Aiming to validate the use of bone age determined by ultrasound (BAUS) in Brazilian children, normal control students will be studied. X-Ray bone age (RXBA) and BAUS will be determined in 500 children and adolescents of both genders, with chronological age varying from 6-16 years.

Concordance analysis and the correlation between both BA determination methods will be performed.

Bone age is a valuable method to recognize the maturation status of development and growth. Classical analyses is performed by using the Greulich and Pyle X-Ray measurement. Such analyses have some restrictions such as intra- and inter observer variability, and variable synchronicity of bone maturation.

Bone age determined by ultrasound (BAUS) has been indicated as a fast and reproducible method, allowing decimal BA determination and avoiding the need for X-Ray.

Our aim is to validate the BAUS method in Brazilian normal controls. School students of both genders, with age varying from 6 to 16 years will be included.

Inclusion Criteria:

• absence of chronic illness and drug ingestion

Exclusion Criteria:

• any chronic disease or medicine use
• body mass index: < -2SDS or > +2SDS
• stature : < -2SDS or > +2SDS

normal control school students