DCT

2:25-cv-00804

Align Technology Inc v. Angelalign Technology Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-00804, E.D. Tex., 09/26/2025
  • Venue Allegations: Plaintiff alleges venue is proper because Defendants are foreign entities, and that the court has personal jurisdiction based on Defendants importing, offering to sell, and selling the accused products within the United States and Texas, including through an accessible website and by hosting educational events in Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s Angel Aligner System infringes six patents related to the multilayer materials used to make clear dental aligners and specific geometric features on the aligners, such as "Power Ridges" and "Bite Ramps," designed to improve tooth movement.
  • Technical Context: The technology at issue is in the field of orthodontic treatment, specifically concerning the materials science and mechanical design of removable clear dental aligners used to correct malocclusion.
  • Key Procedural History: The complaint alleges that Defendants submitted 510(k) Premarket notifications to the U.S. Food and Drug Administration (FDA) seeking clearance for their Angel Align System, identifying Plaintiff's Invisalign® system as the "predicate device." This submission, which allegedly characterized Defendants' aligners as substantially equivalent to Plaintiff's, may be presented as evidence of Defendants' awareness of Plaintiff's technology.

Case Timeline

Date Event
2008-01-29 Earliest Priority Date for ’977, ’321 Patents
2012-05-14 Earliest Priority Date for ’313, ’314 Patents
2014-02-21 Earliest Priority Date for ’616, ’996 Patents
2014-12-02 ’977 Patent Issued
2021-04-20 ’616 Patent Issued
2022-11-08 ’996 Patent Issued
2023-01-01 Accused Products Entry into U.S. Market (approx. date)
2023-09-26 ’313 Patent Issued
2023-09-26 ’314 Patent Issued
2024-08-13 ’321 Patent Issued
2025-09-26 Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,766,313 - "Methods for Making Dental Aligners from Multilayer Sheets"

Issued September 26, 2023

The Invention Explained

  • Problem Addressed: Single-layer materials used for clear aligners may not provide the ideal combination of properties for effective orthodontic treatment. There is a need for aligners that can produce a more continuous force over time to better guide teeth into their desired positions (U.S. Patent No. 11,154,384, col. 1:59-62).
  • The Patented Solution: The invention describes a method for manufacturing dental aligners from a specific three-layer polymer sheet. This sheet has a harder co-polyester layer and a softer thermoplastic polyurethane elastomer layer, each with defined physical properties like elongation at break and hardness (’313 Patent, Abstract). This composite structure is designed to offer a superior combination of elasticity for consistent force and rigidity for durability compared to single-layer materials (U.S. Patent No. 11,154,384, col. 5:14-22).
  • Technical Importance: This multilayer material approach sought to improve clinical outcomes by providing more consistent force application over the wear period of the aligner, enhancing both the predictability and efficiency of tooth movement (Compl. ¶16).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶53).
  • Claim 1 is a method claim with the following essential steps:
    • Providing a multilayer sheet with a first, second, and third layer.
    • The first layer consists of a co-polyester with an elongation at break greater than 70%.
    • The second layer consists of a thermoplastic polyurethane elastomer with an elongation at break greater than 200% and a hardness of about 60 A to about 85 D.
    • The first layer has a hardness greater than the second layer.
    • Providing a mold of a patient's teeth.
    • Thermoforming the multilayer sheet over the mold.
    • Trimming the excess material to form the final aligner.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 11,766,314 - "Methods for Making Multilayer Dental Aligners"

Issued September 26, 2023

The Invention Explained

  • Problem Addressed: As with the ’313 Patent, the invention addresses the need for aligner materials with improved physical properties to deliver more consistent and effective orthodontic forces (U.S. Patent No. 11,154,384, col. 1:59-62).
  • The Patented Solution: This invention also claims a method of making a dental aligner from a multilayer sheet. The claim specifies a first co-polyester layer and a second thermoplastic polyurethane elastomer layer, but adds further material property requirements for the second layer, including an ultimate tensile strength greater than 5000 psi and a light transmission greater than about 75% (’314 Patent, Abstract). These additional constraints aim to further optimize the material for both mechanical performance and aesthetic clarity (U.S. Patent No. 11,154,384, col. 5:14-22).
  • Technical Importance: By defining additional properties like tensile strength and optical clarity, the invention aimed to create aligners that are not only mechanically effective but also durable and aesthetically pleasing to the patient (Compl. ¶16).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶78).
  • Claim 1 is a method claim with the following essential steps:
    • Providing a multilayer sheet with polymer layers, including a first co-polyester layer, a second thermoplastic polyurethane elastomer layer, and a third layer.
    • The second layer has specific properties: elongation at break > 200%, hardness of 60A to 85D, ultimate tensile strength > 5000 psi, and light transmission > 75%.
    • Providing a mold.
    • Thermoforming the sheet over the mold.
    • Trimming the excess material to form the aligner.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 8,899,977 - "Orthodontic Repositioning Appliances Having Improved Geometry, Methods and Systems"

