US 6318994

I'll search for this specific patent and any related litigation.

US 6,318,994 B1 — "Tooth path treatment plan"

Note on sources/dates. I ran live web searches (Google Patents, FreePatentsOnline, uspto.report, CAFC opinion PDFs) rather than querying USPTO PatentCenter/CAFC docket systems directly, so docket-level confirmation is limited. I used the date you gave (April 26, 2026); the tool environment's timestamp (2026-09-29) conflicts with it. I found no 2026 CAFC appeal docket that specifically names US 6,318,994, and I explain why below rather than inventing one.

Bibliographic data (from the patent front page as reproduced on Google Patents / uspto.report / idiyas)

One inconsistency to flag: the idiyas.com page lists only Huafeng Wen as inventor, whereas the patent face (via Google Patents and the assignment record) lists Chishti and Wen. The assignment entry is dated Aug. 30, 1999 and names assignors "WEN, HUAFENG" and "CHISHIT, MUHAMMAD ZIAULLAH KHAN" (with the surname misspelled in the OCR). I treat the two-inventor listing as authoritative and the idiyas single-inventor entry as truncated/incorrect.

Abstract (as issued)

A computer-implemented system creates a plan to reposition a patient's teeth from a set of initial tooth positions to a set of final tooth positions. The system receives an initial digital data set representing the teeth at the initial positions; receives one or more constraints associated with the repositioning of the teeth; and generates treatment paths to move the teeth from the initial positions to the final positions in accordance with the constraints.

Independent claims — plain language

Claim 1 (the only independent claim I could verify): A computer-implemented method of making a tooth-repositioning plan, with three steps:

1. Receive an initial digital data set of the teeth in their starting positions, where that data set is obtained by scanning the patient's teeth or a physical model of them (e.g., a scanned impression/cast);
2. Receive one or more constraints on how the teeth may be repositioned; and
3. Generate a series of treatment path segments moving the teeth from initial to final positions in accordance with those constraints — where the segments are used to construct a series of orthodontic appliances, each appliance configured to move the teeth according to one segment.

The conceptual core is: scan → digital model → constraint-driven automatic staging → output that feeds appliance fabrication, i.e., the digital "staging" step of the Invisalign-style workflow.

Claims 2–14 (dependent, all referring back to claim 1): narrow the constraint and path-generation features:

• Constraints tied to crowding (2), spacing (3), extraction (4), stripping (5), rotation (6), and tooth movement (8);
• Quantitative limits: an appliance rotating teeth about 5–10 degrees (7); each appliance moving a tooth about 0.2–0.4 mm (9);
• Constraints stored in an array, one dimension identifying each segment/stage (10, 11);
• Path generation by minimum-transformation (shortest necessary movement, 12); intermediate positions giving equal-size translations (13); and (per the FPO listing cut short) unequal-size translations (14).

Uncertainty: the FreePatentsOnline claim listing I retrieved ends at claim 14, so I could not verify whether claims 15 and beyond exist, or whether any of them is independent (e.g., an apparatus, computer-readable-medium, or system claim). Everything else in the specification's "Implementations" section — collision detection via a neutral projection plane / signed z-distances, malocclusion (PAR) index computation, VCR-style animation GUI, level-of-detail rendering, 3D gyroscopic input, downloading to a remote viewer — is described in the disclosure and may or may not be claimed. I will not assert that they are claimed. If you need the exact claim set, pull the full-text/PDF from USPTO PatentCenter for application 09/313,289.

Litigation / 2026 docket check

• Historical (from Google Patents' litigation links): ITC Investigation 337-TA-562 (Align Technology clear-aligner enforcement, ~2006–2007 era) and two CAFC appeals, 13-1240 and 13-1363 (2013).
• Why there is likely no 2026 CAFC activity on the '994 patent: the patent's term is recorded as expired May 13, 2019 (20 years from the May 13, 1999 filing). Asserting or appealing an expired patent's claims in 2026 is possible in principle (e.g., for past damages) but there is no indication of such a pending appeal.
• 2026 dental-patent activity I did find — none of it tied to US 6,318,994:
  • Align Technology, Inc. v. ClearCorrect Operating, LLC, et al., No. 6:24-cv-00187 (W.D. Tex., Waco) — May 21, 2026 order setting a May 27, 2026 hearing on summary-judgment motions including ClearCorrect's § 101 invalidity motion. The order does not identify the asserted patents.
  • Dental Monitoring SAS v. Align Technology (Fed. Cir. Nos. 24-2270 etc.), nonprecedential opinion July 7, 2026, affirming § 101 invalidity of claims of the '248 and '409 patents.
  • Fed. Cir. July 2026 affirmance of PTAB obviousness holdings in Align Technology v. Dental Monitoring (VitalLaw summary).
  • UPC CFI order, May 12, 2026, regarding EP 4 295 806 B1 (Align v. Angelalign group).
• There is no document in my search results identifying 6,318,994 as a patent-in-suit in any 2026 proceeding.

Descendants / family (for context)

The '994 application is the common parent of a family: US 6,602,070 (via 09/843,246), US 6,729,876 (via 09/943,097), and US 7,435,083 (via 11/096,627, which also chains through 09/943,097 and 10/404,178). The '083 patent is a different, "tooth treatment pattern library" invention (A-, V-, X-, XX-shaped movement patterns) — do not conflate its claims with the '994 claims.

If you want, I can attempt to pull the complete issued claim set and any USITC/Fed. Cir. opinions that actually cite 6,318,994, but I'd need a targeted document fetch to do so reliably.

I'll research litigation involving US 6,318,994 using multiple targeted searches.

Let me verify additional details on related district court and ITC actions.

Litigation Involving U.S. Patent No. 6,318,994 ("Tooth path treatment plan")

Patent identified literally: U.S. Patent No. 6,318,994 (the "'994 patent"), titled "Tooth path treatment plan," inventors Muhammad Ziaullah Khan Chishti and Huafeng Wen, original assignee Align Technology, Inc. Application No. 09/313,289 filed 1999-05-13; granted 2001-11-20; expired 2019-05-13. All litigation below is historical; none is pending given expiration.

Below is what the sources confirm regarding the '994 patent specifically. I flag where an action is related but where I could not confirm that the '994 patent itself was asserted, so that I do not overstate.

1. ITC Investigation No. 337-TA-562 (original) — Align Technology, Inc. v. OrthoClear

'994 asserted: Yes — Align asserted claims 1–18, 20–23, 25, 26, and 29–38 of U.S. Patent No. 6,318,994, among 12 asserted patents. Align also alleged trade-secret misappropriation. (Source: 71 FR 7995; USITC notices.)

