Table 1.

Principal pros and cons related to the different methods utilized for the definition of skeletal age [82, 85, 94, 95, 97, 98, 102, 116, 121, 122, 123, 126, 129,132, 135,137, 138].

	Method	Disadvantages	Advantages	Radiation risk
GP	Visual inspection Correspondence method	Greater variability between observers compared to the TW method	Quick execution Used by more than 76% of pediatricians	Very low
TW	Visual and scoring method: the sum of scores reflects general skeletal development	Subjective evaluation of bone age. Takes time	More reliable than GP method	Very low
Fels	More reliable than GP method	Limited experience	Standardized evaluation of errors Useful for forensic use	Very low
Computerizedassisted techniques	Computerized calculation of bone age using wrist radiographs	Automated evaluation, but not totally eliminated radiologist and pediatrician evaluation	Accuracy Precision	Very low
Ultrasound	The technique uses growth cartilages dimensions in three orientations: front, back and side	Operator-dependent Difficulty of standardization Needs further improvements	Accessibility Quick scan Low cost Multiplanar capacity Comparison with contralateral	Absent