Chapter 1
The Edentulous State
Aim
Population studies indicate that the proportion of dentate older adults is increasing dramatically in industrialised countries. This chapter aims to provide a view of changing patterns of oral health of older adults in industrialised countries.
Outcome
At the end of this chapter, the practitioner should be aware of the consequences of edentulism and the desirability of avoiding total tooth loss in older adults.
What is an "Older Adult"?
It is often said that age is a state of mind, and to a degree there is no consensus as to what constitutes an "older adult". Some authors have classed adults over the age of 60 as young elderly (60-75 years old) and older elderly (> 75 years old). In this book, an older adult is arbitrarily over the age of 65 years. It should, however, be remembered that planning to maintain teeth for life in older adults starts much sooner than this. In the past, a large proportion of adults had lost all of their teeth long before this age. Improving adult oral health has led to increasing numbers of adults retaining teeth later in life, but oral disease levels in this age group remain high. Consequently, dentists need to plan early and strategically to face the many challenges posed to maintaining teeth for life in older adults.
Epidemiology
The percentage of the population over the age of 65 years is increasing in countries in the industrialised world. This is a reflection of increased life expectancy and the approach of middle age for the "baby boom" generation. In the United Kingdom, for example, the mean age of the population is expected to rise from 38.4 years in 1996 to nearly 42 years by 2021. The number of adults over the age of 65 years is projected to increase by 2.7 million during the same time frame. The proportion of the "elderly" elderly (i.e. aged 85 years and over) in the UK is also expected to rise, from approximately 800,000 in 1991 to 1.5 million in the year 2010.
The dental status of older adults is also changing dramatically. In 1968, 37% of adults (aged 16 years and over) in England and Wales were edentulous. By 1988, this figure for the whole of the UK was 21% and figures from the 1998 UK Adult Dental Health survey show that 13% of the adult population are edentulous. Long-term predictions indicate that the prevalence of edentulousness in the UK will eventually level out at 6% by the year 2028.
The level of edentulousness at the present time is strongly associated with dental problems of the distant past, with those who were rendered edentulous 30 to 40 years ago strongly influencing the edentulous statistic. As the population is generally ageing, and as it takes a long time for age cohorts to pass through the population, it will be some time before edentulousness will be a thing of the past. An examination of the most recent UK Adult Dental Health survey in 1998 shows that one-fifth of the 55-64 age cohort were edentulous, with this fraction rising to three-fifths of the over-75-year-old adults. Even if dental clearances stopped now, which is unlikely, it would take until 2038 before edentulousness was eradicated. While the proportion of the dentate adult UK population has increased, the DMFT index score for cohorts over the age of 45 has not substantially changed. In terms of periodontal health, 75% of the 35-44-year-old cohort had periodontal pocketing, 13% of which were classified deep pockets. These data suggest that the burden of maintenance of heavily restored dentitions will remain a major requirement for the dental profession.
A further factor to consider is the attendance pattern of adults, and their attitudes to dental care. At the present time, significant proportions of adults do not attend the dentist regularly, and only attend when in pain or when they need emergency treatment. Barriers to the uptake of dental care include cost, fear of dental procedures and negative images of the dental practice environment. It seems likely that many in this group of adults will remain a "hard core" of non-attenders, and are unlikely to remain dentate throughout their lifetime.
Attitudes to Edentulousness
The attitude to tooth loss is also changing. Greater numbers of adults are reporting that they find the thought of losing their teeth upsetting and are likely to seek treatment to retain some of their natural teeth. Owing to the high prevalence of dental disease in the older-age cohorts, many will not achieve their aim of being dentate for life. Consequently, the loss of natural teeth will, for some, occur late in life at a time when denture control skills are difficult to acquire.
The attitudes to edentulousness, and satisfaction with complete dentures will, in the future, be influenced by current trends in adult dental health. As the proportion of adults retaining teeth into old age increases, the transition to the edentulous state will, for some, occur later in life. As the ability to learn the complex series of reflexes required to control complete dentures diminishes with age, it seems possible that denture-wearing complaints may increase in the elderly age groups.
Anatomical Consequences of Edentulousness
The anatomical changes which occur following extraction of natural teeth can broadly be divided into intraoral and extraoral changes. These will differ between individuals who remain partially dentate and those who are edentulous following tooth loss. As people age, loss of alveolar bone is inevitable. However, following total tooth loss, alveolar bone resorption is greatly increased. Alveolar bone height and width decrease markedly (Figs. 1-1 and 1-2). Most of this change occurs in the first year following extractions, but remains an inexorable process throughout life. Resorption occurs on the buccal aspect of the maxillary ridge and the lingual aspect of the mandibular ridge. In a mixed longitudinal study over 25 years, Tallgren demonstrated the extent of bone loss in edentulous individuals. She demonstrated that the loss of bone is four times greater in the mandible than the maxilla. Despite extensive research, the reason for great individual variation in bone loss remains unclear. It seems likely that a combination of local and systemic factors may be responsible for this phenomenon.
Fig 1-1 Orthopantomogram showing the edentulous jaws of a 62-year-old female. Note how thin the lower jaw is following extensive loss of alveolar bone.
Fig 1-2 Orthopantomogram of 75-year-old female with retained dental roots in the anterior mandible. Note the bone height around teeth compared to edentate areas in the lower jaw.
As well as anatomical changes, further consequences of tooth loss include:
The influence of tooth loss on masticatory ability, performance and dietary selection has been well documented. Objective tests of masticatory performance indicate that chewing efficiency of edentulous adults is approximately 20% that of a dentate individual.
Subjective tests that assess patients' attitudes to food choice suggest that edentulous patients tend to favour highly flavoured soft foods that are of low nutritional value. Reasons for this are complex, and include socio-economic factors as well as denture-related causes. Surveys of nutritional intake, report that edentulous adults have lower intake of fibre, vitamin C and other important nutrients, compared with dentate adults. This suggests that edentulous patients with poor-quality diet are at a higher risk of serious illness, including cardiovascular disease and cancer.
Loss of anterior teeth affects speech and can be a difficult problem to deal with, particularly in patients with a skeletal Class 2 jaw relationship.
In addition to preserving bone, teeth support soft tissues such as the cheeks and lips. This in turn has an influence on appearance, and appearance is adversely affected once teeth are lost. This is most noticeable in the circumoral region, as the commisures of the lips collapse inward. A further consequence is loss of vertical dimension and this has the affect of approximating the nose to the chin (Fig 1-3). Complete replacement dentures can rectify some of these changes, but there are limitations. In cases of severe resorption, it may be impossible to meet the patient's aesthetic requirements and at the same time provide stable replacement dentures.
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