数種哺乳動物の頭蓋骨, 歯列弓および口蓋の比較解剖学的研究
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概要
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The experimental mammalian were classified by the food habit into the carnivora (old world badgers, racoon dogs, and yellow weasels), the omnivora (pigs and wild boars), and the herbivora (guinea pigs, rabbits, shika deer, and sheep). A total of 138 specimens were measured for the skull, dental arch, and palate, and a comparative-anatomical study was made. The results were as follows : 1. Although cephalic index and cephalic length-height index varied among various animals, cephalic index was larger in old world badgers and pigs, and smaller in wild boars and shika deer. Cephalic length-height index was larger in pigs and smaller in wild boars. Thus, the greatest differences were seen in the omnivorous pigs and wild boars. The fact that pigs were brachycranic and high cranic as compared with wild boars was considered to arise from the differences in their life environment. 2. Mandibular length-width index was larger in the carnivorous animals as compared with the omnivorous and the herbivorous animals. This indicates that the lateral curvature is greater in proportion to the mandibular length. 3. Maxilla and mandibular dental arch index were largest values in the carnivorous animals, and the herbivorous and omnivorous animals followed in descending order. Yellow weasels showed the largest values and their dental arch width was comparatively large in proportion to the dental arch length. Inversely, wild boars showed the smallest values with transversally narrow dental arch forms. Reciprocity between the dental arch form and skull form was fully recognized. 4. With regard to the dental arch, a comparison of the index values of the ratios between the regio anterior teeth and regio posterior teeth indicated that the proportion of the regio posterior teeth to the regio anterior teeth was greater in the carnivorous animals than in the omnivorous animals. This suggests that their food habit caused the regio posterior teeth to develop more. 5. As to the palatal form, three measurements, namely, the length, width, and height were taken. The index values among them indicated that followings : the omnivorous animals, especially wild boars, have narrow palates and their width and height are very small. The carnivorous animals have lateral curvature in the palate and the palate depth is shallow. The herbivorous animals showed about the same findings. However, guinea pigs alone have narrow palates and the length and height were relatively large.
- 九州歯科学会の論文
- 1982-06-25