Comparison of craniofacial characteristics of typical Chinese and Caucasian young adults.

The purpose of this study was to determine the cephalometric norms of typical Chinese young adult subjects with normal occlusions and well-balanced faces and to compare these norms with those derived from a matched Caucasian sample. Lateral cephalograms of 65 untreated Chinese adults (25 males, mean age 19.3 ± 3.0 years and 40 females, mean age 20.3 ± 3.4 years) were compared with a sample of 90 untreated Caucasian adults (30 males, mean age 24.1 ± 5.7 years and 60 females, mean age 22.9 ± 5.2 years). Each lateral cephalogram was traced and digitized, and conventional cephalometric analyses were applied. Independent sample t-tests were used to compare the values between the two ethic samples. Smaller midfaces and shorter mandibles were observed in Chinese young adults compared with those of Caucasians. The average value of lower anterior face height (ANS-Me) was longer in the Chinese females than that in the Caucasian females (P < 0.001). A greater vertical dimension also was seen in Chinese males compared with Caucasian males when evaluated by analysis of the facial axis angle (P < 0.05). The upper and lower lips were more protrusive in the Chinese, and a more convex facial profile was seen compared with the Caucasian sample. Significant differences in hard and soft tissue characteristics were found between Chinese and Caucasian young adults with normal occlusions and well-balanced faces. Gender and racial/ethnic differences must be taken into consideration during orthodontic diagnosis and treatment planning for the individual patient.