Opinion by
LARRY JOPLIN, Presiding Judge.T1 Petitioners Anderson Mechanical, Inc. (Employer) and Bituminous Casualty (Insurer, or collectively, Petitioners) seek review of an order of a three-judge panel of the Workers' Compensation Court affirming the trial court's order(s) dismissing Respondent Massachusetts Bay Insurance Co. (MBI), and denying Employer's motion to add a previous insurer as a party-respondent. Having reviewed the record, however, we discern no error. Accordingly, the order of the three-judge panel is sustained.
T2 Respondent David Spiegel (Claimant) worked for Employer for twenty-four years. Employer obtained workers' compensation insurance from MBI for the period January 1, 2000 to January 1, 2002, and from Arch Insurance Company (Arch) for the period January 1, 2002 to January 1, 2008. Bituminous became the workers' compensation insurer January 1, 2008.
13 By Form 3 filed March 3, 2008, Claimant asserted repetitive trauma injuries to his left shoulder, hands and arms while working for Employer, date of last exposure, February 28, 2003.1 In April 2003, Petitioners filed a Form 18, Motion to Join Additional Parties, seeking to join MBI and Arch as party-respondents, and MBI entered an appearance in May 2003. In July 2003, Petitioners filed another Form 18, Motion to Join Additional Parties, seeking to compel joinder of Arch, and Arch entered an appearance in August 2008.
4 In September 2008, MBI filed a Form 13, Motion to Dismiss, citing 85 O.S. § 11(B)(5). Following a hearing in November 2003, the trial court found MBI was not a "proper party," dismissed MBI from the proceedings, and denied Insurer's motion to add *1289Arch by order filed in December 2008. Petitioners appealed, and a three-judge panel unanimously affirmed.
15 In this review proceeding, Petitioners assert that Claimant became aware of his job-related injuries in May 2000 when he first received medical treatment for those injuries, and that the law in effect at the time of Claimant's awareness of his job-related injuries controls the rights and obligations of the parties. See, Cole v. Silverado Foods, Inc., 2003 OK 81, 78 P.3d 542; CR Industries v. Dorsey, 1998 OK 111, 970 P.2d 179; Southwest United Industries v. Polston, 1998 OK 78, 964 P.2d 210; Rankin v. Ford Motor Co., 1996 OK 94, 925 P.2d 39.2 So, say Petitioners, because Claimant's date of awareness pre-dates the effective date of § 11(B)(5), that section cannot be applied retroactively to justify dismissal of MBI and denial of Areh's joinder.
T6 Prior to enactment of § 11(B)(5), the Court of Civil Appeals recognized that, where a claimant suffered cumulative trauma injuries in successive employments, or while insured by successive insurers, apportionment of liability for the claimant's benefits was proper. See, Ball-Incon Glass v. Adams, 1995 OK CIV APP 16, 894 P.2d 489; Kerr Glass Co. v. Wilson, 1994 OK CIV APP 69, 880 P.2d 414; Lummus Const. v. Vanceourt, 1992 OK CIV APP 113, 838 P.2d 43; Pauley v. Lummus Const. 1992 OK CIV APP 96, 836 P.2d 692. However, effective October 23, 2001, the Oklahoma Legislature amended 85 0.8. § 11, and subsection (B)(5) now provides:
Where compensation is payable for an injury resulting from cumulative trauma, the last employer in whose employment the employee was last injuriously exposed to the trauma during a period of at least ninety (90) days or more, and the insurance carrier, if any, on the risk when the employee was last so exposed under such employer, shall alone be liable therefor, without right to contribution from any pri- or employer or insurance carrier....
