Differences in dentofacial characteristics between southern versus northern Chinese adolescents

To compare the dentofacial characteristics of southern and northern Chinese adolescents.

A southern Chinese sample comprised 70 males (Mean age 12.4 +/- 0.60 years) and 60 females (Mean age 12.5 +/- 0.4 years), and a northern Chinese sample consisted of 50 males (Mean age 12.8 +/- 1.8 years) and 50 females (Mean age 12.4 +/- 1.2 years). All subjects had a Class I molar relationship with no or minimal crowding, a well balanced cephalometric profile, and no history of orthodontic treatment. Patient cephalograms were traced and digitized and McNamara's analysis applied.

A smaller midface and a shorter overall mandibular length were observed in southern Chinese, whereas significantly increased vertical dimension and a retrusive chin were noted in northern Chinese. Protrusive upper and lower incisors and a protrusive upper lip were found in southern Chinese.

There were significant differences in dentofacial morphology between southern and northern Chinese adolescents. It is suggested that separate cephalometric norms be used for patients originating from different parts of China.