title: Template-based registration for image-guided maxillofacial surgery.
abstract: OBJECTIVE
  Fiducial marker registration using bone screws is a proved and tested method for patient-to-image registration for image-guided surgery of the head. The use of intraoral fiducial markers mounted on a template for the maxillary dentition is a less invasive alternative and is in use for intraoral image-guided surgery. The aim of this study was to verify if this method is sufficiently accurate for extraoral use.
  
  
  METHODS
  Registration was performed using 243 different configurations of fiducial markers mounted on a maxillary template. The accuracy of the identification of artificial skull-mounted targets located in surgically relevant locations was determined for each registration.
  
  
  RESULTS
  Targeting accuracy was sufficient for image-guided surgery of the maxilla, the midface, the orbit, and the pterygopalatine fossa. In the regions of the calvarium, however, average target registration error was > or =1.5 mm. Average target registration error was >3 mm.
  
  
  CONCLUSIONS
  Fiducial marker registration based on a maxillary template is a safe and non-invasive alternative to bone-mounted fiducial markers for image-guided surgery in the regions of orbit, face, maxilla, and pterygopalatine fossa.
authors.affiliation: Department of Oral and Cranio-Maxillofacial Surgery, Heidelberg University Hospital, Heidelberg, Germany. georg.eggers@med.uni-heidelberg.de
authors.forename: Georg
authors.initials: G
authors.lastname: Eggers
authors.forename: Joachim
authors.initials: J
authors.lastname: Mühling
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Marmulla
mesh_terms: D001863:Bone Screws; D005147:Facial Bones / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008437:Maxilla / Q000601:surgery; D019647:Oral Surgical Procedures / Q000295:instrumentation / Q000379:methods*; D009915:Orbit / Q000601:surgery; D010159:Palate / Q000601:surgery; D013100:Sphenoid Bone / Q000601:surgery; D013165:Splints; D013238:Stereotaxic Techniques / Q000295:instrumentation; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*