Background: International studies have reported an early age of onset of puberty in girls and boys. However, the current situation of puberty onset in Taiwanese children is unknown. In this study, the timing of menarche and pubertal change in testicular volume (TV) in Taiwanese children was examined, and bone age (BA) was used as an internal somatic maturity scale and compared with the chronological age (CA) at pubertal timing. Methods: Clinical data from October 1, 2010, to March 31, 2018, were retrospectively collected from a general hospital in Taipei. The data of patients who were diagnosed with endocrine/genetic disorders were excluded. Clinical data included CA, timing of menarche, and X-ray images of TV and BA. BA was determined by a senior pediatrician and a senior pediatric radiologist. The reliability and validity of BA readings were tested. Collected data were analyzed statistically. Results: Overall, TV records of 241 boys and the menarche timing data of 98 girls were collected from 1823 children. CA for menarche was 11.35 ± 1.06 years (mean ± SD), and BA for menarche was 12.95 ± 0.80 years. CA and BA at TV = 15 mL in male puberty was 12.32 ± 1.22 and 13.46 ± 0.68 years, respectively. A stronger correlation was observed between TV and BA than between TV and CA during the pubertal period. Conclusion: The secular trend of earlier puberty timing continues. The decline rate of menarche timing was approximately 0.43 years per decade in the past 30 years. Among boys, an advance of more than 1 year in pubertal timing age was observed over the past 20 years. BA and TV showed high correlation during puberty.

Background: The Greulich and Pyle (GP) method is one of the most common radiographic techniques for bone age (BA) assessment. The applicability of this method to ethnic populations outside of the United States has been investigated in several recent studies worldwide. Currently, limited data are available on the accuracy of the GP method for the Taiwanese population. The purpose of this study was to determine whether the GP standards are applicable to contemporary Taipei children. Methods: Clinical data from October 1, 2010, to March 31, 2020, were retrospectively collected from a general hospital in Taipei. BA was determined by a senior pediatrician and was reviewed by a senior pediatric radiologist according to the GP standards. Comparison of BA and chronological age (CA) was performed in children with body weight and height in the 15th to the 85th percentiles of normal children. Ethnic variations in the maturation process in the ulnar bone were investigated. All data were statistically analyzed. Results: In total, 2465 medical records were collected. After excluding those with diseases and unqualified data, 654 records of boys and 809 of girls were analyzed. In boys, the mean BA was significantly delayed between 6 and 9 years of age compared with the CA. In girls, the mean BA was generally advanced between 7 and 15 years of age. Ulnar bone maturation tended to be delayed in young boys. Conclusion: A significant discrepancy between CA and BA was observed in our population. Delayed ulnar bone maturation in young boys was confirmed. Children in Taipei exhibit a different maturation pattern than children on whom the GP standards were based.