Applicability of two commonly used bone age assessment methods to twenty-first century UK children.

• The Greulich and Pyle method can be applied to the present-day United Kingdom (UK) population. • The Tanner and Whitehouse (TW3) method consistently underestimates the age of twenty-first century UK females by an average of 5 months. • Secular change has not advanced skeletal maturity of present-day UK children compared with those of the mid-twentieth century.