Registration of implant templates with patient images according to anatomical landmarks is one of the major features of implantation planning. For that purpose, geometric features can be attached to Implant Template Instances. Three kinds of landmarks are defined: Points, lines, and planes. Each landmark consists of its geometric definition which is defined per template and a description.
When registering an Implant Template to a patient dataset like an Image or a Surface Segmentation, the planning software should establish a spatial transformation that matches to planning landmarks to corresponding geometric features in the patient dataset.