Issued December 2, 2014

  • Technology Synopsis: This patent, related to Align's "Power Ridge" technology, describes orthodontic aligners with integrated geometric features, such as ridge-shaped protrusions, designed to apply specific, controlled forces to a tooth. The goal is to improve torque control and achieve more predictable and efficient tooth rotation and movement around its center of resistance (’977 Patent, Abstract; Compl. ¶¶17-18).
  • Asserted Claims: Independent claim 1 is asserted (Compl. ¶100).
  • Accused Features: The complaint alleges that Defendants' "angelAttach" features, specifically the "Torque Ridge," "Intrusion Ridge," and "Rotation Ridge attachments," infringe the ’977 Patent (Compl. ¶31).

U.S. Patent No. 12,059,321 - "Orthodontic Repositioning Appliances Having Improved Geometry, Methods and Systems"

Issued August 13, 2024

  • Technology Synopsis: This patent is also part of the "Power Ridge" family and relates to an orthodontic appliance with multiple "active regions." One region is an integral protrusion that applies a force, while a second region is configured to mate with a bonded attachment on the tooth to apply a countermoment, thereby reducing unwanted rotation and providing more precise control over tooth movement (’321 Patent, Abstract; Compl. ¶¶17-18).
  • Asserted Claims: Independent claim 1 is asserted (Compl. ¶115).
  • Accused Features: The complaint alleges that the combination of Defendants' "aligner pressure points" (e.g., ridges) and "conventional attachments" that are bonded to the teeth infringe the ’321 Patent (Compl. ¶¶127-128).

U.S. Patent No. 10,980,616 - "Treatment Plan Specific Bite Adjustment Structures"

Issued April 20, 2021

  • Technology Synopsis: This patent, related to Align's "Bite Ramp" technology, describes a system of aligners used in series to correct deep bites. The aligners feature "bite adjustment structures" (ramps) that are formed of the same material as the aligner shell. The position of these ramps changes between successive appliances in the treatment plan, allowing a tooth from the opposing jaw to slide along a planar surface and progressively correcting the bite (’616 Patent, Abstract; Compl. ¶¶19-21).
  • Asserted Claims: Independent claim 1 is asserted (Compl. ¶130).
  • Accused Features: The complaint alleges that Defendants' "occlusal ramps," which are described as molded prominences that are part of a series of aligners for progressive treatment, infringe the ’616 Patent (Compl. ¶¶33, 141, 145).

U.S. Patent No. 11,490,996 - "Treatment Plan Specific Bite Adjustment Structures"

Issued November 8, 2022

  • Technology Synopsis: This patent is also part of the "Bite Ramp" family and covers a method of making a series of aligners. The method involves generating digital models for different treatment stages where the bite adjustment structures are located at different distances from the tooth's incisal surface in successive models. This planned, stage-specific change in ramp position is central to the claimed method for correcting deep bites (’996 Patent, Abstract; Compl. ¶¶19-21).
  • Asserted Claims: Independent claim 1 is asserted (Compl. ¶151).
  • Accused Features: The complaint alleges that Defendants' process of creating a series of aligners with "occlusal ramps" that change position over different treatment stages infringes the ’996 Patent (Compl. ¶¶33, 162, 167-168).

III. The Accused Instrumentality

Product Identification

  • The accused products are the components of the "Angel Aligner System," including but not limited to the Angel Aligner Pro, Angel Aligner Select, and Angel Aligner KiD clear aligners (Compl. ¶23).

