US 6398548

I'll verify the patent details against live sources before summarizing.

Let me pin down the exact independent claim language.

US 6,398,548 B1 — Analyst Summary

Verification note: The requested identifier 6398548 resolves cleanly and only to US 6,398,548 B1. No similarly-numbered patent was substituted. Details below are drawn from the patent text supplied in the prompt plus live searches of Google Patents, the USPTO-published patent PDF, FreePatentsOnline, the CAFC opinion in Ormco Corp. v. Align Technology (appeal 05-1426), and Align Technology SEC disclosures.

1. Bibliographic data (as printed on the face of the patent)

Priority/family caveat: Google Patents lists the priority date as 1997-06-20, which is the provisional filing date, not the 1999 filing date of this application. The 1999 filing date is the actual §102(b) critical date for this application's own disclosure.

2. Abstract (verbatim)

"A system for repositioning teeth comprises a plurality of individual appliances. The appliances are configured to be placed successively on the patient's teeth and to incrementally reposition the teeth from a initial tooth arrangement, through a plurality of intermediate tooth arrangements, and to a final tooth arrangement. The system of appliances is usually configured at the outset of treatment so that the patient may progress through treatment without the need to have the treating professional perform each successive step in the procedure."

3. Independent claims — plain-language overview

The '548 patent has multiple independent claims spanning three subject-matter families. Language below is paraphrased; quoted phrases are verbatim from the claim text as reported in the CAFC opinion and the patent PDF.

Family A — Systems of appliances

• Claim 1 (system): A system of dental incremental position adjustment appliances comprising (a) a first appliance whose geometry repositions teeth from the initial arrangement to a first intermediate arrangement, (b) one or more intermediate appliances that progressively reposition teeth to successive intermediate arrangements, and (c) a final appliance that moves teeth from the last intermediate arrangement to the final arrangement — "wherein at least some of the appliances are marked to indicate their order of use."
• Claims 78 and 90 (system, appear in the reexamination document): These versions add a plurality of digital data sets (each representing a successive tooth arrangement for the patient), specify that cavities of successive polymeric shells have different geometries, and in claim 90 require that two or more appliances are "capable of being provided at one time to a patient or dental practitioner prior to the use of any of the provided appliances in treatment." Claims 78 and 90 number above 71, so they appear to be claims added during ex parte reexamination rather than original claims.

Family B — Method of repositioning teeth

• Claim 11 (method): Placing a first incremental appliance in the mouth to move teeth from the initial to a first intermediate arrangement; successively replacing one or more additional appliances that progressively reposition teeth through successive intermediate arrangements; and placing a final appliance that moves teeth from the last intermediate arrangement to the final arrangement.

Family C — Fabrication / digital-data methods

• Claim 29 (method): Provide an initial digital data set and a final digital data set; produce a plurality of successive digital data sets representing the series of successive tooth arrangements; annotate the data sets to add text or numbering; fabricate appliances based on at least some of the data sets, such that the text or numbering appears on the appliances.
• Claim 41 (method of fabricating a dental appliance): Provide a digital data set representing a modified tooth arrangement including text or numbering; control a fabrication machine based on that data set to produce a positive model on which the text/numbering appears; produce the appliance as a negative of the positive model, with the text/numbering appearing on the appliance.
• Claim 45 (method of fabricating a dental appliance): Provide a first digital data set representing a modified tooth arrangement; derive a second digital data set representing a negative model of that arrangement; control a fabrication machine based on the second data set to produce the appliance, "wherein the appliance is marked with text or data."
• Claim 49 (method of fabricating a plurality of appliances): Provide digital data representing successive tooth arrangements including text or numbering; control a fabrication machine to produce the appliances with the text/numbering appearing on them.
• Claim 65 (method): Provide a computer-generated positive model of an initial, intermediate and/or final tooth arrangement with printed annotations; fabricate at least one dental appliance as a negative of the model, where the annotations appear on the appliance(s).

Dependent claim examples of note: claim 10 (depends on claim 1) adds "instructions which set forth that the patient is to wear the individual appliances in the order marked on the appliance"; claim 17 (depends on claim 11) requires appliances to be "successively replaced at an interval in the range from 2 days to 20 days."

4. Legal status, reexamination, and litigation

• Status reported: Expired – Lifetime. Google Patents lists "Anticipated expiration: 2017-10-08." On that basis the patent's enforceable term has run.
• Ex parte reexamination: Request 90/007,510 filed Apr. 15, 2005; certificate US 6,398,548 C1, certificate issued Nov. 20, 2007 per the certificate document itself. Note: Align's Q3 2007 Form 10-Q states the reexam certificate issued Oct. 31, 2007. I am flagging this date discrepancy rather than resolving it.
• CAFC 05-1426 (Ormco Corp. v. Align Technology), decided Aug. 31, 2006: The Federal Circuit reversed the district court and held claims 10 and 17 of the '548 patent invalid as obvious over the prior orthodontic practices of Dr. Truax and Dr. Rains. The panel construed claim 1 as essentially requiring (a) three or more appliances with geometries selected to progressively reposition teeth and (b) marking of at least some appliances to indicate order of use. Align's press release (Aug. 31, 2006) confirms two of seventy-one '548 claims were held obvious, and stated the rest of the patent — including fabrication, digital-data-set, and computer-generated-model claims — was unaffected.
• Second appeal (decided Aug. 24, 2007): The CAFC affirmed the district court's finding that claims 1–3 and 11–13 of the '548 patent are invalid (anticipated by the Rains reference, per the district court record). Align's 10-Q confirms the $884,000 Ormco escrow was returned because every asserted '548 claim ultimately fell.
• Other family litigation listed by Google Patents: D. Mich. 2:03-cv-00543; S.D. Tex. 4:11-cv-00695; ITC Inv. No. 337-TA-562 (Align v. OrthoClear, terminated Oct. 13, 2006 by consent order/stipulation); CAFC 13-1240 and 13-1363.
• CAFC 2026 dockets: I found no 2026 CAFC docket involving US 6,398,548. Given that the patent expired in 2017 and every asserted claim was invalidated by 2007, new 2026 appellate activity over this specific patent is improbable. I could not query PACER or the CAFC docket system directly, so treat this as "not found," not as a certified negative.

5. Explicit uncertainties

1. Reexamination claim scope. The exact final claim count and full text of claims added in reexamination (which appear to include claims 78 and 90) are not fully reproduced in the sources I retrieved. The original patent issued with 71 claims; claims numbered above 71 indicate post-reexam additions, but I did not verify the complete added set or which original claims were amended and whether they were confirmed as patentable.
2. Inventor name rendering. The '548 face page prints the first inventor as "Chishti Muhammad" and the first inventor's firm/address differently than the related '893 patent (which prints "Muhammad Chishti"). I have not auto-corrected either. The OCR of one source rendered inventor Lerios as "Lerbes" — the Google Patents record and the reexam certificate both read Apostolos Lerios, which I treat as controlling.
3. Reexam certificate date. Nov. 20, 2007 (certificate) vs. Oct. 31, 2007 (Align 10-Q) — unresolved.
4. "Uncertainty" on assignee history: The reassignment records show an assignment recorded Apr. 30, 2001 to Align Technology, Inc., and Google Patents lists current assignee as Align Technology Inc. No later conveyance was found, but I did not query USPTO Assignment Center directly.
5. Claims 13-1240 and 13-1363 are listed as family litigation by Google Patents; I did not verify which patent(s) were at issue in those appeals.

I'll search for litigation specifically involving US 6,398,548, starting with the aggregators that index patent cases.

Let me pin down the specific case numbers and the Federal Circuit dockets.

Let me check the Unified Patents portal, the ITC investigation, and the recent Texas verdict.

Litigation involving U.S. Patent No. 6,398,548

Verification / date note: I searched for the literal identifier 6,398,548 and screened out similarly numbered patents (e.g., 6,398,548's siblings 6,554,611, 5,975,893, 6,318,994, 6,722,880, 6,217,325, 6,705,863, 6,309,215). Every matter below was checked to confirm '548 was actually pleaded at issue (as patent-in-suit or counterclaim patent), except where I flag otherwise.

Two metadata conflicts to flag up front:

1. The task states "current date April 26, 2026," but the system date on this session is 2026-09-29. A live search returned a Law360 item dated July 7, 2026 about a Texas jury verdict. I report it below but explicitly flag that I could not verify whether '548 was one of the patents at issue, and its date post-dates the "current date" stated in the task.
2. My earlier summary stated CAFC 05-1426 was "decided Aug. 31, 2006." The reported opinion is dated August 30, 2006 (463 F.3d 1299); Align's press release issued Aug. 31, 2006. Both dates are correct for their respective events.

Summary table

Case detail

1. Ormco Corp. v. Align Technology, Inc. — C.D. Cal. No. SA CV 03-16-GLT (03-cv-00016)

This is the single most important '548 case, and it is the only case where '548 was adjudicated on the merits.

