-negative bacterial flora is established.

If left undisturbed, microbial plaque calcifies to form calculus (tartar). Calculus must be removed to prevent damage to the gingival fibers, which is when gingivitis develops into periodontitis. The gingiva progressively separates from the tooth. This widens the gingival sulcus which becomes a deep periodontal pocket. Microorganisms colonize the periodontal pockets and cause further inflammation in the gum tissues with progressive bone loss.

Prevention

Oral hygiene measures to prevent periodontal disease include:

e Brushing and flossing properly to physically remove bacteria and fungi e Using an antiseptic Chlorhexidine gluconate-based mouthwash. e Regular dental check-ups and professional teeth cleaning.

Dental hygienists and dentists use special instruments to remove plaque beyond the reach of toothbrushes and floss. After professional cleaning,

Treatment

Periodontal treatment starts with establishing a routine of brushing twice a day and flossing once. Removal of microbial plaque and calculus may involve mechanical cleaning below the gumline in a procedure called scaling and root planing. This may require multiple visits and local anesthesia.

Nonsurgical scaling and root planing are usually successful if the periodontal pockets are shallower than 4-5 mm (0.16—0.20 in). The need for further treatment is determined through monitoring of gingival inflammation. Pocket depths greater than 5-6 mm (0.20—0.24 in) with bleeding upon probing indicate an active disease with further bone loss over time.

Surgery may be needed to stop progressive bone loss and regenerate lost bone. The goal is complete calculus removal and correction of bony irregularities which have resulted from the disease process to reduce pockets as much as possible. In flap surgery, the gum is detached from the tooth for complete removal of tartar. Sutures are used to position the gum back into place until the tissue reattaches to the tooth. In more advanced cases, bone and tissue grafts may be required. These involve the placement of synthetic or natural tissues in the area of tissue loss. The transferred material is taken from another part of the patients body.

If you have it, you’re not alone. Many adults nationwide have some form of gum disease. It can simply cause swollen gums or give you bad breath. It can also ruin your smile or even make you lose your teeth. The good news is that gum disease can be prevented with daily dental care.

The problem begins with bacteria. Our mouths are packed with these tiny microbes. They combine with mucus and other particles to form a sticky, colorless film—called plaque—on our teeth. Brushing and flossing can get rid of some plaque. But any that remains can harden and form tartar, a yellowish deposit that can become rock-hard.

Plaque and tartar buildup can lead to gum disease—technically known as periodontal disease. The most common and mild type of gum disease is called gingivitis. The gums become red and swollen, and they can bleed easily. Daily brushing and flossing and regular cleanings by dental professionals can usually clear up gingivitis.

If gingivitis is not treated, it can become a more severe type of gum disease called periodontitis. Symptoms of periodontitis include bad breath that won’t go away; gums that are red, swollen, tender or bleeding; painful chewing; and loose or sensitive teeth.

In periodontitis, the gums pull away from the teeth and form “pockets” that become infected. Bacterial toxins and your body’s natural response to infection start to break down the bone and soft tissues that hold teeth in place. If not treated, the tissues will be destroyed. Your teeth may eventually become loose and have to be removed. If you have periodontitis, your dentist may recommend a deep-cleaning method called scaling and root planing. In more severe cases, you may need surgery.

Most people don’t show signs of gum disease until they’re in their 30s or 40s. But getting older doesn’t necessarily mean you’ll get gum disease. Daily dental care and regular visits to your dentist can reduce your risk of gum disease.

Smoking greatly increases your risk for periodontitis—another reason not to smoke. Other factors that boost your risk include hormonal changes in women, certain medications and some illnesses like diabetes, cancer and AIDS.

NIH-supported researchers are working to learn more about preventing and treating gum problems. Some are exploring whether stem cells might help to restore damaged tissues that support the teeth. Others are searching for genes and proteins produced by our bodies and by the bacteria in our mouths to see how they interact to affect gum health.

Some studies suggest that gum disease may increase the risk of heart attack or stroke or cause other health problems. But so far, it hasn’t been confirmed that gum disease contributes to these conditions.

Although many aspects of gum disease are still being investigated, one thing is clear: controlling gum disease can save your teeth. That alone is an excellent reason to take good care of your teeth and gums every day.

To Prevent Gum Disease

• Brush your teeth twice a day with a fluoride toothpaste.
• Floss every day.
• Visit the dentist routinely for a check-up and professional cleaning.
• Don’t smoke.

You can keep your gums and teeth healthy by:

• Brushing your teeth twice a day with a fluoride toothpaste.
• Flossing regularly to remove plaque from between teeth. Or, you can use a device such as a special brush, wooden or plastic pick, or a “water flosser” recommended by a dental professional.
• Visiting the dentist routinely for a check-up and professional cleaning.
• Quitting smoking.