Section 4-1. Do teeth affect blood pressure? Proof of the correlation with autonomic nervous system

If the hypothesis “Teeth are involved in the autonomic nervous functions” which was explained in the previous chapter is really correct, we can anticipate that signals relating to chewing stimulation would affect not only secretion of saliva as the local effect but also provide systemic influences. So as to sustain this hypothesis, we focused our attention on the factor, namely the blood pressure which is significantly affected by systemic and autonomic nerves.　　If this hypothesis is correct, the blood pressure should be also changed. Unless similar changes as did saliva are found in the blood pressure, we can conclude that influences of teeth on secretion of saliva must be local ones and they could not be the systemic influences in which autonomic nerves are involved. However, presence of similar changes in the blood pressure as did secretion of saliva eventually proves the said hypothesis that teeth are implicated in autonomic nervous system.
Upon pursuing the correlation between teeth and blood pressure, the interdisciplinary features of this research project played a significant role. Unless this project provides broader information covering other fields in addition to dental profiles, I am afraid that the study on teeth could not have been completed and furthermore, I failed to recognize the said “Teeth-organ theory” and eventually this book would not have been published. As the results, my life has been probably changed.
In the previous Chapters, I briefly explained the process by which I recognized the correlation of teeth with blood pressure. Frankly speaking, the hypothesis that teeth are involved in the central life function such as autonomic nerves would appear incredible from the viewpoint of conventional dental common senses. However, I ventured into an uncultivated world to destroy and revise the existing medical paradigm, which has not been challenged by dental researchers in the past. To tell the truth, I had emotional conflict over sticking to the established paradigm and unexpected internal resistance against continuing this research. For example, when I was engaging in input of the blood pressure data for statistical analysis into a computer at night, my body and fingers showed rejection responses contrary to my will, with some doubts “I really wonder whether I am trying to do some foolish and unnecessary tasks”. Triggered by the word “Doctor, I can bite any food” by an old woman wearing dentures, I have opened the way so far but I was wondering where I could find the final destination, namely the goal for this research. I was puzzled by these questions and quite at a loss. However, now that I came from the very beginning all the way, I could not stand still at this point. All I have to do is to go forward even if I encounter any obstacles. At that time, I was driven by obsession and sense of mission as a researcher, and simultaneously, I felt premonition that extremely important fact can be excavated by this survey.
First of all, I input the available data to a computer where the current number of teeth and the minimum blood pressure (diastolic blood pressure) were placed on the horizontal and the vertical axes on the graph. The software to analyze the correlation was activated. Whenever the correlation between the two relevant factors was assessed, usually the dots were widely scattered on the graph like sky full of stars and the correlation line indicative of the correlation could hardly be observed. In sharp contrast, however, completely different findings were observed at this time. The clear correlation line suddenly appeared on the monitor. That was an incredible sight. I could not help but give a call to an internist, one of the co-researchers even at 1 O’clock in the midnight and I shouted “Obvious correlation exists between teeth and blood pressure!” Despite of having performed our survey, I was so surprised to find the clear correlation between teeth and blood pressure because the involvement of teeth in systemic functions had remained unclear until that time. To tell the truth, I could not believe the graph on the monitor. Nevertheless, the computer display clearly shows the correlation line. I confirmed our findings following input of various relevant data to strengthen them.



Figure 19
Correlation between the minimum blood pressure (diastolic blood pressure) and the current number of teeth by the correlation line
Correlation was observed between the number of the left teeth and the diastolic blood pressure. There was a folding point around the current number of 13～15 teeth, and the direction of the correlation line was changed before and after this folding point.

Section 3-6. Why don’t you play piano with teeth?

The followings are the explanation about influences of each tooth on secretion of saliva. The analysis was performed by using the partial correlation coefficient obtained from multi-variable analysis as the index. Figure 17 illustrates the intentionally expanded row of teeth on upper and lower jaw while influences of each tooth on secretion amount of saliva and protein concentrations are shown with the length of pillars. White pillars denote secretion amount while black pillars show protein concentrations.
Shall we start with secretion amount of saliva shown by white pillars? The order of influences was the strongest in primary and secondary molar, followed by teeth in the anterior part in this decreasing order. How are the protein concentrations? Please look at black pillars in the figure. In sharp contrast with the secretion amount, higher peaks are found in maxillary canine and teeth in anterior part, as well as submaxillary primary bicuspid, with their influences decreasing toward the posterior teeth. These results are quite consistent with the outcomes obtained by the equation models. In more details, loss of bicuspid and the anterior teeth on jaw is associated with reduction or changes of salivary quality whereas loss of posterior teeth is accompanied by vulnerability to decrease in secretion amount of saliva. For your better understanding, shall we confirm it by referring to actually determined values of salivary secretion.Figure 18 shows the actually determined secretion amount of saliva from the following teeth; maxillary first molar as the representative teeth which are heavily involved in secretion amount of saliva; maxillary canine and submaxillary first bicuspid which showed strong influences on protein concentrations; and submaxillary canine which showed equivalent influences on both secretion amount of saliva and protein concentrations. As evidenced in this figure, the teeth indicative of strong influences on secretion amount of saliva and protein concentrations in Figure 17 demonstrated special features in that even a single loss of these teeth resulted in about 2-fold decrease in the actually observed values. On the other hand, the teeth which showed shorter pillars but no biased influences exerted no significant changes in both secretion amount of saliva and protein concentrations even if these teeth were lost. Do you understand these trends?As explained above, secretion of saliva is mainly affected by parasympathetic nerve among autonomic nerve system while protein concentration in saliva is primarily controlled by sympathetic nerve.
If we convert involvement of each tooth to nervous stimulation, we might say that posterior teeth, in particular submaxillary first and second molar and the maxillary first molar easily induce parasympathetic nerve stimulation whereas teeth in the middle part such as maxillary canine and submaxillary first bicuspid as well as maxillary anterior teeth cause sympathetic nerve stimulation. As the next step, you are asked to visualize the curves which are plotted by connecting the tops of white and black pillars. You will find a beautiful wave pattern woven by both curves which resembles an alternating electric curve. It seems to us as if individual tooth generates slightly different continuous tones which create a beautiful harmony. To be noted is the fact that 8 teeth starting from central incisor to the third molar in the posterior part constitute one unit, corresponding to one octave in the musical scale. This unit is associated with the basic structure of brain and it is easy for us to understand that there might be the transmission system of information comparable to do, re, mi, fa, sol, la, and ti, from anterior teeth to posterior teeth. In fact, chewing food with our teeth can be represented by hitting keyboards in brain with teeth like playing piano and playing music with our body when taking into account the transmission system of information with our teeth to brain. Although there is no difference in the music scales by individual tooth keyboard, foods to be chewed are responsible to alteration of tone timbre. Imagine varieties of foods such as bamboo shoots, devil’s tongue, rice cracker, soybean curd, rice, apples, herring roe, pickled radish and the like, and you could understand that various kinds of tone timbres are available on the earth. Meals can be compared to orchestrated music, in a sense, comprising of trumpet, violin, tuba, harp and timpani.
Dining is filled with lots of joyful sounds including food stuffs comparable to sounds from various kinds of musical instruments, “tastes and cold/warm sensation”, “flavor”, “beautiful harmony of arranged food layout”, “thoughtfulness by the host”, and “conversation on food”. Dining can be compared to an orchestra while teeth play a role as the concert master. You are the conductor. So as to offer actual experiences of the tone images by teeth to you, we have already prepared the relevant CD with the title of “Lets play the piano with teeth keyboards – Secrets of Teeth –“. This CD was prepared with the objective of having children recognize that every tooth is an indispensable living organ, thereby contributing to propagation of a life-long campaign to stimulate teeth health of them. This has been extensively employed as the educational material for elementary and middle schools. If you are interested in it, please have a contact with KOS.We have reviewed the correlation of teeth with autonomic nervous system whereby we are confident of the possibility of teeth influences on autonomic nervous systems in various aspects. Our survey of the relationship between teeth and health in vivid elderly persons happened to advance the following hypothesis “Teeth are involved in autonomic nervous system”. Thus, close correlation between teeth and autonomic nervous system has been verified during the course of investigating the relationship of teeth with secretion function of saliva; in this connection, however, another issue directly implicated in secretion of saliva has secretly occurred. If you will find this issue, you can recognize that the aforementioned hypothesis would not miss the mark. May I explain it in details as follows?Its is a dry mouth. Recently, about one out of four Japanese is suffering from xerostomia or its related symptoms. I anticipate that some of the readers of this book might be suffering from dry mouth and often lick the throat drops. These persons predispose to occurrence of decayed teeth particularly at the interface between teeth and therefore, a relevant term, “Throat-drop syndromes” is coined to denote such situations. In this connection, about 40 percents of elderly persons complain about dryness of their mouths, indicating a serious problem among them.Xerostomia mainly observed in elderly persons throughout Japan is caused by loss of teeth and abnormal occlusion which also occur nationwide. With advancing age, teeth are extracted in such a manner as 5 teeth in 50s, 10 teeth in 60s and 17 teeth in 70s in an average. In the former half of 80s of age, only 7 teeth are left (Reference 39), suggesting that 21 teeth are extracted. Since teeth are lost from the more posterior parts, this means that more parasympathomimetic teeth are tended to be removed earlier. As explained before, the parotid gland which secretes serous saliva is controlled by parasympathetic nerve to secrete saliva. Accordingly, if posterior teeth are lost, anterior teeth and bicuspids characteristic of mainly exhibiting sympathomimetic properties remain, leading to augmented function of submaxillary gland and secretion of viscous saliva. As the result, inside of the oral cavity becomes sticky, resulting in stimulating dry sensation within the cavity. It is quite natural for these persons to want to lick throat drops. Although elderly persons abandon their pursuit of ample secretion of saliva because of aging, xerostomia is not attributed to aging but is due to problems related to their teeth. Nobody can revive lost teeth but improvement of abnormal occlusion is sometimes associated with adequate secretion of saliva. It is anticipated that satisfactory chewing simultaneously improves internal transmission of information from teeth. Shall we review actual examples of such representative patients as follows?