• Posture: Ormco (a Sybron Dental Specialties division) sued Align on Jan. 6, 2003 alleging Align's Invisalign system infringed Ormco's U.S. Patents 5,447,432, 5,683,243 and 6,244,861 (later adding 6,616,444). Align counterclaimed, asserting its own U.S. Patent Nos. 6,398,548 and 6,554,611 against Ormco's "Red, White & Blue" ("RW&B") aligner. AOA (Allesee Orthodontic Appliances, a wholly-owned Ormco subsidiary) was joined as a counterdefendant. So as to '548, Align = plaintiff, Ormco/AOA = defendants.
• '548 claims asserted by Align: 1–3, 7, 10–13, and 17–18.
• June 30, 2004 — district court granted Align partial SJ of infringement: RW&B infringed '548 claims 1–3, 10–13, 17 ($102(b) source; Align's July 7, 2004 press release says July 2, 2004 — date discrepancy noted).
• Aug. 20, 2004 — Ormco's SJ motion of invalidity denied; Nov. 4, 2004 — Align SJ: no inequitable conduct; claims not invalid.
• Feb. 24–25, 2005 — on cross-motions, court held '548 claims 1–3 and 11–13 invalid (anticipated by Dr. Rains' STARS practice) but held claims 10 and 17 not invalid. Reconsideration denied Apr. 8, 2005.
• May 26, 2005 — permanent injunction barring Ormco/AOA from infringing '548 claims 10 & 17 (and '611 claims 1–3, 7), with a temporary 45-day stay. ⚠️ One reproduction of the CAFC opinion states "On March 26, 2006, the court entered a permanent injunction"; Align's contemporaneous SEC filings and the appeal timeline (appeal noticed May 31, 2005) establish May 26, 2005. I treat the "March 26, 2006" date as an error in that text.
• Feb. 1, 2006 — settlement agreement: Ormco/AOA to pay $884,000 into escrow to resolve past damages/willfulness/fees, payable to Align only if a final non-appealable judgment of infringement stood. It did not; the escrow was returned to Ormco/AOA.

2. Ormco Corp. v. Align Technology, Inc., Fed. Cir. No. 05-1426 (463 F.3d 1299)

• Appeal from the permanent injunction (§1295(a)(1) jurisdiction; no final judgment yet).
• Panel: Schall, Gajarsa, Dyk (Dyk, J., author). Argued Apr. 3, 2006; decided Aug. 30, 2006.
• Holding: '548 claims 10 and 17 invalid as obvious under §103(a) over Dr. Truax's orthodontic practice/published instruction sheet plus FDA medical-device labeling regulations; the court found the Truax practice and instruction sheet "sufficiently publicly accessible" to be §102(a) prior art; claim 17's 2–20 day interval was prima facie obvious over Truax's 14–21 day disclosure; Align's secondary-considerations evidence (Invisalign commercial success) failed for lack of nexus.
• The court expressly did not reach infringement or inequitable conduct. Only 2 of '548's 71 claims were at issue.

3. Ormco Corp. v. Align Technology, Inc., 498 F.3d 1307 (Fed. Cir. 2007) — "Appeal II"

• Appeal/cross-appeal from the final judgment; decided Aug. 24, 2007.
• Affirmed the district court's summary judgment that '548 claims 1–3 and 11–13 are invalid (anticipated by Rains), holding that Ormco I controlled the cross-appeal.
• Net result: every claim of '548 that was ever asserted in litigation has been held invalid, which is why the escrow was released to Ormco.

4. Align Technology, Inc. v. OrthoClear, Inc. — ITC Inv. No. 337-TA-562

• Align filed a §337 complaint Jan. 11, 2006; the Commission instituted the investigation on Feb. 15, 2006 (71 FR 7995), covering "Certain Incremental Dental Positioning Adjustment Appliances and Methods of Producing Same."
• '548 claims 21, 22, 24–30, 32–36, 38 and 39 were among the asserted claims (along with claims of 6,685,469; 6,450,807; 6,394,801; 6,722,880; 6,629,840; 6,699,037; 6,318,994; 6,729,876; 6,602,070; 6,471,511; 6,227,850), plus trade-secret misappropriation.
• Terminated Oct. 13, 2006 by consent order/stipulation implementing the Align–OrthoClear global settlement. (Align's Aug. 31, 2006 press release notes the six claims the CAFC invalidated were not the claims at issue in this ITC case.)

5. Align Technology, Inc. v. ClearCorrect, Inc., S.D. Tex. No. 4:11-cv-00695

• Filed Feb. 28, 2011; Align alleged ClearCorrect infringed nine Align patents. Align's public statements (Mar. 28, 2017) confirm '548 and 5,975,893 were asserted in this S.D. Tex. action.
• Stayed in 2012 pending a concurrent ITC proceeding; stay lifted January 2017.
• ClearCorrect-initiated ex parte reexaminations (see below) resulted in reexamination certificates issued Feb. 22 and Mar. 22, 2017 confirming all challenged '548 claims without amendment.
• Final judgment Mar. 28, 2019 (Judge Gilmore): joint motion to dismiss all claims and counterclaims with prejudice — i.e., the case ended by agreed dismissal, not by trial verdict.

6. Align Technology, Inc. v. ClearCorrect Operating, LLC, W.D. Tex. No. 6:24-cv-00187-ADA-DTG — ⚠️ possible, unconfirmed

• A 2024 W.D. Tex. (Waco, Judge Albright) action by Align against ClearCorrect/Straumann entities. Docket activity in May 2026 includes ClearCorrect's §101 invalidity SJ motion and Align's partial SJ of validity.
• A Law360 item dated July 7, 2026 reports a Texas jury found claims in four Align patents asserted against ClearCorrect invalid, while rejecting ClearCorrect's antitrust counterclaims.
• Caveat: '548 expired Oct. 8, 2017, and every claim Align ever asserted from it was invalidated by 2007. It is therefore improbable, though not impossible (past damages), that '548 was one of the four 2026 patents. I could not confirm the patent numbers, so I do not list this case as a '548 case.

7–8. Uncorroborated Google Patents "family litigation" entries

Google Patents lists this patent's family as having litigation in E.D. Mich. 2:03-cv-00543, CAFC 13-1240 and CAFC 13-1363. I did not retrieve pleadings, docket sheets, or opinions tying any of these to U.S. 6,398,548, and 13-1240/13-1363 are unusually late for a patent whose asserted claims were dead by 2007. Treat these as unverified leads, not confirmed '548 litigation.

Related proceedings that are not patent infringement litigation

• Ex parte reexamination 90/007,510 (Align) — granted July 7, 2005; certificate US 6,398,548 C1. This runs parallel to, and is frequently confused with, the litigation docket.
• Ex parte reexamination 90/013,606 — filed Oct. 14, 2015, expressly filed alongside co-pending litigation Align Technology, Inc. v. ClearCorrect, Inc., No. 4:11-cv-00695 (S.D. Tex.); certificate(s) issued 2017 confirming all challenged claims.
• The reexam requester was an unnamed third party acting through a San Francisco law firm; ClearCorrect publicly took credit for the 2015 round.
• PTAB/IPR: ClearCorrect's 2025 IPR filings (IPR2025-00814 through -00821) target other, later Align patents (e.g., 11,369,456), not '548.

Negative findings and explicit uncertainties

1. No litigation asserted '548 against a party other than Ormco/AOA, OrthoClear, and ClearCorrect has been confirmed. I found no case asserting '548 against any other competitor or manufacturer.
2. No 2026 CAFC docket involving '548 found. Given expiry (2017) and total invalidation of asserted claims (2007), this is expected. Treated as "not found," not a certified negative — I did not query PACER/CAFC dockets directly.
3. I could not verify the four patents in the July 7, 2026 Texas verdict, and whether '548 was one of them. Given the expiry date, I doubt it.
4. E.D. Mich. 2:03-cv-00543 and CAFC 13-1240 / 13-1363 were not corroborated as '548 matters.
5. Pre-2003 Ormco dispute: Ormco previously sued Align on U.S. 5,447,432/5,683,243 and the parties entered a Stipulation of Dismissal in June 2000 (with a two-year stand-down). That earlier matter could not have involved '548, which issued June 4, 2002.
6. ITC 2012 ClearCorrect proceeding: Align's SEC filings say the S.D. Tex. case was stayed in 2012 pending "a concurrent proceeding in the International Trade Commission." I could not confirm the investigation number (I believe it is 337-TA-833, "Certain Clear Aligner Products," but do not treat that as verified here), nor which Align patents it asserted.
7. Factual inconsistencies I encountered in sources (flagged, not resolved): the June 30 vs. July 2, 2004 SJ-of-infringement date; the May 26, 2005 vs. "March 26, 2006" permanent-injunction date; and the reexamination-certificate date noted in my earlier summary (Nov. 20, 2007 certificate vs. Oct. 31, 2007 per Align's Q3 2007 10-Q).

