Intrinsic Changes

In epithelium, a progenitor population of cells (stem cells), situated in the basal layer, provides new cells. These cells of the basal layer are the least differentiated cells of the oral epithelium. A small subpopulation of these cells produces basal cells and retains proliferative potential of the tissue. A larger subpopulation of these cells (amplifying cells) produces cells available for subsequent maturation. This maturing population of cells continually undergoes a process of differentiation or maturation.

By definition, this differentiated cell, or epithelial cell, can no longer divide. Conversely, the basal cell remains as part of the progenitor population of cells ready to return to the mitotic cycle and again produce both types of cells. Thus there is a constant source of renewal (Figure 39-1). In the aging process, cell renewal takes place at a slower rate and with fewer cells, so the effect is to slow down the regenerative processes. As the progenitor cells wear out and die, there are fewer and fewer of these cells to renew the dead ones. This effect is characteristic of the age-related and biologic changes that occur with aging.

By the action of gerontogene(s) or replicative senescence (Hayflick’s limit and telomere shortening), the number of progenitor cells decreases. Hayflick, an American microbiologist, observed that fetal cells (i.e., fibroblasts) displayed a consistently greater growth potential (approximately 50 cumulative population doublings) than those derived from adult tissues (20 to 30 cumulative population doublings). As a result, the decreased cellular component has a concomitant effect to decrease cellular reserves and protein synthesis. This affects the oral epithelium in that the tissue becomes thin, with reduced keratinization.

Stochastic Changes

Stochastic changes occurring within cells also affect tissue (e.g., glycosylation and cross-linking produce morphologic and physiologic changes). Structures become stiffer, with a loss of elasticity and increased mineralization (fossilization). With a loss of regenerative power, structures become less soluble and more thermally stable. Somatic mutations lead to decreased protein synthesis and structurally altered proteins. Free radicals contribute to the accumulation of waste in the cell.

All these changes produce a decline in the physiologic processes of tissue. Most changes are primarily a result of aging, although some are secondary to physiologic deterioration. For example, loss of elasticity and increased resistance of the tissue may lead to decreased permeability, decreased nutrient flow, and the accumulation of wastes in the cell. Thus vascular peripheral resistance (decreased blood supply) may secondarily decrease cellular function.

Physiologic Changes

In the periodontal ligament, a decrease in the number of collagen fibers leads to a reduction or loss in tissue elasticity. A decrease in vascularity results in decreased production of mucopolysaccharides.

All these types of changes are seen in the alveolar bone. With aging, the alveolar bone shows a decrease in bone density and an increase in bone resorption and a decrease in vascularity also occurs. In contrast, however, cementum shows cemental thickness.

Functional Changes

With aging, the cells of the oral epithelium and periodontal ligament have reduced mitotic activity, and all cells experience a reduction in metabolic rate. These changes also affect the immune system and affect healing in the periodontium. There is a reduction in healing capacity and rate. Inflammation, when present, develops more rapidly and more severely. Individuals are highly susceptible to viral and fungal infections because of abnormalities in T-cell function.

Clinical Changes

Compensatory changes occur as a result of aging or disease. These changes affect the tooth or periodontium that presents the clinical condition. Gingival recession and reductions in bone height are common conditions. Attrition is a compensatory change that acts as a stabilizer between loss of bony support and excessive leveraging from occlusal forces imposed on the teeth.

In addition, a reduction in “overjet” of the teeth is seen, manifesting as an increase in the edge-to-edge contact of the anterior teeth. Typically, this is related to the approximal wear of the posterior teeth. An increase is seen in the food table area, with loss of “sluiceways,” and in mesial migration.

Functional changes are associated with reduced efficiency of mastication. Although effectiveness of mastication may remain, efficiency is reduced because of missing teeth, loose teeth, poorly fitting prostheses, or noncompliance of the patient, who may refuse to wear prosthetic appliances.

