Method for producing a segmented actual state model

A method for producing a current state model of teeth of a patient from a scan of the teeth including at least one of the teeth, the method comprising:

• providing an old model of the teeth including first surface elements wherein each of the first surface elements is associated with precisely one tooth of the teeth to form a segmented old model of the teeth;
• initially capturing the scan of the teeth that differs from the segmented old model of the teeth;
• thereafter;
• bringing, the scan of the teeth and the segmented old model of the teeth into a first alignment by principal component analysis wherein an entirety of the scan is moved relative to an entirety of the segmented old model to form an aligned scan;
• thereafter
• determining a bounding volume of the at least one of the teeth in the segmented old model;
• thereafter
• determining second surface elements in the aligned scan of the teeth arranged within the bounding volume;
• thereafter
• copying copies of the first surface elements associated with the at least one of the teeth from the segmented old model into the aligned scan to form a current state model;
• thereafter
• aligning the copies of the first surface elements in the current state model with a minimum deviation from the second surface elements by an interactive closest point algorithm;
• to form a segmented current state model of the teeth from aligned copies of the first surface elements.