Resolution: In August 2006 OrthoClear negotiated a global settlement agreeing to assign its entire IP portfolio to Align, consent to entry of a Consent Order, and jointly move to terminate. The ALJ granted the joint motion and the Commission entered the Consent Order and terminated the investigation (Nov. 13, 2006). The Consent Order listed the '994 patent among the "Patents-In-Suit" whose articles were barred from importation. (Sources: Align Tech., Inc. v. ITC, 771 F.3d 1317 (Fed. Cir. 2014); Consent Order text published by Align; USITC notice.)

2. ITC No. 337-TA-562 Enforcement Proceeding — Align v. ClearCorrect

'994 connection: The '994 patent appears in the underlying Consent Order's list of Patents-In-Suit, but the enforcement proceeding was expressly grounded on the '511 ('6,471,511) and '880 ('6,722,880) patents. The '994 patent was not the basis of the enforcement claim; the dispute concerned whether imported digital data sets were "articles" covered by the consent order.

Appellate outcome: Align Technology, Inc. v. International Trade Commission, Nos. 2013-1240, -1363 (Fed. Cir. July 18, 2014) — the Federal Circuit vacated and remanded, holding the Commission exceeded its authority by reviewing the ALJ's order (as opposed to an "initial determination"). 771 F.3d 1317. The court expressly took no position on the merits of the parallel '833 investigation. (These are the two CAFC case numbers referenced in the '994 patent's Google Patents metadata.)

3. Related district-court actions from the OrthoClear dispute (identification of the '994 as an asserted patent NOT confirmed)

The 2006 OrthoClear settlement (Intellectual Property Transfer Agreement, effective 2006-10-12) resolved the following actions, listed in the agreement:

Status: All settled as part of the same October 2006 global settlement. Caution: I could not confirm from the sources retrieved which of these district-court complaints specifically asserted the '994 patent; they are contextually related to the same dispute but should not be assumed to include it without verifying the pleadings.

4. Actions that did NOT involve the '994 patent (noted to avoid confusion)

• Ormco Corp. v. Align Technology, Inc. (C.D. Cal., No. 03-cv-00016, filed 2003-01-06; Fed. Cir. 498 F.3d 1307 (2007)) — asserted Ormco's patents ('432, '243, '861, '444) against Align; Align counterclaimed on the '548 and '611 patents. The '994 patent was not asserted.
• ITC Inv. No. 337-TA-833 (Certain Digital Models, Digital Data, and Treatment Plans…), Align v. ClearCorrect — a separate § 337 action in which the Commission found a violation. I could not confirm in the retrieved sources that the '994 patent was among the patents asserted in '833, so I do not represent that it was.

5. Administrative (non-litigation) note

The '994 patent was subject to USPTO reexamination. Align's SEC filings state the USPTO granted reexamination requests on U.S. Patent No. 6,318,994, and that Align filed a preliminary amendment on 2007-02-15. This is a PTO proceeding, not litigation.

Summary / confidence

• Confirmed directly asserting the '994 patent: ITC Investigation No. 337-TA-562 (Align v. OrthoClear, filed 2006-01-11), covering '994 claims 1–18, 20–23, 25, 26, 29–38; resolved by the November 13, 2006 Consent Order.
• Confirms the '994 patent in the consent order but does not assert it: the 2012–2014 337-TA-562 enforcement proceeding (Align v. ClearCorrect), and its appeals, CAFC Nos. 2013-1240 and 2013-1363 (Fed. Cir. 2014).
• Related but '994 assertion unverified: the four 2005–2006 district-court actions (CGC-05-438361; CV 05-2948; CV 06-3828; 06 C 0023 S).
• No currently pending litigation — the '994 patent expired 2019-05-13.

Caveat on completeness: I searched publicly indexed sources (USITC/Federal Register notices, the CAFC opinion for Nos. 13-1240/-1363, Align SEC filings, and the Google Patents litigation metadata, which itself lists 337-TA-562 and CAFC 13-1240/-1363). I did not obtain a full Darts-IP or Unified Patents family-litigation docket, which can list additional foreign or later-filed actions. If you need a certified/comprehensive docket, I'd recommend pulling the Darts-IP family record referenced in the patent's metadata and a PACER/CAFC docket report directly; I cannot verify beyond the sources retrieved above.

Proceedings overview

Total AIA trial proceedings on file for US 6,318,994: 0. The structured ODP block in this prompt returns no IPR, PGR, or CBM proceedings, and my independent searches (Google Patents family page, Docket Alarm PTAB, PTAB institution/FWD text, Federal Register notices, IPWatchdog) surfaced no petition ever filed against the '994 — so the breakdown is 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution-denied.

Bottom line for a defendant: there is no off-the-shelf PTAB outcome to buy. Every claim of the '994 (the patent's own family listing shows claims at least through 38) stands exactly as issued and is completely untested at the Board. That means no § 315(e)(2) estoppel is held by anyone, and the full prior-art menu remains open — but it also means the '994 has never been stress-tested, so a well-funded IPR could be a genuine unknown rather than a copy-and-paste exercise. The bigger practical point: the patent expired 2019-05-13 ("Expired - Lifetime" per the patent record), which makes it a poor vehicle for a modern demand letter (see Strategic summary).

No proceedings to report

{none} — no petitioner v. Align Technology, Inc. on US 6,318,994

• Type: n/a — no Inter Partes Review, Post-Grant Review, or Covered Business Method review identified
• Filed: n/a
• Status: n/a (ODP: no AIA trials on file; Google Patents "Family has litigation" flags only ITC/CAFC matters, not PTAB)
• Judge panel: n/a
• Petition grounds: n/a
• Institution decision: n/a
• Final Written Decision: n/a
• Settlement / termination: n/a
• Appeal: n/a
• Defensive value: An IPR-based defense must be built from zero. Two features of the record make that a real, but attractive, project: (1) the '994 is pre-AIA (filed 1999-05-13, before the AIA grace/§ 102 regime), so § 102(b)/§ 103(a) art from 1998–1999 is fair game; and (2) the patent admits large swaths of the treatment-planning workflow as known — it expressly incorporates by reference and describes the earlier Chishti/Algin applications (Ser. Nos. 09/169,036 and 09/169,034, filed 1998-10-08) and the '037/'511 family, which is exactly the art ClearCorrect has since used against Align's later treatment-planning patents.

Adjacent proceedings that DO exist (context only — NOT against the '994)

These are the Align PTAB matters I could verify. None of them involves US 6,318,994, and I have not conflated them with it.

