[Structural features of submandibular glands in the elderly].

The purpose of this research was to clarify the structural features of submandibular glands in the elderly. Submandibular glands were removed from 28 cadavers (59-96 years) which dental students had used for anatomy practice. These specimens were fixed again with 10% formaldehyde, and then paraffin sections were made from these specimens according to a general method. After Hematoxylin Eosin, Mason-Goldner, Elastica von Gieson, and Alcian Blue staining had been given, these sections were observed with a light microscope. The specimens of the elderly whom the author had used in this research were divided into two groups of the higher elderly (80 years old or more) and the lower elderly (less than 80 years old). The results were as follows: 1) Intralobular and interlobular connective tissues increase in the submandibular gland of the higher elderly. 2) The epithelial cells of the striated portion become short in the higher elderly. 3) As for the epithelial cells of the interlobular ducts, strong Alcian Blue positive reaction is observed in the higher elderly. 4) The terminal portion by which a typical form is shown decreases in the higher elderly, and the number of terminal portions decreases, too. In addition, the terminal portion generally becomes small, and the tendency of extension of the glandular cavity is observed. 5) In the lower elderly, glandular cells which react to various levels of Alcian Blue exist. Such cells are distributed almost uniformly in the lobules. However, it seems that the Alcian Blue positive cells of the higher elderly decrease. 6) It seems that these structural changes of supportive tissue, duct system, and terminal portion in the submandibular gland of the higher elderly are structural features, suggesting that the secretory function decreases.