| Summary: | 碩士 === 國立臺灣大學 === 牙醫學系 === 83 ===
To study the craniofacial structures for Chinese population in Taiwan and establish their cephalometric standards, lateral cephalometric roentgenograms of 863 subjects including 422 males and 441 femals were selected from the files of School of Dentistry, College of Medicine, National Taiwan University. There subjects met the requirements of acceptable occlusion, acceptable facial profile, and absence of previous orthodontic treatment. The subjects aged from six to eighteen were grouped annually for both sexes, and also grouped into four stages corresponded with those of the students in junior primary school (6≦X<9 years old), senior primary school ( 9≦X<12 years old), junior high school (12≦X<15 years old) and senior high school (12≦X<19 years old)respectively. The cephalometric roentgenograms were traced by standardized tracing method. Seventeen cephalometric landmarks of each cephalometric tracing were transfer to computer by digitizer, and 51 variables were measured in the computer. Each item of the measurements was treated statistically to obtain the means and standard deviation at each year age group from 6 to 18 years and at each school age group. The effects of growth change and sexual dimorphism on the cephalometric measurements were also evaluated.
The results of the study offer cephalometric standards which are specific to sex and age from 6 to 18 years old Chinese. The complete cephalometric analysis to evaluate the craniofacial structures of this population was performed via the five categories- Facial polygon analysis, Jaw triangle analysis. Facial and dental procumbency analysis, Facial divergency and facial height analysis and Vector analysis. We expect to evaluate the craniofacial structures via the five different viewpoints.
The effect of sex and age on the cephalometric standards for chiness population can be summarized as follows:(1)Significant difference between the males and the females existed mostly in the linear measurements. White most angular measurements and items of ratio between linear measurements did not show significant sex difference. (2) The mandible became more and more protrusive as related to the maxilla and cranial base, and tended to rotate forward with age.
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