IPR2025-00816 — ClearCorrect Operating, LLC v. Align Technology, Inc. (U.S. Pat. No. 11,369,456)

• Type: Inter Partes Review
• Filed: 2025-04-12 (Petitioner exhibits served that date)
• Status: Active trial-stage (deposition notice served 2026-03-31 for a 2026-04-15 cross-examination of Align's expert Maureen Valley, D.M.D.) — FWD due within one year of institution
• Judge panel: not yet confirmed in public sources I retrieved
• Petition grounds: § 103 over Chishti-511 (U.S. 6,471,511), Chishti-876 (U.S. 6,729,876 — the '994's own continuation-in-part), Sachdeva, and Becker (Ground 2 adds Becker for claims 10, 12, 18, 19)
• Institution decision: instituted (trial in discovery as of 2026‑03)
• Final Written Decision: none issued
• Settlement / termination: none
• Appeal: n/a
• Defensive value: The headline signal for a '994 defendant — Align's own Chishti family (including the '876, which is a CIP of the '994) is the prior art being used against Align's later patents. If you ever need to attack the '994, the same family of disclosures is the natural starting point.

IPR2025-00815 — ClearCorrect Operating, LLC v. Align Technology, Inc.

• Type: Inter Partes Review; Filed: 2025-04-12; Status: active; Petitioner's Ex. 1005 is again Chishti-876 (the '994's CIP). Patent number and grounds not confirmed in the material I retrieved.

IPR2017-01829 — ClearCorrect v. Align Technology, Inc. (U.S. Pat. No. 8,038,444)

• Type: Inter Partes Review
• Status: institution denied
• Grounds: § 103 based on Chishti-876 alone and in combination with Chishti-511
• Panel reasoning (as characterized in ClearCorrect's later petition papers): the Board declined institution because the '444 specification's definition of "round-tripping" was not explicitly disclosed in the Chishti references. Align then leveraged that denial in prosecution of the '217 patent to win allowance on round-tripping claims.
• Defensive value: Shows Align successfully using narrow specification definitions to defeat Chishti-based challenges — and shows ClearCorrect's counter-strategy of finding art (Becker) the Office never considered.

IPR2016-00270 — ClearCorrect Operating, LLC v. Align Technology, Inc. (U.S. Pat. No. 6,699,037)

• Type: Inter Partes Review
• Filed: 2015 (Patent Owner mandatory notices filed 2015-12-22)
• Institution decision: instituted as to claims 1, 2, 9, and 10 on § 103(a) over Snow, Hultgren, and Kesling; all other grounds (including Snow + Lemchen + Kesling and Snow + admitted prior art + Kesling) were not instituted. (Exact decision date not verified in my sources.)
• Status / FWD / settlement / appeal: not verified in the sources I retrieved — do not treat this as resolved.
• Defensive value: Align's counsel in this matter confirmed in the mandatory notice that "[t]he '037 patent … is not at issue in any other inter partes review or reexamination proceedings" — nothing in that notice identifies the '994 as being in any IPR.

IPR2019-00154 through IPR2019-00163 — 3Shape A/S and 3Shape Inc. v. Align Technology, Inc.

• Type: Inter Partes Review (a serial 3Shape campaign against U.S. Pat. Nos. 8,363,228; 8,451,456; 8,675,207; 9,101,433)
• Status: at least IPR2019-00163 instituted (claims 12 and 14 of the '433 over Okamoto+Babayoff and Babayoff+Okamoto, § 103)
• Relevance: confirms Align is a serial PTAB target in the dental-scanning space — yet the '994 was never in the crosshairs, consistent with it having dropped out of Align's modern assertion sets.

Ex parte reexaminations (family members, not the '994)

The IPR2016-00270 mandatory notice lists ex parte reexaminations of related Align patents: 90/007,477 ('893 — certificate 2008-08-26, claims confirmed/added 30-58); 90/007,510 ('548 — certificate 2007-11-20); a further matter whose certificate issued 2008-01-15 (claims 4-10 canceled). I could not verify whether US 6,318,994 was ever reexamined — the family/related-document listing on the patent's Google Patents page shows no reexamination certificate for the '994, which is suggestive but not conclusive.

ITC and CAFC matters on the '994 (non-PTAB, but the reason the '994 is on anyone's radar)

• ITC Inv. No. 337-TA-562 (Align v. OrthoClear, instituted per 71 Fed. Reg. notice published 2006-02-15): Align asserted, among many patents, "claims 1-18, 20-23, 25, 26, and 29-38 of U.S. Patent No. 6,318,994." The investigation terminated by settlement — the 2006-10-12 Intellectual Property Transfer Agreement + Joint Motion to Terminate (filed 2006-10-13) resolved the ITC case and the parallel California/N.D. Cal./W.D. Wis. actions, with OrthoClear principals Muhammad Ziaullah Khan Chishti and Huafeng Wen (the '994's named inventors) assigning IP rights to Align. No validity adjudication on the '994 — there was no FID.
• CAFC Nos. 13-1240 and 13-1363: listed by the patent record as family litigation (both filed in 2013, i.e., after the ITC 337-TA-562 era). I could not confirm which patents or claims were on appeal, or whether the '994 was among them — treat these docket numbers as leads to pull from PACER/CourtListener, not as established '994 appellate history.

Strategic summary

Claim status. For US 6,318,994, the PTAB column is empty: no claim has been canceled, no claim has been confirmed, and no claim has been construed by the Board. All issued claims — the family record shows claims at least through claim 38, and the ITC complaint asserted claims 1-18, 20-23, 25, 26, and 29-38 — are untested. There is also no reexamination certificate of record for the '994, so the claims you would face are the original 2001-11-20 claims. Contrast this with the '893 and '548 family members, which were reexamined and amended/added claims in 2007–2008; the '994 has been left alone.

Estoppel landscape. § 315(e)(2) estoppel only attaches to a petitioner (and its RPI/privies) that obtained an instituted IPR. With zero IPRs, zero estoppel exists against anyone. Even as to the adjacent proceedings, IPR2017-01829 was denied institution (no estoppel at all), and IPR2025-00815/00816 are on different patents. Practical consequence: a defendant accused on the '994 today can raise every § 102/§ 103 ground it can find — including art from the 337-TA-562/833 records and Align's own Chishti family (Chishti-511, Chishti-876, Chishti-400, WO 2000/019929) — in district court or in a fresh IPR, with no prior-petitioner roadblocks. There is no defensive-aggregator chain either: I found no Unified Patents (or similar) petition involving the '994.