Functionality and Market Context

  • The Angel Aligner System is alleged to be a set of patient-specific, removable clear aligners used to treat malocclusion (Compl. ¶23). The system relies on orthodontic software ("iOrtho platform") for treatment planning and manufacturing the aligners (Compl. ¶34).
  • The complaint alleges the accused aligners are manufactured from a three-layer thermoplastic material, specifically Bay Materials's "Zendura FLX" or an equivalent material, which is described as having an elastomeric inner core and a hard outer shell (Compl. ¶26, ¶66). The complaint provides cross-section images of an accused aligner, stating that testing confirmed a tri-layer material structure (Compl. ¶64, p. 23).
  • Functionally, the accused aligners are alleged to incorporate "angelAttach" features, which include "Torque Ridge," "Intrusion Ridge," and "Rotation Ridge" attachments, described as "aligner pressure points" (Compl. ¶¶31, 127). The complaint includes a graphic from the defendant's website illustrating these "Aligner Pressure Points" (Compl. ¶112, p. 41). The system also allegedly incorporates "occlusal ramps" to assist in treating deep bites (Compl. ¶33).

IV. Analysis of Infringement Allegations

’313 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
providing a multilayer sheet comprising: a first layer; a second layer; and a third layer; Angel's method uses a multilayer sheet to make its aligners, which are marketed as being made from "masterControl S," a "Soft Multi-layered Polymer Material." Third-party testing allegedly confirmed a tri-layer structure. ¶64, ¶68 U.S. Pat. No. 11,154,384, col. 5:20-27
wherein the first layer consists of a co-polyester, the co-polyester having an elongation at break of greater than 70%; The aligners are allegedly made from Zendura FLX, whose outer layers are Eastman Tritan MP100 Copolyester. This material is alleged to have an elongation at break of 179%, which is greater than 70%. ¶70 U.S. Pat. No. 11,648,091, col. 6:1-10
wherein the second layer consists of a thermoplastic polyurethane elastomer, the thermoplastic polyurethane elastomer having an elongation at break of greater than 200% and a hardness of about 60 A to about 85 D; The inner layer of Zendura FLX is allegedly Covestro's Texin RxT50D Polyurethane elastomer. This material is alleged to have an elongation at break of 480% (>200%) and a hardness of 50D, which is alleged to be between 60A and 85D. ¶71 U.S. Pat. No. 11,648,091, col. 6:11-20
and wherein the first layer has a hardness greater than the hardness of the second layer; The outer layers (PETG) are alleged to have a Shore hardness of around 70D, which is greater than the alleged 50D hardness of the inner layer (Texin RxT50D). ¶72, ¶73 U.S. Pat. No. 11,648,091, col. 6:21-23
providing a mold; Angel's method allegedly generates physical positive models (molds) of the patient's teeth using rapid prototyping machines based on a digital treatment plan. ¶74 U.S. Pat. No. 11,648,091, col. 3:45-51
thermoforming the multilayer sheet over the mold...; and trimming excess material... to form the multilayer dental aligner. The aligners are allegedly produced by thermoforming the multilayer sheet on each physical model and then trimming the excess material to fabricate the sequence of aligners. ¶75, ¶76 U.S. Pat. No. 11,648,091, col. 3:45-51

’314 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
providing a multilayer sheet comprising polymer layers, the polymer layers comprising: first layer consisting of a co-polyester; and a second layer consisting of a thermoplastic polyurethane elastomer...a third layer; Angel's method uses a multilayer sheet ("masterControl S") with three or more polymer layers, allegedly Zendura FLX or similar. The first and third layers are allegedly a co-polyester and the second layer is a thermoplastic polyurethane elastomer. ¶89, ¶91-¶93 U.S. Pat. No. 11,154,384, col. 5:20-27
wherein the thermoplastic polyurethane elastomer has an elongation at break of greater than 200%, a hardness of 60A to 85D, an ultimate tensile strength of greater than about 5000 psi, and a light transmission between 400 nm and 800 nm of greater than about 75%; The material for the second layer is allegedly Texin RxT50D, which has a claimed elongation at break of 480% (>200%), a hardness of 50D (between 60A-85D), an ultimate tensile strength of 7,110 psi (>5000 psi), and is transparent, allegedly satisfying the light transmission requirement. ¶95 U.S. Pat. No. 11,766,314, col. 6:16-24
providing a mold; Angel's manufacturing process allegedly uses rapid prototyping machines to produce physical positive models (molds) based on a digital plan created from patient scans. ¶96 U.S. Pat. No. 11,648,091, col. 3:45-51
thermoforming the multilayer sheet over the mold...; and trimming excess material... to form the multilayer dental aligner. The aligners are allegedly produced by thermoforming the sheet material over the physical models and then trimming the excess to form the final aligner product. ¶97, ¶98 U.S. Pat. No. 11,648,091, col. 3:45-51

