(a) An order awarding legal custody or an order of probation made by the juvenile court in the case of a child may be modified, revoked, or extended on motion by:

(1) A child, whose legal custody has been transferred to a department, institution, agency, or person, requesting the juvenile court for a modification or termination of the order, alleging that the child is no longer in need of placement or probation and the department, institution, agency, or person has denied application for release of the child or has failed to act upon the application within a reasonable time; or

(2) A department, institution, agency, or person vested with legal custody or responsibility for probation, requesting the juvenile court for a modification, an extension, or a termination of the order on the grounds that the action is in the best interests of the child or necessary to safeguard the welfare of the child or the public interest.

(b) The juvenile court may dismiss the motions filed pursuant to subsection (a) if, after preliminary investigation, it finds that they are without substance. If the juvenile court is of the opinion that the order should be reviewed, upon due notice to all necessary parties as prescribed by rules of court, it may proceed to a hearing in the same manner and under the same safeguards provided for in this chapter for the issuance of the original order. It may thereupon terminate the order if it finds the child is no longer in need of care or rehabilitation or it may enter an order extending or modifying the original order if it finds this action necessary to safeguard the child or the public interest.