Three.js Components for Dental Aligner Treatment Planning System

Based on your requirements for a web-based dental aligner treatment planning system, I can recommend several Three.js components and addons that would be useful for implementing the functionality you need.

Core Objects

For your 3D dental model visualization and manipulation, you'll need these core objects:

• Mesh - For rendering the dental models
• Group - For organizing teeth into logical groups (upper/lower jaw)
• InstancedMesh - Could be useful for efficiently rendering multiple similar teeth

Controls

For manipulating the dental models, these controls would be essential:

• OrbitControls - For rotating and zooming the view
• TransformControls - For adjusting individual teeth positions and rotations
• DragControls - For simpler dragging operations

Loaders and Exporters

For importing and exporting STL files:

• OBJLoader - Can be adapted for STL import
• STLExporter - For exporting individual arches as STLs

Utils

These utilities will help with model manipulation:

• BufferGeometryUtils - For operations like merging and separating geometries
• SceneUtils - For scene management

Implementation Approach

1. Model Import

   • Use a custom STL loader or adapt OBJLoader to import dental scans
   • Display models using Mesh objects

2. Cleaning and Trimming

   • Implement custom geometry editing tools using BufferGeometryUtils
   • Allow users to select and remove unwanted parts of the model

3. Segmentation

   • Create tools to separate the model into individual teeth
   • Use Group objects to organize teeth logically

4. Adjustment and Alignment

   • Use TransformControls to allow precise positioning of teeth
   • Implement a timeline system to show progressive movement

5. Visualization and Export

   • Create a viewer interface similar to Maestro 3D
   • Use STLExporter to export models for 3D printing

Additional Considerations

• You may need to implement custom algorithms for teeth segmentation
• Consider using WebWorkers for heavy computational tasks to keep the UI responsive
• For the treatment simulation, you'll need to implement interpolation between different teeth positions

This approach leverages Three.js's powerful 3D capabilities while providing the specialized tools needed for dental treatment planning. You may need to extend some of these components with custom functionality specific to dental applications.