Before treatment, I was suffering from dry mouth, unpleasant feeling of less
secretion of saliva, and tongue pains. Therefore, these symptoms always made me
gloomy. Since correction of abnormal occlusion and removal of silver
implantation by Dr. Muratsu, ample amount of saliva has been secreted into mouth
and I felt comfortable.
(52-year-old woman, Saga)

Incidentally, this patient has completed the scheduled treatment. Xerostomia observed at her initial consultation has already been eliminated with her heath being recovered, and currently, she spends a happy life since then.



Figure 17
Influences of each tooth on secretion amount of saliva and protein concentrations
Levels of influences are shown by the length of pillars.
The secretion amount of saliva seems to be affected by the posterior molars, in particular, submaxillary primary and secondary molars, and the maxillary first molarThe protein concentrations seem to be most affected by the front teeth. In particular, the submaxillary first bicuspid, maxillary first bicuspid, canine, lateral incisor and middle incisor most notably affected the protein concentrations.

Section 3-5. Teeth-dependent excitation system and spiritual comfort system

As you might know, autonomic nervous system is consisted of two kinds of nerves, namely sympathetic and parasympathetic nerves. Sympathetic nerve is responsible for transmission of excitatory information while parasympathetic nerve exerts comfortable properties, both of them playing a role in the basic transformation of information supportive of the vital activities. If we compare them to music, sympathetic and parasympathetic nerves share the jobs to control daily vital activities thereby attaining the overall harmony. We wonder whether teeth shall make timely and appropriate judgment in order to correspond to the contrary two different nerve stimulations or not. Otherwise, is only homogenous influence providing irrespective of different shapes of teeth or different locations of teeth?
Once again, shall we review the model equations concerning secretion amount of saliva (Figure 10) and protein concentrations (Figure 10) which were obtained by multi-variable analysis. Names of teeth as the explanatory variables on the right-hand side of equation for secretion amount of saliva were submaxillary second molar, maxillary first and second bicuspid, maxillary first molar, and second molar. On the other hand, names of teeth as the corresponding variables for protein concentrations were maxillary canine, submaxillary first, second bicuspid and first molar, indicating different teeth involved; furthermore, +, －signals on top of them were also different mutually. For you better understand, you are kindly asked to note that ＋signal indicates increase in the values of the objective variables for either secretion amount or protein concentrations on the left-hand side of equation while －signal means decrease of these parameters. Namely, locations of teeth seem to show different influences. Based on such a hypothesis, we decided to determine the influences on salivary secretion according to locations of teeth. Teeth including wisdom tooth have 8 teeth each on upper jaw, amounting to 16 teeth while the lower jaw has 16 teeth, reaching 32 teeth in total. Names of respective teeth were three teeth in anterior part such as medial incisor, lateral incisor and canine tooth; two teeth in bicuspid teeth such as first and second bicuspid; and three teeth in molar teeth such as first, second and third molar teeth (wisdom tooth). Accordingly, teeth were divided into three parts such as teeth in anterior part, bicuspid part and molar teeth, followed by investigating influences of loss of teeth on secretion of saliva and protein concentrations.
Figure 14 shows such influences according to respective parts by figures. Coefficient of correlation indicates the correlation between the residual patterns of teeth and secretion amount of saliva while the lower the figures the closer the correlation is. The risk rate means scientific credibility of the figures representing the coefficient of correlation. The smaller the figures the higher the credibility is. For example, if the error probability is less than 5% (P<0.05), the data are considered to be reliable. Complicated figures would be difficult for you to understand the outlines and therefore, I would like to show you the figure which clearly illustrates the correlation between the locations of teeth and secretion of saliva.
Looking at the secretion amount of saliva (Figure 15) and protein concentrations (Figure 16), you might note completely contrary a trend between them.
In other words, the more posterior the higher the secretion amount is affected whereas the more anterior the higher the protein concentrations are affected. There might be a possibility that individual tooth provides different transmission types of information to brain in similar manners as different shapes of respective teeth. It is interesting to pursue what kinds of differences exist per each tooth.
Influences of teeth by areas on the salivary protein concentrations




Figure 14
Correlation between the residual patterns of teeth by areas and secretion amount of saliva as well as protein concentrations
The correlation coefficients indicate significance of influences. The bigger figures, the stronger influences. P value stands for the level of the error probability. The smaller the figures the higher the credibility is. * denotes the error probability. When it is less than 0.05, it can be considered that there is a statistical “Significance”.



