In any event, Father could not have appealed to the superior court the trial court's post-dispositional order denying his request to regain custody of his children. See In re Diane R., 146 N.H. 676, 678, 777 A.2d 290 (2001) (explaining that RSA 169–C:28 "does not allow for de novo review of post-final dispositional review orders"). In the instant case, where the questions that Father raises in his appeal of both the final dispositional order and the post-dispositional order are related and constitute questions of law only, in the interests of judicial efficiency and economy, we exercise our superintendent jurisdiction over the circuit court and treat Father's combined appeal as a petition for a writ of certiorari.

The relevant issue, whether the respondent neglected her sons under RSA chapter 169–C, is germane to both the neglect case and the TPR case. See id. The court's finding of neglect was a “final dispositional order,” RSA 169–C:28 (2002); see In re Diane R., 146 N.H. 676, 678, 777 A.2d 290 (2001), and the respondent did not appeal that order to the superior court for de novo review, see RSA 169–C:28; therefore, the issue of neglect was resolved finally on the merits. Because DCYF has successfully demonstrated the three conditions for collateral estoppel and the respondent has not submitted any argument as to why we should relax this preclusive doctrine, see In re Zachary G., 159 N.H. at 151–52, 982 A.2d 367, we conclude that collateral estoppel bars the respondent from challenging the neglect case findings in the TPR case.

The relevant issue, whether the respondent neglected her sons under RSA chapter 169-C, is germane to both the neglect case and the TPR case. See id. The court's finding of neglect was a "final dispositional order," RSA 169-C:28 (2002); see In re Diane R., 146 N.H. 676, 678 (2001), and the respondent did not appeal that order to the superior court for de novo review,see RSA 169-C:28; therefore, the issue of neglect was resolved finally on the merits. Because DCYF has successfully demonstrated the three conditions for collateral estoppel and the respondent has not submitted any argument as to why we should relax this preclusive doctrine, see In re Zachary G., 159 N.H. at 151-52, we conclude that collateral estoppel bars the respondent from challenging the neglect case findings in the TPR case.

Because there is no statutory right to de novo appeal in superior court from a post-final dispositional order in a RSA chapter 169-C proceeding, a party seeking review may file a petition for writ of certiorari in the superior or supreme court. See In re Diane R., 146 N.H. 676, 678-79, 777 A.2d 290 (2001).Certiorari is an extraordinary remedy that is not granted as a matter of right, but rather at the discretion of the court.