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(1/84) Measurement of sensitivity to olfactory flavor: application in a study of aging and dentures.

Olfaction involves a dual sensory process for perceiving odors orthonasally (through the nostrils) and retronasally (through the mouth). This investigation entailed developing a measure of sensitivity to an odor delivered in an orally sampled food (orange flavoring in a sucrose-sweetened gelatin) and examining sensitivity in the elderly. In experiment 1, olfactory flavor sensitivity was 49 times lower in elderly (n = 21) than in young (n = 28) subjects. In experiment 2, with 73 elderly women, higher olfactory flavor sensitivity correlated significantly with higher orthonasal perception (Connecticut Chemosensory Clinical Research Center test). Some women, however, exhibited low olfactory flavor sensitivity despite high orthonasal perception; none had high olfactory flavor sensitivity and low orthonasal perception. Those who wore complete or palatal covering dentures had lower olfactory flavor sensitivity than those who were dentate or wore dentures that did not cover the palate. Through multiple regression analysis, orthonasal perception and denture status were found to be independent contributors to predicting olfactory flavor sensitivity. In summary, elderly subjects showed depressed olfactory flavor sensitivity (i.e. retronasal sensitivity) that related to poor orthonasal olfactory perception and denture characteristic. Thus, while good orthonasal olfaction may be necessary for good olfactory flavor sensitivity, it is not sufficient. Other factors, some associated with oral conditions, may impede release and retronasal transport of odors from the mouth to the olfactory receptors.  (+info)

(2/84) Oral colonization, phenotypic, and genotypic profiles of Candida species in irradiated, dentate, xerostomic nasopharyngeal carcinoma survivors.

The aim of this study was to investigate oral yeast colonization and oral yeast strain diversity in irradiated (head and neck), dentate, xerostomic individuals. Subjects were recruited from a nasopharyngeal carcinoma clinic and were segregated into group A (age, <60 years [n = 25; average age +/- standard deviation (SD), 48 +/- 6 years; average postirradiation time +/- SD, 5 +/- 5 years]) and group B (age, >/=60 years [n = 8; average age +/- SD, 67 +/- 4 years; average postirradiation time +/- SD, 2 +/- 2 years]) and were compared with age- and sex-matched healthy individuals in group C (age, <60 years [n = 20; average age +/- SD, 44 +/- 12 years] and group D (age, >/=60 years [n = 10; average age, 70 +/- 3 years]). Selective culture of oral rinse samples was carried out to isolate, quantify, and speciate yeast recovery. All test subjects underwent a 3-month comprehensive oral and preventive care regimen plus topical antifungal therapy, if indicated. A total of 12 subjects from group A and 5 subjects from group B were recalled for reassessment of yeast colonization. Sequential (pre- and posttherapy) Candida isolate pairs from patients were phenotypically (all isolate pairs; biotyping and resistotyping profiles) and genotypically (Candida albicans isolate pairs only; electrophoretic karyotyping by pulsed-field gel electrophoresis, restriction fragment length polymorphism [RFLP], and randomly amplified polymorphic DNA [RAPD] assays) evaluated. All isolates were Candida species. Irradiated individuals were found to have a significantly increased yeast carriage compared with the controls. The isolation rate of Candida posttherapy remained unchanged. A total of 9 of the 12 subjects in group A and 3 of the 5 subjects in group B harbored the same C. albicans or Candida tropicalis phenotype at recall. Varying degrees of congruence in the molecular profiles were observed when these sequential isolate pairs of C. albicans were analyzed by RFLP and RAPD assays. Variations in the genotype were complementary to those in the phenotypic characteristics for some isolates. In conclusion, irradiation-induced xerostomia seems to favor intraoral colonization of Candida species, particularly C. albicans, which appeared to undergo temporal modifications in clonal profiles both phenotypically and genotypically following hygienic and preventive oral care which included topical antifungal therapy, if indicated. We postulate that the observed ability of Candida species to undergo genetic and phenotypic adaptation could strategically enhance its survival in the human oral cavity, particularly when salivary defenses are impaired.  (+info)

(3/84) Matrix polymers of Candida biofilms and their possible role in biofilm resistance to antifungal agents.

