Epiphyseal union of the anterior iliac crest and medial clavicle in a modern multiracial sample of American males and females.

Epiphyseal union of the anterior iliac crest and the medial clavicle is examined in 605 males and 254 females in a sample of modern Americans aged 11-40 years. The sample includes American whites, American blacks, Latin-Americans, and Orientals. This is the first skeletal investigation using a large sample of individuals of known age since the McKern and Stewart study of 1957. Epiphyseal union is analyzed in terms of four stages: 1) nonunion with no epiphyses, 2) nonunion with separate epiphyses, 3) partial union, and 4) complete union. The results provide broader age ranges for the stages of union than previous studies. Age ranges for males and females are similar or vary by only 1-2 years. Racially, no major distinguishing patterns are found except for greater variability in age distributions appearing to exist among American black females. The study furnishes valuable data on epiphyseal timing in the teenage years.