Figure 15
Influences of teeth by areas on the salivary secretion amount
Lower teeth affected the salivary secretion amount more than upper teeth did. The more posterior, the higher the secretion amount is affected.





Figure 16
Influences of teeth by areas on the salivary protein concentrations
Upper teeth affected the salivary features (protein concentrations) more than lower teeth did. The more anterior, the higher the salivary features are affected.

Section 3-4. Preclinical evidence obtained in animal experiments

I would like to introduce some important facts which were noted in other publications. The author of this report observed rats divided into two groups kept under different conditions. One group was given water-soluble food indicative of needing no chewing. Another group was fed with the same food which contained the same components but was a solid food, indicating that rats needed to chew this food. Under these different conditions, these rats were raised while time-course changes of parotid gland’s functions representing major three salivary glands were monitored. The results revealed significant differences. In the rats chewing solid food, appropriate sizes of parotid gland and favorable secretion of saliva were maintained; in sharp contrast, however, the rats given no chewing stimulation gradually showed atrophic changes. To our further surprise, internal changes occurred in the receptors for autonomic nerve systems in their teeth. In more details, the number of relevant receptors expressing on cellular membrane of salivary gland was extremely decreased. In addition, the composition of secreted protein was also changed.
Thus, I have obtained new clues. Namely, based on the findings that in the rats given no chewing stimulation, relevant changes were noted on the autonomic nervous system receptors existing on cellular membrane of salivary gland, it would appear likely that information from teeth in parallel with chewing stimulation was continuously transmitted to brain resulting in affecting autonomic nervous systems. In other words, during the course of repeated transmission of the continuous information which was generated as the chewing stimulation every meal to somatosensory area of cervical cortex, it is anticipated that its signals were transformed into autonomic nerve stimulation, evolving into providing definitive influences on both structures of salivary gland under control of autonomic nerve, and secretion systems. This indicates that superior salivary secretion functions in the vivid elderly persons with favorable chewing ability could be attributed to the interesting procedures that continuous stimulation from teeth plays a role as the continuous transmission of important information to brain to keep both the autonomic nerve functions and the subsequent secretion systems of saliva healthy. In response to continuous stimulation patterns of autonomic nerve from individual residual types of teeth, structure and functions of salivary gland are maintained and accordingly, it is anticipated that instinct qualitative and quantitative secretion of saliva to reflect the residual types of teeth could be obtained to respond to the same stimulation for secretion.

Section 3-3. Neural transmission from teeth to brain

It was disclosed that teeth exerted decisive influences on secretion of saliva. “However, wait a minute. Teeth are located close to salivary gland but they are not directly connected each other. By what kind of mechanism do teeth affect secretion of saliva?” This question naturally comes to our mind. Teeth are located close to salivary gland but they are not connected mutually. How is the information transmitted between them? To get the answer to this question, I started survey of the existing documents related to teeth’s function how to transmit information. Please look at Figure 13.
It has been well known that teeth possess periodontal membrane mechanical receptors which act as an antenna for transmission of information. This antenna is expressed as the result of expansion of nerves from two kinds of neuronal nuclei including trigeminal nuclei and mesencephalic nucleus of trigeminal nerve and is extensively distributed as the nerve terminal within periodontal membrane of dental root. We sometimes say “Crunchy texture” when talking about food. The signals indicative of crunchy texture are transmitted from this antenna to brain where such signals are processed to feel the crunchy texture. It is known that this nerve proceeds to somatosensory area of cervical cortex via cerebral limbic system. As regards correlation between teeth and somatosensory area of cervical cortex in terms of such a transmission, “One tooth innervation system” but not “Multi-teeth innervation system” plays a major role in which the primary afferent nerves act as the identification unit. One cerebral cell corresponds to one tooth. Accordingly, this mechanism permits independent transmission of different information by individual teeth. Loss of even one tooth is accompanied by disappearance of the corresponding brain cell; as the natural consequence, information transmission caused by stimulation with chewing and warm-cold sensation on this lost tooth would become absent. The teeth assembly comprising 32 teeth is collapsed with the totality as the information transmission organ being altered and in vain.
On the other hand, how is the nervous innervation in salivary gland? Salivary gland includes three major salivary glands such as parotid gland located under the ear, submaxillary gland under jaw, and sublingual gland, together with minor salivary gland located under mucous membrane in oral cavity.　When the ratio against the total volume of secreted saliva is compared, the saliva from submaxillary gland accounted for almost 70%, followed by 25% from parotid gland. To submaxillary gland and sublingual gland, as well as to parotid gland, parasympathetic nerves such as facial nerve representing parasympathetic nerve and glossopharyngeal nerve invade, respectively, with the salivary nucleus located close to the junctional region between pons and medulla being employed as the center. Simultaneously, involved are sympathetic nerve fibers of which upper center included hypothalamic area, with cerebral cortex limbic lobe being recognized as the lower center. Accordingly, these parts are under control of both sympathetic and parasympathetic nerves. Both sympathetic and parasympathetic nerves stimulate secretion of saliva but do not exert any antagonistic effects. However, their respective roles seem different; in more details, animal experiments on dogs indicated that parasympathetic nerve stimulation is mainly associated with secretion of juicy and serous saliva while sympathetic nerve stimulation mainly contributes to secretion of viscous saliva containing much of solid components. Interestingly, parasympathetic nerve stimulation induces salivary secretion from any of glands such as parotid gland and submaxillary gland whereas stimulation of sympathetic nerves causes secretion from submaxillary gland without secretion from parotid gland.

Figure 13

Information transmission pathways for chewing stimulation from teeth to the brain

Around the dental root, the antenna from the cervical nerve called as periodontal membrane mechanical receptors is set up. The stimulation induced by bites is caught by this antenna, and transmitted via trigeminal nerve to the somatosensory area of cervical cortex.(Keijiro Karita, et al: Cited from Reference 23)

Section 3-2. Proof of the correlation between teeth and salivary secretion by multi-variable analysis

