While this can seem confusing at first, each numbering system has a specific purpose and is designed for a particular audience — the doctor, the patient, or Orthosnap’s internal team.
Let’s break them down simply:
1. Doctor / Treatment Plan Step Number
This numbering system is for doctors and is used in the treatment plan.
Each arch (upper and lower) has its own sequence of numbers.
The number corresponds to the aligner’s position in the treatment plan grid (for example, Upper Step 10 or Lower Step 10).
This same number appears in the ship letter and the treatment plan grid instructions.
Purpose:
To help the doctor know exactly which tooth movements happen at each step of treatment.
In short:
➡️ This number helps the doctor track treatment progress per arch.
2. Patient / Bag Label and DM Step Number
This is the patient-facing number — the one printed on the aligner bag labels and used in the DentalMonitoring (DM) app.
It’s a single number representing both the upper and lower aligners for that stage (for example, Step 10 means both the upper and lower aligners labeled “10”).
This number is consistent with what patients see in the DM app when they’re told to scan or switch aligners.
Purpose:
To make it easy for the patient to know which aligners to wear and when to change them.
In short:
➡️ This number keeps things simple for the patient by using one shared step number.
3. Orthosnap / Manufacturing Layer Number
This one is used internally by Orthosnap’s production and quality teams.
The number is embossed on the aligners (usually in the back or posterior region).
It’s generated automatically by the treatment planning software.
Each time a new impression or STL file is used to create a plan, the numbering starts over from “0.”
Purpose:
To help Orthosnap technicians identify and track each aligner in the manufacturing and 3D setup process.
In short:
➡️ This number is used internally for manufacturing accuracy.
When the Numbers Don’t Match
Sometimes, you’ll notice that the Doctor/Treatment Plan Step number, Patient/DM number, and Manufacturing Layer number don’t line up — and that’s perfectly normal.
This happens when:
The upper and lower arches have different numbers of steps, or
A refinement is done using a new impression (STL file).
For example:
Let’s say a case has 31–34 upper steps and 31–39 lower steps.
To keep things simple for the patient, the bag labels and DM app will show Steps 31–39 (even though there’s no “Upper 39”).
Later, if a refinement is needed and new impressions are taken, the manufacturing software starts again from “0.”
At that point, none of the numbering systems will match — and that’s okay, because they’re meant to serve different functions.
When All Three Numbers Match
All three numbering systems line up only when:
The upper and lower arches have the same number of steps,
There are no refinements, and
No new STL files are submitted.
Why the Numbers Don’t Need to Match
Each numbering system was designed with its own purpose in mind:
The doctor needs detailed per-arch tracking (Treatment Plan Step number).
The patient needs a single, easy-to-follow step number (Bag/DM number).
The Orthosnap team needs precise identifiers for manufacturing (Layer number).
Keeping them separate allows each group to focus on what’s most important for their role — ensuring smooth coordination between treatment, patient experience, and production.
Here's an information graphic of the numbering system:
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