US 6394801

I'll search for this specific patent number across the requested sources.

Now let me check for litigation and CAFC 2026 docket activity.

Let me search for any 2026 appellate activity.

US Patent 6,394,801 — Summary

No 2026 Federal Circuit docket activity was located for this patent. Details below, including the litigation that does exist. I flag where I could not confirm something authoritatively.

Bibliographic data (confirmed)

Source: https://patents.google.com/patent/US6394801/en ; https://uspto.report/patent/grant/[6499997](/patent/6499997) (family/continuation data)

Abstract

The patent describes a manipulable or reconfigurable dental model system and methods for modeling a series of tooth configurations corresponding to sequential tooth movements during orthodontic treatment. Patients progress from an initial configuration through intermediate stages to a final configuration, and appliances (typically thermoformable plastic positioning appliances) are formed over a three-dimensional mold of the patient's dentition. Rather than producing a new mold for each stage, the invention provides a manipulable/reconfigurable mold that models patient dentition and (optionally) gingiva at each stage.

Overview of the claims

One important caveat: the title and abstract describe the apparatus (the reconfigurable dental mold system), but the granted claims of the '801 are all method claims directed to a treatment-planning/repositioning method — the "mid-course correction" concept. The apparatus claims (frame, tooth members, manipulation devices, computer, simulated gingiva) appear in the sibling/continuation patent US 6,499,997, not here.

Claim 1 (independent) — plain language: An improved method for repositioning teeth and/or dental features using appliances that are polymeric shells with cavities shaped to receive and resiliently reposition teeth. The improvement has two parts: (a) at the outset of treatment, determine configurations for a number of appliances sufficient to move the teeth to a final arrangement, and produce that initial set of appliances; and (b) at a later time, determine a configuration for at least one additional appliance to move the teeth from an actual intermediate arrangement to a successive intermediate or final arrangement.

Claim 2: The method of claim 1 where the configurations for at least three appliances are determined at the outset.

Claim 3: The method of claim 1, additionally comprising determining that the initial set of appliances is not producing the desired intermediate arrangement, and determining the actual intermediate arrangement before determining the configurations for the additional appliances.

Claim 4: The method of claim 3, where the actual intermediate arrangement is determined by taking a mold of the patient's teeth after it has been determined that the initial set is not producing the desired result.

Source: https://patents.google.com/patent/US6394801/en (claims section); corroborated by https://uspto.report/patent/grant/6499997 and the Radaris claim transcription.

Litigation history (historical, not 2026)

• ITC Inv. No. 337-TA-562, Certain Incremental Dental Positioning Adjustment Appliances and Methods of Producing Same (Align Technology v. OrthoClear). The complaint (filed Jan. 11, 2006; instituted Feb. 7, 2006) asserted claims 1–4 of U.S. Patent No. 6,394,801 (the '801 patent), among eleven Align patents. Sources: https://www.usitc.gov/secretary/fed_reg_notices/337/337-ta-562.institution.1139514931_0.pdf ; https://www.federalregister.gov/api/v1/documents/E6-2164 ; https://www.govinfo.gov/app/details/FR-2006-02-15/E6-2164
• The investigation was terminated by a consent order (OrthoClear), which is cited in Align's filings: https://investor.aligntech.com/static-files/1656ec96-b2d1-4244-838c-af3ebae08db8
• A parallel federal action in the Western District of Wisconsin (filed Jan. 11, 2006) asserted the '801 patent; it was stayed and then dismissed without prejudice on Aug. 10, 2006: https://aligntech.gcs-web.com/node/13456/html
• ITC enforcement proceeding (from March 2012) and the Commission opinion of Feb. 19, 2013 (public version) held that accused "digital datasets" were electronic transmissions not covered by the consent order: https://www.martindale.com/legal-news/article_oblon-mcclelland-maier-neustadt-llp_1692004.htm
• Google Patents' litigation panel lists a first worldwide-family filing and two CAFC appeals, Nos. 13-1240 and 13-1363 (2013), together with ITC 337-TA-562. These are 2013 dockets, not 2026.

On the "CAFC 2026 dockets" request — explicit uncertainty

I could not find any 2026 Federal Circuit docket, opinion, or order involving U.S. Patent 6,394,801. My searches for the number alone, for "Align Technology Federal Circuit 2026," and for the patent combined with CAFC/appeal returned:

• No hits on "patent 6,394,801 Court of Appeals Federal Circuit 2026."
• The 2026 CAFC activity involving Align Technology that did surface concerns different patents: Dental Monitoring SAS v. Align Technology, Inc., Nos. 2024-2270 (Fed. Cir. July 7, 2026, nonprecedential — §101 ineligibility of U.S. Patent 11,049,248 claim 14 and U.S. Patent 10,755,409 claim 12), 2025-1752 (Fed. Cir. Aug. 10, 2026), and 2025-1879 (Fed. Cir. July 21, 2026 — IPR obviousness affirmance on the '248 and 11,109,945 patents). None of these involves the '801. Sources: https://www.cafc.uscourts.gov/2026/07/07/page/2/ ; https://fedcircuitblog.com/2026/07/21/opinions-orders-july-21-2026/ ; https://ipwatchdog.com/2026/07/07/federal-circuit-finds-deep-learning-patents-ineligible/ ; https://www.oliff.com/wp-content/uploads/2026/08/2025-1752-O.pdf

Interpretation: the '801 patent's 20-year term ended Dec. 3, 2019, and its legal status is "Expired – Lifetime," so 2026 appellate activity on this specific number would be unusual. I cannot rule out a docket I simply did not surface; if you need certainty on 2026 CAFC filings, a direct docket search (PACER/CM-ECF or the Federal Circuit's own docket) would be required, and I do not have a result to cite for one.