Health Status

Increased life expectancy has changed the way the public and healthcare policy makers and providers think about “aging.” Instead of controlling chronic disease and morbidity, aging is seen in terms of “successful aging” or “healthy aging.” This paradigm shift is based on study of what promotes health and longevity. Current research is now examining aging in terms of the physical, mental, and social well-being of older adults, not just disease or morbidity. The MacArthur Studies of Successful Aging asked the fundamental question, “What genetic, biomedical, behavioral, and social factors are crucial to maintaining health and functional capacities in the later years?”⁴²

Despite this paradigm shift, the number of older adults with acute and chronic diseases continues to increase.⁶³ Visual impairments, cataracts, glaucoma, and hearing impairments increase in frequency with advancing age. Almost half of people age 65 and older have arthritis.⁶⁵ Most older adults have at least one chronic condition, and many have several chronic conditions. In 1994 the chronic conditions that occurred most often in older adults were arthritis, hypertension, heart disease, hearing impairment, cataract, orthopedic impairment, sinusitis, and diabetes (Figure 39-2). Although heart disease remains the leading cause of death among older adults, cancer may become the leader during the twenty-first century. Currently, among older adults, approximately 7 in 10 deaths are caused by heart disease, cancer, or stroke.⁶³

In the early 1900s, Dr. Ignatz Leo was the first to recognize that older adults had health needs and concerns that set them apart from younger adults.⁴⁷ Not until the latter half of the twentieth century, however, did geriatrics (medicine for older adults) become a discipline in healthcare. A “geriatric” patient is an older adult who is frail, dependent, or both and who requires health and social support services to attain an optimal level of physical, psychologic, and social functioning. Thus the treatment plan must reflect the professional knowledge to resolve physical and psychologic aspects of health status, as well as being sensitive to an individual’s all-encompassing social functioning. This functioning may include aspects of race, ethnicity, culture, personal relationships, esthetics, and social and economic conditions.

The main focus of geriatrics is frail and functionally dependent older adults. Functionally independent older adults are included but only to make them aware of services that they may need if they experience functional deficits that impair their daily activities (Table 39-1). Specialists in geriatric medicine, geriatricians, have additional training in healthcare for frail and functionally dependent older adults. In geriatric medicine, numerous assessment instruments have been developed to assist the geriatrician, and some aspects of these are important to dentists in identifying risks and functional declines. These instruments include activities of daily living (ADLs), Tinetti Balance and Gait Evaluation, geriatric depression scale (GDS), and Mini-Mental State Questionnaire. Each assesses risks to morbidity and mortality in maintaining a patient’s optimal health and functional independence.

Care for geriatric patients crosses many disciplines. Thus, an interdisciplinary team is formed to care for and treat geriatric patients and may include the dentist. Including dentistry in the interdisciplinary effort has benefits for the patient; for example, oral care has been incorporated into nursing educational programs and practice for the geriatrician nurse practitioner.⁴⁹ Likewise, dieticians have educational content in oral care. The focus is to include oral health as part of medical nutrition therapy (MNT) in achieving the patient’s total health needs.⁷ A “last frontier” for the interdisciplinary team is the community. When geriatric patients require multidisciplinary strategies to improve their conditions at the community level, efforts have been less than satisfactory. Problems have been encountered when coordination is needed for geriatric patients to access multiple providers across a range of healthcare settings. Shared decision making and patient education are needed to improve access and realize successful outcomes.³³ A detailed computer-based model on multidisciplinary and interdisciplinary decision making in the geriatric population can be found in Bauer et al.^13–19

Functional Status

In dentistry, prevention of oral diseases and improvements in healthy lifestyles have contributed to older adults keeping and maintaining their dentition. Dentistry for geriatric patients, or geriatric dentistry, emphasizes an interdisciplinary approach to diagnosis, treatment, and prevention of dental and oral diseases.³¹ Specialists in geriatric dentistry are geriatric dentists. Similar geriatric health and functional instruments used in medicine assist geriatric dentists in assessing risks that compromise oral health.

