In Re the Marriage of: Ngozi Beatrice Nnebedum, petitioner, Appellant, vs. Chimezie Nnebedum, Respondent.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1996).

STATE OF MINNESOTA

 IN COURT OF APPEALS

 C0-97-1884

In Re the Marriage of:

Ngozi Beatrice Nnebedum, petitioner,

Appellant,

vs.

Chimezie Nnebedum,

Respondent.

 Filed June 2, 1998

 Reversed and remanded; motion to dismiss denied

 Schumacher, Judge

Ramsey County District Court

File No. FX971256

Dennis W. Strid, 604 Richfield Bank Building, Post Office Box 201806, Minneapolis, MN 55420-6806 (for appellant)

Joseph M. Hoffman, 1900 One Financial Plaza, 120 South Sixth Street, Minneapolis, MN 55402 (for respondent)

Considered and decided by Kalitowski, Presiding Judge, Schumacher, Judge, and Holtan, Judge*.

*Retired judge of the district court, serving as judge of the Minnesota Court of Appeals by appointment pursuant to Minn. Const. art. VI, § 10.

U N P U B L I S H E D O P I N I O N

 SCHUMACHER, Judge

Appellant Ngozi Beatrice Nnebedum (wife) contends the district court erred when it dismissed her dissolution petition on the grounds of collateral estoppel. We reverse and remand.

FACTS

In 1983, before the parties were married, but allegedly while they were cohabiting, wife married a man named Artie Russ Gregory. Although respondent Joseph Chimezie Nnebedum (husband) claims he was unaware of this marriage, wife claims that he arranged the marriage and drove her to the ceremony, allegedly for immigration purposes. Wife claims she has not seen Gregory since the day of the marriage. Husband located Gregory in Milwaukee in 1995 with the help of a private investigator. Wife's marriage to Gregory was never dissolved.

Nevertheless, in January 1984, the parties were married in a religious ceremony, without a valid marriage license. On June 19, 1989, after procuring a marriage license, they were married in a civil ceremony. They have three children, ages 13, 12, and 10, all of whom were born in the U.S. and have joint U.S. and Nigerian citizenship.

In May 1994, husband filed a petition for dissolution of marriage, alleging that the parties had no children and that he was unaware of his wife's whereabouts. Husband served the petition by publication. The Washington County District Court dissolved the marriage by default judgment and decree. In actuality, during this time, husband had arranged to have wife and the three children visit family in Nigeria. The children have lived in Nigeria since that time.

When wife heard of the dissolution, she returned to Minnesota and petitioned the court to vacate the judgment. After a hearing, the district court vacated the dissolution judgment and dismissed the action.

In addition, the court ruled that, because of wife's prior undissolved marriage to Gregory, the parties' marriage was voidable pursuant to Minn. Stat. §§ 518.01-.02. The court stated that an action for annulment of the marriage was the proper proceeding under these circumstances. The court also held husband in contempt of court for lying to get the default judgment and allowed him to purge the contempt by paying $4,000 and relinquishing the children's passports to the court. The court then turned the money and passports over to counsel for wife. Wife then returned to Nigeria for the children, but husband's family had concealed them from her. She has been unable to return the children to the U.S. since that time.

In December 1995, husband commenced dissolution proceedings in the Republic of Nigeria. Both parties were present in Nigeria at the time, but wife alleges she never received notice of the proceeding.

While that action was pending, wife returned to Minnesota and brought this present petition for dissolution in Ramsey County in May 1997. In her petition, she raised the issues of the legality of the parties' marriage, their status as putative spouses, property division, child custody, child support, and maintenance. Husband moved to dismiss the action on the grounds of res judicata and lack of jurisdiction.

After a hearing, the Ramsey County District Court dismissed the dissolution petition in its entirety. In reaching its decision, the court incorporated by reference the findings, conclusions, and memo of the Washington County District Court order that vacated the 1994 judgment. The Ramsey County District Court concluded that wife was raising issues identical to those decided in the Washington County order and, consequently, was barred by collateral estoppel. Wife appealed the Ramsey County District Court's decision.