Relation to sibling patents (useful context)

The '801 sits in a continuation chain: 09/454,786 (US 6,227,851) → 09/779,802 (US 6,394,801) → 10/087,126 (US 6,499,997) → 10/280,535 (US 7,037,108) → 10/446,029 (US 7,108,508) → later filings including 11/375,602 (US 7,578,674) and 12/072,675 (US 7,837,904). The apparatus claims that match the '801's title/abstract live in US 6,499,997 and its descendants, several of which are expressly identified as terminal disclaimers/continuations of the '801.

I'll research litigation involving US patent 6394801 specifically. Let me run searches across litigation databases.

Good — I found the ITC investigation. Let me dig into the Federal Circuit appeals and the district court case.

Let me verify whether the '801 patent appeared in the ClearCorrect matters and any other cases.

Litigation Involving U.S. Patent No. 6,394,801

Important framing note: I interpreted the number literally as US 6,394,801 ("Manipulable dental model system for fabrication of dental appliances," Align Technology, Inc.). Note there is an unrelated JP 6394801 B2 (Murata Manufacturing, a pump/fluid-control patent) that appears in search results — I excluded it. Also note that my search tools stopped returning results after a few queries, so this is a good-faith compilation of what databases surfaced, not a certified exhaustive docket check. All identified litigation traces to Align Technology, Inc. v. OrthoClear and its ClearCorrect aftermath.

The '801 patent issued 2002-05-28 from App. No. 09/779,802 (filed 2001-02-07), a continuation of App. 09/454,786 (now US 6,227,851), claiming priority to Provisional 60/110,868 (1998-12-04). It expired (anticipated) 2019-12-03.

1. ITC Investigation No. 337-TA-562 — Certain Incremental Dental Positioning Adjustment Appliances and Methods of Producing Same

'801 was one of twelve Align patents asserted (along with the '469, '807, '548, '880, '840, '037, '994, '876, '070, '511 and '850 patents), plus trade-secret misappropriation. This is the core litigation touching '801.

Sources: 71 FR 7995 (Feb. 15, 2006); 71 FR termination notice (Nov. 17, 2006); Consent Order / Joint Motion to Terminate.

2. ITC Enforcement Proceeding (337-TA-562 enforcement) → Federal Circuit Nos. 2013-1240 & 2013-1363

The '801 patent is expressly named among the patents covered by the 2006 consent order that Align sought to enforce. The dispute turned on whether imported digital data sets were "articles manufactured in violation of" the consent order; the Federal Circuit held the ITC exceeded its authority by reviewing an ALJ order (denying a motion to terminate) rather than an initial determination.

Sources: CAFC opinion 2013-1240 (PDF); CourtListener 771 F.3d 1317; Practical Law summary; Finnegan "Last Month" summary.

The Google Patents page for US 6,394,801 likewise lists the ITC matter and CAFC cases 13-1363 and 13-1240: https://patents.google.com/patent/US6394801/en

3. District Court Patent Infringement Action — Align Technology, Inc. v. OrthoClear, Inc.

Sources: Align SEC filing — Patent Infringement Federal Action; Intellectual Property Transfer Agreement.

4. Related OrthoClear Actions (parallel litigation resolved by the same 2006 settlement)

These were named as "the Actions" in the October 12, 2006 Intellectual Property Transfer Agreement. I could not confirm from the sources retrieved whether the '801 patent was specifically asserted in each — several appear to have been Lanham Act / trade-secret / state-law claims rather than '801 infringement counts. I list them for completeness with that caveat:

• Align Technology, Inc. v. OrthoClear, Inc., et al., Case No. CGC-05-438361, Superior Court of California, County of San Francisco (state case).
• Align Technology, Inc. v. OrthoClear, Inc. and OrthoClear Holdings, Inc., Case No. CV 05-2948 (MMC), N.D. Cal., San Francisco Division (Federal Lanham Action I).
• Align Technology, Inc. v. OrthoClear, Inc. and OrthoClear Holdings, Inc., Case No. CV 06-3828 (SC), N.D. Cal., San Francisco Division (Federal Lanham Action II).

All were dismissed with prejudice in the October 2006 settlement, under which OrthoClear ceased worldwide aligner activity, consented to the exclusion order, assigned its IP to Align, and (per Align's SEC filing) Align made a one-time $20 million payment to OrthoClear Holdings.

Source: IP Transfer Agreement / Joint Motion to Terminate.

Cases where '801 was NOT asserted (checked to avoid over-inclusion)

• ITC Inv. No. 337-TA-833 (and the parallel S.D. Tex. action Align v. ClearCorrect, No. 4:11-cv-00695) — asserted the '325, '880, '487, '511, '666, '863 and '874 patents. '801 was not among them.
• Align v. Ormco/AOA — concerned Align's '548 and '611 patents and Ormco's own patents; '801 not asserted.
• Google Patents also flags a "first worldwide family litigation" entry via Darts-ip (family ID 22335346), consistent with the OrthoClear/Align family — no distinct additional case identified.

Summary of the litigation status of '801

All known U.S. litigation involving US 6,394,801 arose from Align's enforcement campaign against OrthoClear (2006 ITC 337-TA-562 and the W.D. Wis. patent case) and the subsequent ClearCorrect enforcement/appeal of the consent order that named '801 (Fed. Cir. Nos. 2013-1240 & 2013-1363, decided July 18, 2014, vacated and remanded). The '801 infringement claims themselves were resolved by OrthoClear's 2006 consent order and global settlement, not by a merits judgment. The patent expired in December 2019, so no live litigation is possible.

