title: [Registration using three-dimensional laser surface scanning for navigation in oral and craniomaxillofacial surgery].
abstract: BACKGROUND
  Recent innovations in laser scanning technology provide a potentially useful tool for three-dimensional surface registration for image-guided surgery. The purpose of this study is to evaluate the clinical reliability of this technique in oral and maxillofacial surgical procedures using image-guided navigation.
  
  
  METHODS
  In an experimental step, a stable anthropomorphic skull model with prelabeled markers was scanned and registered with laser surface scanning (z-touch, BrainLAB) and marker- based algorithms. The registration protocol was then repeated 25-times. Root mean square error (RMSE) and target difference values were compared for their suitability for this application. Twelve patients with different indications for oral and maxillofacial surgery were planned for image-guided surgery using a passive infrared surgical navigation system (VectorVision, BrainLAB). Preoperative computed tomography (CT) scans were carried out with newest 16-line multisclice CT-scanner (Siemens Somatom Sensation 16). The new markerless laser surface scanning technique was applied in all intraoperative patient registrations. Registration error was noted. The clinical application accuracy was determined for anatomical landmark localization deviation.
  
  
  RESULTS
  In the experimental protocol a mean registration error (RMSE) or target difference of 1.3 (0.14) or 2.08 (0.49) mm for laser scanning and 0.38 (0.01) or 0.99 (0.15) mm for marker registration was found. The differences for RMSE and target localization were statistically significant (p < 0.005). Furthermore, a strong correlation between RMSE and target difference was found for laser scanning (r = 0.96) and marker registration (r = 0.95). During various clinical procedures involving oral and maxillofacial surgery, the overall error of the registration procedure determined as RMSE was 1.21 (0.34) mm. Intraoperatively, the mean clinical application accuracy was found to be 1.8 (0.5) mm.
  
  
  CONCLUSIONS
  Three-dimensional laser surface scanning technique may be a interesting and useful approach to register the patient for image-guided procedures, particularly during oral and craniomaxillofacial surgery.
authors.affiliation: Klinik und Poliklinik für Mund-, Kiefer- und Gesichtschirurgie, Universitätsklinikum Tübingen.
authors.forename: D
authors.initials: D
authors.lastname: Troitzsch
authors.forename: J
authors.initials: J
authors.lastname: Hoffmann
authors.forename: F
authors.initials: F
authors.lastname: Dammann
authors.forename: D
authors.initials: D
authors.lastname: Bartz
authors.forename: S
authors.initials: S
authors.lastname: Reinert
mesh_terms: D002508:Cephalometry / Q000295:instrumentation / Q000706:statistics & numerical data; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D007834:Lasers; D008432:Mathematical Computing; D019047:Phantoms, Imaging; D012984:Software; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D013515:Surgery, Oral / Q000295:instrumentation*; D036542:Tomography, Spiral Computed / Q000295:instrumentation*