Ethnic differences in the soft tissue profile of Korean and European-American adults with normal occlusions and well-balanced faces

Abstract

Orthodontic diagnosis typically includes comparing a patient's cephalometric measurements to standard values. Lateral cephalometric norms, however, may be specific to an ethnic group and cannot always be applied to other ethnic types. The purpose of this study was to compare the soft tissue profiles obtained from Korean and European-American adults with normal occlusions and well-balanced faces, in order to understand the ethnic differences in the soft tissue profile between these two ethnic groups. The lateral cephalograms of 60 Korean (30 men and 30 women) and 42 European-American adults (15 men and 27 women) were traced and digitized by one investigator. Ten angular measurements of facial form and seven linear and angular measurements of lip position were computed. A comparison of the slope of the forehead showed no significant differences between the two groups. The Korean sample, however, had a lower angle of nasal inclination and a higher degree of lip protrusion compared to the European-American adults. Chin protrusion of the Koreans was less prominent than that of the European-Americans. These differences between ethnic groups should be taken into consideration when formulating an orthodontic treatment plan for patients of varying ethnic backgrounds.