Paiwan 族(台湾高山族)の歯列弓および口蓋に関する研究

Abstract

Oral traits of Taiwan aborigines have been a subject of interest for anthropology. Little, however, has been reported because of geographical peculiarity. Therefore, a study on the Paiwan tribe, a total of 91 subjects, 34 males from 18 to 74 (X^^-=48.1) in age and 57 females from 16 to 75 (X^^-=46.8) in age, was made on the plaster-casts for the purpose of clarifying their dental arch and palatal vault form. The results were as follows : 1. Upper and lower dental arch lengths were not significantly different between males and females. It was recognized that they were shorter in the Paiwan tribe than in the Okinawa people, the Taiwan males and the Atayal tribe, but longer than in the Ami tribe in both males and females. 2. Upper and lower dental arch breadths were wider in the males than in the females, especially significant differences were shown in upper anterior and posterior dental arch breadths and lower posterior arch breadth. It was recognized that they were narrower at anterior region but wider at posterior region in the Paiwan tribe than in the Okinawa people, wider than in the Taiwan males, and narrower than in the Atayal and Ami tribes in both males and females. 3. Upper anterior-posterior dental arch breadth index and upper posterior dental arch index were significantly higher in the females than in the males. All the items of lower dental arch indices were not significantly different between males and females. It was supposed that many people in Okinawa had parabolical dental arch form, while many of the Paiwan tribe had V-form as dental arch form. 4. Length of dental arch between central incisor and first premolar was significantly longer in the males than in the females. It was recognized that lengths of dental arch were shorter in the Paiwan males than in the Okinawa males but almost the same or a little longer in the Paiwan females than in the Okinawa females. 5. Anterior and posterior palatal heights, palatal height indices and length of sutura palatina mediana were not significantly different between males and females. It was recognized that anterior palatal height was lower but posterior was higher in the Paiwan tribe than in the Okinawa people, and both heights were higher in the Paiwan males than in the Taiwan males. 6. Palatal arch lengths were longer in the males than in the females, especially significant differences were shown for 2nd premolars, 1st and 2nd molars. It was recognized that they were shorter in the Paiwan tribe than in the Okinawa people in both males and females. 7. Palatal breadths were wider in the males than in the females, especially significant differences were shown for 1st and 2nd premolars, 1st and 2nd molars. It was recognized that they, except at the region between right and left canines, were wider in the Paiwan tribe than in the Okinawa people in both males and females. 8. Mandibular alveolar breadths were wider in the males than in the females, especially significant differences were shown for canines, 1st and 2nd molars. It was recognized that mandibular alveolar breadths, at the regions between right and left 1st and 2nd molars, were wider in the Paiwan tribe than in the Okinawa people in both males and females.