Bone age: its contribution to the prediction of maturational or biological age

The bone age of normal children was determined by both the method of Wilkins and the method of Greulich and Pyle. In boys, the mean of the difference between the bone age and the chronological age was significantly greater than zero with the Wilkins method but not with the Greulich and Pyle method. In normal children of both sexes, bone age determined by the Greulich and Pyle method proved to be an important component in equations designed to assess progress along the pathway of growth (Biological Age). These equations combine information concerning body growth, cell growth and body composition. Bone age determined by the Wilkins method, however, was not a significant component in such equations. Biological age equations that include the Greulich and Pyle bone age have been applied to children with a number of diseases that affect growth. In comparison to chronological age, biological age was advanced in obese girls and retarded in boys with both severe congenital heart disease and pituitary dwarfism. Following seven months of therapy with human growth hormone, the latter group showed evidence of catch up growth.