Caveats: (1) I did not have PACER/docket-level access for every resurrectable case, and my search was truncated; (2) the precise '801 counts in the N.D. Cal. and San Francisco Superior Court actions are unconfirmed; and (3) if you need a certified, exhaustive litigation history (including any later assignee/enforcement activity), a full run of Unified Patents' litigation portal and PACER, plus Darts-ip family 22335346, should be performed.

PTAB Proceedings for U.S. Patent No. 6,394,801

Caveat on sourcing: The canonical structured block in this prompt ("PTAB proceedings on file," sourced from the USPTO Open Data Portal) returns no AIA trial proceedings. I independently searched for any IPR/PGR/CBM naming the '801 across the PTAB Petitions portal, PTAB E2E, CourtListener, Docket Alarm, and general web sources. I found none. Everything below that is not about the '801 is labeled as such and is offered only as surrounding context — I have not imported it into the proceeding list.

Proceedings overview

Zero AIA trial proceedings on U.S. Patent No. 6,394,801 (0 IPR, 0 PGR, 0 CBM; no institution decisions, so no grants or denials, no FWDs, no settlements, no PTAB appeals). This is a "no PTAB activity" result, not a clean record. The correct defensive posture for someone receiving a demand letter today is not "the patent survived two IPRs and is hardened" and not "claims 1–4 have been canceled."

Two facts dominate the real posture, and neither is a PTAB fact:

1. The patent expired. Anticipated expiration is 2019-12-03 (20-year term from the 1998-12-04 priority via the 1999-12-03 parent filing); Google Patents carries status "Expired – Lifetime." A demand premised on current infringement of the '801 is legally incoherent — there is no enforceable term left. Any residual exposure is historical (damages window pre-expiration, plus the six-year § 286 lookback, itself long closed).
2. Claims 1–4 were litigated, not PTAB-tested. Claims 1–4 were the operative asserted claims in ITC Inv. No. 337-TA-562 (Align v. OrthoClear), instituted 2006-02-07, and terminated by consent order (Google Patents reflects the ITC action and CAFC Nos. 13-1240, 13-1363, which were the 2014 enforcement appeal). See prior "Litigation summary" section, which remains authoritative. The absence of any IPR is explained by that history: the patent was asserted and resolved in 2006, before IPR practice matured (first IPRs filed 2012), and expired before the modern Align v. ClearCorrect/Straight Smile era of Align-patent IPRs.

Bottom line: If a letter today cites claims 1–4 of the '801, the strongest response is not an invalidity theory — it is expiration plus the 2006 consent-order/settlement coverage. There is no PTAB estoppel to invoke, because no PTAB trial ever occurred.

Proceedings

There are no proceedings to describe. No proceeding number is invented here. For completeness on why the structured list is empty rather than merely under-ingested, the following adjacent data points (all concerning other patents, not the '801) are on the public record:

• IPR2017-01829 — ClearCorrect Operating LLC v. Align Technology, Inc., on U.S. Patent No. 8,038,444 ("'444," a descendant in the same Chishti/Align family). Institution denied (Paper 10, PTAB Feb. 5, 2018), as evidenced by Exhibit 1008 in a later ClearCorrect petition. Cited here only to show the family's patents did attract IPRs — the '801 did not. Link: https://www.docketalarm.com/cases/PTAB/IPR2017-01829/
• IPR2016-00270 — on U.S. Patent No. 6,699,037 ("'037," another Align patent asserted against OrthoClear). Link: https://www.docketalarm.com/cases/PTAB/IPR2016-00270/
• The 2006 ITC record itself documents that respondents/Staff ran invalidity on Lemchen and Kesling against the '487, '511 and '874 patents — not the '801. Source: https://www.usitc.gov/publications/337/pub4555_part4.pdf

None of these involved claims 1–4 of the '801.

Strategic summary

Canceled vs. sustained vs. untested. For the '801, the only accurate statement is "all four claims are UNTESTED at the PTAB." Claims 1–4 were never subjected to an AIA trial, so there is no FWD canceling claim 1, no FWD sustaining any claim, and — critically — no Board or Federal Circuit holding on validity of these claims at all. The validity work that did occur (e.g., the Align v. Ormco/AOA summary-judgment and jury fights over the '548 and '611 patents, and the Lemchen/Kesling challenges in the ITC) concerned sibling patents. Do not let a demand letter blur those into the '801.

Estoppel landscape. § 315(e)(2) estoppel is not in play and cuts no one's way. Estoppel attaches only to a petitioner that reached a final written decision; no IPR on the '801 ever reached any decision, so there is no estoppel barring any party from raising anything, and equally no petitioner-side narrowing to exploit. Conversely, the 2006 consent order and the October 12, 2006 global settlement do constrain OrthoClear and its related parties (consent order precluded OrthoClear from challenging validity of the Patents-In-Suit, which expressly included the '801), but those constraints are personal to OrthoClear/signatories, not a general estoppel. See https://investor.aligntech.com/static-files/1656ec96-b2d1-4244-838c-af3ebae08db8

Pattern signals. Align (the patent owner) is a serial and sophisticated PTAB and appellate participant, and its asserted patents have repeatedly been IPR targets — but not this one. No defensive aggregator (e.g., Unified Patents) has an IPR on the '801 in the public record, and there is no serial-petitioner pattern to report. The absence is best explained structurally: the '801's enforcement life was 2006, pre-IPR; its term ended 2019-12-03. Notably, the only Align-family IPR I could verify in this lineage (IPR2017-01829, on the '444) was denied institution, which is a mild signal that the family's Chen/Chishti disclosure is not trivially attackable on the art the Office already saw — but that inference belongs to the '444, not the '801.

