Received: 26 May 2019
Accepted: 25 September 2019
First Online: 27 November 2019
Ethics approval and consent to participate
: The ethical approval for the Children National Oral Health survey 2016 was obtained from the Research Ethics Committee of Dental Research Center, Shahid Beheshti University of Medical Sciences (Reference: IR.SBMU.RIDS.REC.1394.89). Informed consent form was given to and signed by parents, which explained the main detailes of the study and valuntary-based approach of participation.
: Not applicable.
: The authors declare that they have no competing interests.