2D-to-3D Tooth Reconstruction with Differentiable Rendering

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Solution Overview

Problem

Existing orthodontic treatment planning methods face challenges in accurately and efficiently generating 3D models of an individual's dentition from 2D images, which are resource-intensive and difficult to present, and require complex iterative techniques like EM algorithms.

Innovation Solution

Implementing a 3D geometry optimization framework using differentiable rendering techniques to compare 2D images with 3D dental models, and training machine learning neural networks to reconstruct 3D dental models from 2D images, allowing for automated and accurate 3D model generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional EM algorithms are used to convert 2D images to 3D models, then 3D models can be generated, but the process is computationally intensive and resource-consuming

Engineering Contradiction:
Improve3D model generation accuracyVSAvoidcomputational resource consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent replaces traditional iterative EM algorithms with a differentiable rendering approach that uses gradient-based optimization. Instead of repeatedly iterating through complex computational steps, the system uses differentiable rendering to directly optimize 3D models from 2D images through gradient descent, significantly reducing computational resource requirements while maintaining accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the optimization parameters from iterative algorithm steps to direct gradient-based parameter adjustment. By using differentiable rendering, the system optimizes 3D model parameters directly through gradient descent on the rendering loss, transforming the computational approach from heavy iterative processing to more efficient gradient-based optimization.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If 3D dental models are created from 2D images, then treatment planning can be performed, but the process is time-consuming and inefficient

Engineering Contradiction:
Improve3D model accuracyVSAvoidmodel generation speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces slow iterative EM algorithms with a differentiable rendering system that uses gradient-based optimization. This substitution enables faster convergence to accurate 3D models by directly optimizing through gradient descent on the rendering loss, dramatically improving model generation speed without sacrificing accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback mechanism through differentiable rendering where the system continuously compares rendered 2D images from the 3D model against the original input images, computes loss gradients, and uses these gradients to iteratively improve the 3D model parameters. This feedback loop enables efficient optimization and rapid convergence to accurate models.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If complex iterative techniques like EM algorithms are used, then 3D models can be reconstructed, but the process becomes difficult to present and manage

Engineering Contradiction:
Improve3D model reconstruction accuracyVSAvoidalgorithm complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex iterative EM algorithms with a differentiable rendering framework that uses standard gradient-based optimization techniques. This substitution simplifies the overall process by replacing multi-step iterative algorithms with a more straightforward gradient descent approach on the rendering loss, making the system easier to implement and manage while maintaining reconstruction accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS20250302590A12d-to-3d tooth reconstruction, optimization, and positioning frameworks using a differentiable renderer
Publication Date: 2025.10.02 ALIGN TECHNOLOGY INC
  • US20250302590A1 patent drawing
  • US20250302590A1 patent drawing
  • US20250302590A1 patent drawing

AI summary

Provided herein are systems and methods for optimizing a 3D model of an individual's teeth. A 3D dental model may be reconstructed from 3D parameters. A differentiable renderer may be used to derive a 2D rendering of the individual's dentition. 2D image(s) of an individual's dentition may be obtained, and features may be extracted from the 2D image(s). Image loss between the 2D rendering and the 2D image(s) can be derived, and back-propagation from the image loss can be used to calculate gradients of the loss to optimize the 3D parameters. A machine learning model can also be trained to predict a 3D dental model from 2D images of an individual's dentition.