Masticatory Function and Physical/ Mental Activities

(1)The study investigated the relationship between masticatory function and dementia，grip strength and finger skills in elderly persons。The subjects‘were 80 elderly persons(male 34，female 46，average age：80.4 years)residing in a nursing home and geriatric hospital。Dementia was measured by the Hasegawa‘s Dementia Rating Scale：fingertip skill by the pegboard test using small disks，small balls and pins；grip strength by the Smedlay’s dynamometer for children；and masticatory function by a food intake questionnaire。The correlation coefficient between dementia and masticatory scores was statistical significant(p&lt；0.01)at 0.52，for finger skills and masticatory score the correlation coefficient was 0.39 which was also statistical significant(p&lt；0.01)。However，there was no statistically significant correlation between grip strength and masticatory score。Grip strength and finger skill scores were all lower in person not wearing denture(p&lt；0.01)suggesting that these tests ma…More y have some use as measures for predicting elderly person‘s ability to function with complete dentures。The results of this study suggest a close relationship exists between masticatory function and some measures of physical and-mental activity in this group of elderly subjects.(2)To investigate tongue motor skills and age-related changes in motor behavior，upward and downward tongue movements regulated by a metronome under centric occlusion were recorded by ultrasound diagnostic equipment with a5 MHz electronic convex sculated and the metronome under centric occlusion were recorded by ultrasound diagnostic equipment with a5 MHz electronic convex sculated of and masticatory function and some measures of physical and and.The results were as follows：1)The system provided a useful method to evaluate tongue motor skill with sound signals，showing clear images of the tongue surface and its movements.2)The rhythm of tongue movements in older persons varied more than in younger persons.3)The velocity in the upward and downward movements decreased，statistically significant(p&lt；0.01)，in the older group 4time the betor and the fouignifed and the fulsignificant(p&lt；0.01)，in the older group 4time time the the wate and the wate and the wignificant；the results were as follows：1)the system provided a useful method to evaluate；0.01)and their variations wider in the older group.5)The study shows age-related changes in tongue motor behavior.(3)To elucidate the mandibular morphological changes due to masticatory/occlusal pressure in addition to aging，old rats(88weeks)were used in the experiment。In the experimental group，all the upper and lower molar teeth had been removed at32weeks and fed the soft diet contained the same commponents with solid one after that。On the other hand.The control group had been feeding solid diet without substantial loss until 88weeks。The mandibulae of two groups were compared by using X-ray images，scanning electron microscope and contact microradiograph。The results showed the changes of condyle shape，bone density at coronoid process and histological changes at condyle and the attachment regions of masseter muscle.These findings suggested that the bone remodeling in mandible and the structure of temporomandibular joint of old ruts were influenced considerably by occlusal and masticatory alterations.Less：Less

(1) The study investigated the relationship between masticatory function and dementia, grip strength and finger skills in elderly persons. The subjects' were 80 elderly persons (male 34, female 46, average age : 80.4 years) residing in a nursing home and geriatric hospital. Dementia was measured by the Hasegawa's Dementia Rating Scale : fingertip skill by the pegboard test using small disks, small balls and pins ; grip strength by the Smedlay's dynamometer for children ; and masticatory function by a food intake questionnaire. The correlation coefficient between dementia and masticatory scores was statistical significant (p<0.01) at 0.52, for finger skills and masticatory score the correlation coefficient was 0.39 which was also statistical significant (p<0.01). However, there was no statistically significant correlation between grip strength and masticatory score. Grip strength and finger skill scores were all lower in person not wearing denture (p<0.01) suggesting that these tests ma … More y have some use as measures for predicting elderly person's ability to function with complete dentures. The results of this study suggest a close relationship exists between masticatory function and some measures of physicalーandーmental activity in this group of elderly subjects.(2) To investigate tongue motor skills and ageーrelated changes in motor behavior, upward and downward tongue movements regulated by a metronome under centric occlusion were recorded by ultrasound diagnostic equipment with a 5MHz electronic convex sector scanning probe and a physiological signal unit connected to a heart sound microphone in a younger and an older group of subjects. The results were as follows :1) The system provided a useful method to evaluate tongue motor skill with sound signals, showing clear images of the tongue surface and its movements.2) The rhythm of tongue movements in older persons varied more than in younger persons.3) The velocity in the upward and downward movements decreased, statistically significant (p<0.01), in the older group.4) The time lag between the sound signal and the start of touching the palate and floor was longer (p<0.01) and their variations wider in the older group.5) The study shows ageーrelated changes in tongue motor behavior.(3) To elucidate the mandibular morphological changes due to masticatory / occlusal pressure in addition to aging, old rats (88 weeks) were used in the experiment. In the experimental group, all the upper and lower molar teeth had been removed at 32 weeks and fed the soft diet contained the same commponents with solid one after that. On the other hand. the control group had been feeding solid diet without substantial loss until 88 weeks. The mandibulae of two groups were compared by using X-ray images, scanning electron microscope and contact microradiograph. The results showed the changes of condyle shape, bone density at coronoid process and histological changes at condyle and the attachment regions of masseter muscle. These findings suggested that the bone remodeling in mandible and the structure of temporomandibular joint of old ruts were influenced considerably by occlusal and masticatory alterations. Less