OBJECTIVETo study the characteristics of R bone age, C bone age, and T bone age in children with different causes of short stature based on the Tanner and Whitehouse skeletal age assessment system 2 (TW2), and to provide a reference for the etiological diagnosis of short stature.

METHODSThree hundred and sixty-three children with previously untreated short stature were classified into four groups according to the causes: growth hormone deficiency (GHD; 27 cases), idiopathic short stature (ISS; 280 cases), small for gestational age (SGA; 41 cases), and Turner syndrome (TS; 15 cases). The X-ray films of their left hand-wrist bones were taken to determine the bone age. R bone age, C bone age, and T bone age were assessed by the TW2 method and compared with their chronological age (CA).

RESULTSR bone age, C bone age, and T bone age were over 2 years less than CA in both boys and girls from the GHD group. In the ISS group, R bone age, C bone age, and T bone age were about 1 year less than CA in boys, while there were no significant differences between the bone ages and CA in girls. In the SGA group, there were no significant differences between the bone ages and CA in either boys or girls. In the TS group, R bone age and T bone age were significantly lower than CA, while there was no significant difference between C bone age and CA.

CONCLUSIONSThe children with different causes of short stature have different characteristics of R bone age, C bone age, and T bone age assessed by the TW2 method. The assessment of R bone age, C bone age, and T bone age by the TW2 method is helpful for the etiological diagnosis of short stature in children.