Oral health status is an important factor for nutrition. There is a clear potential for the condition of the mouth and teeth to have an adverse affect on nutrition. According to studies, one in five older people reported that oral condition prevented them from eating the foods they would choose, 15% took longer time to complete their meal and their enjoyment of food was limited by oral condition, 5% avoided eating certain foods because of chewing problems.^5,6

Although the increase in health risks due to tooth loss may be small, the implications could be great, as a large segment of the population is affected. The risk factors for malnutrition in patients with dentures include: loose denture, sore spots under denture, severely resorbed mandible, difficulty in chewing, eating less food, unable to arrange food for oneself, unexpected excessive weight gain or weight loss, alcohol or drug abuse, and undergoing chemotherapy or radiation therapy .^5-7

The sequelae of treatment with complete denture may have adverse effects on the health of both oral and denture supporting tissues. The effects can be direct or indirect. The direct sequelae include: denture stomatitis, denture irritation, hyperplasia, traumatic ulcer, flabby ridges, residual ridge resorption, mucosal ulcerations, altered taste perception, burning mouth syndrome and gagging. Indirect sequelae are related to reduce chewing ability with an overall reduction in the functional capacity and general health. Further inadequate diet can lead to reduced tolerance of the tissues to normal wear and tear and this reduced resistance, in turn, can result in poor adaptation to dentures.^6-9

The effect of dentures on nutritional status varies greatly among individuals.^7-9 Oral impairments affect diet and nutrition due to changes in the ability to taste, bite, chew and swallow foods. Dentures affect the chewing performance adversely. The elderly people tend to use more strokes and chew longer to prepare food for swallowing. According to a recent study, masticatory efficiency in complete denture wearers was approximately 80% lower than in people with intact natural dentition.¹⁰ In comparison with the subjects wearing mandibular implant-retained over-dentures, the subjects with conventional complete dentures needed between 1.5 and 3.6 times more chewing strokes to achieve an equivalent reduction in the particle size.¹¹

Taste sensitivity may be reduced and it is difficult to locate the food in the mouth when the upper palate is covered as in case of full upper denture and these problems are further increased in cases of complete denture wearers. When compared to the sensory perceptions of dentate adults or partial denture wearer, subjective estimates of taste, texture acceptability of test foods and ease of chewing in complete denture wearers were the lowest.⁸ The inability to distinguish the sensory qualities of food reduces patient’s enjoyment of eating and leads to reduced calorie intake.

The comfort of wearing denture is dependent on the lubricating ability of saliva in the mouth. Xerostomia can also impair complete denture retention and is associated with difficulties in chewing and swallowing which can adversely affect food selection and contribute to poor nutritional status. Problems in lubricating, masticating, tasting and swallowing food contribute notably to the complex physiological and psychological manifestations of aging.^6,12

Rhodus and Brown in a study of 67 older adults from institutionalized and free living geriatric population having xerostomia on sialometry reported that statistically significant inadequacies in the nutritional intake patterns. Subjects with xerostomia had significant deficiencies of fiber, potassium, vitamin B-6, iron, calcium and zinc. Taste and food perception were significantly reduced in elders with xerostomia.¹²

In a study done Locker in older adult population, almost one-fifth participants reported dryness. These cases also complained of other oral symptoms such as unpleasant taste, a burning sensation in the tongue and other parts of the mouth and pain from dentures, difficulty in chewing food. Similar problems associated with dryness of mouth were also reported by other authors.⁵

Research also indicates that loss of natural teeth cause reduced masticatory efficiency even after replacement with dentures.^13-15 The reduced masticatory ability may lead to changes in dietary selection with risks for an impaired nutritional status.¹ Some people compensate for declined masticatory ability by choosing processed or cooked food rather than fresh foods. Others may eliminate certain food groups from their diets. There is good evidence that people adapt to tooth loss by altering their dietary intake to compensate for the increased difficulty of eating certain foods, even if masticatory function is restored with conventional dentures.^14-16 Masticatory status thus influences the appearance of gastro-intestinal disorders.¹⁷

Papas et al reported that people with full dentures consumed fewer calories and lower levels of several specific nutrients than did those who had partial dentures or natural dentition.¹⁵ Greksa et al concluded that full-denture wearers consumed significantly lower levels of vitamin A and C than did dentate people.¹⁸ Norlen et al stated that edentulous women had higher intake of fat and higher coffee consumption than dentate ones.⁹

The elderly edentulous avoid many types of food, particularly raw vegetables and other hard and tough foods, because they cannot chew these with conventional dentures.^14,19 As a result such individuals consume significantly less proteins and other key nutrients, fiber, calcium, non-haem iron and some vitamins as compared to the dentate individuals.²⁰ The hard and coarse foods such as fruits, vegetables and meat, which are typically major sources of vitamins , minerals, proteins and fiber, are difficult to chew with conventional dentures. Depending on the degree of impairment, chewing difficulty may result in a shift in food selection patterns.^13,16

Various studies have implicated dietary factors in the cause and prevention of important diseases, including cancer, coronary heart disease, cataracts.²¹ The biochemical measures of plasma ascorbate and plasma retinol is related to dental status. However, dental status is not significantly associated with histological and biochemical measures for the other key nutrients for which intake values vary with oral health.^{22, 23} The relationship between dental status and vitamin C appear to be both real and potentially important to general health. These lower levels of plasma ascorbate and plasma retinol could disturb thin skin and eye sight. Decrease in vitamin C can be associated with cataracts.²⁰

Studies show that edentulous older men have a significantly higher prevalence of type II diabetes than dentate or partially edentulous men. Edentulous men had significantly lower consumption of fruits, vegetables and fiber compared with dentate men and that edentulous women had higher fat consumption as compared with dentate women.²⁴ Decrease in fiber consumption can lead to increased risk of colorectal adenoma. Diets containing fewer vegetables and less carotene and fiber are associated with increased risk of cancer and heart diseases.²¹ Poor oral function thus, is a risk factor for gastrointestinal pathology.¹⁶

The risks for cardiovascular disease are also increased in edentulous patients. Johanansson et al compared the dietary intake and the levels of traditional cardiovascular risk factors in edentulous middle-aged individuals and individuals of the same age and sex with natural teeth. They reported that energy intake did not differ in two groups but edentulous men and women ate more sweet snacks compared to those with teeth. Further edentulous men and women were more obese and had lower serum HDL- cholesterol concentrations. The authors supported the hypothesis that edentulous middle-aged individuals have more unfavorable risk factors for cardiovascular disease.²⁴