Table of Contents
Module Aligner 3D: Panel Trimline
Panel Trimline provides tools for adding and adjusting the aligner trim line. The trim line defined with these tools follows the gingival movement simulated during tooth alignment and can be added as an additional object to the dental arches calculated for aligner production using the thermoforming process in the 3D series export.
In the 3D export of positive aligners, the trim line defines the gingival border of the aligner tray.
Panel Activation
The panel must be activated separately by a patch file which can be requested from Image Instruments.
Buttons
The [Trimline] checkbox activates the trim line function
Button [+] creates the trimline with the predefined parameters on the dental arch as a "fence". The parameters used for Initialization for the gingiva distance can be modified. The path of the trimline can also be individually corrected.
Additional landmarks (points) can be added by clicking on the trim line contour when the [Add landmark] button is active.
Similarly, if the [Delete landmark] button is active, points that are not required can be removed by clicking on the relevant point on the trim line contour.
The [Preview] button can be used to display the trim line as a curve on the gingival surface.
With button [Delete all landmarks] the whole trim line can be deleted. This may be necessary if the line is to be reinitialized.
Optionally, the display of the trim line can be hidden in the 3D view.
Trimline Correction
The trim line is defined for the selected step (e.g. for the planned treatment objective) but is automatically applied to all created steps, taking tooth movements and gingival simulation into account.
The position of the trim line relative to the gingiva can be individually adjusted by dragging and dropping the landmarks (points). If necessary, additional points can be inserted or unnecessary ones deleted.
If the line does not run completely on the surface in certain sections, but partially under the surface, this must be corrected by dragging and dropping the neighboring trim line points.
Initialization
The input window for initializing the trim line relative to the gingival line can be opened with the small arrow on the (+) button or by [CTRL] + left-click on (+).
Here, the gingiva distances for the inner and outer trim line course for the upper jaw and lower jaw can be specified separately on the basis of 1 or 3 support points. Distances too close to the margin are marked red and should be avoided.
Numerical Initialisation
The parameter window for adjusting the initial trim line position relative to the gingival line can be opened with [CTRL] + left-click on (+).
Parameters
| I_UP | point distance to gingiva [mm] inside - all maxilla crowns |
|---|---|
| I_LO | point distance to gingiva [mm] inside - all mandible crowns |
| I_13 | point distance to gingiva [mm] inside - crown 13 |
| O_UP | point distance to gingiva [mm] outside - all maxilla crowns |
|---|---|
| O_LO | point distance to gingiva [mm] outside - all mandible crowns |
| O_13 | point distance to gingiva [mm] outside - crown 13 |
| IM_UP | inserts mid point between 2 crowns at interpolated distance + offset [mm] inside - maxilla |
|---|---|
| IM_LO | inserts mid point between 2 crowns at interpolated distance + offset [mm] inside - mandible |
| OM_UP | inserts mid point between 2 crowns at interpolated distance + offset [mm] outside - maxilla |
| OM_LO | inserts mid point between 2 crowns at interpolated distance + offset [mm] outside - mandible |
Examples
| O_UP=0 | O_UP=2 | O_UP=-1 |
|---|---|---|
| Distance 0 (gingiva) | Distance 2 (below gingiva) | Distance -1 (1mm above gingiva) |
| O_UP=2,O_13=1,O_15=-2 | O_UP=2,OM_UP=0 | O_UP=2,OM_UP=1 |
|---|---|---|
| Distance 2 for all and 1 resp. -2 for 13 and 15 | Distance 2 and mid points at gingiva hight | same, but mid points 1 mm below gingiva |