The present invention relates to a method and a device for determining a deviation between a pre-operatively planned (3 ,4) and a post-operatively obtained real position (6) and direction (7) of a virtual dental implant (2) and a real dental implant (5) in a patients jawbone, comprising the steps of:a) pre-operatively receiving first volume scan data (1a) of the patients jawbone with dentureb) selecting and planning the virtual dental implant (2) within the first volume scan data (1a), so as to position the virtual dental implant (2) within the first volume scan data (1a)c) post-operatively receiving post-operative scan data (1c, 8) of a patients jaw including the denture and information about the real position (6) and direction (7) of the real dental implant (5)d) determining the real position (6) and direction (7) of the real dental implant (5) within the post-operative scan data (1c, 8)e) registering the modified first volume scan data (1b) with the post-operative scan data (1c, 8), such that the jawbone and the denture matchf) determining and indicating the deviation between the pre-operatively planned (3, 4) and the post-operatively obtained real position (6) and direction (7) of the virtual dental implant (2) and the real dental implant (5).
