[Comparative study on maxillo-facial components between human children and Japanese monkeys].
The purpose of this study is to find the cause of the variation of the occlusion and the shape of the maxillo-facial components in the Japanese children at the IIA stage in comparison with the Japanese monkeys. The human materials consist of lateral and P.A. cephalograms of 26 children with a mean age of approximately 4.5 years. The monkey materials consist of dry skulls and their lateral cephalograms. They are categorized into four classes: 18 juveniles, 16 subadults, 17 female adults, and 17 male adults. The factor analysis is employed in this study on 17 measurements which reveal the structure of the maxillo-facial components. The factors of the human children are like those of the Macaca juvenile and female adult. These factors show a tendency that the growth direction of the maxilla is correlated with the cranial base angle and the width of the maxillo-facial components is correlated with its depth. However, as to these factors, human mandibular measurements have a much lower factor loading than those of the Macaca. Contrary to the human, the Macaca's mandibular measurements at every stage and sex are well correlated with the maxillary measurements. These findings suggest that the variation of the human occlusion and the external shape of the maxillo-facial components should be higher than that of the Macaca.
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Department of Pedodontics, Faculty of Dentistry, Tokyo Medical and Dental University.
D000818:Animals; D044466:Asian People; D002675:Child, Preschool; D003766:Dental Occlusion; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007564:Japan; D007568:Jaw / Q000033:anatomy & histology*; D008251:Macaca; D008297:Male; D008445:Maxillofacial Development; D012737:Sex Factors; D012886:Skull / Q000033:anatomy & histology*