User Guide — 3D Mesh Resizer & Converter

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Getting Started

Supported Formats

The tool accepts two industry-standard 3D mesh formats:

How to Upload

  1. Drag & drop your file onto the drop zone area, or
  2. Click the drop zone to open a file browser

The model loads instantly with a real-time 3D preview. Use your mouse to orbit (left-click drag), zoom (scroll wheel), and pan (right-click drag).

Tip: There is no file size limit — everything is processed locally in your browser. No data is uploaded to any server. Your patient scans remain private.

Shrinkage Modes Explained

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 and applies controlled force for tooth movement.

Percentage Scaling (%)

Scales the entire model uniformly toward its center point. All vertices are multiplied by the scale factor (e.g., 99.9% means multiply by 0.999).

Uniform Offset (mm)

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.

Clinical recommendation: Use 0.10 mm uniform offset as your default. This produces 70–160g of force per anterior tooth — the ideal range for comfortable, effective tooth movement.

Force Guide Reference

Expected initial force per anterior tooth based on uniform inward offset:

Offset Force (per tooth) Category Clinical Use
0.05 mm 40 – 100 g Very Light Retainers, minor corrections, sensitive patients
0.15 mm 110 – 220 g Moderate Standard active treatment
0.20 mm 150 – 300 g Heavy Short-term or stronger movements (test seating carefully)
0.25 mm 190 – 380 g Very Heavy High risk of discomfort or incomplete seating
0.30 mm 230 – 480+ g Excessive Generally avoid — may prevent full seating

3D Preview Controls

Mouse Controls

View Modes

After conversion, use the View Mode dropdown in the Professional Fit Preview panel:

Opacity Sliders

Adjust the transparency of the uploaded model and aligner shell independently. Useful for inspecting how the shell sits on specific tooth surfaces.

Clinical Features

Surface Deviation Heatmap

After conversion, click the "Surface Deviation Heatmap" button in the Fit Preview panel. The tooth mesh is color-coded by how much each vertex moved during shrinkage:

A legend bar shows the exact min and max displacement values in mm. For uniform offset, the map should appear mostly uniform. For percentage scaling, outer regions will show higher displacement.

Distance Measurement Tool

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.

Comparison Table

After conversion, a full-width comparison table appears showing original vs converted values for vertices, faces, bounding box dimensions, surface area, and volume — each with a color-coded delta showing the exact change and percentage difference.

Screenshot Export

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.

Conversion History

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.

Redemption Codes

Each account starts with a limited number of free conversions. When you run out:

  1. A code entry field appears in the banner at the top
  2. Enter your redemption code (format: XXX-YYY-ZZZ)
  3. Click Redeem to add more conversions to your account
Note: Each single-use code can only be redeemed once by one account. Contact support if you need additional codes.

Frequently Asked Questions

Is my patient data uploaded to a server?

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.

What file size can I upload?

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.

Which offset should I use for retainers vs active aligners?

For retainers, use 0.05 mm (very light) — just enough for a snug hold without active force. For active treatment aligners, 0.10–0.15 mm is the clinical standard. Avoid 0.20 mm+ unless you have specific clinical justification.

Why does the heatmap show uneven colors with percentage scaling?

Percentage scaling shrinks toward the center, so vertices farther from the center (e.g., posterior molars) move more in absolute mm than vertices closer to the center (anterior teeth). This is expected. For truly uniform shrinkage, use the mm offset mode instead.

Can I re-download a previous export?

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.

The model shows "Not Watertight" — is that a problem?

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.

How do I contact support?

Email us at support@alignersconsultancy.com or visit www.alignersconsultancy.com.