Aligners Consultancy
Aligners Consultancy
The tool accepts two industry-standard 3D mesh formats:
The model loads with a real-time 3D preview. Use your mouse to orbit (left-click drag), zoom (scroll wheel), and pan (right-click drag).
Drop the upper and lower scans of a case together, or load one and click + Add upper / lower. Both arches are shown in their bite position (the scanner's shared coordinate frame) and always use the same offset. Files whose names contain "upper"/"maxilla" or "lower"/"mandible" are labelled automatically; the Upper | Lower switch above the preview chooses which arch the info panels, shrinkage check and cross-section gap describe. Convert & Download 2 STLs saves both files in their original positions and uses one conversion for the pair.
The core purpose of this tool is to shrink the dental model so that when a clear aligner is thermoformed over it, the aligner fits snugly on the patient's actual teeth.
Scales the whole scan about the scanner's origin. All vertices are multiplied by the scale factor (e.g., 99.9% means multiply by 0.999). Because upper and lower scans share the same origin, they stay in occlusion.
Moves every vertex inward along its surface normal by the exact same distance. This means every point on the tooth surface moves inward by exactly the offset value.
Once you pick an offset, the preview updates for free (no conversion is used). Use the View Mode dropdown in the Shrinkage Simulation panel:
Adjust the transparency of the original and shrunk layers independently in Dual Layer mode.
Once you pick an offset, click "Achieved Shrinkage Heatmap" in the Shrinkage Simulation panel. The shrunk model is colored by how far each point actually moved inward from the original surface:
With uniform offset the map should be almost entirely green. With percentage scaling the legend switches to a blue → red range, because the amount of shrinkage varies across the arch.
Tick Cross-section and choose a plane (X, Y or Z). Drag the plane through the model to see the original outline (blue) and the shrunk outline (orange), with the measured gap in mm. Look at section turns the camera to face the cut, and Outlines only hides the meshes. At true size the two outlines overlap — raise Visual exaggeration to see them apart.
Animate from original to shrunk, magnified up to ×50 on screen. Exaggeration is for display only — the downloaded STL always uses the true offset.
Click the "Measure" button on the 3D preview toolbar. Your cursor changes to a crosshair. Click two points on the model surface to measure the distance between them in mm.
Once you pick an offset, a full-width comparison table appears showing original vs shrunk values for vertices, faces, bounding box dimensions, surface area, and volume — each with a color-coded delta showing the exact change and percentage difference.
Click the "Screenshot" button in the preview panel header to capture the current 3D view. A modal opens with the capture and metadata overlay (file name, date, offset, mesh stats). Click "Download PNG" to save a composite image suitable for patient records.
Every conversion in your current session is logged in the History panel at the bottom of the page. It shows the file name, offset used, bounding box before/after, timestamp, and a re-download link for each export.
Each account starts with a limited number of free conversions. When you run out:
No. All 3D processing happens entirely in your browser. Your scan files never leave your computer. The only server communication is for authentication and conversion count tracking.
There is no hard limit. The tool handles files up to several hundred MB depending on your device's available memory. Typical dental scans (5–50 MB) load in under a second.
For retainers, use 0.05 mm (very light) — just enough for a snug hold. For active treatment aligners, 0.10–0.15 mm is a common starting range. Avoid 0.20 mm+ unless you have specific clinical justification.
Percentage scaling scales the scan about the scanner's origin, so points farther from that origin move more in absolute mm than points close to it. This is expected. For an even offset across every tooth surface, use the mm offset mode instead.
Yes — during your current session, all conversions appear in the History panel with a "Re-download" link. Note that history is cleared when you close or refresh the page.
A non-watertight mesh has open edges or holes. While it can still be converted and printed, some 3D printers or slicer software may have issues. Most intraoral scanners produce watertight meshes. If yours doesn't, consider running a mesh repair tool before uploading.
Email us at support@alignersconsultancy.com or visit www.alignersconsultancy.com.