日本における乳歯形態の時代変化に関する研究

日本乳牙形态历史变迁研究

• 批准号: 08740678
• 负责人: 北川 賀一
• 金额: $ 0.64万
• 依托单位: Nagasaki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Encouragement of Young Scientists (A)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08740678/
• 关键词: 乳歯; 歯の大きさ; 非計測的形質; 日本; 時代変化

これまでほとんど明らかにされていない日本列島住民の乳歯の形態の時代変化を、歯冠計測値、非計測的形質の2つの面から調査した。1.歯冠計測値乳歯歯冠の全体的な大きさは在来系弥生>渡来系弥生>縄文>古墳>江戸>現代>中世の順だった。永久歯では縄文人は現代人に比べて歯が小さいことが指摘されており(Brace and Nagai 1982)、乳歯では逆に縄文人の方が現代人より大きいことが明らかになった。現代人の乳歯と永久歯の大きさを基準として比較すると、縄文と在来系弥生は他の集団に比べ大きい乳歯と小さい永久歯を持つことが明らかである。縄文系は渡来系に比べ、永久歯においても形成が早い歯(I,M1)はあまり大きさに差がなく、遅い歯(C,P,M2)ほど小さい(Matsumura 1994)。縄文系と渡来系で乳幼児期の成長パターンに差があるのかもしれない。2.非計測的形質16形質の出現頻度をスミスのMMDで分析したところ、頭蓋骨や永久歯の非計測的形質の分析と同様に、縄文・在来系弥生と渡来系弥生・古墳・中世・江戸・現代日本人の2つのクラスターの差が明らかであった。個々の形質では、縄文系に高頻度な形質はMiddle trigonid crest(dm_2)とCusp 6(dm_2)、渡来系弥生〜現代日本人に高頻度な形質はShovel shape(di^1),Enamel extension(dm^2),Delta shape(dm_1),Distal trigonid crest(dm_2),Distolingual root(dm_2)であった。渡来系弥生〜現代日本人に高頻度な形質は、永久歯でもシノドントに高頻度にみられる形質だが、縄文系に多くみられた形質は必ずしも永久歯でスンダドントに高頻度にみられるわけではない。なぜ乳歯でのみ高頻度にみられるのかは現状では不明である。

Please inform us that the current situation of breast cancer of Japanese residents is very modern, that is, the figure of non-calculation is very high, and that of Japanese residents is different. 1. To measure the size of the whole family, the whole family is from Mi Sheng, gt; Dulai, Mi Sheng, gt;, gt; and gt;. A person of letters is better than a man of letters who criticizes him (Brace and Nagai 1982) and uses his breasts to avoid a person of letters. In the department of Miyasheng, the collection of people is bigger than the others, the breasts are smaller, the breasts are bigger, the breasts are smaller, the breasts are smaller, the breasts are bigger, the breasts are smaller, the breasts are smaller, the breasts are bigger, the breasts are smaller, and the breasts are smaller. In the department of literature and literature, it is better to be born in the department of literature than to be born in the department of literature. It is better than that in the department of literature and literature, and it is better than that in the department of literature and literature. It is better than that in the department of literature and literature, and it is better than that in the department of literature and literature. It is better than that in the department of literature and literature, and it is better than that in the department of literature and literature. It is better than that in the department of literature and literature, and it is better to be born in the department of literature and literature than in the department of literature and literature. It is better than that in the department of literature, and it is better than that in the department of literature and literature. It is better than that in the department of literature and literature, and it is better than that in the department of literature and literature. It is The department of literature and literature has come to China to grow up and grow up in the early childhood. two。 The shape of the non-calculation is 16-shaped, the shape of the MMD is analyzed, the shape of the bone is permanent, the shape of the non-calculation is the same, the paper is in the department of Miyama, the middle age of Miyagi, the present generation of the Japanese, the present generation of the Japanese, the second generation, the second generation of the Japanese. Middle trigonid crest (dm_2), Cusp 6 (dm_2), Miyama (di ^ 1), Enamel extension (DM ^ 2), Delta shape (dm_1), Distal trigonid crest (dm_2), Distolingual root (dm_2). Dulai is a generation of Japanese people who have a high degree of beauty, a permanent family of Japanese, and a family of literature. they have to be in the shape of a family of Japanese. I don't know if I have a high degree of breast cancer.