Age-related oral changes are seen in the oral hard and soft tissues as well as in bone, the temporomandibular joints and the oral mucosa. As older patients retain their natural teeth for longer, the clinical picture consists of normal physiological age changes in combination with pathological and iatrogenic effects.
Sensory changes
It is known that taste and smell sensitivities change throughout life and often decline with ageing.These changes can make food become tasteless thus resulting in a reduction in appetite.Such taste and smell dysfunctions may be due to a variety of contributing factors including oral diseases, systemic conditions and their associated treatments.Most studies suggest that the sense of smell is more impaired by ageing than the sense of taste.Olfactory cells which respond to smells are renewed much more slowly in elderly people.Olfactory acuity declines with age as the number of olfactory nuclei in the brain decline and the olfactory receptors in the roof of the nasal cavity regress.As a result, older people generally have greater difficulty differentiating among food odours than younger people.
A diminution of taste results from the degeneration of taste buds and a reduction in their total number as renewal is much slower in elderly people.Elderly people have considerable differences in their sensory perceptionand capacity to detect the pleasantness of foods compared with younger people.
This can lead to older people adding ingredients such as sugars or salt to food stuffs which can have adverse health effects.Whilst chemosensory deficits experienced by elderly patients generally can not be reversed, interventions including intensification of the taste and odour of foods, can compensate for age related perceptual losses.Amplified flavours increase the number of molecules that interact with receptors and compensate for sensory losses.Evidence shows that such amplification can improve food palatabillity and acceptance, increase salivary flow and immunity, and reduce oral complaints in both sick and healthy older patients.
Worldwide population demographics are changing rapidly and the proportion of older people is growing faster than any other age group.Approximately 600 million people are currently aged 60 years and over,and this number is expected to double by 2025.Globally,poor oral health among older people has traditionally been manifest in high levels of tooth loss,dental caries and periodontal disease experiance,as well as xerostomia and oral precancer/cancer.In addition,evidence of the relationship between oral health and poor general health continues to grow with links between severe periodontal disease and diabetes mellitus,ischamic heart disease and chronic respiratory disease the focus of much research.
Age changes are manifest in oral and dental tissues.What is seen is a combination of physiological age changes with superimposed pathological and iatrogenic effects.
Bone Increasing age is associated with progressive reduction in bone mass resulting in osteoprosis.Age related osteoporosis is common and, in edentulous patients,may play a role in atrophy of alveolar and possible basal bone,although no clear relationship has been established.Atrophy of alveolar bone is related mainly to tooth loss.Its extent increases with age resulting, in the absence of denture, in loss of facial height with upwards and forwards posturing of mandible.Loss of alveolar bone is more extensive and occurs more rapidly in the mandible than in maxilla.
Levels of cyclo-oxygenase 2 (COX2) enzyme.which plays an essential role in bone repair,decline rapidly with ageing.This may explain the delayed bone healing that occurs in older patients.Research is now being conducted to stimulate activity of the COX2 enzyme and subsequent bone healing.
Temporomandibular Joint
(TMJ)
In the TMJ it is difficult to distinguish changes due to ageing from those related to osteoarthrosis.Excluding those changes due to osteoarthrosis,the main age changes are related to remodelling of articular surfaces and disc in response to functional changes following tooth loss.Remodelling may result in disc displacement,particularly anterior displacement.The retrodiscal tissues may show adaptive changes associated with decreased cellularity and vascularity, and increased density of collagen, and may eventually function as an articular disc.However, in some cases the displacement may lead to perforation of the disc, particularly of its posterior attachment, resulting in progressive joint damage
Nerves and musculature
Muscle function is depedent on the performance of the nervous system and both exhibit independent age-related changes.Nerve cells loss is universal in old age and is ehibited in the brain and spinal cord.There are also age related changes in neurotransmitters, resulting in motor dysfunction. Peripheral nerve functiondeclines with ageas there is a reduction in conduction velocity, increased latencies in multi-synaptic pathways,decreased conduction at neuromuscular junctions and loss of receptors.
Continued muscle function is a major requirement for the maintainance of speech and mastication.In all patients with advancing age there is a reduction in total muscle mass which occurs through a reduction in the number of muscle fibre rather than a major reduction in muscle fibre size. Electrophysiological studies have also shown a loss f motor units with age, particularly in those over the age of 60 years, which manifests as a reduction in muscle strength and reduced masticatory forces.Age induces a lengthening of the chewing process associated with reduction in muscle activity, suggesting that elderly patients adapt their chewing activity.
Evidence suggests that edentate patients exhibit an increased reduction in muscle mass and reduction in maximal bite forces compared with dentate patients.However, many edentate individuals successfully rehabilitated using complete dentures regard their masticatory function as satisfactory.
Oral mucosa
The clinical appearance of oral mucosa in older patients is often indistinguishable from that of younger patients.However,changes overtime including mucosal trauma, mucosal diseases, and salivary hypofunction can alter the clinical appearance and character of the oral tissues in older patients.
The stratified squamous epithilium becomes thinner, loses elasticity, and atrophies with age.A declining immunological responsiveness further increases the susceptibility to infection and trauma.An increased incidence of oral and systemic disorders,along with increased use of medication,may lead to oral mucosal disorders in elderly patients.Elderly patients may develop vesiculobullous,desquamative,ulcerative,lichenoid and infectious lesions of the oral cavity.In addition, oral cancer is primarily a disease of ageing and associated cell dysregulation.It is estimated that more than 90% of all oral cancers in developed countries occur in individuals older than 50 years, with a mean onset during the sixth decade of life.Oral cancer is associated with high morbidity and a particularly poor survival raate of less than 50% after 5 years.
It is known that taste and smell sensitivities change throughout life and often decline with ageing.These changes can make food become tasteless thus resulting in a reduction in appetite.Such taste and smell dysfunctions may be due to a variety of contributing factors including oral diseases, systemic conditions and their associated treatments.Most studies suggest that the sense of smell is more impaired by ageing than the sense of taste.Olfactory cells which respond to smells are renewed much more slowly in elderly people.Olfactory acuity declines with age as the number of olfactory nuclei in the brain decline and the olfactory receptors in the roof of the nasal cavity regress.As a result, older people generally have greater difficulty differentiating among food odours than younger people.
A diminution of taste results from the degeneration of taste buds and a reduction in their total number as renewal is much slower in elderly people.Elderly people have considerable differences in their sensory perceptionand capacity to detect the pleasantness of foods compared with younger people.
This can lead to older people adding ingredients such as sugars or salt to food stuffs which can have adverse health effects.Whilst chemosensory deficits experienced by elderly patients generally can not be reversed, interventions including intensification of the taste and odour of foods, can compensate for age related perceptual losses.Amplified flavours increase the number of molecules that interact with receptors and compensate for sensory losses.Evidence shows that such amplification can improve food palatabillity and acceptance, increase salivary flow and immunity, and reduce oral complaints in both sick and healthy older patients.
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