In the present study, vertical craniofacial morphology, hyoid bone position, and morphology of the first cervical vertebra were examined on the lateral cephalometric head films of 45 female and 45 male subjects having different skeletal patterns. All of the subjects were aged 13 to 15 years old. The films were taken at natural head position, and all were divided into three groups according to ANB angle: ANB angles smaller 1°, between 1° and 5° and larger than 5°. In addition each group was also divided into two subgroups according to sex. The effects of the ANB angle and sex on the vertical craniofacial morphology, hyoid bone position, and the morphology of the first cervical vertebra were investigated by means of variance analysis. It has been found that vertical craniofacial morphology was not affected by the change of the ANB angle, and that the larger the ANB angle, the more forward the position of the hyoid bone was, and also the larger the lumen of the first cervical vertebrae became. In addition, it has been observed that there were no statistically significant difference between the vertical craniofacial measurements of the female and male subjects, and the positions of the hyoid bones of female subjects were more superior and posterior than those of male, and also that the antero-posterior dimensions of the first cervical vertebrae were larger in male subjects.

Keywords: Different skeletal pattern, Vertical cranio-facial morphology, Hyoid bone, First cervical vertebra (Atlas)