[Trends in geriatric dentistry and the future--from the point of view of masticatory function]

In recent years the number of aged persons in developed countries has been steadily increasing. Tooth loss is a typical age-associated stomatognathic change, and edentulism rates in Japan have been reported to be 30%. Dentures are made to restore oral functions after the natural teeth have been lost. However, there are also many stomatognathic changes associated with aging as well as oral manifestations of systemic diseases which can make the wearing dentures difficult in elderly persons. Some of the more significant changes occur in the structure of the mucosa, the function of the oral musculature, the temporomandibular joint, the taste perception, salivary function and the nervous system. Studies on the variety of physical and psychological dynamics associated with the aging process are necessary to provide the latest treatment modalities for the aged. The mastication and dentition status in elderly persons are suggested to be closely related with many kinds of physiological functions. On the other hand, stomatognathic functions are suggested to be influenced by the health of the entire body. They are supposed to have an interdependent relationship. The maintenance and care of occlusion are essential to guarantee the quality of life for the elderly. In future, the relationship between masticatory function and physical activities, such as physical exercise, blood flow, respiration, endocrine function, reproduction etc. require further investigation.