Given these points, I used “Multivariable analysis”. Multivariable analysis is a statistical procedure to assess the obtained data correctly by summarizing the characteristics of the obtained data on the mutually-correlated multivariates (plural characteristic features) and collating them in accordance with the objectives. In such occasions, the systemic factorial data including the data on a trace amount of materials in blood was input to a computer because the forerunner researchers’ studies indicated association of the systemic factorial data with saliva secretion functions (Figure 9). As the soft-ware for analysis, we employed SAS (Statistical Analytical System). Then, these data were subjected to computer analysis to prepare the equation models (General linear multiple regression model) comprising the highly correlated factors to both secretion amount of saliva and protein concentrations in saliva. As the next step, these equation models were used to perform various investigations. For example, suppose that any teeth-related factors remain within these equation models, it is conceivable that teeth play an important role in affecting saliva secretion. If such an influence is so limited, they are eliminated during the course of computer analysis.Upon performing this analytical study, veteran internists of the Health Science Center of Kyushu University and specialists on statistics working for Department of mathematics, Faculty of Science of Kyushu University were kindly asked to cooperate to avoid detracting its medical and statistical scientific features. For calculation, super-computer installed in the Computer Center of Kyushu University was used; however, it took about 1 year only for conducting calculation. As the results, we have obtained scientifically extremely reliable equation models concerning salivary secretion amount (Figure 10).Although some steps concomitantly using the “Principal component analysis” were performed as the preliminary steps so as to decide directly the equation models about secretion amount of saliva and protein contents, these steps were omitted from the provision of this book because these steps are too difficult for the general publics to understand and furthermore, they are only the process to obtain the final equation models. However, if you are interested in reading these parts, please refer to my thesis with the title of “Influences of teeth on autonomic nervous system” (Reference 59) carried in “The NIPPON Dental Review” No. 584, a medical journal specified for dental specialists.Now looking at this equation model which includes teeth as the explanatory valuable, it is obvious that teeth play an important role in secretion of saliva. Incidentally, the selected teeth were maxillary first molar, second molar, first and second bicuspid and submaxillary second molar. Figure 11 shows the equation model indicating protein concentration in saliva. This equation demonstrates that as shown in this figure, multiple correlation coefficient, contribution ratio and p value show excellent levels, and this extremely reliable equation model like those for secretion of saliva is now available, indicating that teeth are included as an important factor. The selected teeth were maxillary canine, submaxillary first bicuspid, submaxillary second bicuspid and submaxillary first molar.According to these results, it is obvious that teeth are greatly contributory to secretion of saliva and protein concentration in saliva. For your easy confirmation of compatibility of the equation models to the actually observed values, Figure 12 is illustrated. Tendency of each value is beautifully consistent while it is anticipated that the equation models obtained by multivariable analysis remarkably reflect the actually observed values. Based on the above-stated facts, multivariable analysis based on background factors proved the correlation between teeth and salivary fluid. Existence of teeth influenced secretion of saliva directly. Qualitative and quantitative remarkable decreases in secretion of saliva which were noted during the course of the study on the vivid elderly persons were deeply associated with loss of teeth.


■Figure 9
Systemic parameters used for the Multivariable analysis
Systemic factors comprising 22 items were selected by cooperation of internal physicians.
1. Gender
2. Age
3. Body weight
4. Pulse rate
5. Blood pressure
6. RBC
7. Hb
8. Hematocrit (Blood bio-Chemical test data)
9. Adrenaline
10. Noradrenaline
11. Blood glucose level
12. Cholesterol
13. Triglyceride
14. Total protein
15. β-lipoprotein
16. HDL-cholesterol
17. Albumin
18. Albumin/globulin ratio
19. Ca
20. Na
21. Mg
22. K


■Figure 10
Equation model for salivary secretion volume
The equation models (General linear multiple regression model) showed that the “Contribution ratio” indicative of power of explanation and reliability was as high as 0.828. The multiple correlation coefficient indicating the compatibility between the actually determined values and the calculated values from the equation model was as high as 0.91; furthermore, the p value indicative of the statistical significance was as small as 0.0005. All of them suggest that the scientific credibility is extremely high. The fact that the dental factors are selected as the explanatory variables on the right-hand side means that teeth affect definitely the salivary secretion amount. Difference of signals such as (+) and (－) at the top of the factors according to teeth is to be noted. This indicates that kinds of teeth exert different influences.Salivary secretion volume=－7.62
+0.03 X Submaxillary second molar
+0.06 X Maxillary first bicuspid
－0.11 X Maxillary second bicuspid
+0.19 X Maxillary first molar
－0.15 X Maxillary second molar
+1.49 X Total protein amount
－2.59 X Albumin amount
+4.23 X Albumin/globulin ratio
+0.91 X Mg amount
+0.005 X Blood glucose level
－0.21 X K amount
+0.016 X Ht value
－0.043 X salivary protein concentration
Multiple correlation coefficient=0.91
Contribution ratio =0.828
P value＜0.0005


■Figure 11
Equation model for salivary protein concentrations
In this equation model concerning the protein concentrations,the contribution ratio, the multiple correlation coefficient and p value were favorable in the similar manners as those of the salivary secretion amount, indicating higher scientific credibility. These findings suggest that teeth provide definitive influences on the salivary protein concentrations.Salivary protein concentrations=－9.57
+1.06 X Maxillary canine
+1.97 X Submaxillary first bicuspid
－1.48 X Submaxillary second bicuspid
－1.13 X Submaxillary first molar
+0.03 X Blood glucose level
+0.0059 X Adrenaline amount
+4.08 X Mg amount
－2.19 X salivary secretion amount
Multiple correlation coefficient=0.89
Contribution ratio =0.79
P value＜0.0001


■Figure 12
The values calculated by the equation model were well coincident with the actually determined values.

In both the salivary secretion amount and the protein concentrations, the values calculated by the equation model were well coincident with the actually determined values. This proves that the credibility of the obtained equation model was scientifically high.