Recommended next steps

• If you are a defendant today: say plainly that no PTAB proceeding has ever been filed against U.S. Patent No. 6,394,801, and do not treat that as a merits victory. Then pivot to the dispositive points: the patent expired 2019-12-03 (Google Patents "Expired – Lifetime"), and claims 1–4 were resolved against OrthoClear by the 2006 ITC consent order and October 12, 2006 global settlement, not by any adjudicated invalidity. Where the demand rests on those claims, the expiration/coverage argument is stronger and cheaper than an invalidity theory.
• If you nevertheless want an IPR-based fallback: understand that an IPR on the '801 is not available — IPR requires a live patent whose claims can be canceled, and this term has expired. There is no trial-stage milestone (institution deadline, hearing, 1-year § 316(a)(11) FWD deadline) to track because there is no trial.
• If you need certainty beyond this analysis: the absence of PTAB activity is corroborated by the structured ODP block plus my searches, but a certified check should be run directly on USPTO PTAB E2E / the ODP API "proceedings" endpoint and, for the pre-AIA era, the ex parte/inter partes reexamination records (I found no reexam certificate for the '801; the reexam certificate that surfaced in my searches — Jan. 8, 2008 — was for the '863 attachment patent, per the ITC record at https://www.docketalarm.com/cases/PTAB/IPR2016-00270/, not the '801).

Explicit uncertainty statement: I did not have direct PTAB E2E docket-level query access during this run, and my search tool truncated after a limited number of queries. I can state with high confidence that no AIA trial proceeding names U.S. Patent No. 6,394,801, but I cannot certify a negative across every one of the ~70,000+ petitions filed since 2012 from search alone. If a certified negative is required for a filing, pull the ODP proceedings endpoint directly and cite that output.

I'll research the assignment record for US 6,394,801 across USPTO Assignment Center and related sources.

Let me look for the recorded assignment data and Google Patents legal events.

I was unable to retrieve a reel/frame-level record for this patent — my search tool was exhausted before I could pull the Assignment Center entry directly, and no third-party source surfaced a reel/frame for US 6,394,801. Below I separate what is verified from what I could not verify, and I do not invent reel numbers.

Inventors

Sources: the patent face (Chishti, Muhammad; Phan, Loc X. — both listed as inventors of US 6,394,801); family/PCT record https://patentimages.storage.googleapis.com/ea/0a/d2/7674b473cfcb6e/WO2001080762A3.pdf (identifies Align Technology, Inc., 851 Martin Ave., Santa Clara, CA 94086 as applicant and gives both inventors' addresses); http://patentimages.storage.googleapis.com/0d/f0/ae/ea462a91676ed8/[US7037108](/patent/US7037108).pdf (same two inventors, assignee Align Technology, Inc., Santa Clara).

Employer determination: Both inventors are named on the common specification alongside Align's applicant data, and Muhammad Chishti is a co-founder of Align Technology (the "Chishti et al." inventor group at 442 Potrero Ave. / 851 Martin Ave., Sunnyvale–Santa Clara, is the founding Align engineering team). Loc X. Phan was an Align employee and prolific Align inventor on the '215, '863, '511-family and related filings. I am confident both were Align personnel at the relevant time, but I did not retrieve an employment agreement or an inventor-assignment instrument to prove it.

Unusual-pattern check — departure/fire-sale precursor: NOT present. There is no evidence of "all inventors departing the assignee within 12 months of filing." To the contrary, both inventors continued to invent on later Align filings after the '801 (e.g., Phan on US 7,128,825; Chishti on US 7,331,783, US 7,121,825, US 6,783,360), and the patent remained with Align. Chishti's later personal departure from Align (he went on to other ventures) did not carry the '801 with him. No inventor-originated transfer is indicated.

Original assignee

Align Technology, Inc. — named on the patent face ("(73) Assignee: Align Technology, Inc., Santa Clara, CA") and as "Original Assignee" and "Current Assignee" on Google Patents (https://patents.google.com/patent/US6394801/en). No assignment from Align is recorded anywhere I could find.

• Product embodying the claims: Yes. Align is the maker of the Invisalign clear-aligner system, and its clinical practice of making an initial set of aligners and then issuing mid-course corrections when a stage is not tracking maps onto the '801's granted claims (which are the "mid-course correction" method claims, not the mold-apparatus claims). Align accused OrthoClear's competing aligner product of infringing claims 1–4 (see my earlier litigation section), so the claims were treated by the parties as product-reading.
• Primary line of business: Orthodontic/dental devices — manufacture and sale of clear polymeric aligners (Invisalign), scanners (iTero), and digital treatment-planning software. Public company (NASDAQ: ALGN), headquartered Santa Clara → San Jose → Tempe, AZ today.
• Current status: Operating. Not acquired, not dissolved, not in bankruptcy. It is a sophisticated operator with an in-house IP department and an active enforcement program (ITC 337-TA-562 against OrthoClear; the ClearCorrect ITC/Fed. Cir. matters; current W.D. Tex. actions such as Align v. ClearCorrect, No. 6:24-cv-00187).

Assignment timeline

This is where I must flag a limitation. I could not retrieve the USPTO Assignment Center record for US 6,394,801 (searched by patent number and by inventor/assignee; my query budget was exhausted before reaching the Assignment Center index). I therefore have no reel/frame, execution date, or recording date to report, and I will not fabricate them.

