CAFC Rejects ‘Ministerial Requirement’ Standard for Non-Provisional Patent Application Priority Dates

Today, the U.S. Court of Appeals for the Federal Circuit (CAFC) issued a precedential decision in Dental Monitoring SAS v. Align Technology, Inc. vacating a final written decision of the Patent Trial and Appeal Board (PTAB), which had invalidated patent claims directed to dental arch imaging as obvious. In so ruling, the Federal Circuit rejected the PTAB’s conclusion that a prior art reference was entitled to the priority date of its provisional patent application regardless of whether it provided written description support for the later-filed non-provisional application’s claims as long as that later filing complied with certain procedural, or “ministerial,” requirements.

Substantive Written Description Requirement Incorporated Into Section 102

Align Technology filed a petition for inter partes review (IPR) proceedings at the PTAB to challenge the validity of U.S. Patent No. 10755409, Method for Analyzing an Image of a Dental Arch. During IPR proceedings, the priority date of Align’s prior art reference U.S. Patent Application No. 20210068923 (“Carrier”) was critical as the ‘409 patent’s own priority date fell between the filing dates of Carrier’s provisional patent application and Carrier’s non-provisional application.

Dental Monitoring argued that CAFC precedent required that Carrier’s provisional filing provide written description support for the claims of Carrier’s non-provisional for Align to rely on the earlier date of the provisional filing. Citing to the PTAB’s 2023 ruling in Penumbra v. RapidPulse, designated precedential by then-U.S. Patent and Trademark Office Director Kathi Vidal, the PTAB rather ruled that Carrier’s provisional describe the subject matter relied upon in Carrier’s non-provisional, which itself need only satisfy the “ministerial requirements” of 35 U.S.C. § 119 and 35 U.S.C. § 120 governing earlier priority dates to claim the benefit of the earlier date for the Carrier reference.

Beginning with a discussion of the statutory framework, the Federal Circuit highlighted that the plain language of 35 U.S.C. 102(d)(2), governing patents and published applications effective as prior art, conditions entitlement to an earlier priority date upon satisfying the conditions of Section 119, including Section 119(e)(1) which requires “disclos[ure] in the manner provided by [35 U.S.C. §] 112(a)” for patent owners to be entitled to claim the earlier priority date. “Thus, the statutory text expressly conditions entitlement to priority on satisfaction of [Section] 112’s written description requirement,” the Federal Circuit reasoned, adding that this substantive requirement was incorporated into Section 102(d) without any text creating a less demanding “ministerial” standard.

Section 102(d)’s language providing that a patent application would be “entitled to claim a right of priority” further supported the Federal Circuit’s conclusion. Congress’s use of that language naturally refers to a substantive entitlement under Section 119 rather than the merely procedural act of claiming priority. The PTAB’s conclusion rendered this “entitled to” language superfluous with an interpretation treating this language as if it simply referred to any claim to right of priority.

Dynamic Drinkware’s Concerns Over Backdating Priority Without Proper Support Still Valid

On appeal, Align argued that the Federal Circuit should not apply its reasoning from Dynamic Drinkware v. National Graphics (2015), which requires that a provisional patent application provide written description support for at least one claim of the non-provisional application to claim the earlier priority date. Whereas Align argued that Dynamic Drinkware only dealt with pre-America Invents Act (AIA) patents, the Federal Circuit noted that reserving this decision did not establish that the AIA eliminated the written description requirement from this analysis; it simply addressed the pre-AIA statute at issue in the appeal. “The concern… that a patent challenger should not be able to backdate prior art by claiming priority from an earlier application that would not have supported a patent on the claimed invention—still remains valid,” the Federal Circuit found.

Align also argued that the AIA created a distinction between effective filing dates for prior art references under Section 102(d)(2) and effective filing dates for claimed inventions under 35 U.S.C. § 100(i). This argument relied upon the PTAB’s precedential Penumbra decision and in a footnote, the Federal Circuit acknowledged that Penumbra was affirmed in a Rule 36 summary ruling, which establishes that the PTAB was correct without endorsing any part of the Board’s reasoning. However, the appellate court found nothing in Section 100(i) altering Section 102(d)(2)’s requirements for determining when a reference is entitled to an earlier priority date.

Concluding that nothing in the record establishes whether Carrier’s provisional patent application provides the written description support required for entitlement to the earlier priority date, the Federal Circuit dismissed Dental Monitoring’s calls to reverse the PTAB’s decision, deciding that remand was the more appropriate route so that the Board could make the required factual findings for that determination.