台湾 Bunun 族の歯の形質人類学的研究
スポンサーリンク
概要
- 論文の詳細を見る
A series field survey was undertaken among the Bunun tribe of the Taiwan aborigines to examine their teeth characters. Investigations were conducted on 178 hard plaster models of the upper and lower jaws from both males and females of Bunun tribe. The data obtained from these investigations were compared with those of other Taiwan aborigines, Japanese and inhabitants of neighboring regions. The results were as follows. 1. The tooth size of the Bunun tribe was little different from that of the other Taiwan aborigines, but slightly smaller than that of the Japanese, especially in the mesiodistal diameter of the tooth crown. 2. The occurrence of the double shovel-shaped incisor in the upper central incisors was found in 17.9%, and this was less frequent than in Japanese. The occurrence of the shovel-shaped incisor was found in 86.2% in the upper central incisors and in 79.4% in the upper lateral incisors. The occurrence was less frequent than in the other Taiwan aborigines, but exceeded that found in Japanese and in inhabitants of Kyushu regions. 3. Caninization of lateral incisors was noted in 22.2% in the males and in 9.4% in the females in the upper jaw, and in 34.2% in the males and in 31.5% in the females in the lower jaw. The appearance was more frequent in the upper jaw than in the lower jaw, and in the males than in the females. 4. The occurrence of the distal accessory ridge found on the lingual surface of canine teeth was found in 84.2% in the upper jaw, and it showed higher appearance than in 67.9% in the lower jaw. The occurrence was almost the same rate as that of the other Taiwan aborigines and Japanese. 5. As for the occlusal surface groove pattern on the upper first premolar, the occurrence of the most basic type A was less frequent in the Bunun tribe than in the other Taiwan aborigines and in the inhabitants of the neighboring regions ; type B was more frequent in the Bunun tribe than in the others. The occurrence of the type A and type B on the upper second premolar was less frequent in the Bunun tribe than in the inhabitants of the other regions, and the occurrence of the types C, D and E was more frequent. 6. With regard to the cuspal types in the lower first premolar, the occurrence of type 2- was extremely more frequent in the Bunun tribe than in the inhabitants of Kyushu regions. This suggested that the development of the lingual cusp was very poor in the Bunun tribe. In the second premolar, the occurrence of the type 2 was found in 63.0%, and it showed that the occurrence of the second premolar was more frequent than in the inhabitants of the other neighboring regions. 7. With regard to the cuspal types in the upper molars, type 4 was found in 97.9% in the first molars. Namely, no greater tendency toward retrogression of hypocone could be noticed in the first molars of Bunun tribe. These trends were almost the same as those of the other Taiwan aborigines, but the occurrence of the type 4 in the Bunun tribe was more frequent than in the Japanese. The tendency toward retrogression of hypocone in the second molars of the Bunun tribe was stronger than that of the first molars, and consequently the occurrence of the type 4 in the second molars decreased in 27.2%. But its occurrence was more frequent than that of the Japanese. 8. The occurrence of a mesiodistally compressed crown type in the upper second molars could be observed in 24.8% of the Bunun tribe. There was no noticeable difference between Bunun tribe and the other Taiwan aborigines, but this occurrence was seen more frequently in the Bunun tribe than in the Japanese. 9. The occurrence of Carabelli cusp in the upper first molars was 16.8%, which was more frequent than that of the other Taiwan aborigines and Japanese. 10. Dryopithecus pattern (Y5) in the lower molars was seen in 46.0% in the first molars and in 2.7% in the second molars, and the occurrence of the +5 and +4 patterns increased. The occurrence of Y5 pattern in the Bunun tribe was almost the same rate as that of the other Taiwan aborigines and was less frequent than that of the Japanese. 11. The occurrence of the protostylid was 11.5% in the lower first molars. The occurrence of the 6th cusp was found in 24.7% of the lower first molars and in 12.5% of the second molars, which was almost the same rate as that of the other Taiwan aborigines and Japanese. The 7th cusp was seen in 12.7% of the lower first molars, which was more frequent than that of the other Taiwan aborigines and Japanese. The deflecting wrinkle was seen in 66.3% in the lower first molars. This occurrence was seen more frequently in the Bunun tribe than in the other Taiwan aborigines and Japanese.
- 九州歯科学会の論文
- 1985-04-25