What the available record does support:

• The application was filed 2001-02-07 by Align Technology, Inc. (applicant/assignee shown on the published application and the issued patent), as a continuation of App. 09/454,786 (filed 1999-12-03, now US 6,227,851), claiming priority to Provisional 60/110,868 (1998-12-04). Family ID 22335346.
• Correspondence address of record in this family (prosecution/recorded documents): Townsend and Townsend and Crew LLP, Two Embarcadero Center, Eighth Floor, San Francisco, CA 94111-3834 (from uspto.report for sibling App. 10/087,126, https://uspto.report/patent/app/20020094503). Note: the assignment correspondent can differ from the prosecution correspondent, and I could not confirm the assignment correspondent here.
• No post-issuance assignment appears anywhere in the sources I reached: Google Patents lists the "Current Assignee" as Align Technology Inc. — identical to the original assignee — and its legal-events panel for '801 (as contained in the authoritative text you supplied) shows only priority/filing/publication/grant/expiration and litigation entries, with no "AS – Assignment" event. For comparison, a sibling document on the same page (US 2005/0275129 A1) does show an "AS Assignment … REEL/FRAME: 015481/0162" event — i.e., Google Patents does render AS events when present, so the absence for the '801 is at least weak corroboration that the chain terminates at Align.

Net finding: I found no evidence of any post-issuance assignment or change of ownership of US 6,394,801. The presumption is that Align Technology, Inc. is and always has been the sole owner, with (at most) the standard inventor→Align assignment recorded around the 2001 filing — the reel/frame of which I could not verify. If you need the exact reel/frame, run the search directly at https://assignmentcenter.uspto.gov/ (search "6394801" or "09779802") and/or https://assignment.uspto.gov/patent/index.html; the Google Patents legal-events tab for '801 is a secondary check.

Timeline diagram

timeline
    title Ownership of US 6394801
    1998 : Provisional 60110868 filed
    1999 : Parent app 09454786 filed
    2001 : Continuation app 09779802 filed
    2002 : Patent issues to Align Technology
    2006 : Align asserts claims 1 to 4 at ITC
    2014 : CAFC vacates in Align v ITC
    2019 : Patent expires

Diagram note: no ownership-transfer event exists to plot — the chain has no assignment node after issuance. The only ownership fact is the constant "Align Technology, Inc." from filing through expiration.

NPE / troll-pattern signals

Verdict

Operating-company assertion.

Align Technology, Inc. — the original and (per Google Patents' "Original/Current Assignee" fields and the absence of any "AS – Assignment" legal event on the '801) apparently the only owner — is a public operating company that ships Invisalign aligners embodying the claimed method, and it asserted claims 1–4 of the '801 itself against OrthoClear in ITC Inv. No. 337-TA-562 (complaint 2006-01-11; instituted 2006-02-15; terminated by consent order 2006-11-13), with the consent order later enforced in the ClearCorrect proceedings (Fed. Cir. Nos. 2013-1240 & 2013-1363). Not a single NPE signal is supported by the record: no shell-entity transfer, no known asserter, no cascading or pre-litigation transfer, no defensive aggregator. The one-line honest caveat is that I could not pull the Assignment Center reel/frame to prove the chain has only one node — but every secondary source is consistent with an uninterrupted Align ownership from the 2001 filing to the 2019-12-03 expiration.

Verification link: https://assignmentcenter.uspto.gov/ (search "6394801" or application "09779802"); mirror at https://assignment.uspto.gov/patent/index.html; secondary at https://patents.google.com/patent/US6394801/en (Legal Events tab).

Caveats I want on the record: (1) I could not retrieve the Assignment Center index itself, so I cannot certify that zero assignments are recorded — I can only report that none surfaced and that Google Patents shows none. (2) I did not verify the reel/frame of the presumed inventor→Align assignment. (3) I took the patent number literally as US 6,394,801 and excluded the unrelated Japanese patent JP 6394801 B2 (Murata Manufacturing, a pump/fluid-control patent) that pollutes search results.

I'll search for the specific patent and its cited prior art references.

Let me search specifically for the cited references (front page) of this patent.

Let me try to locate the actual front-page reference list from the patent PDF and USPTO records.

⚠️ Important limitation on this analysis (please read first)

I was not able to retrieve the actual front‑page "(56) References Cited" list for US 6,394,801. The authoritative Google Patents full text you supplied does not include the References Cited / Patent Citations panels for this document (the fetched text jumps from the abstract/description straight past the bibliography to the claims), and my targeted searches for the '801's own front‑page citations did not surface the (56) list before my search tooling was cut off.

Per the operating rules, I will not fabricate a (56) list. Instead I have separated what is confirmed from what is inferred, and I flag each item's status. If a certified (56) list is required, the authoritative source is the USPTO PatentCenter document for Application 09/779,802 (the front‑page PDF) or the EPO/Espacenet "References Cited" tab.

1. Patent identity (confirmed, literal interpretation)

Sources: https://patents.google.com/patent/US6394801/en

2. References expressly cited inside the '801 specification (CONFIRMED)

These are drawn from the authoritative full text you provided. They are references the applicants incorporated by reference, and they are the only prior‑art‑type citations I can confirm appear in the '801 itself.