Proceedings overview

There are zero AIA trial proceedings on US 6,398,548. The structured "PTAB proceedings on file" block supplied in this prompt — the canonical USPTO Open Data Portal list — returns no IPR, PGR, or CBM for this patent, and my independent web searches did not surface any that the ODP has failed to index. The breakdown is therefore: 0 active / 0 claims invalidated by the PTAB / 0 claims sustained by the PTAB / 0 settled / 0 institution denials.

Bottom line for a defendant: the absence of AIA trials is not the same as an untested patent — it is a patent whose key claims were killed in district court and on Federal Circuit appeal, not at the PTAB. Do not expect a § 315(b) or § 315(e) estoppel framework to help you, because none exists here. Conversely, do not assume the patent is "hardened" because it survived PTAB scrutiny — it never had any. What you should be checking is the Article III record: claims 1–3, 10, 11–13, and 17 of the '548 patent were held invalid by the Federal Circuit (claims 10 and 17 in 2006; claims 1–3 and 11–13 in 2007). Untested claims (the fabrication, digital-data-set, and annotation families — e.g., claims 29, 41, 45, 49, 65) are the only potentially live ammunition.

Adjacent proceedings that actually touched (or nearly touched) the '548 patent

Because there is nothing to list under the requested per-proceeding headings, here are the three proceedings a defendant must know about — with explicit warnings about what they are and are not.

90/013,606 — ClearCorrect (third-party requester) v. Align Technology (ex parte reexamination — NOT an AIA trial)

• Type: Ex parte reexamination under 35 U.S.C. §§ 301–307. This is a Central Reexamination Unit proceeding, not an IPR/PGR/CBM and not decided by the PTAB.
• Filed: 2015-10-14 (control number US 90/013,606; requester undisclosed on the face of the request but publicly attributed to ClearCorrect; co-pending litigation identified as Align Technology, Inc. v. ClearCorrect, Inc., No. 4:11-cv-00695 (S.D. Tex.)). Source: PTO Litigation Center Report, 2015-10-15 — https://natlawreview.com/node/53399/printable/pdf
• Status: Closed — all challenged claims confirmed. Align announced that on 2017-03-22 the USPTO issued a reexamination certificate "confirming the patentability of all challenged claims" of the '548 patent, and that "Align was not required to amend or narrow any of the challenged patent claims." Source: https://investor.aligntech.com/index.php/news-releases/news-release-details/align-technology-prevails-additional-us-patent-office
• Judge panel: N/A (examiner/CRU, not an APJ panel).
• Petition grounds: Not public in a § 312-style petition format; ex parte reexam grounds are limited to patents and printed publications. ClearCorrect's 2015–2017 campaign relied on art that Align characterized as "not new, and were all previously of record with the USPTO."
• Outcome: Claims confirmed without amendment. This proceeding is the reason the '548 patent's reexamination certificate family exists alongside the earlier Certificate C1 (from 90/007,510, filed 2005-04-15, used during the OrthoClear litigation).
• Defensive value: Low as a defensive tool (you cannot join or participate — estoppel-free but also leverage-free), but highly relevant as prior-administrative history: the examiner affirmatively re-confirmed the asserted claims over ClearCorrect's art in 2017, which strengthens the patent owner's § 282 burden arguments on the claims that were not invalidated by the CAFC.

IPR2016-00270 — ClearCorrect Operating, LLC v. Align Technology (the only Align-adjacent IPR ClearCorrect ever filed — on a different patent)

• Type: Inter Partes Review.
• Filed: 2015 (petition; institution May 2016).
• Status: Final Written Decision issued 2017-03-24 — claims 1, 2, 9, and 10 of US 6,699,037 held invalid. ("The other un-challenged claims remain valid and enforceable." — Align, 2017-03-28.)
• Judge panel: Michael P. Tierney (Vice Chief APJ), Josiah C. Cocks, James J. Mayberry. Source (hearing transcript, 2017-02-01): https://www.docketalarm.com/cases/PTAB/IPR2016-00270/Inter_Partes_Review_of_U.S._Pat._6699037/docs/02-21-2017-Board/Hearing_Transcript-41-Record_of_Oral_Hearing.pdf
• Grounds: § 103 obviousness over Snow in view of Hultgren and Kesling (and an alternative Snow–Lemchen–Kesling ground that was not adopted at institution).
• ⚠️ Critical caveat: This IPR is on the '037 patent, not the '548 patent. It is listed here only because (a) it is the closest thing to a PTAB precedent against Align's clear-aligner family and (b) the FWD expressly identified the '548 patent as "undergoing ex parte reexamination" (Control No. 90/013,606) — i.e., the Board itself treated the '548 patent as a reexam matter, not a trial matter. Source: https://www.docketalarm.com/cases/PTAB/IPR2016-00270/Inter_Partes_Review_of_U.S._Pat._6699037/docs/03-24-2017-Board/Final_Decision-43-Final_Written_Decision.pdf
• Appeal: Align stated its intent to appeal to the Federal Circuit. (I could not confirm the CAFC docket number or disposition within my search budget — flagging as unverified.)
• Defensive value: The Snow/Hultgren/Kesling and Lemchen art combinations are not estoppel-barred as to the '548 patent, because they were never part of an instituted IPR on the '548 patent. That is genuinely useful prior art to mine.

The real "invalidations" — Ormco v. Align (Article III, not a PTAB trial)

• CAFC 05-1426, decided 2006-08-31: reversed the district court and held claims 10 and 17 of the '548 patent invalid as obvious over the Truax/Rains orthodontic practices. Opinion: https://cases.justia.com/federal/appellate-courts/cafc/05-1426/05-1426-2011-03-27.pdf
• Second appeal, decided 2007-08-24: CAFC affirmed the district court's invalidity finding as to claims 1–3 and 11–13 of the '548 patent. (Source: Align 10-Q legal-proceedings notes: https://aligntech.gcs-web.com/static-files/991edbf2-42a5-46fd-b03c-7ab590c1f1a6)
• Why this matters more than any PTAB record: the claims that a demand letter is most likely to assert (system claim 1 and method claim 11, plus 2, 3, 12, 13, and dependents 10 and 17) are judicially dead. That is a stronger, cheaper defensive posture than an IPR would have produced.

Strategic summary

Claim status. Canceled/invalidated by final judgment: 1, 2, 3, 10, 11, 12, 13, 17 (CAFC 2006 and 2007). Adminstratively confirmed by the examiner in reexamination: the challenged claims of the '548 patent as of the 2017-03-22 certificate — but note the tension flagged in the prior section: judicial invalidation of claims 1–3, 10–13, 17 coexists with administrative confirmation of "all challenged claims," which is only reconcilable if the 2015 reexam challenged a different (probably narrower) claim set than the claims Ormco litigated. I have not resolved that claim-by-claim overlap and you should pull the actual 90/013,606 file history before relying on it. Untested claims: the fabrication / digital-data / annotation family (independent claims 29, 41, 45, 49, 65, and their dependents). Those are the only claims a careful plaintiff would assert today.

Estoppel landscape. Because no IPR/PGR/CBM was ever instituted on the '548 patent, no § 315(e)(2) estoppel attaches to this patent at all — for ClearCorrect, OrthoClear, or anyone else. Every ground ClearCorrect raised in its 26 reexaminations (including the art it used against the '548 patent in 90/013,606) remains fully available in district court, and the IPR-ground estoppel from IPR2016-00270 is limited to the '037 patent. Practically, this means your invalidity case is wide open: you can re-run, in court, exactly the art ClearCorrect ran at the examiner — though be aware the examiner already rejected it once, so you will need either new art or a better expert record. The more valuable effect runs the other way: because the examiner confirmed the claims in 2017, the patent owner can argue a "presumption of validity fortified by reexamination," and you should expect that argument.

Pattern signals. ClearCorrect is the dominant challenger: 26 ex parte reexam requests 2015–2017 (control numbers listed in its own petition at https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557671](/patent/1557671)/download-documents) resulting in only one canceled claim and one amended claim across the entire portfolio — and neither of those was the '548 patent. It filed exactly one IPR in that era (the '037 patent) and only later moved into IPR territory against newer Align patents (e.g., IPR2025-00817, which per the Docket Alarm caption involves US 10,791,936, not the '548 patent — https://www.docketalarm.com/cases/PTAB/IPR2025-00817/ClearCorrect_Operating_LLC/docs/04-10-2025-Petitioner/Exhibit-1002-Prosecution_History_of_the_936_Patent_Part_1_of_2.pdf). There is no defensive aggregator (e.g., Unified Patents) in the chain for the '548 patent; Google Patents lists only district court, ITC, and CAFC cases. The patent owner (Align) has litigated aggressively and did pursue appeals, but the CAFC activity on the '548 patent ended in 2007.

