Section 2-2. Elderly persons can bite vinegary octopus. Their teeth were favorable

Figure 3 showed me the memorable information whereby my subsequent direction was decided but the occasion I reviewed the data was just the beginning of my severe journey. In other means, this turned out to be a bud which grew to a big tree for pursuing the medical changes indicative of “Hazo” revolution while this was cultivated by a simple question raised by a short sentence “Doctor Umetsu, I can bite any foods.” of that old woman. To my surprise, the vivid elderly persons had about 2-fold teeth relative to the national mean of the elderly persons of the same age! The national mean values were cited from the latest data with the title of the Survey Report on Current Situations of Dental Diseases which was published by the Ministry of Health, Labor and Welfare following national survey performed every 6 years. Teeth of the vivid elderly persons were quantitatively superior and the difference was statistically significant. To verify difference in quality of teeth, we made questionnaire surveys by which more than 60 % of them could bite vinegary octopus. Since the mean age of the vivid elderly persons was 71.3 years and even high school students feel difficulty to bite vinegary octopus, we can say that the vivid elderly persons have very stout teeth. It is generally difficult to obtain the data on bites of the general elderly people and therefore, we employed the already-reported data on the biting ability of the elderly people which had been determined at an elderly hospital with use of the same determination apparatus as those in our study. As the results of such a comparison, it was obvious that the biting ability of the vivid elderly persons was superior to those of the general elderly people (Figure 4). In other words, the vivid elderly persons had quantitatively and qualitatively superior health conditions of their teeth than those of the general elderly people. Now that we assessed the teeth conditions of the “vivid elderly persons” in such a way, the healthy conditions of teeth of vigorous elderly were proved qualitatively and quantitatively superior to those of the general aged people. This clearly suggests the correlation between teeth and health; however, if we can prove that good teeth to bite food thoroughly are accompanied by healthy conditions of the whole body, we can scientifically prove the bidirectional relationship between teeth and health. Based on this concept, internal physicians calculated the healthy degree index from the view point of internal medicine based on the carefully investigated data on each subject while I, as a dental physician assessed the “Biting degree” indicative of biting ability of each subject in a double-blind fashion based on the biting ability and chewing data, followed by comparison of them. As the result, the group with good biting ability showed higher internal medicine-related healthy degree index by about 40% compared with those of the persons with less biting ability (Figure 5). In other words, these facts not only indicated that the vivid elderly persons had their own teeth but also bidirectionally proved that the elderly persons with their own teeth had higher healthy degrees than those without teeth. When these studies on both teeth and systemic health were conducted, there was a tendency to complete the discussion simply by saying that residual teeth allow satisfactory chewing of food and attain better digestion and absorption of food, leading to higher health degrees. Further analysis needs much more data, indicating that only the dental studies were inadequate to obtain necessary data. Even if we made a search among overseas literatures, similar study reports studied functions of teeth as a part of digestive organs, by combing teeth with health; finally, the reports completed the discussion and were closed innocuously. I wondered if such an uneventful assessment would be adequate. In this connection, we must say that this study project on the vivid elderly persons was extremely a rare study and therefore, this could be regarded as a significant study for human beings. These comments are supported by the following two aspects. Firstly, whenever we discuss reliability of the final results in such a scientific etiological study, it is of no use to say that the size of the parent population for investigation, as well as scientific extraction of the eligible subjects is important. As stated above, this survey on vivid elderly persons was totally backed up by Kasuga city, one of the local administrative organizations in the form of joint hosting for this research project. As a natural consequence, this project employed Kasuga city with population of more than 80 thousand as the mother population; in addition, its citizens including elderly clubs positively contributed to this project, together with cooperation of health nurses, municipal employees as a part of their jobs to survey and research activities. Nevertheless, despite of such a big mother population, their joint cooperation made it possible to extract eligible subjects and to perform smooth implementation of investigations. If one research organization belonging to a university wished to conduct similar survey and research with enormous amount of money as research expenses, it might be impossible to do the same survey. The success of this survey on vivid elderly persons could be attributed to the cooperative form with local administration. Secondly, another outstanding feature of this survey existed on its interdisciplinary research. Human beings are not a simple assembly of individuals but exists as a micro-cosmos characteristic of possessing the integrity. So as to investigate humans comprehensively without compromise, integrated research approach among various relevant fields and their mutual cooperation are required. However, under the current situation in which university is composed of faculties and its organizations are divided according to specialized fields, it is very difficult for researchers from different fields to participate in one big research project under close communications across specialized boundaries. The same might be true with not only Japan but other overseas countries. In the survey on vivid elderly persons, the Health Science Center of Kyushu University with specialized staffs for various fields played a role as the responsible organization. Thanks to such a feature, effective and highly cross-disciplinary study became feasible. Not coincidentally, well-conditioned, comprehensive study on humans came true in this survey on vivid elderly persons.



■Figure 3
The vivid elderly persons had 2-fold teeth relative to the national mean
In comparison with the national mean of the elderly persons at the same age, the number of healthy teeth without any treatment as well as the number of the total residual teeth were about twice in the vivid elderly persons while the ratio of the persons with no teeth was about one half in the vivid elderly persons, indicating that the health conditions of teeth of the vivid elderly persons were excellent in average. * denotes statistical significance with p<0.05; ** means p<0.01; ***shows p<0.001, respectively, demonstrating scientifically significant meanings.



■Figure 4
Vivid elderly persons had strong biting power
In comparison with the elderly persons in hospitals designated for elderly, the vivid elderly persons had more than 2-fold stronger biting power in average, suggesting that the healthy conditions of teeth were also extremely superior to those of general aged persons qualitatively. (Cited from Reference 26 (K. Okimoto et. al.))



■Figure 5
The elderly persons with good biting ability showed the higher healthy degrees in terms of internal medical assessment
The elderly persons with good chewing ability also showed higher degrees of internal medical healthy degrees; therefore, positive correlation between “Biting ability” and health was scientifically proved. The healthy degree index was judged by internists based on the abnormal values of detailed examination among the following 8 variables such as internal examination, blood pressure, hematological tests, urinalysis, electrocardiogram at rest, echocardiogram, and determination values of subcutaneous fat. (Reference 27: T. Fujino, et.al.)