3. Related patents in the same family (cross‑referenced, NOT prior art)

These are continuations/parents sharing the 1998‑12‑04 priority, so they are not prior art to the '801 — but a patent analyst must note them, because they can raise obviousness‑type double patenting issues (and they are the documents whose citation lists are often confused with the '801's):

• US 6,227,851 B1 (parent, 09/454,786) — apparatus claims (the reconfigurable dental model system)
• US 6,499,997 B2 (10/087,126) — apparatus/method claims
• US 7,037,108 B2 (10/280,535) and US 7,108,508 B2 (10/446,029)
• US 7,578,674 B2 (11/375,602) and US 7,837,904 B2 (12/072,675)

Sources: https://patents.google.com/patent/US6394801/en (Continuity/Family panels); https://uspto.report/patent/app/20020094503

4. Prior art that bears directly on the '801's claim subject matter (INFERRED from related proceedings — flagged)

The '801's granted claims are all method claims directed to a two‑step treatment‑planning method. The patent‑office/PTAB art that was used against this same family of claims on the sibling US 6,398,548 ('548/'037 lineage, IPR2016‑00270, ClearCorrect v. Align) is therefore the most probative prior art to consider against '801 claims 1–4:

Sources: IPR2016‑00270 demonstrative exhibits; Fed. Cir. 17‑2106 nonprecedential opinion

5. §102 analysis — claim by claim

The governing rule: for §102 anticipation the entire claim must be disclosed in a single reference, arranged as claimed. Claim 1 is conjunctive: it requires BOTH (a) at the outset, determining configurations for a number of appliances sufficient to move teeth to a final arrangement and producing that initial set, AND (b) at a later time, determining a configuration for at least one additional appliance to move from an actual intermediate arrangement (i.e., mid‑course correction at the time of a revised configuration). That second prong is the point of novelty.

Bottom line on §102: On the record I can actually verify, no single reference is confirmed to anticipate all of claim 1, because the claimed combination—(a) an at‑outset set of configurations sufficient to reach the final arrangement, plus (b) a later‑time determination tied to an actual intermediate arrangement—is the distinguishing element, and the strongest candidates (US 5,975,893/Snow/Hultgren/Kesling) each supply only part of it. Claims 2–4 are dependent and add nothing that changes this; claim 2 ("at least three at the outset") would be anticipated only by a reference that additionally discloses ≥3 outset cases, and claim 4 (taking a mold of the actual intermediate arrangement) is directly supported by Hultgren‑type scanning art.

6. What I could not confirm, and how to close the gap

1. The exact (56) "References Cited" list for US 6,394,801 — not retrieved. The Google Patents text supplied does not contain it, and my searches were truncated before surfacing it. Do not treat items in §4 as "of record" for the '801 specifically without verification.
2. Whether US 5,975,893, US 5,605,459, or any foreign/NPL item was formally listed on the '801 front page — the specification citations in §2 are confirmed as textual citations, but I cannot confirm they were also printed in the (56) panel.
3. Whether the '801 was ever subjected to an ex parte reexam or IPR — not surfaced; the '801 expired (anticipated) 2019‑12‑03, so it is not challengeable now.

Recommended authoritative sources to close the gap: USPTO PatentCenter for App. 09/779,802 (front‑page PDF, "(56) References Cited"); Espacenet "Description/Documents cited"; and the file wrapper (IFW) "References Cited by Examiner" / "Notice of References Cited (PTO‑892)." These will give the certified (56) list needed for a formal validity/anticipation opinion.

Search‑integrity note: My web tooling stopped returning further results partway through, so §§4–5 are a good‑faith analysis grounded in the confirmed text you supplied plus related Align proceedings, not a certified USPTO record review.

I'll ground this obviousness analysis in the actual prior art cited on the '801 page and check for validity challenges. Let me search.

Good grounding. Let me pin down a few more key references and check whether '801 was ever directly challenged.

Obviousness Analysis of U.S. Patent No. 6,394,801 under 35 U.S.C. § 103

Building on the prior sections: this analysis assumes the claim construction and family data already established (a 4‑claim, all‑method patent; Jepson‑style improvement claim 1; priority to Dec. 4, 1998; apparatus claims residing in the sibling US 6,499,997).

0. Threshold determination: which § 102/§ 103 regime applies

The '801 has an effective priority date of December 4, 1998 (Prov. 60/110,868) / December 3, 1999 (parent App. 09/454,786), with the instant application filed February 7, 2001. All of these predate March 16, 2013, so the pre‑AIA §§ 102/103 framework governs. That matters because the pre‑AIA § 103(c) "common ownership" safe harbor applies only to art disqualified under §§ 102(e), (f), and (g) — not to art that independently qualifies under § 102(a) or (b). This point was litigated and decided against Align in the Align/ClearCorrect ITC proceeding (discussed below) and is the pivot on which much of this analysis turns.

I. The claims to be analyzed

The preamble (polymeric shells having cavities shaped to receive and resiliently reposition teeth) and step 1(a) are, on their face, the Invisalign architecture described in the '801's own incorporated-by-reference documents. The only arguable point of novelty is the mid-course revision of 1(b)/3.

II. Level of ordinary skill in the art (Graham factor 1)

A person having ordinary skill in this art as of late 1998 would have: (a) a dental or orthodontic degree (DDS/DMD with orthodontic training) or an engineering/computer-science background with several years of experience in dental CAD/CAM; and (b) familiarity with (i) removable tooth-positioning appliances as practiced since Kesling, (ii) digital scanning of dental casts and generation of three-dimensional digital data sets, and (iii) the standard orthodontic protocol of monitoring progress at periodic visits and revising the plan when teeth do not move as predicted. This skill level is deliberately high because the field had already combined clinical orthodontics with 3‑D imaging and stereolithography before the critical date.

III. The prior-art landscape (Graham factor 2)

The '801's own "Description" cites or incorporates the most damaging references. I treat those as the primary corpus, supplemented by the art the tribunals actually applied to this family.

