Bone age assessment relies on normative data for which characteristics?

• A. Height percentile
• B. Age and sex
• C. Ethnicity
• D. Weight percentile

Answer: (B)

Bone age relies on comparing skeletal maturity to reference standards that are organized by two factors: chronological age and sex. Skeletal maturation progresses with age, but the timing differs between boys and girls, so the standards are separated by sex and matched to the child’s actual age. Height or weight percentiles describe overall size and nutrition but do not define the specific stage of bone development, and ethnicity can influence growth patterns to some extent but is not the primary basis for standard bone-age references. Therefore, the normative data used are specific to age and sex.