Nutrition and Oral Medicine (Nutrition and Health)

36 Part I / Nutrition and Healthindividuals with impaired dentition can fall below minimum recommendations, especiallyif the eating pattern is already marginal in quality and the patient is subjected tosudden insults such as illness, loss of taste, inability to chew, or changes in economicstatus and living situation (12,38,43). In addition, a high number of smokers and formersmokers is found among the edentulous, and adults who smoke generally have poorerdiets (38).2.3. Sensory PerceptionTaste buds on the tongue and oropharynx are responsible for the sensations of bitter,sweet, salty, and sour. Tactile and temperature sensations in the tongue help discernflavor. Depressed senses of taste and smell have been attributed to the aging process,disease, medications, smoking, lack of tongue cleaning, and other dental problems. Indeed,many oral conditions can directly or indirectly affect smell and taste. These include oralinfections, oral lesions, salivary gland dysfunction, poorly fitting dentures, and systemicdiseases (44).Diminished salivary secretions have an adverse effect on many oral functions such aschewing, tasting, swallowing, speaking, and wearing dentures successfully. There mayalso be burning or soreness of oral mucosa, increased susceptibility to oral candidiasis,and an increase in the incidence of severe caries (45,46). Salivary gland dysfunction and/or inadequate saliva contribute to the inability to obtain proper nutrition via difficultiesin lubricating, masticating, tolerating, tasting, and swallowing food (47). Elders withxerostomia experienced a reduction in taste and food perception, and these subjects alsoexperienced significant (p < 0.001) deficiencies of dietary fiber, potassium, vitamin B 6 ,iron, calcium, and zinc as compared to the 1989 recommended dietary allowances (47).Compared to people with normal salivary flow, those with xerostomia have been shownto have significantly lower caloric intake and inadequate intakes of fiber, potassium,vitamin B 6 , iron, calcium, and zinc, despite the cause of the xerostomia (47). Craniofacialand oral surgery, chemotherapy, and radiotherapy to head and neck regions can also causetemporary or permanent changes in taste and smell (12).A full upper denture can impede optimal taste and swallowing ability and may contributeto choking. Taste sensitivity can be reduced when an upper denture covers the hardpalate (which contains taste buds). When the upper palate is covered, it is also difficultfor a person to determine the location of food in the mouth, thus making swallowing lesswell coordinated (48,49). Dentures are considered to be a major contributing factor todeaths from choking for this reason (50).Considerable differences exist between older and younger people regarding sensoryperception and pleasantness of foods (51). Several studies have also shown that peoplewith poor odor perception have lower nutrient intakes than those with good odor perception.Dental status may be a contributing factor to odor perception in those who have otherhealth conditions as well (53). Tongue brushing can help increase taste sensation for olderpatients (52).2.4. Digestion and Gastrointestinal FunctionThe chewing of foods is important for the initiation of food digestion. Tosello showedthat subjects with “a natural set of teeth” had significantly less gastrointestinal pathologythan did partially edentulous subjects (54). More specifically, poor oral function may lead