Recommended next steps

1. Do not look for an IPR. There isn't one, and the patent expired 2017-10-08, so an AIA petition against the '548 patent is now time-barred by the patent's own expiration (and would be economically pointless). Your defense is § 282 invalidity + the preclusive effect of the Ormco judgments between align and those parties, plus design-around.
2. Pull the 90/013,606 file history (Public PAIR / Patent Center) to determine the exact claim set challenged and confirmed, and reconcile it against the CAFC invalidations of claims 1–3, 10–13, and 17. Link: https://patents.google.com/patent/US6398548/en lists the family; use USPTO Patent Center for the reexam documents.
3. If a demand letter asserts claims 1–3, 10–13, or 17, respond by quoting the dispositions: CAFC 05-1426 (2006-08-31) invalidating claims 10 and 17, and the 2007-08-24 CAFC affirmance invalidating claims 1–3 and 11–13. Those claims are dead by judgment.
4. If a demand letter asserts the untested fabrication/digital-data/annotation claims, mine the Snow, Hultgren, Kesling, and Lemchen references from IPR2016-00270 (all estoppel-free as to the '548 patent) plus ClearCorrect's 90/013,606 reexam art. Be candid about the headwind: the examiner confirmed those claims in 2017.
5. Note the verification gap: I could not access PACER, the CAFC docket system, or the PTAB E2E API directly. My negative finding on 2026 AIA trial activity rests on the supplied ODP block plus web search. Treat "no PTAB activity" as confirmed for the patent's lifetime (the searches surfaced none across 2015–2017, the peak assertion window), but as "not found" for any hypothetical filing after my search window.

I'll research the assignment chain for US 6,398,548 across the sources specified.

Let me dig deeper into the specific assignment records and Align's corporate history.

I need the specific reel/frame numbers. Let me search the assignment databases directly.

I hit the tool-call limit before I could complete direct queries against the USPTO Assignment Center search API, so I could not retrieve the reel/frame numbers or the recorded correspondent for this patent. I am flagging that gap explicitly rather than filling it in. What follows is built from the Google Patents legal-events ("reassignment") block in the authoritative patent text supplied in the prompt, plus corroborating public sources.

Inventors

Pattern notes and caveats:

• No departure-to-fire-sale pattern is evident here. The classic red flag — all inventors leaving the assignee within 12 months of filing, ahead of a portfolio dump — does not apply in the way it usually does, because the patent was never sold. What did happen is that founder-level personnel churn hit Align in the early 2000s (publicly reported departures of Chishti and Wirth from Align around 2001–2002, after the board replaced founding management). I am not certain of the exact dates and am not asserting them as fact; what is verifiable is that Align remained the assignee and the patents became Align's own assertion weapons, not sold assets.
• Name rendering is genuinely inconsistent across official records, and I am not auto-correcting it:
  • The issued face page and the reexamination certificate (US 6,398,548 C1) print the first inventor as "Chishti Muhammad" / "Muhammad et al."
  • EPO family records print "Muhammad Chishti."
  • One Google Patents reassignment entry renders him "CHISTI, MUHAMMAD" (missing "h") — a record typo.
  • Separately, related Align patents list "Zia Chishti" as an inventor. Muhammad Chishti and Zia Chishti are distinct individuals appearing on different Align filings; do not merge them.
• One source OCR'd Lerios as "Lerbes." Google Patents and the reexam certificate both read Apostolos Lerios — treat that as controlling.

Original assignee

Align Technology, Inc. — named on the issued patent at Santa Clara, CA (later 2560 Orchard Parkway, San Jose, CA 95131; early filings list 442 Potrero Avenue, Sunnyvale, CA 94086).

• Did they ship a product embodying the claims? Yes. Align commercialized the claimed subject matter as the Invisalign clear-aligner system — a series of polymeric shell appliances worn successively to incrementally reposition teeth. That is literally the claimed system of claim 1.
• Primary line of business: Medical devices — digital orthodontics. Clear aligners (Invisalign), intraoral scanners (iTero), and orthodontic treatment-planning software/services.
• Current status: Operating, publicly traded (NASDAQ: ALGN). Not acquired, not dissolved, not in bankruptcy. Align remains a large, healthy operating company and is still the record assignee.

Assignment timeline

Confirmed records (from Google Patents legal events on the authoritative patent page):

• 2001-04-30 (executed) / recorded 2001-04-30 — Reel/Frame NOT RETRIEVED

  • Conveyance: Assignment of assignors' interest ("ASSIGNMENT OF INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignors: Muhammad Chishti; Brian Freyburger; Kelsey Wirth — recorded as "who are co-inventors together with Apostolos Lerios & Richard Ridgley"
  • Assignee: ALIGN TECHNOLOGY, INC.
  • Correspondent: not retrieved (I could not reach the record's correspondent field; note the patent's agent of record is Townsend & Townsend and Crew, LLP — likely but unconfirmed as the recording correspondent)
  • Context: Founder/inventor-to-company assignment — perfecting Align's chain of title from the named inventors.

• 2001-04-30 (executed) / recorded 2001-04-30 — Reel/Frame NOT RETRIEVED

  • Conveyance: Assignment of assignors' interest ("ASSIGNMENT OF INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignors: Richard Ridgley; Brian Freyburger; Muhammad "Chisti"; Apostolos Lerios; Kelsey Wirth
  • Assignee: ALIGN TECHNOLOGY, INC.
  • Correspondent: not retrieved
  • Context: Second inventor-to-company assignment recorded the same day — an internal housekeeping/perfection of title, not an arm's-length transfer. The two same-day entries most likely cover different applications in the family chain (this application and its '893/PCT predecessors); I could not confirm which document maps to 09/466,353 without the record images.

No post-issuance assignments exist. There is no conveyance from Align to any LLC, holding company, trust, or asserter anywhere in the record. Google Patents' legal events for this patent show only: filing (1999-12-17), the two 2001-04-30 assignments, issuance (2002-06-04), and anticipated expiration (2017-10-08). The absence of any downstream assignment is itself the central finding here.

Verification links:

• USPTO Assignment Center: https://assignmentcenter.uspto.gov/
• Legacy Assignment Search: https://assignment.uspto.gov/patent/index.html
• Google Patents legal events: https://patents.google.com/patent/US6398548/en

Data-integrity flag: I am reporting assignment events, parties, and dates only. I have not fabricated reel/frame numbers or a correspondent name. Those fields must be pulled from the Assignment Center record directly (search by patent number 6,398,548 or application 09/466,353).

Timeline diagram

timeline
    title Ownership of US 6398548
    1997 : Priority provisional filed
    1999 : Application filed by Align Technology
    2001 : Inventors assign rights to Align Technology
    2002 : Patent issued to Align Technology
    2003 : Align sues Ormco for infringement
    2006 : CAFC invalidates claims 10 and 17
    2007 : Reexam certificate issued
    2017 : Patent expires

NPE / troll-pattern signals

Verdict

Operating-company assertion.

The assignment chain contains exactly two recorded conveyances, both dated 2001-04-30 and both running from the named inventors to ALIGN TECHNOLOGY, INC. — a routine perfection of the founder/employee title chain. No downstream assignment, LLC transfer, security interest, or aggregator transaction appears anywhere in the record, and Google Patents' legal events show ownership resting with Align from the 1999-12-17 filing through the 2017-10-08 expiration. Align both ships product embodying the claims (the Invisalign aligner series) and asserted this patent in its own name against direct competitors (Ormco/AOA; OrthoClear), which is the textbook inverse of an NPE pattern.

Confidence caveat: Strong on the absence of any NPE transfer (that is corroborated by the legal-events record and by Align's own SEC-disclosed litigation posture). Incomplete on the record-level detail — reel/frame numbers and the correspondent of record were not retrievable in this session and should be confirmed directly at https://assignmentcenter.uspto.gov/.

Cross-reference flag for the earlier section: No contradiction found. The two 2001-04-30 assignments corroborate the prior summary's note that "reassignment records show an assignment recorded Apr. 30, 2001 to Align Technology, Inc., and no later conveyance was found." The two same-day entries explain why the earlier analyst saw what looked like one assignment where the record actually lists two — both to the same assignee.

I'll research the prior art citations for US 6,398,548 B1, starting with the patent's own references and the litigation-tested art.

I have the litigation-tested art. Now let me nail down the patent citations on the face of the '548 patent.

I've gathered the material I can within my source budget. Note upfront: I was unable to retrieve a machine-readable version of the front-page "References Cited" block from the '548 image, so the list below is reconstructed from (a) the specification's own "Description of the Background Art" section (which mirrors the face citations), and (b) the litigation/reexam record. I flag where dates or mappings are unverified.

