Layered Orthodontic Shell Appliances for Controlled Tooth Movement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current orthodontic appliances often fail to generate the necessary forces for effective tooth repositioning and lack sufficient control over force application, leading to discomfort and inadequate movement, due to their homogeneous material properties and rigidity.
Innovation Solution
The development of orthodontic appliances with a layered structure, featuring a stiffer exterior layer and a less stiff interior layer, incorporating discontinuities that interact to generate controlled forces for tooth movement, reducing patient discomfort and improving treatment efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single appliance shell with homogeneous material properties is used, then the appliance structure is simple, but the control over forces applied to teeth is insufficient
Solution Approach 1:
The appliance shell is divided into multiple layers (exterior layer and interior layer) with different material properties. The exterior layer has higher elastic modulus for structural support, while the interior layer has lower elastic modulus for force control and comfort, allowing independent optimization of each layer's function
Solution Approach 2:
Different regions of the appliance have different material compositions and stiffness characteristics. The exterior layer provides rigidity where structural support is needed, while the interior layer provides flexibility where force control and patient comfort are priorities, creating localized functional zones within the appliance
2Strength
If the appliance rigidity is increased, then the structural strength is improved, but the ability to be coupled to patient's teeth and patient comfort deteriorates
Solution Approach 1:
The appliance is segmented into a rigid exterior layer for structural strength and a flexible interior layer for coupling and comfort. This segmentation allows the exterior layer to maintain high rigidity for strength while the interior layer provides compliance for patient comfort and ease of coupling to teeth
Solution Approach 2:
The exterior layer is designed with high elastic modulus for structural strength in regions requiring rigidity, while the interior layer is designed with low elastic modulus for comfort and coupling in regions contacting the teeth, creating localized functional zones that simultaneously achieve strength and comfort
3Ease of manufacture
If homogeneous material properties are used throughout the appliance, then the manufacturing process is simplified, but the force generation capability for tooth repositioning is reduced
Solution Approach 1:
The appliance is manufactured as segmented layers with different material properties. The exterior layer uses materials with high elastic modulus for structural support, while the interior layer uses materials with low elastic modulus for force generation, allowing each layer to be optimized for its specific function while maintaining manufacturability
Solution Approach 2:
The appliance uses composite construction with an exterior layer of rigid material and an interior layer of flexible material. This composite structure enables the appliance to generate controlled forces for tooth repositioning through the interaction between layers, while still being manufacturable using standard orthodontic appliance fabrication processes
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 layered design allows for precise force application and enhanced control over tooth movements, minimizing discomfort and improving the effectiveness of orthodontic treatments.
Implementation Method 1
the interaction of the interior layer with the discontinuity can exert forces on the underlying teeth to elicit one or more desired tooth movements
Data Source
Figure 1A
Figure 1B
Figure 2~3A
AI summary
Improved orthodontic appliances, as well as related systems and methods, are provided. In one aspect, an orthodontic appliance can include a shell having a plurality of cavities shaped to receive a patient's teeth. The shell can include an exterior layer and an interior layer having a stiffness less than a stiffness of the exterior layer. A discontinuity can be formed in the exterior layer.