Flexible Orthodontic Aligner Shell for Continuous Tooth Engagement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional orthodontic aligners lack flexibility, leading to intermittent force delivery and difficulty in engaging teeth properly, especially when teeth are not initially aligned, requiring reworking of treatment plans and bonded attachments.

Innovation Solution

Incorporating flexible zones and patterns into the appliance shell, using materials like urethanes and polycarbonates, and employing 3D printing or CNC milling to create zones of enhanced flexibility for controlled tooth alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional orthodontic aligners are made from rigid materials, then structural strength is maintained, but flexibility is reduced leading to intermittent force delivery

Engineering Contradiction:
Improvestructural strengthVSAvoidflexibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The aligner incorporates flexible zones with different material properties or structural characteristics in specific locations (such as between teeth or at stress concentration points) while maintaining rigid structure in other areas. This allows the aligner to have localized flexibility for continuous force delivery while preserving overall structural strength.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The aligner uses composite material construction combining rigid and flexible materials, or a gradient material structure where material properties vary spatially. This enables different regions of the aligner to exhibit appropriate mechanical properties - rigid for structural support and flexible for continuous force delivery to teeth.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If rigid shell structure is used, then manufacturing precision is improved, but adaptability to misaligned teeth deteriorates

Engineering Contradiction:
Improveappliance precisionVSAvoidtooth engagement capability
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The aligner transitions from a completely rigid static structure to a dynamic structure with flexible zones that can adapt and deform. The flexible zones allow the aligner to dynamically adjust to teeth that are not in their final positions, maintaining precise force application while accommodating misalignment during treatment progression.

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If continuous material structure is used, then structural integrity is maintained, but flexibility and force continuity deteriorate

Engineering Contradiction:
Improvestructural integrityVSAvoidforce delivery continuity
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The aligner incorporates flexible zones constructed as thin film structures or flexible shell regions that can bend and deform continuously. These flexible zones maintain structural integrity through their material composition and geometric design while enabling continuous force delivery to misaligned teeth, preventing force interruption during tooth movement.

Inventive Principle:
Principle #30Flexible shells and thin films

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

The appliance achieves continuous, gentle force delivery to effectively engage teeth, ensuring precise alignment.

Implementation Method 1

a flexible assembly (42) for flexibly joining portions of the tooth-clasping assembly

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The resilience of the material from which the positioner is made provides the energy to move the teeth from their original position toward the new straightened position

Methodology Applied
Scientific EffectResilience: Elasticity

Data Source

PatentEP3972523B1Dental model and method of forming a tooth-positioning appliance
Publication Date: 2026.01.07 MARTZ ANDREW S
  • EP3972523B1 patent drawingFigure 1~2
  • EP3972523B1 patent drawingFigure 3
  • EP3972523B1 patent drawingFigure 4

AI summary

Tooth-positioning appliances and apparatuses, components, methods, and techniques for producing and using tooth-positioning appliances are provided. An example tooth-positioning appliance for adjusting the position of teeth of a patient includes a tooth-clasping arrangement shaped to secure the orthodontic appliance to at least one tooth and a flexible arrangement connected to the tooth-clasping arrangement. The flexible arrangement is less rigid than the tooth-clasping arrangement.