(A) US 5,975,893 — Chishti et al., "Method and system for incrementally moving teeth."
Filed Oct. 8, 1997 (App. 08/947,080), priority to Prov. 60/050,342 (June 20, 1997); issued Nov. 2, 1999. Expressly incorporated by reference into the '801. It discloses the full pipeline: obtain an initial digital data set (IDDS) of the dentition; determine a final tooth arrangement (FDDS); generate a plurality of intermediate data sets; and fabricate a series of polymeric-shell appliances worn successively to move the teeth incrementally. Its continuations/divisions confirm the "configured at the outset" teaching — e.g., US 6,699,037 (a continuation of the '893 application) states the system 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." (US 6,699,037)

(B) WO 98/58596 — Align/Chishti, published Dec. 30, 1998 (PCT/US98/12861), the published counterpart. Its summary states that repositioning is accomplished "incrementally… in a series of at least three successive steps, usually including at least four successive steps, often including at least ten steps, sometimes including at least twenty…" — which maps directly onto claim 2's "at least three." (INPI record; AU 744385 B2) Note the wrinkle: the INPI title is in French and the PCT publication language should be verified, because pre-AIA § 102(e) availability of a PCT depends on English-language publication. If it is not § 102(e) art, US 5,975,893 and US 6,471,511 independently supply the same disclosure.

(C) US 6,471,511 — Chishti et al., "Defining tooth-moving appliances computationally."
Filed Oct. 8, 1998; issued Oct. 29, 2002. Discloses that when a computed aligner is found unacceptable — e.g., a collision or an orthodontically unacceptable movement — "the process transfers control to a path definition process … to redefine those parts of the treatment path having unacceptable aligners," including "changing the increments of tooth motion, i.e., changing the segmentation… changing the path followed by one or more teeth." That is a recalculation-and-new-appliance teaching — precisely the mechanism of claim 1(b). (Quoted from the IPR record at PTAB petition materials.)

(D) Kesling, US 2,467,432, "Method of making orthodontic appliances and of positioning teeth."
Filed 1943; issued 1949. The foundational removable-positioner reference: cast the teeth → cut/separate the teeth from the model → reset them in the desired position → make a new model → mold a resilient appliance that "constantly tend[s] to move the teeth toward… that ideal position." (US 2,467,432) Critically, and as Align itself argued in the ITC proceeding, Kesling is a "reactive process, done one step at a time, where subsequent appliances are created by repeating the process for making the first appliance." (ITC Pub. 4555). That characterization is claim 1(b).

(E) US 5,605,459 — cited in the '801 as describing production of plaster casts and generation of digital models by laser scanning. Relevant to claim 4 (obtaining the actual intermediate arrangement from a mold/scan).

(F) Graber, Orthodontics: Principles and Practice, 2d ed., Saunders (1969), pp. 401–415 — cited in the '801 for conventional mold-making. As a general orthodontic treatise it also establishes the ordinary clinical practice of observing the patient at each stage and revising the plan.

(G) Align's US 6,450,807 ("System and method for positioning teeth"), App. 09/169,036, filed Oct. 8, 1998, and its continuation US 6,783,360. The '360 specification states: "At least one of the appliances used in a single course of treatment is preferably generated at the beginning of the treatment so that they are available when needed. The remaining appliances can be produced when needed so that the efficiency of the fabrication process is enhanced." (US 6,783,360) That splits the "initial set vs. later-produced appliances" concept precisely as claim 1 recites.

IV. Element-by-element mapping and the combinations

Combination 1 (primary): Chishti '893 in view of Chishti '511

There is no meaningful structural gap. The advance over '893 is, at most, the timing of a recalculation that '511 already performs and that Align's own later family member explicitly contemplates.

Combination 2 (alternative/stronger on motivation): Chishti '893 (or '325 / WO 98/58596) in view of Kesling and Graber

This is the combination the tribunals actually credited in this family. In the Align v. ClearCorrect IPR on the related '037 patent (IPR2016‑00270), the Board found a skilled artisan would have been motivated to combine a computerized dental-CAD reference with 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." The Federal Circuit affirmed that motivation finding. (CAFC 17‑2106, Align v. ClearCorrect; see also ITC Pub. 4555.)

Applied to the '801: '893 supplies the "determine/produce at the outset" half; Kesling supplies the "later, make the next appliance as treatment proceeds / when the result is off" half. Graber supplies the routine clinical practice of evaluating progress and revising. Because the resulting method does no more than combine the known computer-planning of '893 with Kesling's known iterative appliance-making, it is "a combination of familiar elements according to known methods [that] does no more than yield predictable results." KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007).

Combination 3 (claim 4 specific): Combination 2 + US 5,605,459

Claim 4 requires that the actual intermediate arrangement be determined "by taking a mold of the patient's teeth." '459 (and Kesling itself, and Graber) discloses making casts/molds and generating digital models from them. This limitation is not even arguably an advance; it recites the oldest step in the art.

V. Motivation to combine (Graham factor 3; the KSR rationales)

A POSITA would have been motivated, with a reasonable expectation of success, for several independent, articulable reasons:

1. The problem was known and the solution was appreciated. Teeth do not always track a pre-computed plan; the '801's own specification admits the mid-course steps "are described in U.S. Pat. No. 5,975,893" and that "subsequent successive movement steps can be calculated and appropriate positioning appliances planned, also as described in U.S. Pat. No. 5,975,893." An applicant's own specification characterizing the claimed improvement as already disclosed in an incorporated reference is a powerful admission that the subject matter was known or obvious.

2. Design need / market force. Orthodontic practice — and the "reactive" Kesling method — already entailed remaking appliances when the achieved position differed from the plan. A practitioner adopting the '893 computerized system would foresee exactly the same need and would implement the same revision step once an aligner proved "unacceptable," as '511 teaches.

3. Efficiency and cost. The '801 itself is framed as a cost/time-saving advance. Producing a partial initial set and then topping it up "when needed" to enhance fabrication efficiency (Align's '360) is a straightforward optimization that the art already suggested.

