P. MahachoklertwattanaU. SuthutvoravutP. PoomthavornS. CharoenkiatkulU. UdomsubpayakulR. RajatanavinMahidol University2018-09-242018-09-242010-01-01Journal of Pediatric Endocrinology and Metabolism. Vol.23, No.1-2 (2010), 65-710334018X2-s2.0-77950838830https://repository.li.mahidol.ac.th/handle/123456789/28812Background: A worldwide secular trend towards earlier onset of puberty in girls has been noted during recent years. However, the data on sexual maturation of boys are relatively scarce and normative data of sexual maturation in Thai boys are still lacking. Aim: To determine the age of secondary sexual maturation in normal Thai boys. Methods: Three hundred healthy urban boys aged 9-18 years were recruited during January 1997 to December 1999. Genital and pubic hair maturity staging was determined using the method of Marshall and Tanner. Testicular size was assessed by Prader orchidometer. Probit analysis was used to analyze the onset of puberty (gonadarche) and pubarche. Results: Median (range) ages of the onset of puberty and pubarche were 10.8 (9.5-12) and 12.4 (10.9-13.9) years, respectively. Conclusion: The age of onset of genital development in boys living in Bangkok seems to be slightly earlier than that of boys in other countries. However, the onset of pubic hair development is comparable. © Freund Publishing House Ltd.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyMedicineArticleSCOPUS10.1515/JPEM.2010.23.1-2.65