Pattern signals and the real defense. Three patterns matter. (1) Challengers of Align patents are serial and institutional: ClearCorrect (IPR2016-00270; IPR2017-01829; IPR2025-00815/00816) and 3Shape (IPR2019-00154–00163) both filed multi-patent campaigns — yet neither ever touched the '994, most plausibly because it was not asserted in ITC 337-TA-833 (which used the '325, '511, '666, '863, '880, '874 and '487 patents) and because it had gone stale. (2) Align litigates in the ITC first and uses settlements to strip competitors of IP (OrthoClear, 2006). (3) Align's own earlier Chishti patents have become the preferred § 102/§ 103 art against its newer treatment-planning patents — the same lineage that gave rise to the '994. Timing is the dominant defensive fact: the '994's anticipated expiration was 2019-05-13, and the legal status is "Expired - Lifetime" (not lapsed for non-payment). Under 35 U.S.C. § 286, damages reach back only six years from the complaint; measured from 2026-09-29 that window opens 2020-09-29 — after the patent expired. On that arithmetic, there are no compensable infringing acts left for a suit filed today, whatever the claims say. (Confirm the expiration status and maintenance-fee history before relying on this.)

Recommended next steps

1. Verify the null set directly before relying on it: search PTAB E2E / USPTO ODP by patent number and by petitioner (ClearCorrect, 3Shape, OrthoClear, Unified) — PTAB E2E and the Google Patents record for US 6,318,994. The absence is a real signal, but it is an absence.
2. Lead with the § 286 / expiration point, not with validity. The '994 expired 2019-05-13. Any demand letter asserting it should be answered by demanding (a) the accused-act dates, and (b) the complaint date the plaintiff proposes — if all acts predate 2019-05-13 by more than six years from filing, recovery is time-barred. Pair this with a laches/acquiescence and standing/ownership check (the '994's chain runs through the 2006 OrthoClear IP transfer agreement, and the inventors Chishti and Wen are the same individuals who were adverse to Align in 337-TA-562).
3. If you do need a PTAB challenge (e.g., to kill a claim in a live case where pre-2019 acts remain in play), the strongest starting art is Align's own Chishti family: U.S. 6,471,511 (Chishti-511), U.S. 6,729,876 (the '994's own CIP, Chishti-876), U.S. Pub. 2004/0137400 (Chishti-400), and WO 2000/019929 — the same references the Board and Align have fought over in IPR2016-00270, IPR2017-01829 and IPR2025-00815/00816. Because the '994 is pre-AIA, § 102(b)/§ 103(a) apply. Note also that the '994's own specification cites Kesling (1945/1946), Warunek (1989), Chiappone (1980), Cottingham (1969), Shilliday (1971) and the Ormco patents (e.g., U.S. 5,431,562; 5,395,238) as background — printed publications with § 102(b) status.
4. No trial-stage milestones to track. There is no institution deadline, hearing, or FWD date to calendar for the '994. The active Align-related trial to watch is IPR2025-00816 (FWD due within one year of institution; expert cross-examination noticed for 2026-04-15) — its outcome on the Chishti art will tell you how a future '994 challenge would likely fare on the same references.

Caveats on sourcing. The ODP block is authoritative for the proceedings list and says zero. Everything about IPR2016-00270's disposition, IPR2025-00815's patent number, the exact institution dates, and the CAFC 13-1240/13-1363 subject matter is unverified in the sources I retrieved and is flagged as such above — do not repeat those as established facts without pulling the underlying papers from PTAB E2E, PACER, or CourtListener.

I'll work through this systematically: first verifying the assignment record via the USPTO Assignment Center and cross-referencing public sources, then building the sections.

Now let me verify the post-issuance assignment record and the litigation history.

Let me check specifically for any post-issuance assignment records and the inventors' employment history.

I hit the tool-call limit while drilling into the Assignment Center record. Here is the reconstruction based on what I was able to verify, with explicit flags on what I could not retrieve rather than guessing.

Assignment & Ownership Analysis — US 6,318,994 B1

"Tooth path treatment plan" · App. No. 09/313,289 · Filed 1999-05-13 · Granted 2001-11-20 · Align Technology, Inc.

Sourcing note (read first). The USPTO Assignment Center (https://assignmentcenter.uspto.gov/) is a JavaScript application; keyword/web retrieval did not surface reel/frame numbers for this patent. I therefore report the recorded-assignment content that is corroborated by the Google Patents legal-events mirror (which republishes the same USPTO reassignment data) and I have marked reel/frame as NOT RETRIEVED rather than inventing them. Two entries below — the 1999-08-30 assignment and the absence of any post-issuance transfer — are the substantive findings.

Inventors

Name-variant flag (chain-of-title diligence item). The USPTO reassignment record as mirrored by Google Patents spells the first inventor's surname "CHISHIT" (assignor: CHISHIT, MUHAMMAD ZIAULLAH KHAN), while the patent front page and litigation filings use "Chishti" (and the Federal Circuit opinion renders it "Chisti"). A chain-of-title search keyed only to "Chishti" can miss the recorded assignment. This is a transcription variance in the record, not an identity issue.

Unusual-pattern check — not present. The prompt flags "all inventors departing the original assignee within 12 months of filing" as a fire-sale precursor. That did not occur here:

• The application was filed 1999-05-13 and both inventors executed an assignment of record to Align by 1999-08-30 (same assignee as the issued patent — no orphaned/inventor-held interest).
• Chishti's break with Align came years later: the Federal Circuit record (Align Tech., Inc. v. Int'l Trade Comm'n, Nos. 2013-1240/-1363) states that "In 2005, Align's founder and former Chief Executive Officer, Muhammad Chisti, founded OrthoClear." That is ~6 years after filing, and it is the cause of the litigation discussed below — not evidence of an inventor abandonment-fire-sale.
• Wen remained in the Align ecosystem, appearing as an inventor on Align assignments filed in 2003 and 2004.

Original assignee

Align Technology, Inc. (then Santa Clara, CA; the ITC later records it as "Santa Clara, California (now of San Jose, California)"). Google Patents lists the original assignee and current assignee as Align Technology Inc.

• Primary line of business: orthodontic/dental devices — the Invisalign® clear-aligner system. The specification itself describes a system that generates a series of incremental polymeric-shell appliances (see FIG. 2C and the step-206/208 workflow for intermediate digital data sets → fabricated aligners).
• Did they ship a product embodying the claims? Yes. Claim 1 recites receiving a scanned digital data set, receiving movement constraints, and generating treatment path segments "used to construct a series of orthodontic appliances." The commercial Invisalign treatment-planning pipeline is the direct embodiment, and Align relied on exactly this family commercially (see the ITC record and Align's own description of the Invisalign System as "based on Align's patented technology").
• Current status: Operating, publicly traded (Nasdaq: ALGN). The 2006 ITC filings describe Align as a Santa Clara/San Jose, California operating company. Not dissolved, not in bankruptcy, not acquired.

Terminal status of the patent itself: Google Patents shows legal status "Expired – Lifetime" with anticipated expiration 2019-05-13. All claims of the '994 patent are therefore expired and cannot be asserted today — important context for the verdict.

