3D OCT Imaging of Dental Aligner Fit and Tooth Contact

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Solution Overview

Problem

Existing methods struggle to accurately measure the fit and interaction between oral appliances, such as dental aligners, and teeth due to difficulties in simultaneous imaging of both structures, with current techniques like CT scanning exposing patients to harmful X-rays and providing inaccurate quantitative measurements.

Innovation Solution

The use of optical coherence tomography (OCT) for simultaneous imaging of dental appliances and teeth, allowing for 3D measurements of aligner shape, tooth positions, and contact interactions, with stitching techniques to create comprehensive models, and optional CT scanning with shielding for reduced radiation exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional imaging methods (intraoral cameras, extraoral photos, scanning systems) are used to capture aligner geometry and fit, then multiple separate devices and procedures are required, but this increases device complexity, patient discomfort, and inability to capture true 3D geometry

Engineering Contradiction:
Improve3D geometry measurement precisionVSAvoidimaging system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple imaging functions into a single optical coherence tomography system that simultaneously captures both the aligner geometry and the oral structures in one integrated device, eliminating the need for separate intraoral cameras, extraoral photos, and scanning systems

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The OCT system performs multiple functions including capturing aligner geometry, imaging oral structures, measuring gaps between aligner and teeth, and verifying fit all through a single multi-functional imaging platform

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If 2D imaging methods are used to assess aligner fit, then the equipment is simple, but the measurement precision and ability to determine true contact locations is insufficient

Engineering Contradiction:
Improvecontact location detection precisionVSAvoid3D gap measurement difficulty
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent transitions from 2D imaging to 3D optical coherence tomography imaging, enabling measurement of gaps and contact locations in three dimensions with high precision, allowing accurate assessment of aligner fit that cannot be achieved with planar imaging

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Productivity

If multiple separate imaging procedures are performed to verify aligner fit, then each individual procedure is simple, but the total time required and patient discomfort increase

Engineering Contradiction:
Improvefit verification efficiencyVSAvoidtotal imaging time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The OCT system performs continuous imaging during a single patient visit, capturing aligner geometry, oral structures, and fit verification data in one uninterrupted sequence, eliminating the need for multiple separate procedures and reducing total time

Inventive Principle:
Principle #20Continuity of useful action

4Manufacturing precision

If conventional imaging systems are used, then the equipment cost is lower, but the ability to generate accurate 3D models for aligner modification is insufficient

Engineering Contradiction:
Improvealigner design precisionVSAvoidimaging apparatus complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The OCT system creates accurate 3D digital copies and models of both the aligner and oral structures, enabling precise visualization and modification of aligner design based on actual fit data without requiring complex physical prototypes

Inventive Principle:
Principle #26Copying

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

OCT provides precise 3D measurements of aligner fit and tooth interactions, enabling improved treatment planning, defect detection, and reduced treatment time by verifying appliance fit and bone growth, while minimizing X-ray exposure.

Implementation Method 1

System and methods for processing an orthodontic aligner by means of an optical coherence tomography

Methodology Applied
Scientific EffectOptical coherence tomography: Tomography

Implementation Method 2

3D imaging (including 3D optical coherence tomography imaging) to measure the shape of orthodontic aligners, teeth, and other oral structures

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP4278957B1System for analysis of dental attachments bonded to a patient's teeth
Publication Date: 2026.05.20 ALIGN TECHNOLOGY INC
  • EP4278957B1 patent drawingFigure 1
  • EP4278957B1 patent drawingFigure 2A~2B
  • EP4278957B1 patent drawingFigure 3

AI summary

Methods and apparatuses for 3D imaging (including 3D optical coherence tomography imaging) to measure the shape of orthodontic aligners, teeth, and other oral structures simultaneously, in-vivo or in-vitro. These methods and apparatuses may be used to determine contact locations of aligners with teeth and/or teeth with other teeth with very high precision, including determining the size of gaps where they are not in contact. These measurements may be used design, modify or replace an aligner and/or to verify aligner fit. 3D models of the whole aligner and teeth may be generated.