(a) A dispositional order of the court may be modified:
(1) Upon the motion of the probation officer, a department official, the director of the Division of Juvenile Services or prosecuting attorney; or
(2) Upon the request of the child or a child's parent or custodian who alleges a change of circumstances relating to disposition of the child.
(b) Upon such a motion or request, the court shall conduct a review proceeding, except that if the last dispositional order was within the previous six months the court may deny a request for review. Notice in writing of a review proceeding shall be given to the child, the child's parent or custodian and all counsel not less than seventy-two hours prior to the proceeding. The court shall review the performance of the child, the child's parent or custodian, the child's social worker and other persons providing assistance to the child or child's family. If the motion or request for review of disposition is based upon an alleged violation of a court order, the court may modify the dispositional order to a more restrictive alternative if it finds clear and convincing proof of substantial violation. In the absence of such proof, the court may decline to modify the dispositional order or may modify the order to one of the less restrictive alternatives set forth in section thirteen of this article. No juvenile may be required to seek a modification order as provided in this section in order to exercise his or her right to seek release by habeas corpus.
(c) In a hearing for modification of a dispositional order, or in any other dispositional hearing, the court shall consider the best interests of the child and the welfare of the public.