[A study on sexual differences of postero-anterior cephalometrics among Chinese in Taiwan with different occlusions]

The main purpose of this study is to investigate the characteristics of cranio-dento-facial morphology among Chinese in Taiwan with different occlusions by the postero-anterior cephalograms and to examine the differences between sexes in the cranio-dento-facial width as well as morphology. Our study comprised three hundred and seventy three patients with preorthodontic treatment records. They were divided into 12 groups with respect to the Angle's classification, sex, and age. Summarizing the differences of the various cephalometric analyses, 31 kinds of measurement, including 20 values of width dimension and 11 values of the width ratio, were employed. The results of using the Student t-test to study the sex differences of cranio-dento-facial width and morphology are summarized as follows: (1) The sexual dimorphism of the cranio-dento-facial width occurs as early as the age of 9-12. The deviation is augmented continuously with growth and, hence, it is more pronounced in adults. (2) Regardless of the class of occlusion or the stage of maturity, the cranio-dento-facial size of the male is significantly larger than that of the female. However, their cranio-dento-facial morphology is similar. (3) The sexual dimorphism of the cranio-dento-facial width dimensions is most pronounced in the zygoma, the mandibular angle and the condyles.