Cephalometric evaluation of posterior airway space in Chinese and Egyptian races

The aim of this study was to evaluate the size of posterior airway space (PAS) and hyoid bone position in Chinese and Egyptian races in both genders using cephalometry. Lateral Cephalometric X-ray were collected from 195 healthy young adults (96 Chinese subjects and 99 Egyptian subjects). Twenty cephalometric measurements (linear and angular) of the nasopharynx, oropharynx, hypopharynx, tongue, and hyoid bone were recorded. Considering gender, according to the ANB angle, the subjects were classified into three types of skeletal malocclusion: class I (1° ≤ ANB ≤ 3°), class II (ANB > 3°), and class III (ANB < 1°). Probability (P) ≤ 0.05 was considered statistically significant. Confident intervals of 95% were used and P < 0.05 was considered to represent statistically significant differences. Significant differences were founded in (PNS-V) (P ≤ 0.01), (TT-V) (P ≤ 0.05), ([Hy-Me-MP] [P ≤ 0.01] [Hyoid–MP-Prep] [P ≤ 0.05] [Hy-C3] [P ≤ 0.01] and [Hy-S] [P ≤ 0.05]), and (PNS-U) between Class II and Class III (P ≤ 0.05) in Chinese group. Significant differences were founded in (TT_FH) (P < 0.001), (Hy_RGn) (P < 0.001), Hyoid bone and C3 (Hy_C3) (P < 0.05), (DeepPharyxatPog) (P < 0.05), and (Hy_C3) between Class I and Class II (P < 0.05) in Egyptian group. There is no direct clinical implication of this study. However, the study shows a reference of the average size of PAS in both genders of Egyptian and Chinese races. Gender showed a significant influence on the PAS dimensions in both Chinese and Egyptian individuals. Sexual dimorphism may account for larger airway dimensions and hyoid bone geometry in both Chinese and Egyptian males.