Model Trimming

Grundlagenschnitt

Das Werkzeug “Grundlage Kieferorthopädie” ist nur in den Zusatzmodi “Kieferorthopädie” und “Zahnabdruck” verfügbar. Dieses Werkzeug hat die Funktion, eine regelmäßige Grundlage für das Schließen einer oder beider Projektzahnbögen zu erstellen.

Um das Werkzeug zu starten, auf das jeweilige Icon in der Hauptwerkzeugleiste klicken; Das Icon ist nur verfügbar, wenn das Projekt mindestens ein Mesh enthält.

Interface

Das Interface für die Erstellung der Kieferorthopädiegrundlage unterscheidet sich vom Rest der Software. Oben rechts werden die 4 Schritte des Prozesses angezeigt. Der Rest des Fensters besteht aus einer oder drei 3D-Ansichtsfenstern:

• Einzelmaske : Beim Ausschneiden der Ränder, wird eine einzige 3D-Ansichtsmaske bzw. jeder Zahnbogen einzeln angezeigt.
• Drei Masken: Bei allen anderen Schritten werden beide Zahnbögen angezeigt, damit der Nutzer gleichzeitig die Grundlage überprüfen kann.

Schritte

The procedure develops in 4 steps:

1. Move Jaws : adjusts the position of the jaws to respect some reference planes (occlusal plane and simmetric plane)
2. Cut Margins : draws a margin line on the mesh to cut away all the information that will be replaced by the trimmed base
3. Adjust Bases : changes the shape/position of the trimmed bases to adapt to the jaws
4. Finalize : creates the finalized meshes, merging the cut jaws with the trimmed bases

Move Jaws

The positions of the jaw meshes, acquired from the scanner, may vary. This tool allows the user to adjust the position of the meshes with the aid of some commands.

For each movement there are 4 buttons (-10, -, +, +10), which apply a specific movement to the objects.

All the movements (rotations and translations) are defined according to an Axis. The axis can be seen in the 3D views, on the bottom-left angle.

There's an additional option, Show Bases, that allows the user to see a preview of where the trimmed bases will be, in order to aid the positioning process.

Cut Margins

The jaw meshes acquired from the scanner often have residual unnecessary parts of information. This parts have to be removed before merging the data with the new trimmed base.

Fort his purpose, an interactive tool that can draw a line on the mesh surface is provided:

1. The first left mouse click on the mesh surface creates a point and starts the margin definition
2. Any additional left mouse click adds a point to the margin and connects it to the previous one
3. A left mouse click on the first point closes the margin
4. After the margin is closed, the user can:
   • drag one point with the left mouse button to move it to a different position
   • click between two points, to add a new point in the middle
   • press ESC to delete the margin and start again

When the margin is defined, a click on the Cut button will remove all the parts of the mesh below the margin.

Adjust Bases

The user can change 4 different parameters of the bases. When a parameter is changed, the 3D view updates in approximately 2 seconds.

• Width : the maximum width of the base
• Length : the maximum length of the base
• Height : the base height
• Distance : distance between the two bases, which are symmetric to the occlusal plane

After the cut, the jaw meshes have to be completely fitted in the bases. If the bases are too small a warning message will appear below the parameters.

Finalize

This last page shows only the Finalize button. When clicked, the software takes all the data and computes the new, closed, mesh. This process can take up to 2 minutes.

If the result is not satisfactory for the user, it is possible to return to one of the previous steps, change parameters and positions and then return to the Finalize step and compute the meshes again.

Otherwise, if the finalized mesh is satisfactory, click Ok to confirm the base trimming and save the new meshes.