Prior art analysis — US 6,398,548 B1

0. Framing: two different populations of "prior art" exist for this patent

It is important not to blur these together, because they carry very different §102/§103 weight:

• Population A — art that was actually applied against the claims and invalidated them (Truax, Rains). These are prior public uses / printed instructions, invoked under §102(a) in the Ormco v. Align litigation, not patents cited on the face of the '548.
• Population B — the ~35 patents and ~10 journal articles cited on the face / discussed in the background section. These were cited as background context for the state of the art. The examiner allowed all 71 original claims over them; none was used to reject a claim. Their §102 relevance is therefore theoretical, and I say so explicitly below rather than asserting anticipation.

Effective filing/priority date (critical for every §102 call): application 09/466,353 filed Dec. 17, 1999, but it is a continuation of PCT/US98/12861 (Jun. 19, 1998), which is a continuation of US 08/947,080 (Oct. 8, 1997, now US 5,975,893), claiming priority to provisional 60/050,342 (Jun. 20, 1997). So the earliest priority date is Jun. 20, 1997, and any reference published/issued after that date is only available as §102(e) art (and then only if its own filing date precedes). This matters for at least two of the face citations (see §2.6).

1. POPULATION A — the art that actually invalidated claims

1.1 Dr. Truax's orthodontic practice + instruction sheet

• Citation: The prior orthodontic system and patient instruction sheet of Dr. Truax (an orthodontist), as corroborated by documentary evidence; combined with FDA regulations requiring instructions for medical devices.
• Date: Public "knowledge or use by others" predating the Jun. 20, 1997 priority date; promoted through seminars and clinics at which Truax distributed his instruction sheet. No single publication date — it is a §102(a) prior-use/printed-publication reference.
• Brief description: Truax took a single mold of a patient's teeth, repositioned the "tooth cavities" on the mold, and made three appliances at one time from the repositioned mold, each of a different thickness (typically 0.015–0.030 in.). Thinner = less force = used first. Truax gave the patient one appliance at a time and supplied the next after reviewing progress. His instruction sheet indicated appliances were to be replaced every 14–21 days.
• Claim mapping:
  • Claim 10 (depends on claim 1; adds "at least some appliances marked to indicate order of use") — held obvious; the CAFC reasoned Truax's differing thicknesses themselves served as the marking.
  • Claim 17 (depends on claim 11; adds replacement "at an interval in the range from 2 days to 20 days") — held obvious; Truax's 14–21-day instruction overlapped the range (presumption of obviousness).
  • By extension, independent claims 1 and 11 were necessarily rendered obvious (Ormco I reasoning, applied in Ormco II).
• Confidence: High. This is directly from the CAFC opinions and Finnegan's case note.
• URL: https://www.courtlistener.com/opinion/[211087](/patent/211087)/ormco-corporation-v-align-technology/ ; http://g.casetext.com/case/ormco-corp-v-align-technology-inc-2

1.2 Dr. Rains' orthodontic practice

• Citation: The prior orthodontic practice of Dr. Rains.
• Date: Prior public use, predating Jun. 20, 1997.
• Brief description: Rains used a series of three plastic retainers to incrementally adjust teeth. Unlike Truax, Rains generally made the appliances one at a time, taking a mold of the patient's teeth at each visit and creating an appliance based on that mold with the appropriate geometry (i.e., an iterative rather than batch-fabricated process).
• Claim mapping — this is the reference that actually anticipated (not merely rendered obvious) claims:
  • Claims 1–3 — held invalid as anticipated by Rains (affirmed on the second appeal via law-of-the-case).
  • Claims 11–13 — held invalid as anticipated by Rains (same).
• Legal significance: Because claim 1's "system" was read to cover appliances produced by an iterative process, and the "marked to indicate order of use" limitation was construed to permit conveying order information to the orthodontist rather than the patient, Rains' practice was held to anticipate. Align's cross-appeal arguments on the "system" and "marked" constructions were rejected. (FindLaw summary, CAFC 2007.)
• Confidence: High.
• URL: https://caselaw.findlaw.com/court/us-federal-circuit/[1414208](/patent/1414208).html

1.3 Dr. Harrell's work (raised, but not the basis of judgment)

Ormco also argued Dr. Harrell's work would have rendered the claims obvious. This was raised on cross-appeal but the affirmance rested on Rains/law-of-the-case. I did not verify a Harrell-specific anticipation finding — treat as argument, not holding.

Net effect: By Aug. 24, 2007, claims 1–3, 10–13, and 17 of the '548 patent had all fallen — claims 10 and 17 as obvious over Truax (+FDA), and claims 1–3 and 11–13 as anticipated by Rains. This is why Align's $884,000 Ormco escrow was returned.

2. POPULATION B — the face-of-patent citations (background art)

These are grouped by the technical role each reference plays in the '548's specification. None was applied by the examiner. The "§102 role" column states what the reference could be asserted against, with the caveat that these are background citations and the patent issued over them.

2.1 Digital imaging / scanning of teeth and casts (basis for the IDDS acquisition claims)

2.2 Ormco / Andreiko family (designing orthodontic appliances from digital tooth images)

US 5,533,895 (Jul. 9, 1996); 5,474,448 (Dec. 12, 1995); 5,454,717 (Oct. 3, 1995); 5,447,432 (Sept. 5, 1995); 5,431,562 (Jul. 11, 1995); 5,395,238 (Mar. 7, 1995); 5,368,478; and 5,139,419 — all Andreiko et al. / Ormco Corporation.

• Description: Manipulating digital images of teeth to design orthodontic appliances; the parent family of the '444/'432 patents that Align/Allesee litigated against. They claim, broadly, generating scan data of the patient's teeth, displaying a graphic representation, and altering the graphic representation per a prescription to produce a digital model of a desired arrangement.
• §102 role: Could bear on claims 1, 11, 29 (initial/final digital data sets and manipulation per prescription). These are the most substantively overlapping patent citations in the face list, since they are the commercial-competitor art directed to the same CAD/CAM orthodontic workflow.

2.3 Tooth-positioner manufacturing (Kesling-lineage art)

US 5,055,039; 4,798,534; 4,856,991; 5,035,613; 5,059,118; 5,186,623; and 4,755,139.

• Description: Manufacture of orthodontic positioners/retainers — i.e., the polymeric-shell appliance itself, molding a positive model and forming a negative shell over it.
• §102 role: The appliance-structure and molding steps of claims 1, 11, 29, 41, 45, 49 and 65. Note: these are the classic Kesling-family positioner references; they teach the article but not the multi-stage digital scheduling that is the '548's novelty.

2.4 Other "patents of interest"

US 5,549,476 (Stern, Aug. 27, 1996); 5,382,164; 5,273,429; 4,936,862; 3,860,803; 3,660,900; 5,645,421 (Slootsky, Jul. 8, 1997). The specification lists these without technical characterization, so I cannot assign them to specific claims with confidence.

⚠️ Date caveat: US 5,645,421 (Slootsky) issued July 8, 1997 — after the June 20, 1997 priority date. It could therefore only qualify as §102(e) art if its filing date precedes Jun. 20, 1997. I did not verify that filing date. Flagging rather than resolving.

2.5 Family member (NOT prior art)

US 5,975,893 (Chishti et al., Nov. 2, 1999) is the direct parent of the '548 and shares the same inventive entity. It is a continuation-family member, not §102 art as to the '548.

2.6 Non-patent literature cited

Also relevant, from the ITC record (not the '548 face list, but part of the same prior-art universe): Nahoum — taught fabricating series of successive aligners by vacuum-forming thermoplastics over positive models in the 1960s. Treated by the ITC as cumulative.

3. Bottom-line mapping of §102 exposure

4. Explicit uncertainties

1. I could not retrieve the front-page "References Cited" block in machine-readable form. The above list is reconstructed from the specification's background section, which tracks the face citations closely ("Other patents of interest include…") but I did not independently confirm every entry on the printed face page, nor whether the examiner added citations during prosecution or reexamination (90/007,510 → US 6,398,548 C1).
2. References "of interest" without characterization (US 5,549,476; 5,382,164; 5,273,429; 4,936,862; 3,860,803; 3,660,900; 5,645,421) — I could not assign these to specific claims; the specification does not describe them.
3. "Anticipation" vs. "background citation." Only Rains was actually held to anticipate any claim. For every face-of-patent reference in Population B I have stated potential §102 exposure, not a finding — the patent issued over all of them.
4. Truax/Rains are prior use/publication art, not patent citations — they are not among the "patent citation" results the question seems to anticipate, but they are unambiguously the most relevant prior art for this patent.
5. US 5,645,421 (Slootsky) date sensitivity — flagged above; unverified filing date.
6. I did not obtain the examiner's original rejections/allowance for 09/466,353, so I cannot state which cited references (if any) the examiner considered closest.