Identified Points of Contention

  • Technical Questions: A primary factual dispute may center on whether the accused Angel Aligner material, identified as "Zendura FLX" or an equivalent, actually possesses the specific quantitative physical properties (e.g., elongation > 70%, hardness of 50D, tensile strength > 5000 psi) recited in the claims. The complaint relies on publicly available data for the alleged component materials, but the properties of the final composite product as manufactured by Angel will be subject to discovery and testing. The complaint provides an FTIR spectra graph allegedly showing the material composition of an accused aligner (Compl. ¶65, p. 24).
  • Scope Questions: The interpretation of "consists of" in the claims for the first and second layers will be a key legal question. Defendants may argue this term is limiting and precludes the presence of any other additives or processing agents in the specified layers, while Plaintiff may argue for a less restrictive interpretation.

V. Key Claim Terms for Construction

  • The Term: "a hardness of about 60 A to about 85 D" (’313 Patent, Claim 1)

    • Context and Importance: The term "about" introduces ambiguity into a specific numerical range. The scope of this term is critical because the complaint alleges the accused product's material has a hardness of 50D, which is outside the literal range of 60A-85D. The infringement allegation hinges on whether "about 60A" can be construed to encompass 50D, or if Plaintiff will need to rely on the doctrine of equivalents. Practitioners may focus on this term as it appears to be a potential mismatch between the claim language and the infringement theory presented.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The patent specification does not appear to provide an explicit definition for "about." A party arguing for a broader scope may contend that in the context of polymer science, hardness values can vary and "about" should be interpreted functionally to include materials that perform in a similar manner.
      • Evidence for a Narrower Interpretation: A party arguing for a narrower scope may point to the recitation of a specific numerical range as an intentional limitation by the patentee, suggesting "about" only covers minor, insignificant variations. The specification does not appear to provide specific examples that would broaden or narrow the plain meaning of the recited range.

  • The Term: "consists of" (’313 Patent, Claim 1)

    • Context and Importance: This transitional phrase defines the components of the first and second layers. Its construction determines whether those layers can include materials other than the recited co-polyester or thermoplastic polyurethane elastomer. If construed as "consisting essentially of" or "consisting solely of," it could provide a non-infringement defense if the accused product contains other functionally significant components in those layers.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The patent does not explicitly define the term. A party might argue that in the context of the patent, the term was not intended to be as strictly limiting as "consisting solely of," especially if trace elements or processing aids are common in such materials.
      • Evidence for a Narrower Interpretation: In patent law, "consists of" is a closed term that excludes any elements not specified. A party would argue for this standard interpretation, pointing to the absence of any language in the specification suggesting a different meaning was intended.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement of infringement by asserting that Angel advertises its aligners to doctors and directly to patients, thereby encouraging them to use the products in an infringing manner (Compl. ¶¶54, 79, 101).
  • Willful Infringement: The complaint alleges that Angel had pre-suit knowledge of Align's technology and, by reasonable inference, its patent portfolio. This allegation is primarily based on Angel's 510(k) submissions to the FDA, which identified Align’s Invisalign® system as a predicate device and allegedly demonstrated awareness of the specific multilayer material composition used by Align (Compl. ¶¶56-57, 81-82). These facts are alleged to support a claim of deliberate or willfully blind infringement.

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of evidentiary proof: can Plaintiff demonstrate through testing and discovery that the multilayer material used in the Angel Aligner system, as sold, meets the specific quantitative limitations for hardness, elongation, tensile strength, and other properties recited in the asserted claims of the ’313 and ’314 patents? The complaint’s reliance on data sheets for component materials raises the evidentiary question of whether the final, composite product exhibits those same properties.
  • A key question for willfulness will be one of inferred knowledge: does Angel's knowledge of Align's Invisalign® system as a predicate device for FDA clearance constitute pre-suit knowledge or willful blindness to the existence and infringement of the specific patents-in-suit, or will the defendant be able to argue that knowledge of a competitor's product does not equate to knowledge of its specific patent portfolio?
  • The case will also present a central question of definitional scope: can the term "about 60A to about 85D" for material hardness be construed to encompass the alleged 50D hardness of the accused product, or is this a dispositive mismatch that will force Plaintiff to argue infringement under the doctrine of equivalents?