Y¢7 By enactment of § 11(B)(5), "the Legislature intended to make the last exposure doctrine apply to cumulative trauma cases, both for determination of the date of injury and for the determination of the liable employer in cases of multiple employers." - Celestica Inc. v. Hines, 2004 OK CIV APP 22, ¶ 9, 86 P.3d 1095, 1098. By force of this section, where a claimant suffers a cumulative trauma injury in the course of his or her employment for a single employer, and is last injuriously exposed to the trauma "during a period of at least ninety (90) days," "then 'the insurance carrier ... on the risk when the employee was last so exposed ... shall alone be liable, therefor, without right to contribution from any prior ... insurance carrier? " OCT Equipment, Inc. v. Ferrell, 2005 OK CIV APP 36, ¶ 7, 114 P.3d 479, 481 cert. den., 2005 OK 38. "The insurer on the risk on the last day of exposure is solely liable if the claimant worked for a single employer for the 90 days prior to last exposure." - OCT Equipment, Inc., 2005 OK CIV APP 36, ¶ 10, 114 P.3d at 481. Application of § 11(B)(5) is not impermissibly retroactive as to an insurer who assumed the risk after that section's effective date. Celestico Inc., 2004 OK CIV APP 22, ¶ 10, 86 P.3d at 1098.3
8 In the present case, Claimant stated on his Form 3 he was last exposed to the repeti*1290tive-trauma-dealing hazards of the employment on February 28, 2008. Petitioners concede in their appellate brief that Claimant continued to work for Employer after February 28, 2008, and, elsewhere in their brief (filed October 26, 2004), assert "there is no 'last date of exposure' since [Claimant] is still employed by" Employer. Claimant asserts in his response brief that he continued to work for Employer until terminated on April 80, 2004. It further appears that Insurer assumed the risk on or about January 1, 2008, over a year after the effective date of § 11(B)(B).
T9 Under § 11(B)(5), the law then in effect at the time Insurer assumed the risk, and the law in effect at the time of Claimant's last hazardous exposure in his single employment, "[the insurer on the risk on the last day of exposure is solely liable [where] the claimant worked for a single employer for the 90 days prior to last exposure." OCT Equipment, Inc., 2005 OK CIV APP 36, ¶ 10, 114 P.3d at 481. The pleadings and admissions of the parties in the briefs 4 support conclusions that (1) Claimant worked only for Employer over the last twenty-four years, during which he was last hazardously exposed to the repetitive-trauma dealing conditions of that employment for more than ninety days, and (2) Insurer was Employer's workers' compensation insurance carrier on the last day of Claimant's exposure to the repetitive-trauma-dealing hazards of the employment. Pursuant to § 11(B)(5), Insurer is consequently liable for payment of Claimant's benefits, if any he should be adjudicated entitled, without right of contribution from either Arch or MBI.
[ 10 We therefore conclude the Workers' Compensation Court did not err in dismissing MBI or in denying joinder of Arch. The order of the three-judge panel is SUSTAINED.
BUETTNER, C.J., concurs, and HANSEN, J., dissents with separate opinion.. Claimant asserts in his brief that, after he filed his Form 3, he continued to work for Employer until he was terminated in April 2004.
. Petitioner additionally cites Laser Engineering v. Smith, Case No. 100,608 (Ok.Civ.App.Div.I, October 8, 2004) (Released for Publication by Order of the Court of Civil Appeals). However, by order filed January 27, 2005, the Oklahoma Supreme Court denied employer's petition for certiorari, and ordered the Court of Civil Appeals' opinion withdrawn from publication. Any citation to or reliance on Laser is hence unauthorized in the present case. - Okla.Sup.Ct.R. 1.200(b)(5), 12 O.S., Ch. 15, App. 1; 20 O.S. § 30.5.
. "... Celestica took over the plant after the effective date of the statute and was charged with notice of the law in effect at that time. Additionally, Celestica has failed to cite any authority to support its argument that the last exposure rule is unconstitutional. Indeed, the last exposure doctrine, in occupational disease cases, has long been upheld. See Parks v. Flint Steel Corp., 1988 OK 64, 755 P.2d 680... . Accordingly, we find no support for Celestica's argument that the last exposure rule is unconstitutional."
. Admissions made in briefs may be considered as supplementing and curing an otherwise deficient appellate record. See, Macy v. Bd. of County Comm'rs, 1999 OK 53, ¶ 3, 986 P.2d 1130, 1134, fn. 8; Brock v. Thompson, 1997 OK 127, ¶ 3, 948 P.2d 279, 283, fn. 4; Stork v. Stork, 1995 OK 61, 898 P.2d 732, 737, fn. 10; Reeves v. Agee, 1989 OK 25, 769 P.2d 745, 753; Womack v. City of Oklahoma City, 1986 OK 14, 726 P.2d 1178, 1181.