Extracellular polymeric material (EP), comprising the matrix of Candida albicans biofilms, was isolated and its composition was compared with that of EP obtained from culture supernatants of planktonically grown (suspended) organisms. Both preparations consisted of carbohydrate, protein, phosphorus and hexosamine, but biofilm EP contained significantly less total carbohydrate (41%) and protein (5%) than planktonic EP. It also had a higher proportion of glucose (16%) and contained galactose, suggesting that it might possess components unique to biofilms. To investigate whether the EP matrix plays a role in the resistance of biofilms to antifungal agents, susceptibility profiles of biofilms incubated statically (which have relatively little matrix) were compared with those for biofilms incubated with gentle shaking (which produce much more matrix material). Biofilms grown with or without shaking did not exhibit significant differences in susceptibility to any of the drugs tested, indicating that drug resistance is unrelated to the extent of matrix formation. However, biofilms formed on two different types of polyvinyl chloride catheter, obtained from different manufacturers, showed differences in susceptibility to amphotericin B, suggesting that drug resistance may arise as a result of highly specific, surface-induced gene expression.  (+info)

(4/84) Partial spectrum of microorganisms found in dentures and possible disease implications.

While it would appear that denture surfaces alone become colonized by microorganisms, this study showed that the porosity of denture material allows for contamination throughout the entire denture. Further, the numerous opportunistic and pathogenic microorganisms found in this study were unexpected and are known to produce not only substantial oral infections, but also systemic diseases.  (+info)

(5/84) Dental attitudes and behaviours in 1998 and implications for the future.

The 1998 Adult Dental Health Survey included face to face interviews with participants to determine their dental attitudes and behaviours. This article considers reported oral hygiene practices, treatment choices, satisfaction with appearance of teeth, attitudes towards wearing dentures and how these have changed since previous surveys. Although overall there has been a steady improvement in dental health attitudes, adults from disadvantaged households are still lagging behind. This has implications for social equity.  (+info)

(6/84) The spectral analysis of syllables in patients using dentures.

Changes in the oral cavity resulting from the loss of teeth and the ensuing reconstruction of a set of teeth by dentures (partial or complete) may cause changes in the speech and voice of the patient. The aim of the present investigation was to study the changes in speech and voice in patients suffering from teeth loss and the degree of speech improvement using dentures. Voice and speech parameters of a set of tested syllables were analysed in 10 patients at the 2nd Clinic of Stomatology. The analysis was carried out by means of an FFT, SoundForge 5.0 programme. Differently expressed acoustic changes in both consonants and vowels were ascertained in a percentage of the patients under examination. These concerned especially the sibilant ("s", "(see text)"), labiodental ("f", "v") and vibrating ("r", "(see text)") consonants. Changes in the FFT spectrum and air leakage in constrictive consonants were also found. In some patients the vowels, especially the closed ones ("i", "u"), may change their fundamental frequency and show noise admixture manifested as a blurred delimitation of the formants. A denture should, inter alia, render it possible for the patient to produce the same articulation to which he/she had been accustomed before the loss of teeth. For the construction of dentures the most important factors from a phonetic point of view appear to be the following: overbite, overjet, the height of the plate, the thickness of the palatal material, the incisor position, and the modelling of the ruga palatina on the hard palate. In case of wrong denture construction the acoustic changes may continue, resulting in the patient's stress load dependent upon sex, age, psychic condition and seriousness of the problem.  (+info)

(7/84) Vocal cord paralysis and oesophago-broncho-aortic fistula complicating foreign body-induced oesophageal perforation.

A 61 year old man died after presenting with a 24 h history of haematemesis and haemoptysis, and one year history of hoarseness of voice. Post-mortem examination showed a dental plate eroding through the mid-oesophagus into a bronchus and into the descending arch of the aorta, with scarring suggestive of old perforation. An organized haematoma also involved the left recurrent laryngeal nerve. Vocal cord paralysis may be a manifestation of foreign body-induced oesophageal perforation, which can lead to death from an oesophago-broncho-aortic fistula. Both complications of oesophageal perforation from a foreign body have not to our knowledge been previously reported.  (+info)

(8/84) Dentures may be radiolucent.

Diagnosing ingested dental prostheses can be difficult and delays in treatment may result in serious complications. Patients often present with a vague history and very few reliable clinical signs. In addition, the fact that dental plates are often radiolucent may lead to the diagnosis being overlooked with disastrous consequences. A case of successful diagnosis and treatment is presented, and the importance of a high index of clinical suspicion to avoid the morbidity and mortality associated with missed impacted dentures is discussed.  (+info)