[Oral aging and loss of teeth]

The human oral mucosa atrophies with aging, and at the same time, loss of teeth occurs and the muscles involved in mastication weaken, leading to masticatory hypofunction. The loss of teeth in animal is serious in that it leads to death. For humans, however, dental prosthesis may aim at functional recovery. From the viewpoint of oral functional recovery, it is important to have a firm grasp of the change in the oral environment with aging. Elderly patients who complain of dry mouth may often have glossodynia, stomatitis, dysgeusia, prosthetic disorder, etc. Although atrophy of the salivary gland is mainly responsible for these disturbances, influences of complications and/or medications cannot be ignored. Secretory immunoglobulin A (sIgA) secretion in the saliva of elderly cases showed a concentration comparable to that of young subjects in their twenties and was considered to be satisfactory from the view-point of oral infection control. On the other hand, plate prosthetic wearers may have high incidence of oral candidiasis, so that in case of loss of teeth, prostheses with so-called implant dentures using artificial dental implants are regarded as physiologically preferable to conventional plate denture.