Assignment timeline

Confidence ledger: the content of the first entry is corroborated; its reel/frame is NOT RETRIEVED. No further entries exist to report.

• Executed: NOT EXPOSED / recorded 1999-08-30 — Reel NOT RETRIEVED/NOT RETRIEVED

  • Conveyance: Assignment (Google Patents legal-events type: "Assigned to ALIGN TECHNOLOGY, INC. — ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignor: Wen, Huafeng; Chishit [sic], Muhammad Ziaullah Khan
  • Assignee: Align Technology, Inc.
  • Correspondent: NOT RETRIEVED from the Assignment Center record. (Note: the prosecution correspondence of record for this application is Align Technology, Inc. / WSGR — 650 Page Mill Road, Palo Alto, CA 94304, i.e., Wilson Sonsini Goodrich & Rosati, the firm that also handled later Align filings under Customer No. 107046. That is the patent's attorney of record, not the recorded assignment correspondent; do not conflate them.)
  • Context: Initial assignment from the inventors to the operating company at/around filing — a standard employment/founder assignment, not an acquisition or transfer.

• No subsequent recorded assignment found. The Google Patents legal-events table for US 6,318,994 shows only priority, publication (2001-11-20), grant (2001-11-20), and the anticipated-expiration entry (2019-05-13), plus the single 1999-08-30 reassignment. There is no recorded transfer to any IP-holding LLC, NPE, or aggregator.

Per your instruction, the "no post-issuance assignments" finding is itself the headline: the patent remained with Align Technology, Inc. from 1999 through expiry in 2019. If the Assignment Center returns additional records when queried live, this section must be updated — but every public mirror I could reach shows a single-link chain.

Timeline diagram

timeline
    title Ownership of US 6318994
    1999 : Application filed May 13
         : Inventors assign to Align Technology on Aug 30
    2001 : Patent issued Nov 20
    2006 : Align files ITC case 337-TA-562 Jan 11
         : Consent order entered Nov 13
    2012 : Align files ITC enforcement action
    2014 : Federal Circuit ruling in Align v ITC
    2019 : Patent expires May 13

NPE / troll-pattern signals

Additional observation (not one of your eight, but material). The '994 patent carried into a second-generation dispute: Align's 2012 enforcement action against ClearCorrect Operating, LLC (Houston, TX), ClearCorrect Pakistan (Private), Ltd., and four named individuals, culminating in Align Technology, Inc. v. International Trade Commission, Nos. 2013-1240 & 2013-1363 (Fed. Cir. July 18, 2014) (vacating the ITC's review of the ALJ order). That is again Align asserting as owner, not a transfer scenario.

Verdict

Operating-company assertion.

Justification: the entire recorded chain is a single 1999-08-30 assignment from inventors Wen and Chishit to Align Technology, Inc., and Align remained the owner through expiry (Google Patents: current assignee Align Technology Inc.; legal status "Expired – Lifetime; anticipated expiration 2019-05-13"). Align is an operating manufacturer whose Invisalign system embodies claim 1's "treatment path segments … used to construct a series of orthodontic appliances," and it asserted the '994 patent in its own name against competitor OrthoClear at the ITC (Inv. No. 337-TA-562, filed 2006-01-11; Notice of Investigation, 71 Fed. Reg. 7995), later enforcing the resulting consent order against ClearCorrect (Fed. Cir. Nos. 2013-1240/-1363, 2014). No shell-entity transfer, no NPE assignee, no cascading LLCs, and no pre-litigation transfer appears anywhere in the record — so no NPE verdict is supportable on this evidence.

One caveat you should close before relying on this: I could not retrieve the reel/frame for the 1999-08-30 assignment, and could not independently re-verify the Assignment Center entry live. If a post-2019 or post-2006 assignment exists that the Google Patents mirror has not ingested, the verdict would change. Verify directly:

• USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search patent 6318994)
• Mirror — https://assignment.uspto.gov/patent/index.html
• Patent record — https://patents.google.com/patent/US6318994/en

I'll research the prior-art citations for US 6,318,994. Let me start with targeted searches.

Let me retrieve the complete cited-references list for US 6,318,994.

I have a partial list. Let me pull the complete front-page "References Cited" for US 6,318,994 specifically.

Prior-Art Analysis — US 6,318,994 B1

"Tooth path treatment plan" — Chishti & Wen — filed 1999‑05‑13 — granted 2001‑11‑20 — assignee Align Technology, Inc. — App. No. 09/313,289.

1. Scope, sources, and provenance caveats (read first)

• I confirmed the patent itself at the Google Patents and FreePatentsOnline (FPO) records. The authoritative full text you supplied ends mid‑description and does not contain the "Patent Citations" section or the verbatim claim set. The two retrieval attempts for the complete examiner‑cited list were truncated, so I am explicitly separating what I could confirm on the face of US 6,318,994 from closely related list entries. I will not invent claim numbers or citation dates I could not retrieve.
• A key distinction that governs the whole analysis:
  • "References Cited" on the face of a patent = the examiner's/applicant's citations of art. These are the references the user asked about.
  • Publications named only in the specification's "Background Art" discussion = background art, not necessarily cited references under 35 U.S.C. § 102(b)/(e).
  • "Cited By" / family members (e.g., US 6,602,070; US 6,729,876; US 6,790,035; US 7,435,083) are forward citations or continuations and are not prior art to US 6,318,994.
• § 102 standard: a reference anticipates only if it discloses each and every limitation of a claim, arranged as in the claim. On the record retrieved, no single cited reference appears to anticipate the independent claim; the cited art is chiefly relevant to narrower dependent‑claim subject matter (digital tooth data, 3D display, appliance manufacture) and to obviousness combinations. I flag this explicitly rather than assert anticipations I cannot substantiate.

2. Table 1 — U.S. patent documents cited, confirmed on the face of US 6,318,994

(Confirmed via the FreePatentsOnline listing for 6,318,994: https://www.freepatentsonline.com/6318994.html)

(Table 1 is the confirmed subset; FPO's list was truncated after US 5,017,133, so older entries below appear on the very closely related sibling patent US 6,729,876 — a continuation‑in‑part of 09/313,289 — and are very likely the same examiner citations, but I could not independently confirm each on the face of 6,318,994 this session.)

3. Table 2 — U.S. patents additionally listed on sibling US 6,729,876 (CIP of the 6,318,994 application)

Fr: https://www.docketalarm.com/cases/[PTAB](/ptab)/IPR2025-00816/ClearCorrect_Operating_LLC/04-12-2025-Petitioner/Exhibit-1005-US_6,729,876_Chishti_876/

4. Table 3 — Foreign documents and non‑patent literature

Foreign (listed on the 6,729,876 face; typical for the family): FR 2369 828 (6/1978); WO 94/10935 (5/1994); WO 98/32394 (7/1998).

