Oral Health

ORAL HEALTH

In twenty-first century America, a healthy smile is considered necessary for social mobility and acceptance, interpersonal relations, employability, and a good self-image.

Poor oral health may lead to pain and infection, absence from school or work, poor nutrition, poor general health, an inability to speak or eat properly, and even early death. Studies done in the late 1990s showed that poor oral health may also lead to low birth-weight babies, heart disease, and stroke. It is clear that oral diseases play a significant role in compromising health potential. Up until the late 1990s, when the new HIV medications became available, over 90 percent of persons with AIDS had HIV-related oral diseases.

MAJOR ORAL DISEASES

There are many different types of oral diseases, but they are generally differentiated as being of hard tissue or soft tissue origin. Hard-tissue oral diseases are those of the teeth, supporting bone, and jaw; whereas soft tissue diseases affect the tissues in and around the mouth, including the tongue, lips, cheek, gums, salivary glands, and roof and floor of the mouth. Some oral diseases may result in both hard and soft tissue disorders or conditions such as cleft palate or oral-facial injuries. The major oral diseases and conditions are:

• Dental caries (tooth decay, cavities)
• Periodontal disease (gum disease)
• Malocclusion (crooked teeth)
• Edentulism (complete tooth loss)
• Oral cancer
• Craniofacial birth defects such as cleft lip and cleft palate
• Soft tissue lesions
• Oral-facial injuries
• Temporomandibular dysfunction (TMD)

The prevalence of oral diseases varies due to differences in the host, agent, and environment. Some diseases have higher rates in certain population groups due to personal habits such as a sugarheavy diet or poor oral hygiene. Others may occur more frequently in individuals who put themselves at risk for injury by not wearing seatbelts or by playing contact sports without using proper mouth and head protection. Environmental and cultural factors may also affect the rates of oral diseases. For example, persons who live in a community in which the water supply is fluoridated would have much less tooth decay than those who live in a nonfluoridated community. Certain cultures, especially in developing countries, have diets almost completely devoid of refined foods that have high sugar content, and therefore have much less tooth decay compared to the average American. A 1997 report by the U.S. Department of Agriculture found that Americans consume an average of about 154 pounds of sugars a year (or 53 teaspoons a day) most of it in processed foods, drinks, and sweets. This was a 28 percent increase in added sugar or sweeteners since 1982. Tooth decay may be viewed as a disease of civilization.

A NEGLECTED EPIDEMIC

Oral diseases have been called a "neglected epidemic" because, while they affect almost the total population, oral health is not integrated into most health policies or programs. This is especially true in the United States, where, in the year 2000, there were 125 million Americans without dental insurance. In addition, many people who have dental insurance are underinsured. Under such conditions, people who are knowledgeable about oral health and have the resources to pay for it are much more likely to receive regular dental care than are the poorer members of society. This situation has resulted in major disparities in oral health status in the United States. Low-income children between ages two and five have almost five times more untreated dental disease than high-income children, and people without health insurance have four times the unmet dental needs of those with private insurance.

Vulnerable or high-risk population groups like children, the poor, the developmentally disabled, the homeless, homebound and elderly persons, persons with HIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome), and ethnic and cultural minorities are at greater risk for oral diseases, primarily because they do not have access to preventive services or treatment. In 2000, the first ever Surgeon General's report on oral health stressed the importance of oral health as part of total health as well as the need to reduce oral health disparities in the United States.

Although there has been much progress in the improvement of oral health, both nationally and internationally, oral diseases are still epidemic in the United States and many other countries. The nation's dental bill in the year 2000 was about $60.2 billion, or 4.6 percent of total health expenditures in the United States. In 1970, dental care accounted for 6.4 percent of total health expenditures. This 28 percent decrease is primarily due to the higher costs of hospitals and medical care.

PREVENTION

Prevention of dental disease may occur at the individual or community level. Prevention of disease at the community or population level is one of the foundations of public health practice. There are three levels of prevention. Primary prevention is aimed at preventing a disease before it occurs, through programs such as community water fluoridation, school dental sealant programs, and health education. Secondary prevention keeps an existing disease from becoming worse, and includes dental screenings for children and early detection of oral cancer in adults. Tertiary prevention consists of treatment to limit a disability or to help rehabilitate an individual after a disease has progressed beyond the secondary level. Examples of tertiary prevention include complex dental fillings, root canal treatment, and false teeth.

HEALTHY PEOPLE 2010

The United States has developed national health objectives with a focus on prevention. These objectives are renewed every ten years. This effort began with the 1979 report from the Surgeon General, Healthy People, and is spearheaded by the Office of Disease Prevention and Health Promotion of the U.S. Department of Health and Human Services. The purpose of these national health objectives is to provide direction for the country in preventing major health problems in the United States. Each set of national health objectives, including the Healthy People 2010 objectives, contain components on oral health (see Table 1).

