Faced with rapidly aging society, there are no exercise training regimens broadly available in the field to increase physical fitness and to prevent life-style related diseases for middle-aged and older people. We developed interval walking training (IWT) to repeat ≥ 5 sets of a 3-min fast walking ≥ 70% peak aerobic capacity for walking (WVO_2peak)/ day intermitted by a 3-min slow walking at 40% WVO_2peak, for ≥ 4 days/wk, for ≥ 5 months. Moreover, to determine WVO_2peak on individuals and to measure their energy expenditure during even incline walking, we developed a portable calorie meter, JD Mate. Further, to instruct IWT to subjects even if they live remote from trainers, we developed e-Health Promotion System to transfer individual energy expenditure during IWT stored in the meter to a server computer through the internet and to return them their achievements with advices by trainers based on the database on >5,200 subjects accumulated by us, where we confirmed 5-month IWT increased physical fitness and improved the indices of life-style related diseases by 10-20% on average. Thus, since our system is to be run with low cost and less staff for more subjects, it would enable us to develop exercise prescriptions more fitted for individuals. We hope that the system will be broadly used for dental preventive medicine in future.

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In order to objectively evaluate masticatory function of patients wearing complete dentures, the masticatory performance and masseter muscular activity before and after treatment were analyzed.
Subjects were 10 patients who have worn complete denture for 2 to 4 years. The following selection criteria were applied: recognition of habitual chewing side, wear of a new denture with proper flange and occlusal contact over 3 months, sufficient satisfaction with a new denture by the subjective assessment (total assessment as to esthetic, speech, eating, and stability), and sufficient satisfaction with a new denture than an old denture by the subjective assessment.
The masticatory performance and masseter muscular activity of each subject when chewing gummy-jelly for 20 seconds on their habitual chewing side were recorded. As for the masticatory performance, the amount of glucose extraction from chewing gummy-jelly was measured by blood glucose testing device as the indicator. As for the masseter muscular activities, the total integral value of all cycles and the integral value per cycle, and then the average value and coefficient of variation for the cycle time of the ten cycles from the fifth to fourteenth cycle were calculated as the indicators. The results were compared between before and after treatment using a paired t-test.
The amount of glucose extraction, the total integral value, and the integral value per cycle were significantly greater after wearing new complete denture. The average value and the coefficient of variation of the cycle time were significantly smaller after wearing new complete denture.
From these results it was concluded that the masticatory function of patients needing new complete denture improved greatly after wearing new denture, and that method of measuring the amount of glucose extraction from gummy-jelly chewing can be clinically applied to evaluating masticatory function.

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We investigated the development of an objective evaluation method for comfortable occlusion and mastication by analyzing jaw movements. The main occluding area is a very important concept for evaluating the food crushing area that is mainly used during mastication. The purpose of this study was to study kinematic characteristics of condylar movements at the kinematic condylar point during biting a piece of dental stopping at the main occluding area. Five staff and students of our institute (3 males and 2 females; average age, 29.1 ± 9.0 years) participated in this study after providing informed consent. All participants had normal occlusion without any signs and symptoms of temporomandibular disorders. The participants were asked to freely bite a piece of dental stopping once. They were instructed to perform the same trial 5 times each on the left and right sides. Their jaw movements in six degrees of freedom and masticatory muscle activities were recorded simultaneously while they bit on the dental stopping. For all participants, the main occluding areas were located in the first molar region. At the start of the burst activity of the masseter muscle on the working side, the working-side kinematic condylar point reached its rearmost position significantly before the balancing-side kinematic condylar point reached its intercuspal position. At the peak of the burst, both kinematic condylar points reached their intercuspal positions more closely; however, the balancing-side kinematic condylar point reached a more superior position than its intercuspal position. This finding indicated that the masticatory force was loaded onto the surface of the temporomandibular joint. The results suggested that the kinematic characteristics of jaw movement during biting a piece of dental stopping are similar to those reported during mastication, and that biting a piece of dental stopping at the main occluding area is a useful tool for evaluating masticatory ability.

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The purpose of this study was to clarify the influence of an experimental palatal plate on the mandibular position during continuous [n] phonation and to investigate the applicability of the mandibular position for determining the occlusal vertical dimension. The first part of the study investigated the influence of an experimental palatal plate on the mandibular position during continuous [n] phonation in 20 subjects who had normal dentitions. The second part of the study investigated the influence of an experimental palatal plate on the mandibular position during continuous [n] phonation in 15 subjects who were complete denture wearers. The last part investigated the applicability of the mandibular position during continuous [n] phonation in establishing the occlusal vertical dimension in 5 subjects. The mandibular position was recorded with the aid of a mandibular movement analyzing device.
The authors obtained the following results:
1. The interocclusal distance during continuous [n] phonation of the normal dentition were not significantly different between the normal condition and either of the two experimental conditions.
2. The interocclusal distance during continuous [n] phonation in complete denture wearers were not significantly different between the normal condition and either of the two experimental conditions.
3. The mean interocclusal distance during continuous [n] phonation was 0.8 ± 0.6 mm between either of the two and was close to 0.4 ± 0.4 mm of the normal dentition value.
The results suggest that the mandibular position during continuous [n] phonation is not influenced by experimental palatal plates and is valuable for determining the occlusal vertical dimension.

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