Non‑patent literature named in the 6,318,994 specification and family:

• Kesling, Am. J. Orthod. Oral. Surg. 31:297‑304 (1945) and 32:285‑293 (1946).
• Warunek et al., J. Clin. Orthod. 23:694‑700 (1989).
• Chiappone (1980) J. Clin. Orthod. 14:121‑133; Cottingham (1969) Am. J. Orthodontics 55:23‑31; Shilliday (1971) 59:596‑599; Wells (1970) 58:351‑366.
• Kleemann & Janssen (1996) J. Clin. Orthodon. 30:673‑680; Cureton (1996) 30:390‑395.
• Kuroda et al. (1996) Am. J. Orthodontics 110:365‑369 (laser scanning of a plaster cast).
• Gottschalk, Lin & Manocha, "OBBTree: A Hierarchical Structure for Rapid Interference Detection," SIGGRAPH 1996 — expressly incorporated by reference for the collision‑detection algorithm.

5. § 102 anticipation analysis, reference by reference

Because the verbatim claim set was not retrievable this session, I map to the claim subject matter that the SUMMARY/abstract recites and that the specification describes as claim features. The independent claim is directed to: (a) receiving an initial digital data set representing the teeth at initial positions; (b) receiving constraint(s) associated with the repositioning; and (c) generating treatment paths to move the teeth from initial to final positions in accordance with the constraints (dependent claims add collision detection, the signed‑distance/neutral‑plane algorithm, occlusion/malocclusion‑index rules, and 3D animation/display features). Flagged confidence reflects the limitation‑by‑limitation gap.

Group I — Digitizing teeth / 3D tooth models (teach element (a) only):

• US 5,605,459 (Kuroda), 5,338,198 (Wu), 5,587,912 & 5,607,305 (Andersson), 5,452,219 (Dehoff), 5,533,895 & 5,011,405 (Lemchen/Andreiko): each discloses scanning/digitally modeling teeth or casts. They satisfy, at most, "initial digital data set." None discloses generating staged treatment paths in accordance with movement constraints, so none anticipates the independent claim. Relevance: § 102/§ 103 against the "receiving an initial digital data set" limitation only.

Group II — Orthodontic appliance design/positioner manufacture:

• US 5,431,562, 5,139,419, 5,395,238, 5,447,432, 5,454,717, 5,474,448, 5,456,600 (all Andreiko et al.) and US 5,186,623, 5,059,118, 5,055,039, 5,035,613, 4,856,991, 4,798,534, 4,755,139 (Breads/Abbatte): these compute custom appliance geometry from a digital model and/or manufacture positioners. They are the closest manufacturing art. But they compute final appliance/archwire geometry, not a tooth‑by‑tooth treatment path with intermediate positions and constraint‑governed staging. No § 102 anticipation of the independent claim. They are the strongest § 103 combination material for the "appliance is produced" aspects.
• US 5,273,429 (Rekow): models a dental prosthesis — same gap.

Group III — 3D visualization and jaw modeling (map to display/animation dependent claims):

• US 5,528,735 (Strasnick) — displaying data in a 3D information landscape: potentially anticipates narrow claims reciting a 3D graphical interface/viewing, but not path generation.
• US 5,342,202 (Deshayes) — cranio‑facial modelling; US 5,340,309 (Robertson) — recording jaw motion: relevant to occlusion/jaw‑movement dependent claims (the "virtual articulator"), not to claim 1.

Group IV — Most relevant to the core claim element (c):

• US 5,975,893 (Chishti et al., 1999‑11‑02) — "incrementally moving teeth," disclosing successive intermediate tooth arrangements for staged aligners. If it is a cited reference, it is the closest prior art to claim element (c). Two caveats: (i) it is a same‑assignee, overlapping‑inventor reference (its application predates 6,318,994's filing), so its status as "another" under § 102(e) must be verified against the exact inventive entities; and (ii) I could not confirm on the face of 6,318,994 that it was cited there (it appears on the sibling US 6,729,876). Treat as strongest § 102/§ 103 candidate pending that verification.
• US 6,152,731 (Jordan, 2000‑11) — cited by examiner on the sibling, but it postdates 6,318,994's 1999‑05‑13 filing; usable only as § 102(e) art (its application filing date must be checked), not § 102(b).
• US 6,217,334 (Hultgren, 2001‑04) — likewise postdates the filing; § 102(e) only.

Collision‑detection claims (neutral plane / signed distances / sum ≤ 0): I found no cited patent that discloses this specific algorithm. The only cited source is the OBBTree SIGGRAPH 1996 paper (NPL), which is a different interference‑detection approach and is incorporated to the extent it supports the leaf‑triangle routine — it does not anticipate the signed‑distance claims.

Occlusion / malocclusion‑index claims: the PAR index and Kesling/Warunek NPL describe indices and positioners but not computing an index during automated path optimization; no anticipation.

6. Bottom line

• No single cited reference, on the record retrieved, discloses all limitations of the independent claim — in particular, none of the Andreiko, Breads/Abbatte, Kuroda, Andersson, Wu, or Strasnick references teaches generating constraint‑governed treatment paths with intermediate tooth positions. They anticipate at most the "initial digital data set" and "3D display/manufacture" limitations of narrower claims.
• The strongest § 102 candidate is US 5,975,893 (Chishti et al.), but only if it is confirmed as cited on 6,318,994 and only after resolving the § 102(e) "another inventor" issue for the same‑assignee family.
• The collision‑detection claims appear to survive all cited patents; the closest art is the non‑patent OBBTree (SIGGRAPH 1996) paper, which uses a different mechanism.
• Verification still needed (not fabricated above): (i) the complete, unchecked front‑page "References Cited" list for 6,318,994 (FPO truncated after US 5,017,133); (ii) the verbatim claim set of 6,318,994 to fix exact claim numbers; (iii) the U.S. filing dates of US 6,152,731 and US 6,217,334 to test § 102(e).

Primary URLs: https://patents.google.com/patent/US6318994/en • https://www.freepatentsonline.com/6318994.html • https://uspto.report/patent/grant/6318994 • https://patents.google.com/patent/EP1191898B1 (family) • IPR2025‑00816 Exhibit 1005 (US 6,729,876 front page, sibling list) at https://www.docketalarm.com/cases/PTAB/IPR2025-00816/ClearCorrect_Operating_LLC/04-12-2025-Petitioner/Exhibit-1005-US_6,729,876_Chishti_876/

§ 103 Obviousness Analysis — US 6,318,994 B1 ("Tooth path treatment plan")

Prepared April 26, 2026. Note: as in the earlier section, the tool environment's clock (2026‑09‑29) conflicts with the working date given in the task header. It does not affect anything below, which rests on the patent text and the cited art.

