In clinical pediatrics, estimation of the degree of skeletal development is frequently carried out by comparing the roentgenogram of a portion of the skeleton with one of a similar portion of the skeleton of an average or normal child of the same age. In actual practice the number of the bones of the wrist and hand and their degree of development are most widely used for such comparison.
It is recognized that well known standards such as those of Todd,1 Flory2 and Engel and Runge3 must be used with allowances for variations within the norm. Although such standards may be unsuitable for strict investigational purposes they may be used to determine whether skeletal development is grossly retarded, normal or grossly advanced. This report is not concerned with minor variations from the normal or average.
Some conditions, notably cretinism, are known to be accompanied by retarded skeletal development.