PUBLIC HEALTH DENTISTS

Of the nine recognized dental specialties, only dental public health has the potential to make a population-based impact on communities such as schools, neighborhoods, cities, states, or nations or on groups of individuals such as homeless children or persons with HIV. Dental public health is "the science and art of preventing and controlling dental disease and promoting dental health through organized community efforts. It is the form of dental practice which serves the community as a patient rather than the individual. It is concerned with the dental health education of the public, with applied dental research, and with the administration of group dental care programs as well as the prevention and control of dental diseases on a community basis" (Journal of Public Health Dentistry, 46 no. 1). Most states in the United States have a dentist trained in public health in their state health department. The same is true in some major cities. The U.S. Department of Health and Human Services also has dentists trained in public health who work in administrative and policy-making roles.

A public health dentist is primarily involved with the three core functions of public health as defined by the Institute of Medicine: assessment, policy development, and assurance. Dental public health assessment might involve a statewide survey to determine the amount of tooth decay by age group, or a questionnaire to determine the barriers to dental care for the low-income elderly. Policy development could involve efforts to have preventive services included in a dental Medicaid program or to have a state dental practice act allow dental hygienists to work under general supervision in public schools. The assurance function might take the form of a program to provide dental care to homeless children, or to provide some other service that no one else is providing.

As of 2000, only 136 dentists out of 150,000 practicing dentists were board certified in dental public health by the American Board of Dental Public Health, and only about 1,500 dentists were working primarily in this field. Although the number of public health dentists is small, they are trained to work with a variety of health professionals and community groups to improve oral health. This would include, but not be limited to, public health dental hygienists, health educators, epidemiologists, nutritionists, nurses, academicians, researchers, and other health and human services personnel.

There are ten major areas of competencies that a dentist must attain to become board certified in dental public health. These ten competencies are: program planning; population-based prevention; developing, managing, and evaluating programs; needs assessment; communication; advocacy; study design; and critiquing the literature. Public health dentists can be contacted through the oral health program of local or state health departments, or through one of the ten regional offices of the U.S. Department of Health and Human Services.

TOOTH DECAY

Tooth decay, or dental caries, is the most common oral disease in the United States, if not the most common of all diseases. It is the primary cause of tooth loss; and may be considered a lifelong disease—18 percent of children aged 2 to 4 have had tooth decay in their primary teeth and 52 percent of those aged 6 to 8 have had tooth decay in their primary or permanent teeth; 78 percent of 17-year-olds have had tooth decay in their permanent teeth, with an average of seven affected tooth

Table 1

surfaces; 99 percent of adults aged 40 to 44 have had tooth decay in their permanent teeth, with an average of forty-five affected tooth surfaces; and 60 percent of persons over age 75 years of age have had tooth decay on the exposed roots of three of their teeth.

Tooth decay is an infectious disease. The percentage of people with this disease increases with age, and the severity of the disease once it occurs depends on whether or not one has had adequate fluoridation and dental treatment. Tooth decay is not self-limiting unless it is exposed to fluoride just as it is beginning and the demineralized tooth structure can remineralize. Demineralization is the dissolving of minerals such as calcium, carbonate, and phosphate in the tooth structure. Remineralization is enhanced by fluoride. Once tooth decay progresses beyond the tooth's ability to remineralize, mechanical intervention is needed by a dentist, who removes the decayed portion of the tooth and puts in a filling. When tooth decay is not treated it may result in an acute or chronic infection and severe pain, ultimately resulting in an abscess and/or cellulitis, which will then need to be treated with antibiotics, root canal treatment, or removal of the tooth. In the United States, more teeth are lost due to tooth decay than to any other disease.

Causes of Tooth Decay. Bacteria that produce tooth decay can be transferred from a mother to a child, even at an early age. When these bacteria have repeated contact with sugars or sticky sweets, they create an acid that demineralizes the surface or enamel of a susceptible tooth, eventually causing a cavity or tooth decay. The more access to sugars the bacteria have, the greater the likelihood of tooth decay occurring. Sticky sweets are more decay-producing than other types of sugary foods because they stay in the mouth longer. The bacterial mass that resides on the teeth is called dental plaque. Plaque may also, however, contain the minerals from demineralization, which may be available for remineralization.

Prevention of Tooth Decay. Tooth decay may be prevented on the individual level and at the community level. At the individual level, good oral hygiene—brushing with a fluoride toothpaste, sealants, and regular dental checkups—is of primary importance. Avoidance of excessive amounts of sugar and sweets, can also help prevent tooth decay. During the second half of the twentieth century, fluoride became an important tool in decay prevention. When fluoride is ingested, it goes through the body and becomes part of the tooth, resulting in a stronger tooth that is more resistant to tooth decay. When fluoride is placed on the teeth, it affects the tooth and plaque directly, preventing tooth decay. Fluoride is therefore added both to toothpaste and to community water supplies (see Figure 1).

