著者

田辺 文枝

出版者

一般社団法人 口腔衛生学会

雑誌

口腔衛生学会雑誌 (ISSN:00232831)

巻号頁・発行日

vol.9, no.4, pp.328-337, 1960

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For the purpose to find the exact position of neonatal line in Japanese, ground sections of 475 human deciduous teeth were examined histologically. Obtained results are as follows.<BR>1. The position of neonatal line was not characteristic and showed considerable variation in each tooth type, especially on the anterior teeth.<BR>2. The variation of position would be mainly owing to the change of physiologic condion of new- erine period or of the gravity at birth. The considerable variation on the anterior teeth would be ow ng to the constitutional feature of their enamel.<BR>3. The position of neonatal line in Japanese had a trend to appear at incisal or cuspal portion of the tooth crown than the position in American or European people.<BR>4. Toot development in female showed a tendency more earlier than in male at birth-time.<BR>5. The tooth development of the children born after 1950 at birth was thought more fast than of the born at The War-Time and the soon after, but the further investigation about this result will be done.