Orthodontic Aligner Retention via Digital Undercut Modeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Removable orthodontic aligners face challenges in retention due to variations in patient-specific tooth morphologies, which affect the efficacy of orthodontic treatments.
Innovation Solution
A system utilizing a digital scanner and computing environment to create a three-dimensional model of undercut areas on teeth, allowing for the design of thermoformed aligners with customized interior dimensions that match the unique morphology of each patient's teeth, and the use of attachments or anti-relapse features to enhance retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional orthodontic aligners are used, then they are visually desirable and comfortable, but retention is insufficient due to variations in tooth morphology
Solution Approach 1:
The patent applies local quality by creating custom attachments (engagers) with specific geometries that match the local morphology of individual teeth. The system analyzes tooth-specific features such as undercut areas, cervical thirds, and axial contours to design attachments tailored to each tooth's unique shape, thereby improving retention without requiring a complete redesign of the entire aligner system.
Solution Approach 2:
The patent employs preliminary action by performing detailed digital scans and analyses of tooth morphology before aligner fabrication. The system pre-identifies undercut areas, calculates attachment geometries, and plans engagement features in advance, allowing for optimized retention design before the actual aligner manufacturing process begins.
2Reliability
If custom attachments are designed to enhance retention, then aligner retention improves, but device complexity increases
Solution Approach 1:
The patent applies self-service by implementing an automated digital workflow that performs tooth morphology analysis, undercut detection, and attachment geometry calculation without manual intervention. The system automatically processes scan data, identifies optimal attachment locations and shapes, and generates fabrication files, thereby reducing the complexity burden on clinicians while maintaining high retention performance.
Solution Approach 2:
The patent utilizes parameter changes by systematically varying attachment geometries based on measured tooth parameters such as undercut depth, axial contour, and cervical third morphology. The system adjusts attachment dimensions, shapes, and positions according to quantifiable tooth characteristics, transforming complex design decisions into parameter-driven automated processes.
3Manufacturing precision
If detailed analysis of tooth morphology is performed, then aligner fit improves, but measurement and detection difficulty increases
Solution Approach 1:
The patent replaces manual mechanical measurement methods with optical scanning technology. The digital intraoral scanner captures three-dimensional tooth surfaces with high precision, eliminating the need for physical impressions and manual measurements. This substitution of mechanical systems with optical-digital systems significantly reduces measurement difficulty while improving precision.
Solution Approach 2:
The patent creates accurate digital copies (3D models) of tooth morphology through scanning. These digital replicas preserve all surface features, contours, and undercuts, allowing for repeated analysis and measurement without physical manipulation of the actual teeth. The digital copies enable precise measurement and design work to be performed virtually, reducing detection difficulty.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Systems and methods for designing thermoformed removable orthodontic aligners and improving the retention of such aligners to patient teeth are disclosed. The systems generally include a digital scanner that is configured to obtain a digital image of a patient's dentition and a computing environment that is configured to receive a copy of the digital image; create a reference plane relative to one or more teeth featured within the digital image; position a line that runs perpendicular from the reference plane and runs tangential to a height of maximum convexity of each of the one or more teeth; measure an area of undercut between such perpendicular line and an exterior surface of each of the one or more teeth; repeat the foregoing steps at a plurality of points along the perimeter of each of the one or more teeth; and construct a three-dimensional model of an undercut area for each of the one or more teeth.