Section 3-1. Good bites stimulate secretion of saliva with favorable quality

The vivid elderly persons are divided into two groups by the two axes such as chewing ability and occlusion strength into one group with adequate chewing ability and another group with inadequate chewing ability (Figure 7). Subsequently, these two groups are compared in terms of secretion function of saliva including amount (secretion amount) and quality (protein concentration). Incidentally, the former group with adequate chewing ability had 21.4 teeth as an average of remaining teeth number while the latter group with inadequate chewing ability had 6.8 teeth as an average. It would appear likely that their own teeth instead of implanted teeth are responsible for good chewing. However, judging from their systemic functions, it seems that not only the quantitative factors but also the quality of the residual patterns of their teeth are influential to their abilities. As stated in the previous section, this assumption seems correct because the saliva secretion function was not correlated with the currently remaining number of teeth and but instead, with the qualitative chewing ability.
To prove this hypothesis, shall we investigate the obtained results? The results showed that the group with adequate chewing ability exerted superior secretion of saliva and more favorable protein concentration compared with those of the group with inadequate chewing ability (Figure 8).
To our surprise, the former group with adequate chewing ability demonstrated about 2-fold higher secretion amount of saliva. Saliva is produced in salivary gland cells located around oral cavity as the outcomes of activities of these cells, followed by secretion from salivary gland to the mouth. In other words, the elderly persons exhibiting better chewing ability have superior activities of these salivary gland cells qualitatively and quantitatively whereas the elderly persons with inadequate chewing ability have deteriorated activities of these cells. To be careful about this is the fact that the cellular activities of salivary gland are not affected only by dental factors, if teeth are involved therein, but various neurotransmitters or trace amount of substances in blood might be largely implicated as the background factors. Accordingly, despite of correlation being observed between teeth and salivary secretion as the result of simple comparison, these statistic outcomes must be understood as “probably correlated” and further scientific investigations are required to definitely conclude “surely correlated”.For example, you might have heard “With advancing age, secretion amount of saliva is decreased” somewhere. This fact is really described in the text book of Nutritional Science. Which do you think about this opinion, correct or incorrect? Frankly speaking, this is completely incorrect, and a superstition. Advanced age is not responsible for less secretion amount of saliva but few original teeth causes less secretion of saliva. This was discussed at a special session about sputum in the general congress of IADR, International Dental Society, which was held in Cincinnati, USA. As is obvious from the data issued by the Ministry of Health, Labor and Welfare, the elderly persons have usually few original teeth because of extraction of lots of teeth during their lives. Therefore, if salivary secretion amount is compared between the younger generations and the elderly persons with disregarding the lost teeth, it is quite natural to observe that the younger persons showed much larger amount of salivary secretion relative to those of the elderly groups. Only these outcomes led us to wrongly conclude that aging is associated with less amount of salivary secretion. In actuality, loss of their own teeth resulted in less secretion of saliva and the comparison between the elderly persons with their own teeth and the younger persons demonstrated no difference in the salivary amount. On the contrary, the quite opposite findings were noted in some cases.Significance of saliva amount shall be described in the following chapters in details. However, the above-stated misunderstanding stemmed from shortsighted conclusion from the results obtained by simple comparison without any adequate investigations of background factors. It seems to us that such a mistake would frequently occur while studying the themes concerning problems related to teeth and aging. Physiological aging under healthy conditions of teeth is quite different from the pathological aging under abnormal occlusion or implantation of incompatible artificial materials in jaw. If the contents of my “Hazo” theory are generally understood and subsequent correction of the blind spot associated with the modern medicine and the health science is achieved, it is anticipated that incorrect common sense about the previously prevailing common sense on aging must be utterly reviewed. In other words, EBM (Evidence-based medicine) should be implemented. Now coming back to aging problems, survey and analysis of the obtained data on mixed subjects could not provide us with any meaningful information about real aging phenomena unless attention is paid to dental disorders and functional abnormalities existing as the background factors. For example, if we perform investigations on aging phenomena with enrollment of the elderly persons already affected with renal disorders and cardiac dysfunctions, the obtained results only reflect aging of pathological elderly patients; accordingly, these findings cannot be employed as the evidence representing physiological aging phenomena of human beings. Some persons insist that loss of teeth might be one aspect of duration of life and aging. However, they should recognize the fact that loss of teeth is mostly induced by bacteriological infections such as decayed teeth or periodontal infection (alveolar pyorrhea) (Please refer to Figure 8) but it is not due to gene-related duration of life. As shown in Figure IX, some elderly persons without any loss of their own teeth are really observed in the vivid elderly persons and are found within my patients who visit my clinic. Accordingly, I have decided to pursue actual influences of teeth on secretion of saliva by excluding individual differences in the subjects and influences of systemic background factors associated with salivary secretion.



■Figure 7
Tow-dimensional dispersion diagram by maximum occlusion strength and chewing ability
The vivid elderly persons are divided into two groups by the two axis such as chewing ability and occlusion strength into one group with adequate chewing ability and another group with inadequate chewing ability.



■Figure 8
Adequate chewing ability exerted superior secretion of saliva
The group with adequate chewing ability demonstrated about 2-fold higher secretion amount of saliva, with favorable quality (protein concentration)

Section 2-3. It seems that teeth exert something else than “biting”

Now coming back to the study results, since the survey on vivid elderly persons was an excellent cross-disciplinary etiological study project, various data which probably could not be obtained only by Dental Faculty were collected from various fields. These valuable data were inputted into the computer. One of these data was composed of findings on food and nutrition. In this connection, a simple question came to my mind whether the correlation between teeth and health could be explained only by the keyword, consumption of food, as was anticipated from our common senses.A certain researcher responsible for food and nutrition sciences illustrated the two-dimensional distribution about ingested foods by the vivid elderly persons. This pattern is characteristic of the plain meal type, being indifferent from the food patterns shown by the general aged people. Namely, the vivid elderly persons (Figure 6)were revealed not to take anything special even though they had their own residual teeth. If the subject elderly person was a woman, she probably had her husband and vice versa; under these situations, the subject could not take any specifically hard food for himself/herself in complete disregard of the partner’s preference even if the subject elderly person had own teeth. As indicated by the old Chinese idea, “Ishoku Dogen” (The same principles underlie a normal diet and medical treatment.), it goes without saying that food is important because of controlling our lives. However, anticipating from the results obtained in the survey on vivid elderly persons, it would appear likely that some unknown factors rather than “Food” might be involved in the association between teeth and health. As was mentioned by Professor Tonegawa, a Novel prize winner, discovery of divergence and inconsistency between the existing common sense and actually observed data provides us with exciting pleasure. Once such a discrepancy is scientifically investigated, we sometimes come across unexpected facts which cannot be excavated by the common senses. This survey was primarily started to get the answer to the simple question “Whether the vivid elderly persons have own teeth or not”. Suppose that the results obtained show clear difference in consumption amount of nutritious food as the keyword to bridge the causal relation which is consistent with the conventional dental common senses, dental specialists including me would have completed our activities at the stage of analysis of the dental conditions in the vivid elderly persons as the minimal obligations of us. (References 53, 54, 61) However, the actual findings were quite different from the common senses.So, another question comes to our mind as to how teeth are associated with health. There might be unknown systemic effects of teeth, which cannot be explained by simple classical interpretation such as “Teeth are only a part of digestive tracts and good teeth can digest food well….” Teeth surely have unknown functions except for “Food ingestion”. Such an additional function was not reported at that occasion. I became curious about “Sexual charm” possessed by the vivid elderly persons I met during the examinations. Researchers including me are really greedy. When any darkness indicative of a question appears in front of us, we cannot help but clarify it by shedding a light on it. In the meantime, I entered into a deep jungle of unknown field step by step. “Why?” “What on earth connect teeth with systemic health except for eating food?”As explained before, this study project was interdisciplinary one with a global reputation, and therefore, we felt as if we had various tools to cultivate the truly unexplored jungle. I promptly investigated the vast amount of internal medicine and exercise physiological data base concerning individual vivid elderly person, which was already input in a computer to pursue the correlation between teeth and systemic functions. As the results, I noted the two characteristics. One of them was my recognition of the correlation between favorable chewing ability and secretion of saliva. Interestingly, however, there was no relationship between favorable chewing ability and the residual number of teeth (current number of teeth). At first, I could not help wondering “Why?”, and then, I doubted miscalculation for the analysis; however, repeated recalculation demonstrated the same results. Presence of teeth is indispensable for favorable chewing. Therefore, it is quite reasonable for us to consider as if residual situations of teeth might be consistent with favorable chewing ability. However, some cases suggest inconsistent findings. For example, suppose there are 10 teeth in the lower jaw and 10 teeth in upper jaw, 20 teeth as residual teeth in total in a certain elderly person. Six lower anterior teeth are located close to the orifice of the salivary gland and therefore, most of the subjects have them for relatively a long period. Accordingly, there are various combinations of the residual teeth, comprising the remaining 4 teeth in the lower jaw and 10 teeth in the upper jaw; in more details, some cases represent colossal disharmony between upper and lower jaw despite of teeth being remained; other cases have good dental occlusion without back teeth resulting in unsatisfactory chewing ability. From the viewpoint of teeth functions, namely “Whether this example subject can chew food or not”, quantitatively 20 teeth are available in total but the quality of their functions are complicated and different. In fact, this complexity implies the mystery of “Hazo” theory.Secondly, we must point out the correlation between teeth and the balance function of the body which can be assessed by the tests on both teeth functions and the persisting period of time under standing on one foot with both eyes closed. I wish to refer to this test in details in the Section 2, Chapter II. From the next Section, I would like to discuss the relationship between teeth and saliva. In the meantime, you need to cool off for the time being because specific and scientific subjects were dealt with in the previous Chapters. For that purpose, I wish to introduce the testimony of a 75-year old woman who attained vivid lives after healthy recovery of teeth.
After completion of Dr. Muratsu’s treatment on March 2, 2000, Dr. Muratsu congratulated me by saying “You held out to the end of the treatment.” I shouted “Wow, I did it!” I underwent treatment for about 1 year while I was not certain I could continue it because of my age. However, Dr. Muratsu and his staffs gave me hearty and thoughtful treatments for over 4 hours in a certain treatment whereby I was so much impressed with their eagerness. Now, I feel that time passed so quickly. Throughout treatments, I became well and I was very much surprised in alleviation of the previous symptoms, together with vivid feeling, active attitudes to daily works, warm feeling of my limbs in my bed and sound sleep at night.I really agree with Dr. Muratsu’s comment “Teeth are our organs.” Thank you very much. I wish to keep contact with Dr. Muratsu from now on to store my precious assets, my teeth. (A 75-year-old woman, Fukuoka city)