4. Finite, predictable solutions, obvious to try. Given a digital data set for the actual intermediate arrangement, the only available way to build a new appliance is to compute a new configuration and fabricate a shell over a new model. That is a "finite number of identified, predictable solutions," which KSR holds is strong evidence of obviousness. 550 U.S. at 421.

5. No teaching away. Unlike the round-tripping dispute in the sibling IPRs (where Chishti '876 was found to disparage unnecessary tooth travel), nothing in '893, '511, Kesling, or Graber discourages recalculating a treatment path when an appliance fails to produce the desired result. '511 affirmatively embraces it.

VI. Dependent claims 2–4

• Claim 2 ("at least three appliances determined at the outset") is squarely met by WO 98/58596/'893's "series of at least three successive steps, usually … at least four … often … at least ten … sometimes … at least twenty." This limitation adds nothing patentable.
• Claim 3 ("determining that the initial set is not producing the desired intermediate arrangement … before determining the configurations for the additional appliances") is taught by '511's logic of detecting that an aligner is "unacceptable" and then redefining the path, and by ordinary clinical observation (Graber). It is the natural ordering of the claim‑1 steps.
• Claim 4 ("taking a mold of the patient's teeth") is taught by Kesling, '459, and Graber — and by the '801's own admitted practice.

Because each dependent claim merely recites a sequential/dimensional refinement of what the primary references already disclose or suggest, each rises and falls with claim 1.

VII. Objective indicia / counterarguments (Graham factor 4)

The strongest non-obviousness case is secondary considerations, primarily the commercial success of the Invisalign® system and the substantial industry that grew around it. But three caveats blunt it:

1. Nexus. The '801's claims cover the planning/revision workflow, not the aligner product or the scanning/modeling technology. Align's commercial success is attributable to the broader '893/'325/'037 family (and later patents), so a nexus to the claimed improvement is weak.
2. The improvement claims a method the prior art already practiced. Align's own litigation positions cut against it: in the ITC proceedings Align successfully characterized Kesling as a reactive, one-appliance-at-a-time method that it distinguished from its proactive, plan-at-the-outset patents. But claim 1 of the '801 is the reactive half — "at a later time … an actual intermediate arrangement." Align's own distinguishing argument for the sibling patents therefore supports obviousness of the '801.
3. No merits validity ruling exists for the '801. The '801 was asserted (claims 1–4) in ITC Inv. No. 337‑TA‑562 and in the parallel W.D. Wis. action, but both were resolved by the OrthoClear consent order/settlement (Nov. 2006) rather than by an invalidity judgment. The later IPRs (IPR2016‑00270 et al.) and ITC 337‑TA‑833 targeted the '325, '511, '037, '880, '511, '863, '874 and '538 patents — not the '801. So there is no tribunal holding directly on the '801, in either direction. (Sources as compiled in the prior sections: ITC Pub. 4555; Federal Register E6‑2164.)

VIII. Threshold vulnerabilities to flag explicitly

1. § 103(c) common ownership. '893, '511, and '807 are all Align properties, as is the '801. If those references are available only as § 102(e) art, pre-AIA § 103(c) could disqualify them for § 103 purposes. However, the ITC ALJ in 337‑TA‑833 expressly held that Chishti '511 (US 6,471,511) qualified as § 102(a) prior art because the '511 and the challenged patent did not share identical inventive entities (common inventor Chishti, but different co-inventors), citing In re Hubbell, 709 F.3d 1140, 1143 (Fed. Cir. 2013). § 103(c) does not reach § 102(a) art, so the safe harbor would not rescue these references. This is a genuinely contestable point — the ALJ's "known or used by others" reasoning for an unpublished-application-era patent is aggressive — and a defendant relying on it must preserve it. I flag this rather than assert it as settled.
2. Publication-language issue for WO 98/58596 (see § III(B)). If it does not qualify as § 102(e) art, the same disclosure is still available through US 5,975,893 and US 6,471,511, so the combination survives.
3. Source limitation. I have not reproduced the full texts of '893, '511, or '807 in full; where I rely on the '801's own specification's characterization of what '893 discloses, that is an admission and cuts against the patent, but the exact column/line cites should be verified against the reference copies before any paper is filed.

IX. Conclusion

Claims 1–4 of US 6,394,801 would likely be held invalid as obvious under 35 U.S.C. § 103.

• Claim 1 is at minimum rendered obvious by US 5,975,893 in view of US 6,471,511 (and, independently, by '893 in view of Kesling, with the motivation finding already affirmed in Align v. ClearCorrect), with Graber and US 6,450,807 / US 6,783,360 supplying the "remaining appliances produced when needed" and clinical-monitoring teachings. The '801's own specification's admission that the mid-course steps are described in '893 makes the obviousness case unusually strong.
• Claim 2 is met by WO 98/58596 / '893's express "at least three successive steps."
• Claim 3 is taught by '511's "unacceptable-aligner → redefine path" logic plus ordinary clinical practice.
• Claim 4 is taught by Kesling, '459, and Graber.

The principal defense is objective indicia (Invisalign commercial success), but nexus is weak because the claims capture a planning/revision workflow rather than the commercially successful device, and Align's own prosecution/litigation positions in the ITC undercut the argument that the "later-time revision" step was novel.

Explicit uncertainty: I could not locate any inter partes review or court judgment addressing the validity of the '801 itself; all identified challenges to this family were resolved by consent order/settlement, or directed at sibling patents. The above is a technical obviousness assessment, not a legal conclusion, and does not account for claim-construction rulings that would first have to be made in any enforcement proceeding.