Abstract: Objective To discuss the diagnostic value of English,Chinese and Japanese standards of TW2 to skeletal age assessment of children with central precocious puberty(CPP),then to confirm the normal thresholds.Methods Sixty one children as patient group were definitely assured CPP.The control group had 67 children.Among them,61 were normal children,another 6 children as a special control group.Left hand-wrist X-ray radiographs were retrospectively analyzed by two doctors separately and their skeletal ages were assessed with the three standards of TW2 method.The differences between skeletal age and chronological age were analyzed with ROC in SPSS 13.0.Results(1) The skeletal age results showed κ value is 0.776 deduced by two clinical doctors(u=16.128,P<0.05).(2) There were no statistic differences for the areas under ROC curves among three methods.(3) d≥1.15 years in TW2,d≥1.25 years in TW2-CHN and d≥0.65 years in TW2-JP were more susceptive and specific points.Conclusion TW2,TW2-CHN and TW2-JP provided a higher value for the diagnosis of skeletal age in unhealthy children,and TW2-CHN is highest value for Chinese children.

Key words: forensic medicine, age determination by skeleton, puberty, precocious, TW2 method