title: Generation of virtual models for planning orthognathic surgery using a modified multimodal image fusion technique.
abstract: Streak artefacts caused by dental metals deteriorate the quality of computed tomography (CT) images. We developed and evaluated a method for generating three-dimensional virtual models to plan orthognathic surgery in patients with multiple dental materials, to avoid the adverse effects of metal artefacts in image fusion. The method basically consists of four procedures: (1) fabrication of a splint in the open-mouth position with fiducial markers, (2) reconstruction of a virtual skull model in the open-mouth position from CT scanning, (3) reconstruction of two virtual dental models in the open-mouth position and either the intercuspal position (ICP) or centric relation (CR) from surface scanning, and (4) three serial steps of image registration and subsequent repositioning of the mandible to the ICP or CR. This method allows for the registration of skull and dental models under artefact-free conditions. To validate the method, CT and dental cast data from 30 patients were used. The registration accuracy was 0.080 mm for the initial registration, 0.033 mm for the second registration, and 0.028 mm for the third registration. The present method can be used to determine the occlusal relationships and craniofacial morphology of patients with dental metals and can be applied to computer-assisted diagnosis and surgery.
authors.affiliation: Division of Orthodontics and Dentofacial Orthopaedics, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-tobetsu, Hokkaido, Japan. Electronic address: juechi@hoku-iryo-u.ac.jp.
authors.forename: J
authors.initials: J
authors.lastname: Uechi
authors.affiliation: Division of Reconstructive Surgery for Oral and Maxillofacial Region, Department of Human Biology and Pathophysiology, Health Sciences University of Hokkaido, Ishikari-tobetsu, Hokkaido, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tsuji
authors.affiliation: Division of Orthodontics and Dentofacial Orthopaedics, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-tobetsu, Hokkaido, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Konno
authors.affiliation: Division of Orthodontics and Dentofacial Orthopaedics, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-tobetsu, Hokkaido, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Division of Reconstructive Surgery for Oral and Maxillofacial Region, Department of Human Biology and Pathophysiology, Health Sciences University of Hokkaido, Ishikari-tobetsu, Hokkaido, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Shibata
authors.affiliation: Division of Oral and Maxillofacial Radiology, Department of Human Biology and Pathophysiology, Health Sciences University of Hokkaido, Ishikari-tobetsu, Hokkaido, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Nakayama
authors.affiliation: Division of Orthodontics and Dentofacial Orthopaedics, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-tobetsu, Hokkaido, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Mizoguchi
mesh_terms: D000293:Adolescent; D000328:Adult; D016477:Artifacts; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D008297:Male; D008953:Models, Anatomic; D003765:Models, Dental; D064847:Multimodal Imaging; D056948:Orthognathic Surgical Procedures; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed; D014584:User-Computer Interface
keywords: metal artefact; multimodal image fusion; orthognathic surgery; registration accuracy; three-dimensional (3D); virtual model