Key URLs

• Patent: https://patents.google.com/patent/US6398548/en
• Ormco I (CAFC 05-1426, Aug. 31, 2006): https://www.courtlistener.com/opinion/211087/ormco-corporation-v-align-technology/ ; http://g.casetext.com/case/ormco-corp-v-align-technology-inc-2
• Ormco II (CAFC 2007, Rains anticipation): https://caselaw.findlaw.com/court/us-federal-circuit/1414208.html
• Finnegan case note: http://www.finnegan.com/files/Publication/cd345b72-13ad-465a-8c80-7f6c828c7032/.../Last%20Month%20at%20the%20Federal%20Circuit%20September%[202006](/patent/202006).pdf
• ITC Inv. No. 337-TA-562 (PUB 4555, Part 4): https://www.usitc.gov/publications/337/pub4555_part4.pdf

If you want, I can drill into any single reference from Population B (I have the strongest verified data for Kuroda US 5,605,459, Wu US 5,338,198, Dehoff US 5,452,219, and Lemchen US 5,011,405) and pull its full claim text for a side-by-side §102 chart against a specific '548 claim.

I'll ground this analysis in the actual prior-art references of record and the Article III obviousness record, then build claim-by-claim combinations.

Let me pull the specific prior-art references cited during prosecution/reexamination of this family (Snow, Nahoum, Hultgren, Lemchen) since those are the references the examiner actually weighed.

Obviousness Analysis — US 6,398,548 B1 under 35 U.S.C. § 103

Scope note / cross-reference. This section builds on the earlier-generated summary, which established the bibliographic record, the claim families, and the Article III outcomes. It does not repeat that material. Two things from the prior section are load-bearing here and are used as premises: (i) claims 1–3, 10, 11–13, and 17 of the '548 patent are judicially dead (CAFC 05-1426, decided 2006-08-31, invalidating claims 10 and 17 as obvious; second appeal decided 2007-08-24, affirming invalidity of claims 1–3 and 11–13 as anticipated by Rains), and (ii) the fabrication / digital-data-set / annotation family (independent claims 29, 41, 45, 49, 65 and dependents) is the only potentially live family.

Contradiction flagged (carried forward, not resolved): the 2017-03-22 reexamination certificate reflecting confirmation of "all challenged claims" in Control No. 90/013,606 coexists with the 2006–2007 judicial invalidations. That is reconcilable only if the 2015 reexam challenged a narrower/different claim set than the claims Ormco litigated. Nothing in the sources retrieved for this section resolves the overlap. Treat the "confirmed" claims as unverified as to identity.

1. The §103 framework actually applicable to this patent

• Statute: pre-AIA 35 U.S.C. § 103(a) (2000). The application was filed 1999-12-17 and claims priority through PCT/US98/12861 (1998-06-19) → US 08/947,080 (1997-10-08) → provisional 60/050,342 (1997-06-20). The CAFC applied §103(a) (2000) explicitly. 463 F.3d 1299, 1305.
• Effective filing / invention date: 1997-06-20 for subject matter supported by the provisional. Art dated on or after that date is not §102(a)/(b) art for that subject matter; art before 1996-06-20 is §102(b) art; art between those dates is §102(a) art if "known or used by others" or "patented or described in a printed publication."
• Graham v. John Deere factors govern: scope/content of the prior art, differences, PHOSITA level, secondary considerations. 383 U.S. 1 (1966).
• Governing post-KSR rationales used below: (A) combining known elements according to known methods to yield predictable results; (B) simple substitution of one known element for another; (C) use of a known technique to improve a similar device in the same way; (D) applying a known technique to a known device ready for improvement; (E) "obvious to try"; (F) design incentives / market forces; (G) predictable variation of a recognized range.
• Teaching away requires that a POSITA reading the reference "would be discouraged from following the path set out in the reference." In re Kahn, 441 F.3d 977, 990.
• Range overlap creates a presumption of obviousness rebutted only by teaching away or unexpected results. Iron Grip, 392 F.3d 1317; In re Geisler, 116 F.3d 1465. The CAFC applied this to claim 17.

2. Person having ordinary skill in the art (PHOSITA)

The record supports a two-track PHOSITA, and the choice matters:

• Track 1 (clinical/mechanical): an orthodontist or orthodontic-appliance technician with several years of experience fabricating removable elastomeric positioners/retainers (Kesling-type or vacuum-formed) from a plaster setup. This is the PHOSITA the CAFC effectively used for claims 10 and 17.
• Track 2 (computational): a designer with a dental-laboratory background plus working knowledge of 3D surface digitization (laser/contact range scanning), polygonal mesh manipulation, CAD, and rapid prototyping. This is the PHOSITA for the claims 29/41/45/49/65 family.

Both tracks existed by June 1997. Kuroda et al. (1996) reports laser scanning a plaster cast to produce a digital image; U.S. 5,605,459 (issued Feb. 25, 1997) is expressly incorporated in the '548 specification for "producing plaster casts of teeth and generating digital models using laser scanning techniques." A POSITA combining these skills is not a "person of extraordinary skill."

3. The prior-art corpus for this analysis

I organize the corpus by the categories the patent's own Background Art section identifies, supplemented by the references surfaced in the litigation and reexamination records for this family.

4. Combination sets that render the claims obvious

4.1 Combination A — Truax (+ FDA labeling regs) and Rains → claims 1–3, 10, 11–13, 17

This is not a hypothetical. It is the adjudicated combination, and it should be the starting point for any §103 opinion on this patent.

The combination. Truax's practice supplied: (a) a series of clear plastic shells fitting over the teeth; (b) each with a different geometry (different thickness = different "configuration" or "shape" under the CAFC's dictionary construction); (c) used in a prescribed order (thinner before thicker); (d) with cavities shaped to receive and reposition teeth; (e) replacement intervals of 14–21 days. Rains supplied: a series of three plastic retainers used to incrementally adjust a patient's teeth.

Motivation to combine / to modify. The CAFC did not need an express motivation to combine Truax and Rains — each independently disclosed the claimed incremental-series concept. The contested limitation was the instructions limitation of claim 10, and the CAFC supplied the motivation from outside the references: (i) Align's own concession at oral argument "that the general practice of providing instructions on how to use a medical device would have been obvious," and (ii) 21 U.S.C. § 352 ("[a] drug or device shall be deemed to be misbranded … [u]nless its labeling bears … adequate directions for use") and 21 C.F.R. § 801.5. Under KSR rationale (D) — applying a known technique (device labeling) to a known device (a shell series) ready for improvement — claim 10 falls.

The "marking" limitation. For the claim 1 marking element, the CAFC held that "the thicknesses of the devices served as markings to indicate their order of use," and rejected the argument that markings aimed at the orthodontist rather than the patient do not count. That disposes of the "marked to indicate their order of use" element on the merits.

Claim 17's range. Truax's instruction sheet said 14–21 days; claim 17 recites 2–20 days. The court applied the range-overlap presumption: "This interval substantially overlaps with the interval specified in claim 17. Align has also failed to show that Truax teaches away from the claimed range or that the claimed range produces new and unexpected results." That is a textbook rationale (G).

Teaching-away analysis (important and counterintuitive). Align's best argument was that Truax taught away from the claimed "single package / patient-driven" concept, because Truax testified: "No, because we want to manage it… [I]t would be ridiculous" to expect the patient to replace appliances on his own. The CAFC rejected this: "But there is nothing in the claim language that requires the devices be substitutable by the patient. In other words, the claims do not require that the device be capable of replacement by the patient rather than the dentist, or preclude visits to the dentist during the treatment regimen." The specification itself confirms periodic visits. So the teaching-away defense fails as a matter of claim scope, not as a matter of fact.

Outcome: claims 10 and 17 obvious (2006); claims 1–3 and 11–13 anticipated by Rains (district court, affirmed 2007).

Note the §102/§103 boundary: claims 1–3 and 11–13 fell on anticipation, not obviousness. For a §103 opinion these claims are a fortiori obvious (a reference anticipating a claim necessarily renders it obvious), but the cleanest citation is the anticipation holding. Where Rains' public practice is disputed as a reference, Truax alone supplies the same teachings and supports §103.

4.2 Combination B — Kesling + Warunek + Nahoum (+ the positioner-manufacture patents) → the appliance-structure limitations of claims 1, 2, 3, 11–16, 18–28

This is the strongest purely-documentary §103 case, and it is stronger than the litigated Truax case because Kesling himself supplies the express motivation.

Kesling supplies the concept and the suggestion to iterate. As reproduced in Warunek et al. (1989):

"The positioner has many uses other than final positioning and retention. Major tooth movements could be accomplished with a series of positioners by changing the teeth on the setup slightly as treatment progresses. At present, this type of treatment does not seem practical. It still remains a possibility, however, and the technique for its practical application might be developed in the future."

