RESUMEN
The 2nd to 4th digit ratio (2D : 4D) reflects exposure level of sex hormones in fetal period and there are various methods for finger length measurement. The aim of this study is to identify an accurate and effective method for finger length measurement. This study was done on 272 individuals (115 males, 157 females). Data were collected by measuring index and ring finger length on both hands by calipers, ruler, photocopy, and radiography. The data were analyzed through independent t-test, paired t-test, Pearson correlation analysis using SPSS win 19.0. This study showed that the 2nd and 4th finger measured by radiography were the longest finger both of males and females and revealed the largest length difference between 2nd and 4th finger. There were significant sex differences all of 4 measurement methods in 2D : 4D, especially remarkable sex difference by radiography and photography. The 2D : 4D by indirect measurement was lower than that of direct measurement. Correlation between digit ratio by radiography and by photocopy was 0.590 and correlation between digit ratio by radiography and by calipers was 0.586. The results of this study suggest that indirect measurement by radiography can be alternated by photocopy primarily and by calipers secondarily.