■Figure 6
Two-dimensional distribution about consumed foods by the vivid elderly persons
The pattern irrespective of the gender is characteristic of the plain meal type, being indifferent from the food patterns shown by the general aged people. (Reference 27: K. Ito, et. al.)

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.)

Section 2-1. Elderly persons with adequate teeth have sexual charm.

Now, shall we review the results obtained in this “Survey on healthy degrees of vivid elderly persons” which triggered the paradigm changes of dental medicine leading me to recognize “Teeth are our organs”.First of all, I will explain the investigation methods. The subjects enrolled in the primary investigation were about 1800 elderly persons who belonged to 37 elderly clubs located in Kasuga city. Incidentally, the total population of this city amounted to 80,628 persons at that time. It is well known that 1800 persons as the subjects for investigation would be adequate for epidemiologic investigation. Out of these subjects, 86 healthy, vivid and vigorous elderly persons (58 males and 28 females) at ages from 65 to 79 years old without any subjective and objective diseases were selected by nurses with enough knowledge about local situations working for Department of Health, Kasuga city, with the cooperation of respective elderly clubs. This selection was conducted independently from healthy conditions of oral cavity. Then, detailed medical investigations were performed by internal physicians at the Health Science Center of Kyushu University whereby the persons suspected being affected by certain diseases with some abnormalities, the persons who took oral medicines within the past 3 months reaching 21 persons in total were excluded from the eligible subjects. Finally, 65 persons (44 males and 21 females, with the mean age of 71.3 years) were selected as the subjects for investigations. Figure 1 shows numbers of them according to gender and ages. In the sophisticated clinical laboratory tests and investigations, internal physicians, dental physicians, psychologists, exercise physiologists, food and nutrition scientists and health nurses carefully investigated physical and psychological health conditions of vivid elderly persons; what kinds of ways of thinking about health maintenance and way of life were held by vivid elderly persons; and life-style habits at presents, during younger generations and in the prime of manhood. In our dental fields, we carefully investigated residual conditions of teeth, dental caries, periodontal pocket as an index representing periodontal infection (alveolar pyorrhea), wobbling degree of teeth, conditions of dental occlusion, strength of dental occlusion, chewing ability, secretion amount of saliva and protein amount in saliva. Incidentally, the residual conditions of teeth in the subjects were nonbiased, indicating fair distribution from totally artificial teeth to more than 30 teeth remained (Figure 2). Such a nonbiased distribution permitted this study to be reputable. Dental examinations were performed in a certain spacious auditorium where the selected elderly subjects gathered together under the assistance with staff members working for Health Department of Kasuga city and health nurses. Several dentists examined the subjects one after another. Dentists were patient to investigate elderly men and women for a long time. While examining elderly persons, we, dentists made a funny bet. As stated above, the vivid elderly persons ranged from those with all artificial teeth to those with their own teeth. They were requested to come to the examination chair from the waiting bench but dentists could not know whether each of them has their own teeth or artificial teeth before they opened mouths. So, for a diversion, we bet each other that the next visitor would have his own teeth or artificial teeth before they came to us. Because of advanced current technologies on artificial teeth implantation, we could not correctly anticipate it initially according to local appearances around mouth or general impression such as complexion. However, after comparing 2 dozens ~ 3 dozens of subjects, we noted one interesting clue, that was “sexual charm”.To win the bet, all we had to do was to ask ourselves a question such as “Whether the next elderly person can enjoy romance if desired? or whether this person possesses sexual charm? , otherwise, “Whether the next person already graduated such a romantic stage?” When we started to evaluate the subjects from these criteria, our assumption came true. Through this bet, we have discovered the fact that the elderly persons with their own teeth have vividness and sexual charm. In this sense, the elderly persons without their own teeth were drowsy. They looked as if they were dead branches without beauty or sexual charm. Through these experiences, it was postulated that presence of own teeth possessed its significance and unknown functions which could not be identified by only outer appearances or superficial complexions but played a role in the dynamic worlds. While examining teeth of the subjects in the auditorium, concrete information about their teeth was available to us, indicating that our victory in bet was only based on our instinct; however, it was true that “sexual charm” played a significant role in them. Our discoveries in Kasuga city adequately provided us with some expectation and foresight, “Something unknown exists in teeth.” for the future outcomes to be obtained by data processing. However, if there are opposite findings obtained by this scientific etiological survey, I had a solid decision that was only in my heart, namely to discontinue the future activities in the field of preventive dentistry; as a natural consequence, my body was trembled by secret excitation during collating the examination results. The cross-road in my life was just around the corner.



■Figure 1
Distribution of the number of vivid elderly persons by gender, and ages
When ages were divided by 5 years from more than 65 years to less than 80 years, they were homogeneously distributed, indicating that the ratio of men was about 2 times higher than those of women.



■Figure 2
Distribution of the number of vivid elderly persons by residual teeth numbers
From the persons without teeth to the persons with more than 30 residual teeth, the number of persons by each 10 teeth or 5 teeth was homogeneously distributed, indicating no bias.

