TMJ Movement Recording Using Virtual Spatial Geometric Models
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Solution Overview
Problem
Current methods for recording and modeling the temporomandibular joint (TMJ) movement and geometry in prosthodontics and orthognathic surgery are imprecise, relying on standardized assumptions that do not account for individual anatomical variations, leading to inadequate dental prosthetic adjustments and potential TMJ disorders.
Innovation Solution
A method using accelerometric, gyro, or mixed sensors to record mandible and skull base movements, combined with cone beam tomography or MRI for 3D imaging, to create a virtual spatial geometric model of the stomatognathic system, allowing for precise tracing of the condylar head's movement and geometry, and dynamic parameters of the cartilage and ligament apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If standardized articulators with fixed elements are used to simulate TMJ movements, then the device complexity is reduced and ease of operation is improved, but the measurement precision and manufacturing precision of individualized TMJ models deteriorate
Solution Approach 1:
The patent creates accurate digital copies of individual patients' TMJ anatomy and movement patterns through 3D imaging and motion capture technology. These digital models precisely replicate the unique geometric parameters and movement trajectories of each patient's temporomandibular joint, replacing standardized articulator elements with customized virtual representations that maintain measurement precision while enabling computer-aided simulation and planning.
2Device complexity
If manual design methods by surgeons are used during orthognathic procedures, then the device complexity and measurement systems are simplified, but the manufacturing precision and reliability of surgical outcomes deteriorate
Solution Approach 1:
The patent performs comprehensive measurements, 3D imaging, and virtual surgical planning before the actual orthognathic procedure. All critical parameters including TMJ geometry, condylar movement trajectories, and anticipated surgical outcomes are determined in advance through computer simulation. This preliminary digital planning allows surgeons to optimize surgical approaches and predict outcomes with high precision before entering the operating room, reducing intraoperative decision-making complexity.
3Ease of manufacture
If top-down assumed standards for TMJ hinge axis position are used in articulators, then the device complexity is reduced and ease of manufacture is improved, but the measurement precision and adaptability to individual anatomy deteriorate
Solution Approach 1:
The patent determines the precise location of each patient's individual hinge axis through direct measurement using motion capture technology and 3D imaging, rather than assuming standardized positions. The system captures the actual rotational center of condylar movement for each individual, creating locally optimized digital models that reflect true anatomical variations. This approach allows the simulation system to adapt to each patient's unique TMJ geometry and movement patterns while maintaining ease of use through automated computational methods.
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
This approach enables the creation of highly accurate, individualized models of TMJ movement and geometry, improving the precision of dental prosthetics and orthognathic procedures, reducing the risk of TMJ disorders and enhancing the stability of prosthetic restorations.
Implementation Method 1
recorded by a measurement system with sensors (accelerometric, gyro or mixed (gyro-accelerometric) sensors) to be placed on the patient's head
Implementation Method 2
recorded by a measurement system with sensors (accelerometric, gyro or mixed (gyro-accelerometric) sensors) to be placed on the patient's head
Implementation Method 3
cone beam tomography or magnetic resonance imaging (MRI)
Implementation Method 4
cone beam tomography or magnetic resonance imaging (MRI)
Data Source
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AI summary
Method of recording the movement and geometry of the temporomandibular joint TMJ characterized according to the invention in that, a virtual spatial geometric model of the stomatognathic system is obtained, wherein the geometry of the skull base with the maxilla is selected on the virtual spatial geometric model independently from the geometry of the mandible with condylar heads. On the spatial geometric model, a virtual reference coordinate system is built and a virtual measurement coordinate system is built. A physical measurement system is built that contains at least one reference sensor that records the values of displacement and/or angular position within the space of the local reference coordinate system as well as at least one measurement sensor that records the values of displacement and/or angular position within the space of the local measurement coordinate system. Anatomical positions of the sensors correspond to at least one measurement and reference point marked on the virtual geometric model. During mandibular movements, signals from measurement and reference sensors are being recorded and transferred into the virtual spatial geometric model and then the image of the spatial mandibular volume movement is created. The trajectory of the individual tracing points in the form of curves are being created, between which surfaces are extended, creating a dimensional surface that maps the condylar head functioning within the TMJ.