Community water fluoridation consists of the adjustment of the fluoride level of a central water supply to a level that is optimal for oral health. The recommended level of fluoride for fluoridation in the United States varies from 0.7 to 1.2 parts per million, depending on a community's mean maximum daily air temperature over a five-year period. At the recommended level, the fluoride in water is odorless, colorless, and tasteless. In 1992, when the last national data was available, about 145 million Americans, or 62 percent of the population, were using fluoridated public-water supplies (see Figure 1).

Effective community prevention programs for tooth decay are considered in terms of effectiveness, cost, and practicality. Fluoridation is the most cost-effective. Fluoridation is considered one of the ten most significant public health measures of the twentieth century. Unfortunately, it has also been one of the more misunderstood public health measures, with some people at different times making claims such as it caused mongolism, pollution, sterility, or cancer. None of these allegations has ever been demonstrated by scientific studies. Most reputable national health organizations, such as the American Academy of Pediatrics, the American Dental Association, the American Medical Association, the American Public Health Association, and most other national health organizations, have supported or endorsed fluoridation for years. Salt fluoridation, which is not used in the United States, has been used as an alternative to water fluoridation in countries where central water supplies are not readily available.

Early Childhood Caries. The threat of tooth decay begins with the first appearance of teeth in a baby's mouth. The first teeth to appear are usually the two lower front teeth, which appear at about six months of age. All twenty primary, or baby, teeth usually erupt by two years of age. The permanent teeth begin erupting at six years of age, and with the eruption of the third molars (wisdom teeth), usually between eighteen and twenty-one years of age, all thirty-two permanent teeth are in place.

Early childhood caries (ECC) may be due to several factors, including the introduction of decay-producing bacteria into the child's mouth— usually transmitted from the mother or caused by poor feeding practices, various medical conditions, poor oral hygiene, and chronic malnutrition, which may also affect tooth development. ECC, also known as baby bottle tooth decay, or nursing tooth decay, occurs in the primary teeth of infants as young as nine months of age. When an infant sleeps with a baby bottle containing milk, infant formula, or sweetened liquids, there is a prolonged source of food for the decay-producing bacteria in the child's mouth. Among American Indians, as many as 53 percent of infants have this disease, and in inner city populations as many as 11 percent are affected. When early childhood caries is not treated and the disease is allowed to progress, severe pain or infection may result.

Root Surface Caries. This type of tooth decay usually occurs in older persons whose gums have receded exposing the roots of their teeth. As people retain their teeth for longer periods of time, this type of tooth decay becomes more frequent. Over 60 percent of seventy-five-year-olds who have teeth have root caries.

GUM (PERIODONTAL) DISEASE

Gum disease is the second most common reason for the loss of teeth. There are two major types of

Figure 1

gum disease: gingivitis, which is an inflammation or infection of the gums, and periodontitis, which is an inflammation or infection of the gums and the surrounding bone. Gingivitis may occur in adolescents or adults and is often self-healing once the area is properly cleaned. However, poor oral hygiene, stress, lack of sleep, or poor nutrition can all aggravate the condition and lead to an acute case of gingivitis, which can be very painful.

Gingivitis may lead to periodontitis in susceptible individuals who have risk factors such as bacterial plaque, calculus (calcified deposits around teeth), smoking, or systemic diseases. Periodontitis usually increases in severity with age. It is not selfhealing and requires mechanical intervention such as a deep scaling or surgery by a dentist. About 48 percent of adults aged thirty-five to forty-four have gingivitis, and 22 percent have destructive periodontal disease. Dentists who specialize in treating gum diseases are called periodontists.

The best way to prevent gum disease is with proper oral hygiene. This includes brushing the teeth properly with a fluoride toothpaste after breakfast and before going to bed, utilizing dental floss appropriately, and visiting a dentist or hygienist on a periodic basis for a professional cleaning. A combination of personal and professional prevention is very important, as there are no population-based preventive measures for gum disease. Good health habits, including proper nutrition and avoidance of tobacco products, is also important.

MALOCCLUSION

The permanent teeth may not erupt in their proper alignment, resulting in malocclusion, or crooked teeth. In its most severe form, called handicapping malocclusion, this condition can affect an individual's chewing ability. The main causes of malocclusion are a lack of space for the permanent teeth to erupt properly and the premature loss of the baby teeth, which usually guide the permanent teeth to their proper location, may also be a factor.

To prevent malocclusion due to premature loss of the primary teeth, space maintainers may be used to guide the teeth into proper alignment. Dentists who specialize in treating malocclusions are called orthodontists.

