A Study on the Dental Arch and the Palate of Nagashima Population in Kagoshima Prefecture (1987)

Many investigators indicated that there are differences in human oral traits by race, area and sex. Therefore, this study, with the purpose of clarifing the dental arch and palatal vault form of Nagashima population, was made on the plaster-casts of 116 Nagashima males ranging in age from 16 to 32 years and 130 Nagashima females ranging in age from 16 to 35 years. 319 Kitakyushu males ranging in age from 22 to 33 years and 314 Kitakyushu females ranging in age from 18 to 32 years were selected as controls. The results were as follows : 1. Upper and lower dental arch lengths were significantly longer in Nagashima males than in both Nagashima females and Kitakyushu males. It was recognized that they were almost the same in Kitakyushu and Nagashima females. 2. Upper and lower dental arch breadths of Nagashima population were significantly wider in males than in females. It was recognized that they were significantly narrower in Nagashima males than in Kitakyushu males except at the lower canines region. They showed a little wider levels in Nagashima females than in Kitakyushu females, but no significant differences. 3. Upper anterior-posterior dental arch length index and anterior dental arch index of Nagashima population were significantly higher in males than in females. It was recognized that upper anterior and posterior dental arch indices, lower anterior and posterior dental arch indices and lower anterior-posterior dental arch breadth index were significantly higher in Nagashima males than in Kitakyushu males. Upper anterior-posterior dental arch length index and anterior dental arch index in Nagashima females showed significantly lower levels than in Kitakyushu females. 4. Upper and lower lengths of dental arch were significantly longer in Nagashima males than in both Nagashima females and Kitakyushu males. It was recognized that they were longer in Nagashima females than in Kitakyushu females. 5. Palatal heigths and length of sutura palatina mediana of Nagashima population were significantly higher at the posterior region and significantly longer in males than in females. It was recognized that anterior palatal height was a little higher in Nagashima males than in Kitakyushu males, significantly lower in Nagashima females than in Kitakyushu females. Lengths of sutura palatina mediana in Nagashima population showed significantly longer levels than in Kitakyushu population, in both males and females. 6. Palatal breadths in Nagashima males were significantly wider than in Nagashima females, but significantly narrower than in Kitakyushu males. It was recognized that they were wider in Nagashima females than in Kitakyushu females. 7. Palatal arch lengths of Nagashima population were significantly longer in males than in females. It was recognized that palatal arch length was significantly longer at the canines region, but significantly shorter at the 1st and 2nd molars region in Nagashima males than in Kitakyushu males. All the items showed no differences between in Nagashima and Kitakyushu females. 8. Mandibular alveolar breadths of Nagashima population were significantly wider in males than in females. It was recognized that they, except at the canines region, were significantly narrower in Nagashima males than in Kitakyushu males. They showed wider in Nagashima females than in Kitakyushu females.