exocad GmbH v. 3Shape AS

1. Case Identification

• Case #: IPR2018-00785
• Patent #: 9,336,336
• Filed: March 15, 2018
• Petitioner(s): EXOCAD GMBH AND EXOCAD AMERICA, INC.
• Patent Owner(s): 3Shape As
• Challenged Claims: 1-30

2. Patent Overview

• Title: 2D IMAGE ARRANGEMENT
• Brief Description: The ’336 patent describes a computer-implemented method for designing a dental restoration. The method involves arranging a 2D image of a patient's face with a 3D virtual model of the patient's oral cavity, allowing visualization of the final restoration while keeping the 2D and 3D data as "separate representations."

3. Grounds for Unpatentability

Ground 1: Anticipation/Obviousness over Malfliet, Kopelman, and Wiedmann - Claims 1-14, 16-20, and 22-30 are anticipated by Malfliet under 35 U.S.C. §102, or alternatively obvious over Malfliet alone or in view of Kopelman or Wiedmann under 35 U.S.C. §103.

• Prior Art Relied Upon: Malfliet (International Publication No. WO 2008/128700), Kopelman (Patent 6,845,175), and Wiedmann (a 2008 article in Digital Dental News).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Malfliet, a reference overcome during prosecution, actually discloses every limitation of the independent claims. The core of the argument was that the patent owner incorrectly distinguished Malfliet by asserting it only taught creating a 3D face model from 2D images, not using a 2D image directly. Petitioner contended Malfliet explicitly teaches using a "single 2D photograph of the patient" as an alternative face model to be aligned with a 3D tooth model. Malfliet allegedly taught providing a 2D facial image (including lips), virtually cutting teeth from the image, providing a 3D dental model, and arranging them in a virtual space to design a restoration, thus anticipating the claims. To the extent Malfliet was found not to teach keeping the models as "separate representations," Petitioner argued this would have been an obvious design choice to avoid unnecessary computation and allow for future modifications.
  • Motivation to Combine (for §103 grounds): If Malfliet was deemed not to teach using a 2D image directly, a POSITA would combine Malfliet's general framework with Kopelman or Wiedmann. Both Kopelman (showing alignment of a 2D X-ray with a 3D tooth model) and Wiedmann (showing alignment of a 2D facial photo with a 3D tooth model) explicitly taught the 2D-to-3D visualization approach. A POSITA would have been motivated to substitute Malfliet’s 3D face model with the simpler 2D approach from Kopelman or Wiedmann to achieve the same predictable result with less computational overhead, especially when only a 2D photo was available.
  • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success, as combining 2D and 3D dental data for visualization was a well-known and predictable technique in the art, as demonstrated by Kopelman and Wiedmann.

Ground 2: Obviousness of Claim 15 over Malfliet (with or without Wiedmann/Kopelman) in view of Lehman

• Prior Art Relied Upon: Malfliet, Kopelman, Wiedmann, and Lehman (a 1999 IEEE article titled "Survey: Interpolation Methods in Medical Image Processing").
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addressed dependent claim 15, which adds the limitation that alignment is performed by "interpolation or extrapolation of other perspective views." The primary combination of Malfliet, Kopelman, and/or Wiedmann established the base system for aligning 2D and 3D models.
  • Motivation to Combine: Petitioner argued that interpolation and extrapolation were well-known image processing techniques. Lehman taught using interpolation to change the perspective views of medical images, such as X-rays. A POSITA would combine the teachings of Lehman with the base system of Malfliet to provide users with the desirable and known functionality of adjusting perspective views, a predictable improvement over a static view.

Ground 3: Obviousness of Claim 21 over Malfliet (with or without Wiedmann/Kopelman) in view of Seeger

• Prior Art Relied Upon: Malfliet, Kopelman, Wiedmann, and Seeger (Application # US2002/0075389).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addressed dependent claim 21, which adds the limitation of "de-warping the perspective view of the at least one 2D image."
  • Motivation to Combine: De-warping to remove lens distortion was a known and conventional image processing step. Seeger explicitly taught this technique. A POSITA would have been motivated to add this feature to the Malfliet system to improve image quality, as an undistorted image is inherently preferable for accurate dental planning. This combination would yield the predictable result of a clearer base image for the restoration design.

Ground 4: Obviousness of Claims 6-8 over Malfliet (with or without Wiedmann/Kopelman) in view of MacDougald

• Prior Art Relied Upon: Malfliet, Kopelman, Wiedmann, and MacDougald (Patent 6,568,936).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addressed dependent claims 6-8, which require using two 3D models—one with prepared teeth and one with unprepared teeth.
  • Motivation to Combine: MacDougald taught a CAD process for designing restorations that involved capturing data from a tooth before and after it was prepared by a dentist and comparing the two models. Petitioner argued it was well-known and obvious to use and compare models of both prepared and unprepared teeth. A POSITA would combine this known technique from MacDougald with Malfliet's system to achieve the predictable and clinically useful benefit of visualizing the restoration in the context of both the original and prepared tooth anatomy.

4. Key Claim Construction Positions

• "Remain separate representations after being arranged": Petitioner argued this term, added during prosecution to overcome Malfliet, means "the 2D image and the 3D virtual model remain in their respective formats and are not merged into a single representation." Petitioner contended this construction was critical because its own arguments for patentability hinged on this distinction, yet prior art like Malfliet, when using a 2D photo, necessarily kept the data separate until a final visualization step, rendering the distinction meaningless.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the grounds were not substantially the same as those presented to the patent examiner, precluding discretionary denial under §325(d). It was asserted that the Examiner never considered the specific teaching in Malfliet regarding the use of a 2D face image, which was the central point of Petitioner's anticipation argument. Furthermore, the Examiner never considered the combinations with Kopelman, Wiedmann, Lehman, Seeger, or MacDougald.

6. Relief Requested

• Petitioner requested the Board initiate an IPR and cancel claims 1-30 of the ’336 patent as unpatentable.