Functional impairments have a significant impact on oral health and self-care. Sensory impairments and arthritis make it more difficult for older adults to understand dental outcomes, communicate oral healthcare needs and concerns, and perform effective oral self-care. Functional testing or measuring instruments may become part of the dentist’s armamentarium to assess an older adult’s ability to perform oral care tasks in achieving and maintaining oral health. The index of Activities of Daily Oral Hygiene (ADOH) is one such dental assessment instrument that quantifies the functional ability of older adults, specifically frail and functionally dependent older adults, in performing oral self-care tasks.¹⁰ The index of ADOH provides the dentist or dental assistant with the means to determine the functional ability of an older adult to manipulate aids used in daily oral hygiene care. From these findings, strategies may be developed to rehabilitate and then remeasure for improvements in functional deficits. If improvements are not forthcoming, alternative strategies and assistive devices are recommended.

Accommodating dentists in the interdisciplinary team is increasing, including their participation in primary care. For example, edentulism and denture wearing in older adults may be related to poor quality of life and risk for undiagnosed oral disease. They may also indicate other medical comorbidities. Thus medical and dental geriatricians must incorporate knowledge of comorbidities to identify risks that manifest as reciprocation of disease and poor quality of life.68,73 In managing periodontal disease, the dental geriatrician is challenged with integrating primary care, oral health, and patient and caregiver education in nontraditional settings such as residential, institutional, and hospital practice settings.

Although geriatric medicine training programs have grown remarkably over the past three decades, this growth is still not producing the number of geriatricians needed to care for the growing older adult population. Comparatively, the training of dental geriatricians is much less. In response, the geriatric dentistry community has advocated the use of dental geriatricians to train general dentists in the care of geriatric dental patients. Kayak and Brudvik⁴⁰ see this type of training essential to “successful aging” and periodontal healthcare in both dental practice and nontraditional settings. Thus dental geriatricians as faculty are needed to train practitioners.⁶⁸

In an article on periodontal dental education, Wilder et al stated “that dental schools are confident about the knowledge of their students regarding oral-systemic content. However, much work is needed to educate dental students to work in a collaborative fashion with other healthcare providers to co-manage patients at risk for oral-systemic conditions.”⁷⁵

Nutritional Status

Whereas “diet” refers to the consumption of types and varieties of food resources, nutrition is the process by which food is used to provide energy and sustain, restore, and maintain tissue of living organisms. With aging, there is an increased risk of nutritional deficiencies among older adults. However, the real risk is not malnutrition; among older adults in the United States, the rate of malnutrition is low. The real risk is attributed to unbalanced diets.

An older adult’s dietary patterns may be associated with numerous factors, including the aging process, diseases and the medications used in their treatment, and social and economic conditions. In general, energy needs and intake in older adults decline with age.

Beyond middle age, body weight and lean body mass decline with age, in part because of primary aging. Age changes in physiologic functioning, including metabolic, hormonal, and neural changes, have been associated with poor quality diets in older adults.

Older adults do not compensate well, or take in more food, when bodily changes alter their energy levels. For example, a slower metabolic rate accompanied with decreased levels of physical activity explains why older adults have reduced food intake. This is also associated with altered sensations of hunger, thirst, and satiety or fullness. Reductions are seen in fluid intake, uncompensated by increased thirst. The variety of foods eaten is reduced, or characteristic bland diets may result from lowered sensory-specific satiety. In other words, older adults have a lowered enjoyment of foods because of deficits in smell and possibly taste. More than half of people age 65 to 80 have a major olfactory impairment, with 75% of those age 80 and older affected. Thus food recognition diminishes with age.

All these factors may place the older adult at risk for serious problems. Anorexia, or low food intake, increases the risk of nutrition-related illnesses. Electrolytic imbalances (e.g., salt and water imbalances) are associated with age-related changes in regulatory systems, such as changes in central nervous system (CNS) receptors that detect changes in the level of sodium in blood. Dehydration, which can lead to illness and death, is a common cause of fluid and electrolyte disturbance. Deconditioning is an almost complete disturbance of physical functioning. These conditions may present when a frail older adult comes to the dental office seeking care and are seen more often in homebound persons, hospitalized patients, and nursing home residents.

