著者

植田 英澄

出版者

九州歯科学会

雑誌

九州齒科學會雜誌 : Kyushu-Shika-Gakkai-zasshi (ISSN:03686833)

巻号頁・発行日

vol.38, no.4, pp.629-653, 1984-08-25

被引用文献数

3

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Difference by sex in human tooth was investigated with regard to the followings : size of the upper central incisors, cuspids, first premolars, and upper and lower first molars ; measurement of each part of the occlusal surface of the upper and lower first molars and upper first premolars ; hardness of the hard tissue and measurement of the hard tissue and dental pulp chamber of the upper central incisors, cuspids, and first molars. The results were as follows : 1. Men showed greater measurement for every item than women. The greatest difference was seen for the upper cuspids and first molars. In contrast, the difference was slight for the upper central incisors and first premolars. The greatest difference by site was in the longitudinal length and the least difference was in the crown width. 2. Of the measurements of the upper and lower first molars, inter cuspal peak distance and occlusal surface area were significantly greater in men than in women. However, little difference was seen for talonid as compared with trigonid of the lower first molars. 3. Microhardness of the hard tissue of tooth was higher in men than in women. That is, enamel was harder in men than in women for all of the upper central incisors, cuspids, and first molars, Similarly, dentin showed greater hardness in men for all the measured items. The crown showed higher hardness than the root, and the hardest site in the crown was at about 300-500μm deep from the enamel-dentin border. Hardess of cementum was considerably lower than that of enamel and dentine. Men showed higher values than women for the upper first molars, but very little difference was seen for the upper central incisors and cuspids. 4. Although little difference by sex was seen in thickness of enamel, women tended to show higher values. This suggested that attrition and abrasion are greater in men than women. No difference at all was seen in dentine thickness for the upper central incisors. For the upper cuspid and first molars, no great difference was seen, although significant diffirence was seen in part. Thickness of cementum showed no difference for the upper central incisors and first molars. Thickness was significantly greater in men than in women for the upper cuspids. 5. Size of the pulp chamber showed no difference for the upper central incisors and first molars. For the upper cuspid, only the labiolingual distance of the pulp canal was significantly greater in men than in women.