Morphological relationship between food・foodintake and the masticatory apparatus in Primates

本研究的目的是阐明灵长类动物食物/饮食习惯与口腔体积之间的关系。本次研究使用了在Dokkyo大学医学院、京都大学灵长类动物研究所、日本猴子中心保存的成人干骨。由于口腔的容量随着牙齿的磨耗而减少，所以选用磨耗小的材料。咬合后，上、下牙弓被外部薄薄的牙石蜡覆盖。下颌基部也覆盖有厚厚的牙蜡。注射是用来测量口腔容量的。对灵长类动物和其他哺乳动物的上颚形态也进行了观察。使用统计程序（Statview）对数据进行分析。日本猕猴被用来研究种内变异。日本猕猴的口腔体积有很大的种内变异。在灵长类动物中，口腔体积与最大颅骨长度呈高度相关系数，即使在表现出极端前突的狒狒中也是如此。因此，灵长类动物上颚的突出与口腔体积的增加并不直接相关。叶食性灵长类动物的上颚较深，但与其他灵长类动物相比，它们的上颚略窄。人和尼安德特人有不同的口腔形态。这可能取决于他们的语言能力。这些物种的上颚宽度比其他灵长类动物的要宽。

The purpose of this study is to clarify the relationship between food/food habit and oral volume in primates. Adult dry skeletons held in Dokkyo University School of Medicine, Primate Research Institute of Kyoto University, and Japan Monkey Center were used here. Becouse the capacity of oral cavity decrease with teeth attrition, materials with small tooth attrition are used. After occlusion, upper and lower dental arches were covered with thin dental paraffin from outside. Mandibular base is also covered with thick dental wax. The shot was used to measure the capacity of the oral cavity. Observation of the morphology of the palate was also carried out in primates and in other mammals. The data was analyzed using the program for statistics (Statview). The Japanese macaque was used to examine an intraspecific variation.An intraspecific variation was large in the oral volume of the Japanese macaques. In primates, the oral volume showed high correlation coefficient with maximum cranial length, even in baboons which show extreme prognathism. Consequently, the projection of the palate in Primates does not correlate directly with an increase in oral volume. The folivorous primates have deep palate, but they have slightly narrow palate compared with those in other primates. Homo and neanderthals have different oral cavity form. This may depends on their ability in speech. Tthe palate width in these species are relatively wider than those in other primates.