ORAL-FACIAL INJURIES

Most oral-facial injuries occur as a result of falls, automobile accidents, and sports. About 25 percent of Americans aged six to fifty have injured their upper or lower front teeth. Falls at work or at play are difficult to control. Some of them may be prevented, however, by self-discipline and by environmental controls such as railings, good lighting, smooth walkways, and proper injury-prevention education.

Oral and facial injuries are a frequent result of automobile accidents. Seatbelts, airbags, and safe driving techniques can greatly reduce the injuries. Sports-related oral-facial injuries may be prevented by wearing protective mouthguards and helmets. In competitive high school sports such as football, ice hockey, lacrosse, and soccer, mouthguards are required by many states. A school-based mouthguard program, in which a dentist fits each student athlete with a custom mouthguard, greatly improves the chances that the athletes will use the devices, which can otherwise be uncomfortable and inhibit breathing and talking.

ORAL CANCER

Oral and pharyngeal cancers occur primarily in individuals over fifty-five years of age, especially in those who smoke and drink heavily. About 30,000 Americans are diagnosed with oral cancer each year, and about 8,000 die from this disease. The earlier oral cancer is detected, the better it can be controlled. Only 7 percent of adults over the age of forty, however, have reported having an examination for oral cancer. Individuals who use spit tobacco beginning at an early age may have a greater risk for developing oral cancer and gum disease. Baseball players have traditionally used spit tobacco, luring younger children to also use it. According to the National Cancer Institute, over 15 percent of high school boys use spit tobacco. Marijuana use has also been linked to oral cancer. The incidence of oral cancer is two times greater in developing countries than in industrialized nations.

The best way to prevent oral cancer is not to smoke or to use spit tobacco, and, if one drinks, to drink in moderation. Adults, including those wearing dentures or false teeth, should have regular dental examinations that include an oral cancer screening. In 1994, the National Collegiate Athletic Association (NCAA) banned the use of spit tobacco and other tobacco products by student athletes and coaches during games and practices. Spit tobacco has also been banned in minor league baseball, and its use has been significantly reduced among major league players. Diets high in vitamin C, vegetables, and fruits may decrease the risk of oral cancer. A workshop to develop a national strategy to prevent and control oral cancer recommended a multifaceted approach that includes public advocacy, collaboration, public and professional education, and evaluation.

MOUTH ODOR

Mouth odors may be caused by poor oral hygiene or the foods that one eats. Mouth odors also occur when people have not eaten or had liquids for extended periods of time, such as in the morning upon waking. During sleep, there is a decrease in the flow of saliva, allowing bacteria to grow. Certain medications may also cause a condition known as xerostomia, or "dry mouth," which can lead to an increase in tooth decay over time. Over five hundred drugs and medicines list dry mouth as a potential side effect.

Proper oral hygiene and choice of foods can decrease or prevent mouth odors. In addition, sometimes bacteria accumulate on the tongue and brushing or scraping the back of the tongue periodically can help. Regular eating and drinking habits are also helpful. Dry mouth cannot be prevented, though water, ice chips, or sugarless gum may provide some relief.

CRANIOFACIAL DEFECTS

Approximately one to two in 1,000 children are born with a cleft lip or a cleft palate—two of the more common craniofacial defects. A cleft lip occurs when the lips of the developing fetus are not complete, resulting in a split in the child's lip. This usually occurs in the upper lip. A cleft palate is similar—the bone in the roof of the mouth is not fused properly and has an opening in it. Individuals born with cleft lips or palates should have corrective surgery and receive appropriate adjunctive therapy as needed, depending on the severity of the cleft.

There is no known way to prevent a cleft lip or palate. Proper prenatal care and food consumption during pregnancy may be important. Alcohol and tobacco consumption during pregnancy have been shown to increase the likelihood of cleft lip, so these substances should not be used by pregnant women.

TEMPOROMANDIBULAR DISORDERS

Temporomandibular (jaw) disorders (TMDs) are a group of conditions that affects the jaw joint. The lower jaw acts like a hinge with the upper jaw, and when the hinge joint is traumatized it may affect one's bite, cause pain in the chewing muscles, or cause pain or clicking in the joint located in front of the ears. This disorder affects twice as many women as men. Treatment varies depending on the severity of the problem. In many cases, the disorder dissipates by itself. This group of disorders is also referred to as myofacial pain-dysfunction syndrome of TMJ syndrome.

There is no simple way to prevent temporamandibular disorders. Avoiding trauma to the jaw or mouth may be helpful, and protective mouthguards should be used for contact sports.

MYRON ALLUKIAN, JR.

(SEE ALSO: American Association of Public Health Dentistry; Baby Bottle Tooth Decay; Caries Prevention; Community Dental Preventive Programs; Community Water Fluoridation; Dental Fluorosis; Dental Sealants; Gingivitis; Healthy People 2010; Oral Cancer; Plaque)

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