Section1-3. Survey on healthy degrees of vivid elderly persons

The formal name of the survey on vivid elderly persons was “Survey on healthy degrees of vivid elderly persons”. This was an epoch-making challenge to explore the know how of elderly health scientifically by the cooperative investigations by the Health Science Center of Kyushu University, and Kasuga city, Fukuoka prefecture. For the purpose of making the enrolled elderly persons understand the objective of this survey, the mayor of Kasuga city sent the address upon publication of the Summarized report (Reference 27) on this survey in March 1994. For your reference, this report shall be described in the following pages.
In the modern society, various senses of values established after the World War II were collapsed while no new senses of values and new principles anticipating the 21st century have been founded, indicating that we are facing a big turning point. Under these situations, our generations possess the important mission to convey the bright and hopeful local society to the future. Incidentally, the 21st century is characterized as the ultra-aged society and therefore, “To keep healthy” is one of the key words. However, it is a current situation not to achieve clear positioning of the definition of “Healthy”. It seems to me that “Healthy condition” not only means the situation without affected diseases but also implies “Vividly spend daily lives” under co-existence with diseases with positive association with the local society. It goes without saying that all of us wish to be physically healthy but we can say that “To produce vividness”, one step advanced from simple “To keep healthy” might be one of the new principles toward the 21st century.In this meaning, the Survey on healthy degrees of citizens cooperatively conducted by Kasuga city and the Health Science Center of Kyushu University made the challenge to clarify the long-lasting theme beyond the notion of “Healthy conditions” as to what is the factor to bring about “Vividness”. The report describes the survey results including “Correlation of elderly persons with teeth” which might bring the findings to the world-wide attention as well as lots of creative recommendations.We appreciate many expert doctors for their kind cooperation to preparation of this survey report, and we sincerely hope that various recommendations proposed by this report would contribute to not only planning of the measures for producing healthy conditions but also employment as the references to the relevant organizations.
As written in the forward by Mayor of Kasuga city, interesting characteristics of this survey existed in evaluating the whole health conditions of citizens including “Vividness” “Vigorousness” which cannot be assessed by digital valuables, rather than measuring health by hematological data and cardiac function data which are usually employed for conventional medical studies. From this survey, we intended to learn from vivid elderly persons how people should spend their young days including physical behaviors and life-style related customs if we wish to live in the ultra aged society in the 21st century as favorable elderly persons. The survey project team consisted of mainly the stuffs of the Health Science Center of Kyushu University and other specialists in the related fields associated with human health from other universities and other faculties of Kyushu University. They were internal physicians, psychiatric physicians, exercise physiologists, food and nutrition scientists, statisticians, nurses and I. I was responsible for investigation about teeth and oral cavity fields as a dental physician. To tell the truth, however, some difficulty awaited me before my participation in this study. It took a long time before our professor admitted my cooperation to the new project which would be controlled by other departments even though these departments belonged to the same university. Repeatedly I explained the significance of my involvement while the leader of the new project was asked to meet with our professor and finally I was permitted to join the project. Within the frame work of a university called as the ivory tower, participation in any studies against the professor’s will threatens the career ascent in the university organization or sometimes spoils the current position as a researcher. Nevertheless, I wanted to be involved in that survey because of not doing the study for the study but strong desire to work as one dental physician or a health scientist for the benefits of general publics. Accordingly, I was quite out of self protection and I had neither hesitation nor anxiety.At that occasion, I could not anticipate that subsequent progress of this survey would knock the door contributing to opening the bright future of humans. I felt as if solution of one simple question raised another question to be answered by the survey, like striking a precious vein in uncultivated areas. This is the most pleasant occasions for any scientists. Frankly speaking, I was so much excited despite of various difficulties to go forward with this study in unexcavated fields where conventional medical common sense was useless. The histories of such fundamental studies and the relevant scientific data shall be introduced in the following sections.The contents covered from the next Section to Chapter II, Section 1 are described in somewhat specialized technical modalities, which can be compared to the most grueling part of the course; however, after running this hot-corner, you will find a flat plain comprising anecdotes based on actual examples of some patients. Therefore, you are kindly recommended to work your way through this book. Sometimes people stick to a fixed idea and cling to it. Accordingly, you must get the key, called as “Science” to open the closed common senses followed by investigation of its contents even if you feel it difficult. This is the reason why technical figures and tables filled with technical terms are included in this book to maintain its scientific features although this book is not a medical thesis but a book of general interest.

Section1-2. Are teeth necessary or unnecessary?

Mr. Y was a junior fellow in Karate Club during my university days. Mr. Y was studying in the postgraduate school, Kyushu University and lived in the same apartment with me. He was a Karate player but at the same time, he was so much interested in “Kiko (A traditional Chinese health-maintenance method)”. One day, he asked me “Why do not you come with me to go to Osaka where a famous Kiko player will visit there? Shall we learn Kiko from him?”. I promptly agreed with him and went to Osaka with him. After Kiko lesson, we decided to drink alcohol with my friends who went to Osaka together with me. At that occasion, an associate professor of Health Science Center, Kyushu University happened to be with us in a drink bar. This associate professor, an internal physician, was a leader of “the Survey on healthy degrees of vivid elderly persons” to be cooperatively performed by the Health Science Center of Kyushu University and Kasuga city. At that time, I heard about this study project for the first time. I was so much interested in the quite new approach and comprehensive view of this project.Automatically, I asked a question. “Although dental fields should be included as a natural consequence because this is characterized as the comprehensive study on humans, who is responsible for this?”To my surprise, he muttered shortly “What?” I said once again, “Are dental studies not included? As far as this study is aimed at the comprehensive survey on humans and most of University has Faculty of Dentistry, I am sure that the dental study is indispensable for this study project.”He said “You are correct. Do you join us to do such a dental study? And, I was suddenly requested to participate in this project.Initially, the original plan about “the Survey on healthy degrees of vivid elderly persons” did not include dental investigations. We might say that such a negligence of dental fields clearly represents the blank point of the (theoretical framework) of the modern medical paradigm. Even a most advanced health scientist and internal physician characterized with possessing high degrees of specific knowledge forgets about presence of teeth upon planning the comprehensive survey project on humans. Probably, he might have thought that loss of teeth provides us with inconvenience but does not affect the systemic health.It is conceivable that since isolation and independence of Faculty of Dentistry from Faculty of Medicine, incorrect recognition about teeth has been augmented more and more. In other words, there is a kind of territorial imperative, indicating creation of habitat segregation. Accordingly, the concept “Everything about teeth should be entrusted to dentist.” has been entrenched, while the subjects related to teeth and oral cavity have been disregarded in the teachings for medical students and the state-sanctioned examination for providing medical license. As the result, physicians who are responsible for recognition of the whole body have little information about teeth. In parallel with removal of dental department offices from hospitals detached to universities, concepts about “teeth” have been dropped from considerations about possible causes of systemic disorders.On the other hands, dentists insist that systemic diseases should be treated by physicians, resulting in limiting their interest to local abnormalities in oral cavity including treatment of dental caries and alleviation of alveolar pyorrhea. Human bodies are not the mere aggregation of respective parts but are regarded as a small universe in which all the organs in bodies beautifully cooperate each other and are harmonized. No one is permitted to separate teeth and oral cavity from the systemic recognition based on extremely selfish speculation of humans. Worst-hit victims are the patients because diseases which are totally curable cannot be cured. These situations represent the most important drawback for the modern medicine whereby lots of diseases with their causes unknown still remain untouched despite of such a striking advance of modern medicine. It might be devils in human form that removed dental recognition from the systemic systems for the first time and implanted the seed of structural defects in progress of medicine on the earth. The objective of this book is to clarify such a defect by means of scientific and clinical approaches while the afore-mentioned survey project included the serious drawbacks therein unselfconsciously.
In a drink bar, I was asked to join the project “Survey on healthy degrees of vivid elderly persons” in by its project leader whom I have not met before. Promptly, I thought “This survey might provide me a certain answer to my pending question “Doctor Muratsu, I can bite any food” declared by that old woman; in more details, I felt an expectation that the eternal theme in the dental medicine “Are teeth indispensable or not?” could be answered to some extent. If there are any evidence that the elderly persons who spend vivid daily lives have adequate number of teeth is obtained in the survey, there is a possibility that teeth are actually involved in maintaining health of the aged persons. On the contrary, however, unless there remain any teeth, we must conclude that teeth are not indispensable for longevity, and vivid daily lives of them even if we anticipate ideally necessity of teeth. In such cases, we can say that substitution of the lost teeth with artificial teeth can regain systemic health and vivid daily lives, even if we lose own teeth unfortunately. As the extension of this consideration, all we need to do is to perform dental prevention if time is permitted, besides our precious time being used for other hobbies and the like.I intuitively recognized the possibility that this “Survey on healthy degrees of vivid elderly persons” will give us precious indication and orientation for both dental medicine and preventive dental medicine. Frankly speaking, immediately after I met an old woman of the English teacher, I started literature surveys on significance of teeth on our whole body. However, there was no description about significance of teeth particularly toward systemic functions except for description about chewing functions. Few literatures were available but they were not written systematically. In other words, the issue I was pursuing was of complete darkness. Among the limited literatures, a certain report depicted the findings that following ingestion of rice either without chewing or with chewing, its digestion and absorption was not different, indicating that this report completely ruled out significance of teeth. Of course, teeth have their own roles in eating, talking and cosmetic significance. These features are well understood even by primary school children.Under the canopy, “Are teeth necessary or unnecessary?”At that occasion, I made myself a promise that if these vivid elderly persons had teeth, I would continue preventive dental medication. I believed that some not-yet clarified significance might exist in such facts. However, unless vivid elderly persons had any teeth, I should overcome my regret to preventive dental medicine and focus my future efforts on prosthetic restoration to prepare well-designed artificial teeth. Simultaneously, I must recommend people to pay attention to your whole bodies rather than to make teeth care. This really implies an EBM (Evidence-based medicine). I started my own study after such a commitment to myself. In other words, “Survey on healthy degrees of vivid elderly persons” was the study to mark a watershed for my life-long decision. Now looking back upon the unexpected encounter of me with “Survey on healthy degrees of vivid elderly persons”, it seemed to me that this happened by coincidence but I was still wondering if the inevitable features of this encounter might be led by unusual turn of destiny.

