title: In vitro comparison of the maxillary occlusal plane orientation obtained with five facebow systems.
abstract: BACKGROUND
  The sagittal and coronal orientation of the maxillary occlusal plane plays an important role in the esthetic and functional outcome of dental prostheses. The accuracy of contemporary facebow transfer systems in transferring this orientation to semiadjustable articulators has not been quantified.
  
  
  OBJECTIVE
  The purpose of this in vitro investigation was to analyze the sagittal and coronal orientation of the occlusal plane with 5 different facebow transfer systems.
  
  
  METHODS
  A phantom head containing a maxillary typodont (control) was oriented so that the Frankfort horizontal plane was horizontal. The angle between the occlusal plane of the maxillary arch of the phantom head and the Frankfort horizontal plane was measured along the sagittal and coronal planes with a digital protractor. Fifteen facebow records using each of 5 facebow transfer systems (test groups) were made on the phantom head containing the maxillary typodont. Diagnostic casts of the maxillary typodont were mounted on semi-adjustable arcon articulators from the facebow records. The same angles measured on the control were measured on the test groups. These angles were compared with the same angle measured on the maxillary arch of the phantom head (control). All measurements were made by 2 operators.
  
  
  RESULTS
  Significant differences in the sagittal and coronal orientation of the occlusal plane were noted. Compared with the control, the Denar system had the least significant difference in the coronal orientation of the occlusal plane, while the Pana-Mount system had the least significant difference in the sagittal orientation of the occlusal plane. An intergroup comparison of the test groups showed significant differences among the groups. The Kois system showed the greatest difference in the coronal plane orientation, while the Denar system showed the greatest difference in the sagittal plane orientation.
  
  
  CONCLUSIONS
  None of the tested facebow systems exactly replicated the sagittal and coronal orientation of the maxillary occlusal plane. Significant differences in the sagittal and coronal orientation of the occlusal plane were observed between the test groups and the control. Intergroup comparisons revealed significant differences in the sagittal and coronal orientation of the occlusal plane.
authors.affiliation: Graduate student, Advanced Specialty Education Program in Prosthodontics, Department of Restorative Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif. Electronic address: tmaveli@llu.edu.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Maveli
authors.affiliation: Assistant Professor, Department of Restorative Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif.
authors.forename: Montry S
authors.initials: MS
authors.lastname: Suprono
authors.affiliation: Professor and Director, Advanced Specialty Education Program in Prosthodontics, Department of Restorative Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif.
authors.forename: Mathew T
authors.initials: MT
authors.lastname: Kattadiyil
authors.affiliation: Professor, Department of Restorative Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Goodacre
authors.affiliation: Assistant Professor, Epidemiology, Biostatistics, and Population Medicine, School of Dentistry, Loma Linda University, Loma Linda, Calif.
authors.forename: Khaled
authors.initials: K
authors.lastname: Bahjri
mesh_terms: D002508:Cephalometry; D003725:Dental Articulators; D003768:Dental Occlusion, Centric; D006801:Humans; D066298:In Vitro Techniques; D007574:Jaw Relation Record / Q000295:instrumentation*; D008437:Maxilla; D003765:Models, Dental; D019047:Phantoms, Imaging