The aim of this study is to compare breath odors and odor emission sources (saliva, tongue coat, and dentures in current use) of the elderly and to define the relation-ships between the odors. Fifteen patients visiting theoutpatient clinic, Tokyo Medicaland Dental University Geriatric Dentistry, wererecruited. The breath, saliva, denture, and tongue coat of each individual wer collected as samples. Then, the gas evaporatingfrom each sample was saved in a sampling bag. The sampling gas was measured by anelectronic nos (Odor Discrimination Analyzer FF-1, Shimazdu, Japan). In principle component analysis, principle component 1 showed significant differences between threepairs of items: breath odor (BR) and the odor of the saliva (SL), breath odor and the odorof the denture (DE), and breath odor and the odor of tongue coat (TC) (p<0.001). Therewere no significant differences between SL and TC, SL and DE, and TC and DE. The meandifferences between BR and the each odor emission source showed that DE was the nearest to BR, then SL, and TC lastly. In this study, TC, previously named as one ofthe main causes of breath odor, has no relation with BR. Moreover, TC is related to SLand DE in the elderly. It is suggested that one of the main odor emission sources ofbreath odor may be the dentures.

View full abstract

The purpose of this study was to evaluate the effects of occlusal support on labial function in elderly denture wearers.
Thirty one elderly individuals (8 male and 23 female, mean age 81.9 years) who had no feeding or swallow-ing disorders were chosen for evaluation oflip closing pressure when taking food, to analyze te effect ofocclusal support. The number classified as having posterior support for occlusionwith natural teeth (OS) was 13, and that with no occlusal support (NOS) was 18. A water-repellent pressure sensor (PS-2Ka, Kyowa Electric Co., Tokyo, Japan) was embedded in the ball of aspoon. One gram of yogurt was repeated-ly given to the subject to ingestLip closing pressure against the sensor was evaluated by acomputerized system.
The results demonstrated that lip closing pressure wassignificantlyhigher lip closing duration wassignificantly longer, and pressure integral wassignificantly larger, when subjects took food without occlusalsupport. In the NOS group, lip closing pressure, lip closing duration and pressureintegral showed a significant difference between with and withoudentures. It was concluded that loss of jaw stability by occlusion had a significant effect on labial function when taking food.

View full abstract

An easy method of evaluating the oral hygiene status isconsidered to contribute greatly to improving oral hygiene status.Therefore, we developed an easy andobjective method of evaluatingthe total food residue in the oral cavity from the state offoodresidues on the tongue after swallowing.
Biscuit (Bisco^®, EzakiGlico) was used as the test food, and one bite wa defined as2.25g. Thirty healthy volunteers (14 males and 16 females, meanage 32.7±7.3 years) participated in this study after giving informe consent. After brushing the teeth andtongue by a dentist, each participan was instructed to chew the biscuit in his or herown way, then swallowaccording to three swallowing patterns (swallowing once only, twiceonly, and freely). We then took a digital photograph of the fooresidues on thetongue. All the food residues in the oral cavity werecollected by brushing and rinsingthe participants' mouths, and thenth weight of the food residues was measured by theheated air-drying method t give a weight score (W-score).
We established the criteria for 4 grades ofappearance of the food residues. These criteria are referred to as thevisual inspection score (I-score). The data of both parameters (W-score I-score) were collected and analyzed with multiple regression. To examinethevalidity of the I-score, the 90 images of the tongue wereclassified according to the criteria. The mean residual weight of al 4 grades was compared with the weight of the testfood.
1. The correlation coefficient (r) between the W-score and the I-score wa 0.784 (p<0.01).
2. Each mean weight indicates approximate value to 1/2, 1/4, 1/8 of apiec of testfood at regular intervals, and differed significantly among thegrades, indicating thevalidity of the 4 grades of I-score.
There was substantial correlation between the total food residue in the oral cavityandthe food residues on the tongue, suggesting that one can evaluat the total food residuein the oral cavity from the state of the foodresidues on the tongue alone.

View full abstract

To determine suitable food for the elderly, it is much important to know the salivary flow rate during chewing their daily food. We compared the water contents of the food bolus just before swallowing in the young (20s years, n=33) and in the non-institutionalized elderly (70+ years, n=30). Nine daily foods were selected: dried apricot, white bread, cooked burdock, cooked chicken, mushi-kamaboko, boiled mushroom, boiled spinach, arare and baked yellowtail. The bolus of each food was collected just before swallowing. The water contents of the bolus were analyzed, and the salivary flow rates were calculated.
With the comparatively salty foods, there was no significant difference in the water contents of the bolus between the young and the elderly, but the salivary flow rate of the elderly was signficantly less than the young. It was considered that a longer period of chewing before swallowing compensated for the reduction of saliva.
The relation between the salivary flow rate and the use of dentures was not clear. However, a clear relation between the symptom of dry mouth and the salivary flow rate was evident. The subjects who took an above average amount of drugs (men 2.5, women 2.6) were likely to have a lower salivary flow rate. The influence of drugs on the salivary flow rate was suggested. We conclude that forthe elderly who take a lot of drugs, attention should be given to suitable food, in addition to medical treatment.

View full abstract

Candida albicans is often isolated from the oral cavity of the elderly. However, the pathogenicity of C. albicans present in the oral cavity of the elderly has not been clarified.
In the present study of oral candidiasis, the pathogenicity of C. albicans was investigated in vivo using a mouse model. The results showed that all strains isolated from the oral cavity of the elderly induced candidiasis. Tongue fur formed on the surface of the mouse tongue three days after inoculation. Further, the number of residual C. albicans cells in the oral cavity ranged from 1.58±0.54×10⁴ to 18.66±5.69×10⁴.The results of the present study suggest the possibility that C. albicans in the oral cavity induces candidiasis in the elderly, who have reduced immunity. Therefore, it is necessary to control C. albicans colonization through everyday oral care as much as possible in compromised hosts, such as the elderly requiring care.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract