Received: 31 July 2019
Accepted: 29 January 2020
First Online: 16 March 2020
Ethics approval and consent to participate
: All participants’ parents were informed about the aim of our study and written informed consent was obtained from parents after approval of the Ethical committee of Qena Faculty of Medicine, South Valley University. The Ethics committee reference numbers: 02/18
: Not applicable
: The authors declare that they have no competing interests.