Evaluation of skeletal maturity score for Korean children and the standard for comparison of bone age and chronological age in normal children

Background: The growth assessment of bone age (BA) is an essential feature in diagnosing various diseases in children. In the clinic, the Tanner and Whitehouse (TW3) method and the Greulich-Pyle (GP) method are used to estimate bone age. Because those methods were developed for foreign children, it is necessary to evaluate the applicability of those methods to Koreans. Objectives: This study was designed (1) to compare the skeletal maturity score (SMS) in Koreans to the SMS in foreign children, and (2) to establish a correlation between the BA and chronological age (CA) on the basis of gender and age in normal Korean children. Material and methods: We estimated the SMS and BA for 378 healthy children (141 boys and 237 girls) who visited the pediatrics clinic in Ewha Womans University Mokdong Hospital (Seoul, Korea) from 2000 to 2009. The SMS and BA were estimated using the TW3 and GP methods. Results: The SMS in Koreans was higher than in foreign children, and on average, the BA measured by both methods was higher than the CA. The correlation between the BA and CA were different according to gender and age. Conclusions: We suggest that there are differences between the SMS in Korean and foreign children and between the BA and CA. Therefore, the results can be used in evaluating the skeletal maturity of Koreans, and a correlation between the BA and CA would be a useful reference in diagnosis.