Poor nutrition and low body weight may often precede and predispose older adults to secondary age changes. Secondary aging changes are a result of acute and chronic disease and medication use. The most common age-associated chronic diseases are hypertension, hyperlipidemia, atherosclerosis, and diabetes. Compounding effects of secondary aging may include impaired mobility, inability to feed oneself, poor oral health, and the use of dentures, all of which may affect the amount and types of foods consumed. Age-associated decreases in saliva production and swallowing problems may also make eating difficult. In addition, nutrient malabsorption can be caused by altered gastric acid secretion or by interaction with medications. The cumulative effect of these changes may account for taste loss in the older adult.

Economic and social factors have also been linked with significant changes in eating patterns, such as loss of appetite. Economic factors include a lower economic status resulting from retirement, failing health, living on a fixed income, or death of a spouse. Social factors include isolation, loneliness, and the effects of depression or dementia. All these factors may affect the type and quality of food consumed. For example, socialization at meals may increase the amount of food consumed by older adults.

In addition, impaired chewing can cause changes in food selection, such as decreasing the variety in the diet, which may contribute to nutritional problems. Currently, 42% of older adults have no natural teeth. Rehabilitation with complete dentures may restore only 25% of normal chewing effectiveness.⁵⁴ Of those with teeth, 60% have tooth decay and 90% have periodontal disease, which may contribute to impaired chewing ability or loss of appetite.

These aging-related disease states and social factors may result in inadequate consumption of nutrient-dense foods or inadequate intake of some vitamins and minerals. Minerals are important to the absorption and utilization of vitamins. Both are important to antibody formation and the immune system in combating infection, foreign substances, and toxins (Table 39-2).²³

Psychosocial Factors

Dental diseases have their greatest effect on behaviors and mental and social well-being. In other words, dental diseases impact psychologic and social functioning and thus are almost always preventable by behavioral and social means. On average, older adults use fewer dental services, perhaps because of conflicting economic priorities between medical and dental needs. For many older adults, dental services are a discretionary choice and not part of their primary care options. This may result in part from their poorer health status, lack of dental insurance or coverage by government-sponsored healthcare programs, or simply their functional status or independence.

Older adults with positive attitudes toward oral health have predictably better dental behaviors that translate into higher utilization rates of dental services. Positive attitudes are highly associated with educational level.¹² The education level of older adults is increasing. In 1995, only 64% of noninstitutionalized older adults completed at least high school, and 13% possessed a bachelor’s degree. By 2015, it is estimated that 76% of older adults will have completed at least high school, with 20% obtaining a bachelor’s degree. Those with more education were three to four times more likely to have visited a dentist in the past year, indicating that an informed and knowledgeable public provides a culture of healthy behaviors that guide older adults toward the long-term preservation of teeth and function.

Impediments to the utilization of dental services are associated with low income and an associated lack of a regular source of care. Those with higher education tend to be better off financially than those with low education. Poverty is less prevalent today among older adults for all race, gender, and ethnic groups.63,64 In general, older adults have the highest disposable income of all ages.⁷¹ Thus higher educational achievement with lower poverty levels is a predictor for an increase in demand for oral healthcare among older adults.³⁹

However, differences in the prevalence of periodontal disease were seen in relation to race. Among dentate non-Hispanic blacks, non-Hispanic whites, and Mexican Americans 50 years of age and older, blacks had higher levels of periodontal disease, even those in higher income groups. Thus Borrell et al²² suggested that race and ethnicity are important factors in combating health disparities.

Reciprocally, oral disease may affect behaviors, and behavioral problems may adversely affect oral health. Adverse oral health conditions affect three aspects of daily living: (1) systemic health, (2) quality of life, and (3) economic productivity.

