[Structual changes of the apex region of the tongue in the elderly].

The purpose of this research was to clarify the morphological changes of the apex region of the tongue in the elderly. Apexes of tongue were removed from 44 Japanese adult cadavers (64-99 years) which were contributed for dental studies at Tokyo Medical and Dental University. These specimens were fixed again with 10% formaldehyde, and then paraffin sections were made from these specimens according to a general method. After several stainings, these sections were observed with a light microscope. The results were as follows : 1) The epithelium, propria mucosae and muscle layers became thin with aging, and the boundaries between these layers became unclear. 2) The tendencies of fibrosis also became remarkable, and the arrangement and distribution of collagen fibers and elastic fibers became disordered in propria mucosae. 3) The numbers of myocytes and myofibrils tended to decrease. 4) The connective tissue which is the outer layer of nerves tended to increase. Moreover, in some nerves, the paths of each neurofibril became tangled. 5) These findings are structural features in the apex of the tongue of the elderly, involving morphological changes of layers, fibrosis, structural changes of myocytes and myofibrils, nerves and neurofibrils in this region. These changes suggest some relationships to functional disorder in motion, pain and paresthesia of the tongue.