DECISION ORDER
ORDERED that the order is reversed, on the law, with costs, the motion is granted, the cross motion is denied, and the complaint is dismissed.
To avoid a default after receipt of the 90-day demand pursuant toCPLR 3216, the plaintiffs were required to comply therewith either by timely filing a note of issue or by moving, before the default date, to vacate the notice or to extend the 90-day period (see, Pollucci v. Rizzo, 261 A.D.2d 594 ; Rubin v. Baglio, 234 A.D.2d 534 ;Lopez v. Pathmark Supermarket, 229 A.D.2d 566 ). Having failed to do so, the plaintiffs, to avoid dismissal, were required to demonstrate a justifiable excuse for the delay in properly responding to the demand and the existence of a meritorious claim (see, Hayden v. Jones, 244 A.D.2d 316 ). Were this court to excuse the delay premised upon law office failure, the plaintiffs still had to show the meritorious nature of their malpractice claim alleging that the defendant negligently performed the Caesarean operation. That issue is not a matter within the ordinary experience of laypersons (see, Mosberg v. Elahi, 80 N.Y.2d 941 ; Fiore v. Galang, 64 N.Y.2d 999 ), and the injured plaintiff failed to submit her own affidavit and an affidavit of merit by a medical expert competent to attest to the meritorious nature of her claim. Accordingly, the complaint must be dismissed.