That is a §103 suggestion in the prior art to make a series of positioners, each differing "slightly" in the setup — precisely the "incrementally reposition … in small increments" heart of the '548 claims. The only gap Kesling identified was material elasticity.

Warunek closes the gap. Warunek's 1989 papers: (a) report silicone elastomers introduced for "comprehensive orthodontic realignment"; (b) explicitly note that "conventional Kesling-type tooth positioners are relatively inelastic and are primarily indicated as finishing devices," while newer materials have "claims of a greater range of tooth movement"; and (c) quantify force vs. displacement at 0.5, 1.0, 1.5, 2.0, and 2.5 mm of incisal displacement for four positioner materials. The '548 claims require increments of "less than 2 mm, preferably less than 1 mm, and more preferably less than 0.5 mm" — a range whose endpoints sit inside Warunek's measured grid. That is a range/result overlap (rationale G), not a leap.

Nahoum supplies the fabrication unit operation for the polymeric shell: vacuum-forming a thin polymeric contour appliance directly over a dental model. Nahoum (1964) predates the 1996 §102(b) bar by roughly three decades. The Breads/Abbatte patents (U.S. 5,186,623; 5,059,118; 5,055,039; 5,035,613; 4,856,991; 4,798,534; 4,755,139) supply the commercial molding-over-positive-model practice.

Motivation to combine (KSR (A)+(C)+(F)). All references are in the same field (removable elastomeric orthodontic appliances), address the same problem (moving teeth without fixed brackets/wires), and the combination is no more than the predictable union of: Kesling's appliance + Warunek's improved elastic material + Nahoum's vacuum-forming method + conventional molding. The '548 specification itself concedes the point: "[i]n a broadest sense, the methods of the present invention can employ any of the known positioners, retainers, or other removable appliances which are known for finishing and maintaining teeth positions in connection with conventional orthodontic treatment." That admission — quoted by the CAFC in the parallel '611 analysis — is fatal to any argument that the appliance structure was novel.

Teaching away? The only candidate is Kesling's "At present, this type of treatment does not seem practical." That is an express identification of an unsolved problem, which motivates the combination; it does not discourage it. A statement that a thing "still remains a possibility" that "might be developed in the future" is the paradigm of a §103 starting point, not a teaching away.

Predictability / reasonable expectation of success: yes — Warunek measured the forces; Nahoum and the Breads patents teach the fabrication; incremental staging was Kesling's own stated program.

Bottom line: claims 1–3 and 11–13 are obvious over Kesling + Warunek + Nahoum even if one rejects the Truax/Rains public-use evidence. The dependent claim set (2 mm limit, polymeric shells with cavities, instructions, interval) is obvious for the reasons in §4.1 plus the range-overlap of claim 17.

4.3 Combination C — Ormco digital-manipulation family + Kuroda + U.S. 5,605,459 → claims 21–28 (successive digital data sets) and 29–40 (data-set + fabrication)

What these claims require. Claims 21–28 (per the specification's corresponding disclosure) require: providing an IDDS and an FDDS, and producing a plurality of successive digital data sets by determining positional differences and interpolating them, optionally with key frames, and with the maximum linear movement of any point ≤ 2 mm / ≤ 1 mm / ≤ 0.5 mm. Claims 29+ add controlling a fabrication machine based on those data sets and fabricating appliances as negatives of positive models.

The combination.

• Kuroda (1996) and U.S. 5,605,459 supply the IDDS: laser-scanning a plaster cast into a digital representation.
• U.S. 5,607,305 / 5,587,912 supply digital computer manipulation of tooth contours.
• U.S. 5,533,895 / 5,474,448 / 5,454,717 / 5,447,432 / 5,431,562 / 5,395,238 / 5,368,478 / 5,139,419 supply "methods for manipulating digital images of teeth for designing orthodontic appliances" — i.e., the FDDS and the appliance-design bridge.
• U.S. 5,011,405 supplies determining "optimum" tooth/bracket positions computationally.
• U.S. 5,452,219 supplies scan → manipulate → mill a mold, which is the CAM half of the fabrication claims.
• U.S. 5,338,198, 5,342,202, 5,340,309, 5,549,476, 5,382,164, 5,273,429, 4,936,862, 3,660,900, 5,645,421 fill out range acquisition and appliance-design practice.

Motivation to combine (KSR (A), (C), (D), (F)). Every element is the application of a known computer-graphics technique (linear/spline interpolation between two keyed states) to a known data type (digitized tooth surfaces) for a known purpose (designing an orthodontic appliance). Interpolation between two endpoints over N stages is the definition of keyframe animation and is elementary in computer graphics; the '548 specification even cites Kochanek's spline paper and the standard "key frame" terminology. Market forces (rationale F) are documented: the CAFC noted Align's own CEO testified that Invisalign's success resulted "in part from the computerized design and manufacture of the aligners" — a feature the court held was unclaimed/non-novel.

Caveat. These claims are untested — no court has construed "producing a plurality of successive digital data sets" or "key frames." A defendant must be prepared for a narrow construction informed by the specification's path-scheduling and collision-detection embodiments, which is where Combination D comes in.

4.4 Combination D — Snow + Hultgren + Nahoum (+ Kesling) → claims 29–40 and 45–49 fabricating claims

This is the combination the examiner actually made in the sibling reexaminations, and it is the one Align successfully beat back.

The combination as the examiner framed it.

• Snow (U.S. 6,068,482) — "Method for Creation and Utilization of Individualized 3-Dimensional Teeth Models"; filed 1999-01-19 as a continuation of 08/785,664 filed 1997-01-19 (a date before the '548 provisional's 1997-06-20, supporting §102(e) treatment for any '548 claims entitled only to the later PCT/1998 filing). Snow discloses a 3D model, interpolation steps between a standard model and an individualized model, and "animation" through the series.
• Hultgren (U.S. 6,217,334) — digital dental modeling from a scanned impression, with the data electronically manipulable and usable "for creating dental appliances."
• Nahoum — mold-over-model fabrication of the appliance.

Motivation to combine (as the Board articulated it in the parallel IPR2016-00270 on U.S. 6,699,037). The Board found "a person having ordinary skill in the art would have had a reason to combine the teachings of Snow, Hultgren, and Kesling to replace Kesling's labor-intensive process with a computerized process, resulting in labor cost savings and resulting in modeling of more precise teeth movement." That is a textbook (C)/(F) articulation and it is directly transposable to the '548's fabrication claims.

Align's rebuttals — what a defendant must defeat.

1. Snow's model is generic. Align argued, and the examiner credited in the FR-16 interview summary, that Snow's teeth are not identical to any particular patient, so the combination would produce "a non-functional article" that fits no patient. This is a reasonable-expectation-of-success attack and it has teeth: the examiner twice wavered on it ("Examiner Phillips argued that the teeth of the standard model of Snow were not generically shaped, while Examiner Wehner indicated Snow was so limited").
2. Snow's interpolation is non-fabricable viewing animation. Align argued Snow's "animation" is for "the specialist or patient to view," does not output to a fabrication machine, and does not avoid tooth collisions. At least one Align expert (Dr. Mah) went further: Snow's 2D-X-ray eyeball matching "would likely lead to imprecise 3D representations," and successive appliances built on Snow's data "would lead to improper fit of the appliances and improper movement of the teeth."
3. The examiner ultimately confirmed. In the 2017 reexamination Align stated the USPTO "confirm[ed] the patentability of all challenged claims" and that Align "was not required to amend or narrow any of the challenged patent claims." The examiner's stated reason for patentability in the sibling '840 reexam was narrowly textual: the prior art did not teach "wherein the providing digital data representing the plurality of successive tooth arrangements … is accomplished before any of the plurality of dental appliances are used by the patient," and (as to claim 29) that "an intermediate successive tooth arrangement … is generated before a preceding tooth arrangement."

Assessment. Combination D is viable but contested. The "before any use by the patient" limitation is a genuine §103 obstacle that no reference in this corpus squarely addresses; the best counter-argument is rationale (D) — the whole point of the '548 system is batch fabrication at the outset (the abstract says so), and batch production of a series is the natural consequence of any computer-driven manufacturing plan, so it is an obvious design choice, not a patentable distinction. The FR-16 interview summary also undercuts the examiner's position procedurally: the examiners themselves "were unable to reach consensus on what they believed each reference actually disclosed." That inconsistency is useful cross-examination material.

4.5 Combination E — Truax marking + FDA labeling + stereolithography/milling (U.S. 5,452,219; SLA-250) → claims 29, 41, 45, 49, 65 (annotation family)

What these claims require. Claim 29: annotate the digital data sets "to add text or numbering," then fabricate appliances so the text/numbering appears on them. Claim 41: a digital data set "including text or numbering," fabricate a positive model on which the text/numbering appears, then the appliance as a negative. Claim 45: derive a negative-model data set, and "the appliance is marked with text or data." Claim 49: digital data "including text or numbering." Claim 65: a computer-generated positive model "with printed annotations," appliance fabricated as a negative.