Section1-1. “Doctor, I can bite any food!”

Unintentional word sometimes decides a human life. Now looking back upon the past events, one word of an old woman with teeth lost “Dr. Muratsu, I can bite any food!” stimulated my desire to study vivid elderly persons.After my completion of the graduate school courses, I moved to Texas University Life Medical Institutes and then, studied the concept about “Latent disease status” (Appendix － References 44~51) which implies that apparent healthy appearance would not necessarily represent actual health conditions. Following return to Japan from the USA, I worked as an assistant teacher appointed by the Ministry of Education for the Preventive Dentistry, Detached Hospital to Faculty of Dentistry, Kyushu University. Now that I obtained the new concept, some changes were raised in my way of thinking concerning prevention of teeth disorders. More frankly speaking, it might be better to say that my eyes have been more widely opened to gaze at the truth. As the results, I can view from the different ways the already-established stereotyped concept which has been accepted as “quite natural” without any doubt on it.One day. I visited a teacher’s home to report my safe return from the USA. Incidentally, he had kindly given me a special lesson for English conversation before my departure to the States. He lived with his grand-mother at more than 70 years of age. She was very well with good complexion. However, I found that she had a full denture but to my surprise, she told me “Dr. Muratsu, I can bite any food”.Unless I had studied in the States, I would probably have disregarded this word but in the face of this elderly woman, one simple question came to my mind because I came back to Japan after study on the concept about “Latent disease status”. The questions were “This woman looks very well but is she really healthy?” and “Are teeth really indispensable for humans?”Incidentally, preventive customs to maintain healthy conditions including “Tooth brushing” include various items covering from jugging to ingestion of health-food. Nevertheless, within the limited framework of a day, we cannot afford to do everything. Therefore, in compliance with the preventive principle “To the most dangerous lesion, the most effect measure should be applied.” we must select the most practical method among the candidate procedures and implement it. Irrespective of good or bad, the obtained influence would be significant because such a method is customarily repeated every day. Based on such a preventive principle, I have so far enlightened people for their performing the preventive measures in favor of teeth including tooth brushing, while believing in the theory “To retain own teeth is important.” as a health scientist or a preventive dentist.Contrary to my belief, the said woman with a full denture was very well and she declared that she could bite any food. This was really a shock to me because I had studied preventive dentistry and then entered the postgraduate school. I might say, my mind went blank all of a sudden. When I turned my eyes to my family, my grand-mother with a full denture lived without her own teeth. I was puzzled with these examples, besides believing in “Teeth are important” but this concept was only a theoretical one which was not supported by any actual survey or scientific data. Since an old saying tells us “There are no unnecessary things under the heaven.” and loss of teeth induces difficulty in eating food, people simply consider “Teeth might be necessary.” In recent years, a term of TBM (Evidence Based-Medicine) has been extensively used in many fields and its significance was noted; however, the scientific and medical grounds to support “Importance of teeth and its significance” have not been clarified. Accordingly, such ignorance is responsible for easy grinding of teeth or pulling out of teeth.“Human beings do not need teeth?”“Without teeth, do we feel only inconvenience for eating food? No teeth provide no disorder to our health?”“Even if we lose own teeth, is it all right for us to do well by using a full denture?”Almost 60 years have passed since the end of the World War II. During such a long period of time, dental medicine has progressed significantly. However, we come across this unique question which has been disregarded by dental specialists and dentists because of its too simple features. Scientific clarification of this question seems to be the eternal theme for the dental medicine field. I faced directly such an eternal theme which comprises the starting point for the dental medicine.In the similar question “To be or not to be, that is the question” raised by Hamlet, “Are teeth necessary or not?” and “Dr. Muratsu, I can bite any food.” mentioned by that old woman triggered my agony as a scientist dealing with health problems. In more detailed health-scientific explanation, I was wondering which the truth is, either “Teeth are regarded as only a part of chewing organ. Loss of them is associated with only lowered chewing function but no influences are given to systemic health conditions and biological mechanisms.” or “Teeth are indispensable for the whole body health rather than playing a role in chewing food. Teeth are involved in certain bio-mechanisms. The said old woman would appear healthy at a glance whereas she might have latent disease states both in mental and physical conditions thereby having lowered vital functions.” This question once again haunted under the unexpected situations later.