While this appeal was pending, the Nigerian court issued an order dissolving the parties' customary marriage and granting husband custody of the three children. Husband has moved this court to dismiss the appeal as moot in view of the Nigerian court order.

D E C I S I O N

 Motion to dismiss appeal

Husband contends the Nigerian dissolution order renders this appeal moot. We disagree. An appeal is moot and should be dismissed if the affirmance or reversal of the trial court's order would make no difference with respect to the controversy at hand and if the court cannot possibly grant relief because of events that have occurred while the appeal was pending. Barnes v. Macken, 252 Minn. 412, 415-16, 90 N.W.2d 222, 225-26 (1958).

The mere existence of the Nigerian order for dissolution of the parties' customary marriage does not render this appeal moot when procedural and substantive questions about the judgment still exist. Husband has not filed the Nigerian order pursuant to the Uniform Enforcement of Foreign Judgments Act so as to require Minnesota courts to give the order full faith and credit. See Minn. Stat. § 548.27 (1996). Further, it is unclear whether the dissolution of a Nigerian customary marriage would have legal impact on a U.S. civil marriage. Finally, the validity of the Nigerian order is questionable, because wife claims she never received notice of the proceeding and did not have an opportunity to present her case. Cf. Nicol v. Tanner, 310 Minn. 68, 76-77, 256 N.W.2d 796, 800-01 (1976) (holding reciprocity is not prerequisite for enforcement of foreign judgment so long as foreign court had jurisdiction and parties fully adjudicated issues). The motion to dismiss is denied.

 Dismissal of wife's petition for dissolution

In challenging the dismissal of her petition, wife contends the Washington County District Court order should not collaterally estop her from bringing an independent petition for dissolution. We agree. Whether a trial court has erred in applying the doctrines of issue or claim preclusion is a mixed question of fact and law that this court reviews de novo. Sautter v. Interstate Power Co., 567 N.W.2d 755, 759 (Minn. App. 1997), review denied (Minn. Oct. 31, 1997).

Collateral estoppel applies when these elements are met: a party raises an issue identical to one raised in a prior adjudication; the party was a party to, or in privity with a party to, the prior action; the party had a full and fair opportunity to be heard on the issue in the prior adjudication; and the prior adjudication resulted in a final judgment on the merits. Kaiser v. Northern States Power Co., 353 N.W.2d 899, 902 (Minn. 1984).

Although the parties are the same in this action as in the Washington County action, no other elements for collateral estoppel exist here. First, the action in Washington County District Court was simply a motion to vacate the default judgment that husband had fraudulently procured in wife's absence. The validity of the parties' marriage and related issues were not part of that motion to vacate.

Second, contrary to the district court's finding, when the parties went before the Washington County District Court on the motion to vacate, they did not have a full and fair opportunity to litigate the nature and legality of their marriage, their status as putative spouses, and property division; they were simply litigating the default judgment. They did not present any proof of wife's prior marriage, of the consummation or dissolution of that marriage, or of either party's motivation to arrange the wedding for immigration purposes. The Washington County District Court, and now the Ramsey County District Court, have stated that this case can proceed only as an annulment, but a trial on the merits regarding the validity of the prior marriage or the parties' marriage has never occurred.

Third, because the parties never had the opportunity to litigate the specific issues wife has raised in her present petition for dissolution, most notably a division of property, custody, and child support and maintenance, no final judgment on these merits yet exists. Once the Washington County District Court vacated the default judgment, the remainder of its remarks, relating to the validity of the marriage and related issues, was gratuitous. See Lipka v. Minnesota Sch. Employees Ass'n, Local 1980, 550 N.W.2d 618, 622 (Minn. 1996) (in declining to issue advisory opinion on issue that was not necessary to disposition of case, court noted, "judicial restraint bids us to refrain from deciding any issue not essential to the disposition of the particular controversy before us"). The vacation of the default judgment does not have collateral estoppel effect on this action. We reverse and remand for trial on the merits.

  Reversed and remanded; motion to dismiss denied.