The combination.

• "Marked to indicate order of use": Truax — thickness-as-marking; and Truax's instruction sheet prescribing order of use.
• Motivation to provide textual/labeling instructions on the device: 21 U.S.C. § 352; 21 C.F.R. § 801.5; confirmed as motivation by the CAFC (rationale D).
• The physical mechanism by which a mark appears on a molded part: this is the weak link, and it is where the analysis must be careful. A recessed or raised alphanumeric on a molded article is produced by the corresponding feature on the mold. Milling/engraving text into a mold is ancient, and U.S. 5,452,219 (laser scan tooth model → mill a tooth mold) supplies the milled-mold pathway; stereolithography (the '548 specification's own SLA-250 from 3D Systems) builds geometry directly from a data set, so text in the data set necessarily appears in the model.
• The '548 specification's own admission: the annotation "is added as recessed text (i.e. it is 3-D geometry), so that it will appear on the printed positive model." The claim thus recites the natural and inevitable consequence of putting geometry into a data set that is then built — rationale (C) in its purest form.

Motivation to combine. Once the appliance series is fabricated from digital data (Combination C/D), placing the order number in the data is a design choice with a recognized benefit: the specification itself concedes the annotation may be placed where it "will appear on the delivered repositioning appliance(s)." No new technical result is obtained. Rationale (B) (substitution) and (F) (regulatory/market incentive to label).

Headwind — be candid. This family was not invalidated in the Ormco litigation, and the 2017 reexam certificate purports to confirm challenged claims. Align will argue the claims are directed to non-obvious manufacturing integration (marking the data set so the mark is co-extensive with the appliance geometry), which none of the cited references performs. A defendant should not assume these claims are weak merely because claims 1–3 and 11–13 are dead; they are the family Align designed to survive.

4.6 Combination F — Gottschalk "OBBTree" (1996) + U.S. 5,607,305/5,587,912 (digital contour manipulation) → path-scheduling / collision-detection dependent claims

What the claims require. The specification's FIG. 8A–8D and 9A–9C embodiments (visibility function, children function, randomized search, OBB-tree recursive collision testing, lazy tree construction) support dependent claims directed to non-linear interpolation with interference avoidance and the "maximum linear movement … 2 mm / 1 mm / 0.5 mm" limitations.

The combination and motivation. The '548 specification expressly incorporates the SIGGRAPH OBBTree article (Gottschalk, Lin & Manocha 1996) and states that the collision detection algorithm "is based on" it. That is a self-identified prior-art starting point. Applying a published, general-purpose interference-detection algorithm to the known problem of tooth-tooth interference during orthodontic staging is rationale (D) — applying a known technique to a known device ready for improvement — with a reasonable expectation of success supplied by the article's own results. The '548's purported enhancements (lazy OBB-tree building; excluding triangles not needed for collision; supplying relative-motion information) are, on their face, optimization of a known algorithm (rationale (G)) and are documented in the specification as efficiency improvements ("to save memory and time," "improves the time taken for the collision detection by avoiding recomputation").

Caveat. No court has construed these dependent claims, and Align has consistently framed path scheduling as a differentiator. If asserted, expect a construction fight over "randomized search technique" and the "visibility"/"children" functions, and expect Align to argue the specific combination of interpolation + collision-checking + minimum-increment bound is not disclosed.

5. Secondary considerations — as actually adjudicated

This is where the '548 story is most instructive, because the objective indicia were litigated and Align lost on the nexus.

• Commercial success (Invisalign): Align proved it. The CAFC held the presumption of nexus was rebutted: "the evidence clearly rebuts the presumption that Invisalign's success was due to the claimed and novel features." The court credited Align's own witnesses — including CEO Thomas Prescott and expert Dr. Covell — that success flowed from transparent, bracket-and-wire-free aesthetics, comfort, and the computerized design and manufacture, and that Align itself argued only "partially" that success derived from claimed features.
• Long-felt need: rejected — no probative evidence that the claimed/novel features (as opposed to transparency and comfort) met it.
• Failure of others: rejected — the prior attempts failed "because the devices lacked the claimed features" was not supported.
• Interim/partial replacement: the court held that "the use of a series of clear appliances that are designed to be delivered to the patient in one appointment (which must be marked to indicate the order of their use), rather than braces that must be periodically adjusted, contributed to the success" — but the time savings from multiple appliances "was not new; Truax had already accomplished this," and the time savings from skipping the dentist "was not claimed."

Strategic takeaway: for the dead claims, secondary considerations are foreclosed as a matter of law by the 2006 judgment. For the untested fabrication/annotation claims, Align has not yet litigated nexus; but the CAFC's finding that Invisalign's success was driven by computerized design and manufacture cuts both ways. It undercuts nexus for the structural claims, yet it arguably supports nexus for the fabrication-family claims, because "computerized design and manufacture" is exactly what claims 29/41/45/49/65 cover. Expect Align to press that inversion if it ever asserts those claims.

6. Claim-by-claim bottom line

7. What a POSITA-motivation paragraph should say (model language)

A person of ordinary skill in the art in June 1997, seeking to move teeth without fixed brackets and archwires, would have been led directly to the Kesling positioner — the standard removable elastomeric appliance in the field — and would have read Kesling's own 1945 statement that "major tooth movements could be accomplished with a series of positioners by changing the teeth on the setup slightly as treatment progresses" as an invitation to develop exactly that technique. The obstacle Kesling identified was material elasticity. Warunek et al. (1989) removed that obstacle by reporting silicone positioner elastomers for "comprehensive orthodontic realignment" and by quantifying the force delivered at 0.5–2.5 mm of displacement — the very increments the '548 claims recite. Nahoum (1964) and the Breads/Abbatte positioner-manufacture patents (U.S. 4,755,139; 4,798,534; 4,856,991; 5,035,613; 5,055,039; 5,059,118; 5,186,623) supplied the vacuum/pressure molding-over-a-positive-model step that the '548 specification adopts verbatim. Independently, Truax's publicly promoted system and distributed instruction sheet disclosed a series of clear plastic shells of different geometries, used thinnest-first, replaced every 14–21 days, and Rains's practice disclosed a three-appliance incremental series. Finally, Kuroda et al. (1996), U.S. 5,605,459, and the Ormco digital-image-manipulation patents (U.S. 5,139,419; 5,368,478; 5,395,238; 5,431,562; 5,447,432; 5,454,717; 5,474,448; 5,533,895) demonstrated that tooth geometry could be digitized and manipulated computationally, and U.S. 5,452,219 demonstrated that a scanned tooth model could drive a machine to produce a mold. Combining these teachings required no more than the predictable application of known computer-graphics interpolation between two keyed states and a known fabrication pipeline, with the recognized benefit of reduced chair time and greater precision.

8. Uncertainties and verification gaps (explicit)

1. Claim text. Verbatim claim text for claims 4–9, 14–16, 18–28, 30–40, and 42–44, 46–48, 50–71 was not retrieved. The analyses above use the specification's corresponding disclosure plus the '611 analogs; they should be confirmed against the printed patent before being relied on.
2. Both §102 and §103 appear in the Article III record. I have kept them distinct: claims 10/17 = obviousness (2006); claims 1–3/11–13 = anticipation by Rains (district court, affirmed 2007). A casual reading of secondary sources conflates them.
3. The reexam "confirmation" cannot be matched to specific claims (see contradiction flagged at the top). Until the 90/013,606 and 90/007,510 file histories are pulled, statements that a given claim is "confirmed" are unreliable.
4. Snow's citable date depends on which '548 claims are entitled to provisional priority. Snow's U.S. application was filed 1999-01-19 as a continuation of 08/785,664 filed 1997-01-19. If a given '548 claim is entitled to the 1997-06-20 provisional, Snow's effective date (1997-01-19) still precedes it — but this turns on §112 support in the '664 parent and should be verified against the actual Snow patent, which I did not retrieve in full.
5. The examiner's 2017 rejection reasoning is drawn from the '840 sibling's file history (Control No. 90/011,199) and Align's characterization of the '548 result, not from the '548's own 90/013,606 record. Do not treat the '840 reasoning as binding on the '548 claims.
6. No PTAB proceeding exists on the '548 patent (per the earlier section and confirmed here), so unlike the '037 patent, there is no Board reasoning directly transposable. The IPR2016-00270 FWD's Snow/Hultgren/Kesling rationale is persuasive authority on the same art, not precedent on these claims — and the Federal Circuit vacated and remanded the Board's obviousness determination on the "final tooth arrangement" limitation (CAFC 17-2106, decided 2018-08-22), holding the Board's Snow finding deficient because Snow's model was generic. That remand undercuts Combination D as much as it supports it, and Align will cite it heavily.