0. Flagged contradiction with the previously generated section

The earlier section stated: "Uncertainty: the FreePatentsOnline claim listing I retrieved ends at claim 14, so I could not verify whether claims 15 and beyond exist, or whether any of them is independent... I will not assert that they are claimed."

That uncertainty is now resolved, and the earlier section should be corrected. The Google Patents rendering of US 6,318,994 (patents.google.com/patent/US6318994/en, "Claims (50)" panel) reproduces the full issued claim set: claims 1–50, with two independents — claim 1 (method) and claim 40 (system, means‑plus‑function). Claims 15–17, 20–22 (collision detection), 23–24 (occlusion/PAR index), 18 (feedback revision), 19 (multiple candidate paths), and 26–39 (3‑D rendering, animation, level‑of‑detail, remote download, 3‑D gyroscope) are claimed, not merely described. Everything in the earlier "Implementations" list is thus claim‑supported somewhere in 1–39. Residual caveat: the panel carried a "translated from" tag, so I treat it as the best available rendering rather than a certified copy; the claim numbering and dependency structure are consistent with the earlier FPO listing through claim 14, which cross‑validates it.

A second defect worth noting: claim 40's preamble recites a "system... comprising:" and then recites "receiving an initial digital data set..." rather than "means for receiving." That is a mixed method/system claim and is facially vulnerable under § 112(b).

1. Framework

• Filing/priority date: May 13, 1999. Pre‑AIA § 103(a) governs (KSR, Graham factors).
• Critical date for § 102(b): May 13, 1998. Every reference in the patent's own Background/"Prior Art" section predates that date, i.e., the entire body of art relied on below is statutory‑bar art under § 102(b). The applicant cannot swear behind any of it with a Rule 131 declaration.
• POSITA: a person with a bachelor's degree in computer science or mechanical/dental engineering plus 2–3 years' experience in dental CAD/CAM or 3‑D graphics, or an orthodontist with working familiarity with computer‑aided treatment planning. This mirrors the skill level the ITC and PTAB accepted for the Align family.
• § 103(c) issue flagged up front: the two copending applications named in the '994 specification — Ser. No. 09/169,036 ("System and Method for Repositioning Teeth") and 09/169,034 ("Defining Tooth-Moving Appliances Computationally"), both filed Oct. 8, 1998 — and their parent US 5,975,893 (Chishti et al., 08/947,080, filed Oct. 8, 1997) have § 102(e) dates before the '994 filing date. But they were commonly owned by Align Technology, Inc. at the time the invention was made, so under pre‑AIA § 103(c) they are disqualified as prior art for obviousness. They remain usable for anticipation under § 102(e) (and 5,975,893 has a different inventive entity — Chishti, Lerios, Freyburger, Wirth, Ridgley). Any challenger should therefore run '893 as a § 102 reference, not as a § 103 combinant.

2. The prior art actually of record on this page

The '994 front page / Background cites, among others: Kesling (1945, 1946, and US 2,467,432); Warunek et al. (1989); Kuroda et al. (1996) and US 5,605,459; US 5,011,405 (Lemchen) and its reissue RE 35,169; the Andreiko/Ormco family (US 5,139,419; 5,368,478; 5,431,562; 5,447,432; 5,454,717; 5,474,448; 5,533,895); US 5,338,198 (Wu); US 5,452,219 (Dehoff); US 5,587,912 and 5,607,305 (Andersson); US 5,342,202 (Deshayes); US 5,340,309 (Robertson, jaw‑motion recording); US 5,273,429 (Rekow); US 5,527,373 (Strasnick, 3‑D information‑landscape display); the Bredas/Abbatte positioner‑manufacture patents (4,755,139; 4,798,534; 4,856,991; 5,035,613; 5,055,039; 5,059,118; 5,186,623); and the Gottschalk et al. OBBTree paper (SIGGRAPH '96, pp. 171–180, DOI 10.1145/237170.237244), which the specification expressly incorporates by reference.

3. Ground 1 — Claim 1 (the strongest ground)

Combination: Kuroda US 5,605,459 + Kesling US 2,467,432 (with the 1945/46 Kesling papers) + Lemchen US 5,011,405.

Element‑by‑element:

Motivation to combine. Kuroda '459 and the 1996 Kuroda paper identify the problem in so many words: "handmade set‑up models... are extremely time consuming and [make] comparing multiple alternative treatment plans in an individual case a long and laborious process." Kesling's technique is the handmade set‑up model. Converting it to Kuroda's scanned/computed set‑up is the substitution of a known digital process for the manual step it was expressly designed to replace, with a predictable result (KSR, simply substituting one known element for another to obtain predictable results). Lemchen supplies the further express motivation and enablement — that orthodontic modeling and appliance construction "is done mathematically by appropriate software programs," and that CAD/CAM can produce models and appliances from the digital data. All three are in the same field (orthodontics), address the same problem, and are combinable by design choice.

Kuroda's own "interference check... to avoid any possible overlap" also supplies the collision‑detection concept of claim 15, and the "confirmation of occlusal position... by causing the maxillary and mandibular teeth having the three‑dimensional shape to bite" supplies claim 23's bite‑occlusion check.

4. Ground 2 — Claim 1 (alternative)

Combination: Lemchen '405/RE 35,169 + Kesling + Andreiko family (US 5,431,562; 5,447,432; 5,533,895). Andreiko teaches staged tooth movement with a succession of digitally designed/formed orthodontic appliances toward a computed finish position, supplying the "series of appliances, each corresponding to a segment" element with an explicit staging rationale. This ground is weaker than Ground 1 for claim 1 because Lemchen alone was found (in the ITC's 337‑TA‑562 analysis of the sibling '325/'511/'666 patents) not to disclose "fabricating intermediate or successive tooth repositioning appliances based on digital data sets" (see USITC Pub. 4555, part 4). Ground 1 avoids that gap by using Kuroda '459 + Kesling for the successive‑appliance element.

5. Dependent claims

6. Collision claims (15–17, 20–22)

Combination: Gottschalk OBBTree (incorporated by reference into the '994 spec) + Kuroda '459's interference check + conventional depth/Z‑buffer techniques.

Claims 15 and 20 (apply rules to detect collisions along the path) are met by Kuroda's per‑tooth interference check applied across the set‑up, plus Gottschalk, whose OBBTree is a general efficient interference‑detection algorithm for arbitrary triangulated models "undergoing rigid motion" — teeth are exactly such models. The applicant's own incorporation of Gottschalk is an admission that tooth‑collision detection was a known, available technique.

