Skeletal maturity assessment, defined also as bone age (BA), has an important role in pediatrics and pediatric endocrinology, used mainly for evaluating growth and puberty related endocrine disorders. Repeated BA assessment is important during the follow up of children with short stature, with precocious puberty and those treated by growth promoting medications.

The most commonly used method used for determining skeletal maturity, and thus BA is based on comparison of a hand and wrist radiographs to a standard series of representative films in the "Radiographic atlas of skeletal development of the hand and wrist" by Greulich and Pyle (GP), which has been issued several decades ago. The suggested method in this study is based on ultrasound technology, and therefore it is quick, objective, and radiation-free. It delivers an immediate non biased result without the need to rely on an observer's evaluation of the hand radiograph and without the need for a specialized radiology facility.

Skeletal maturity assessment, defined also as bone age (BA), has an important role in pediatrics and pediatric endocrinology, used mainly for evaluating growth and puberty related endocrine disorders. Repeated BA assessment is important during the follow up of children with short stature, with precocious puberty and those treated by growth promoting medications.

The most commonly used method used for determining skeletal maturity, and thus BA is based on comparison of a hand and wrist radiographs to a standard series of representative films in the "Radiographic atlas of skeletal development of the hand and wrist" by Greulich and Pyle (GP), which has been issued several decades ago. Among the disadvantages and drawbacks in this BA assessment method are: the obligatory need for using radiology units that are often available only in special facilities or hospitals, not available at the physicians office, the exposure to ionizing radiation, and the known limitation of the method for the need of an endocrinologist to assess the BA, with a known large inter observers variability of the BA interpretation.

The suggested method in this study is based on ultrasound technology, and therefore it is quick, objective, and radiation-free. It delivers an immediate non biased result without the need to rely on an observer's evaluation of the hand radiograph and without the need for a specialized radiology facility.

This technique was innovated in order to find an efficient, convenient and non radiation based method of skeletal maturity assessment for the primary care physician that can be performed in an office setting.

The aim of this study is to establish a new bone age database by an ultrasound apparatus (SonicBone) that will eventually replace the X-ray based assessment using Greulich and Pyle and Tanner & Whitehouse Atlas and methods.

The design of the study is to perform a concomitant skeletal maturation assessment by reading of an ultrasound technique using the SonicBone apparatus. Skeletal maturation assessment will be performed in females and males at various age groups from 4-17 years old.

Inclusion Criteria:

Children aged 4-17 years old Children with normal (3%-97%) height values for their age Children with normal (3%-97%) weight values for their age Children with normal (5%-85%) BMI value for their age Children of Caucasian ethnical origin A signed Informed Consent Form that was obtained from at least one parent or legal guardian, prior to ultrasound study.

An assent from the child to perform the SonicBone's BA device measurement

Exclusion Criteria:

Children taking any medication that might change bone metabolism or mineralization within the last year (glucocorticosteroids, sex steroids, oral contraceptives, anticonvulsants, calcium and vitamin D in superphysiological doses) Children with suspected bone diseases, metabolic diseases, chronic diseases or multiple fractures.