Both systemic health and quality of life are compromised when edentulism, xerostomia, soft tissue lesions, and poorly fitting dentures affect eating and food choices. Conditions, such as oral clefts, missing teeth, severe malocclusion, and severe caries, are associated with feelings of embarrassment, withdrawal, and anxiety. Oral and facial pain from dentures, temporomandibular joint disorders, and oral infections affect social interaction and daily behaviors.³⁸

Behavioral problems may worsen oral conditions. Older adults today grew up during Prohibition or the Great Depression, when alcohol consumption was much lower. Since then, alcohol consumption has increased, especially in women, along with alcohol-related health problems. Alcohol-related disorders include alcohol abuse and dependence and alcoholic liver disease, psychoses, cardiomyopathy, gastritis, and polyneuropathy.

A general consensus states that light drinking, or one drink per day, is not harmful as long as the older adult is reasonably healthy and not taking medications that interact with alcohol. However, alcohol may react differently in older than younger adults. A decrease in body water content may produce higher peak serum ethanol levels. In particular, alcohol intake may make older adults vulnerable to changes in the capacity of the liver to metabolize drugs and to symptomatic behaviors such as confusion, depression, and dementia.

The patterns of drinking and alcohol-related problems may not differ between older and younger problem drinkers. However, numerous reports suggest that alcohol as the primary substance of abuse is higher in the older than in the younger adult. A peak onset for alcohol-related problems is 65 to 74 years. Unfortunately, alcohol consumption is directly correlated with clinical attachment loss in periodontal disease.⁶¹

Periodontal disease may also be exacerbated in those with depression.4,41 Depression is a common public health problem among elderly persons, affecting 15% of adults over age 65 in the United States. The suicide rate for those older than 85 is about 2 times the national rate. Geriatric depression is treatable, so recognition of this disorder is a vital step in the prevention of disability and mortality.⁵⁶ However, depression is not easy to recognize. Depression may also accompany a wide variety of physical illnesses such as fatigue, poor appetite, sleep disturbances, cardiovascular disease, and cancer. It may be the primary cause of somatic complaints, including oral discomfort. The classic signs and symptoms for depression include sadness, decreased appetite, weight loss, confusion, difficulty in decision making, dissatisfaction, and irritability. Many older adults, however, present with a less dramatic level of actual sadness and frequently have apparent cognitive impairment, especially memory deficits, and therefore differentiation from dementia is important. Recognizing the signs of depression can significantly reduce depression, by about 70%, in those older than 65 years of age.

Dentate Status

In dentistry the level of illness is measured as “tooth mortality” or tooth loss. Still among the most ubiquitous of human diseases, dental disease places all segments of the population at risk. Older adults are at greatest risk, especially those older than 85 years of age. Oral health changes in health and functional well-being (functional disabilities) potentiate risks to oral disease, including dental caries (particularly root caries), periodontal disease, oral cancer, xerostomia (dry mouth), disorders associated with denture wearers, and systemic disease with oral symptoms.

Over a 30-year period, edentulism and partial tooth loss declined substantially.²⁷ The most current estimates of tooth loss and tooth retention in the U.S. population indicate that 75% of older adults age 65 to 69 and more than half of adults age 75 and older are dentate (Table 39-3).

By the year 2030, the number of teeth retained by older adults is expected to double, which is an estimated 800 million increase in tooth retention. It is expected that over the next 3 decades the average number of retained teeth will increase from the current 20 to 25.9 teeth.³⁰ Thus the risk of periodontal disease and dental caries is expected to be a major problem of older adults. Because few older adults are covered by dental insurance,¹¹ payment for treatments will be the responsibility of the geriatric patient. Costs and the inability to afford care will always affect healthcare utilization, particularly dentistry, which is often considered discretionary.

Periodontal Status

The classic periodontal disease model suggested that virtually all older adults would, at some time in their life, become susceptible to severe periodontitis. This result was attributed to an insidious process in which gingivitis slowly progressed into periodontitis, with probable bone and tooth loss. Thus it was asserted that susceptibility to periodontitis increased with age, resulting in tooth loss seen predominantly after age 35 years.

The current periodontal disease model suggests that only a small proportion of adults have advanced periodontal destruction. Mild gingivitis is common, as is mild/>