Skeletal maturation in adolescence: a comparison between the Tanner-Whitehouse II and the Fels method

UNLABELLED: In this longitudinal study, skeletal ages assessed with the Fels method and the Tanner-Whitehouse II method (TW II) were compared for boys (n = 30) and girls (n = 30) with a mean chronological age between 12 and 16 years. The subjects, participating in the Amsterdam Growth and Health Study, were measured annually between 1977 and 1980, which resulted in four radiographs of the left hand and wrist of every individual. For boys, the mean TW II skeletal age was 0.32 years older than the mean Fels skeletal age (sd 0.50). Tested at the subsequent chronological ages, the mean TW II skeletal ages were 0.05-0.47 years older, the differences being statistically significant at the mean ages of 13, 14 and 15 years. For girls, the mean TW II skeletal age was 0.20 years younger than the mean Fels skeletal age (sd 0.69). At the subsequent chronological ages, the mean TW II skeletal ages were 0.03 to 0.35 year younger, the differences being statistically significant at the mean chronological ages of 14 and 15 years. As a consequence of the differences between the methods, application of the Fels method resulted in classifying a smaller percentage of boys (10%) as rapid maturers, and a higher percentage (6.7%) of boys as normal maturers in comparison to the TW II method. For girls, a higher percentage of female adolescents were classified as rapid (16.7%) and slow maturers (13.3%), but a smaller percentage was classified as normal mature (30%). Differences in the skeletal ages can be ascribed to differences in maturation of the reference population, but also to fundamental differences in the statistical methods of the scoring system and the scales of maturity.

CONCLUSION: There is no agreement in skeletal ages assessed according to the TW II method and the Fels method in adolescence.