Claims 16–17 / 21–22 (neutral projection plane between two teeth, normal z‑axis with signed distances, collision when the sum ≤ 0) are the weakest element of the claim set to attack on this record. The recited scheme is functionally a two‑sided depth‑buffer (Z‑buffer) comparison, and the two‑object/projection‑plane framing is a standard graphics construction — but none of the references on this page squarely discloses a "neutral plane between two objects with opposed signed distances summing to ≤ 0." A challenger would need to add an explicit depth‑buffer/signed‑distance reference (e.g., a Z‑buffer rendering or "collision buffer" teaching not cited on the face of the patent). I do not have such a reference confirmed, and I will not assert one.

7. Occlusion, index, feedback, candidate paths (18–19, 23–24)

• 23–24 (bite‑occlusion rules; malocclusion index computed and displayed): Kuroda '459 (occlusal‑plane determination; occlusal‑contact confirmation on a monitor), Robertson '309 (recording jaw motion — the "virtual articulator" function the '994 spec describes), and the well‑documented, pre‑1998 PAR‑index literature (the '994 spec itself recites PAR as an existing eleven‑component index, and the references‑cited list in the family includes "Biggerstaff, Computerized Diagnostic Setups and Simulations (1970)" and Bernard et al., "Computerized Diagnosis in Orthodontics for Epidemiological Studies"). Computing and displaying an already‑known index is obvious.
• 18 (revise paths based on whether teeth are following them): the classic reactive evaluate‑and‑adjust loop, which is Kesling's own method and the general orthodontic workflow (see the ITC record's description of the pre‑Align "entirely reactive process"). Digitizing that feedback loop is the express purpose of Lemchen's CAD/CAM planning.
• 19 (multiple candidate paths displayed for user selection): Kuroda 1996 supplies the motivation almost verbatim ("comparing multiple alternative treatment plans in an individual case [is] a long and laborious process"), and Strasnick '373 supplies the 3‑D information‑landscape display on which alternatives are compared.

8. GUI / rendering claims (26–39) and system claims (40–50)

Combination: Strasnick '373 (displaying data within a three‑dimensional information landscape) + the general‑purpose 3‑D graphics knowledge of a POSITA + the '994 spec's own admission that the platform is a standard PC/workstation with a CRT/LCD and a modem/network interface.

• 26–27, 31–32, 36 (render 3‑D teeth; animate; user‑modify; orthodontic viewing angles): ordinary application of known 3‑D modeling/display to known digital tooth models (Wu '198; Andersson '912/'305; Kuroda).
• 28 (VCR‑style animation controls): ubiquitous animation UI convention; no technical contribution.
• 29–30 (partial data / level‑of‑detail compression): level‑of‑detail is a standard, textbook 3‑D graphics technique — strong obviousness showing.
• 33–35 (select a tooth and display motion/bistance info): conventional graphical interrogation of a geometric model.
• 37–39 (text comments; download to a remote computer; 3‑D gyroscopic input): network transmission is expressly contemplated by the '994 spec itself (modems, network interface 524); 3‑D input devices were known. These are the most § 101‑exposed claims in the set (cf. the 2026 Federal Circuit affirmances of § 101 invalidity as to other Align patents — Dental Monitoring SAS v. Align Technology, Nos. 24‑2270 etc., July 7, 2026), and § 103‑vulnerable as mere automation of known user‑interface functions.
• 40–50: mirror claims 1–11 in means‑plus‑function form; they rise and fall with the corresponding method claims, subject to the § 112(b) defect noted in §0.

9. Counterarguments, secondary considerations, and honest weaknesses

1. The ITC actually rejected the Lemchen + Kesling theory for the sibling '511 claim 1 (USITC Pub. 4555, part 4), finding Lemchen "does not in any way disclose, or hint at, multiple removable appliances or fabricating intermediate or successive tooth repositioning appliances based on digital data sets." This is why Ground 1 (Kuroda '459 as the primary reference) is materially stronger than any Lemchen‑anchored theory — the Kuroda‑plus‑Kesling pairing closes the exact gap the ITC identified, and Kuroda was not before the ITC in that proceeding.
2. Nonobviousness evidence exists. Patent Owner's expert in the related PTAB proceeding (Dr. Valley, IPR2016‑00270) testified that pre‑Align tooth straightening was "an entirely reactive process" and that the prior art made one adjustment at a time and waited weeks before the next. That is meaningful evidence of a contrary teaching/mindset, and it is the strongest argument Patent Owner has against Grounds based on Kesling alone. It is blunted by Kuroda '459, which is not reactive — it is a complete digital setup computed before any appliance is made, and it expressly flags the multi‑plan comparison problem.
3. Commercial success (Invisalign) is available to Patent Owner, but the nexus to claim 1 is attenuated: the same product is covered by dozens of Align patents, and the '994 is one of several siblings. Expect a nexus fight, not a success fight.
4. No unexpected results data appears in the specification for the recited numerical ranges (claims 7, 9) or for the collision scheme.
5. Claim 16/17/21/22 and claim 7 are the claims I would expect Patent Owner to defend most successfully on this record.

10. Bottom line

• Claim 1 is obvious over Kuroda US 5,605,459 + Kesling US 2,467,432 + Lemchen US 5,011,405 (optionally + Andreiko), with motivation supplied by the express prior‑art recognition that manual set‑up models are slow and that alternative plans are laborious to compare, and by Lemchen's teaching that the same modeling can be performed by software and CAD/CAM machinery.
• Claims 2–6, 8, 12–15, 18–29, 31–39, and 40–50 are obvious for the reasons in §§5–8; the § 103 case is strongest where the feature is (a) an admitted convention in the '994 specification itself (constraints from textbooks/clinicians, standard PC/network platform), or (b) a standard technique (level‑of‑detail, VCR controls, interpolation, depth‑based collision testing).
• Claims 7, 9, and 16–17 (and 21–22) are the weak links for a challenger — 7 and 9 need a routine‑optimization/overlapping‑range showing, and 16–17 need a specific depth‑buffer/signed‑distance reference that is not on the face of the patent and which I have not confirmed. I would not represent that those references exist without a targeted document pull.

Sources used: the authoritative patent text supplied (patents.google.com/patent/US6318994/en); the Google Patents claim set for US 6,318,994; US 5,605,459 as reproduced at uspto.report/patent/grant/5605459 and the Kuroda et al. 1996 article, Am. J. Orthod. Dentofac. Orthop. 110(4):365–369; Gottschalk, Lin & Manocha, SIGGRAPH '96, 171–180, DOI 10.1145/237170.237244; US 5,011,405 / RE 35,169 (Lemchen); USITC Publication 4555, part 4 (337‑TA‑562); and PTAB IPR2016‑00270 filings.