title: Accuracy of virtually planned and conventionally placed implants in edentulous cadaver maxillae and mandibles: a preliminary report.
abstract: BACKGROUND
  The accuracy of mental navigation is thought to depend on the clinician's spatial ability. Mental navigation, therefore, is associated with deviations between the mental plan and the definitive implant position. To learn more about the deviation that might occur, it is important to evaluate the accuracy of mental navigation during placement of implants.
  
  
  OBJECTIVE
  The purpose of the study was to compare accuracy outcomes between virtually planned and conventionally placed implants, and among surgeons with varying experience.
  
  
  METHODS
  Five completely edentulous sets of maxillae and mandibles from human cadaver heads were scanned by computed tomography. Five surgeons planned and placed 60 implants into these jaws, and accuracy was analyzed for 4 parameters: coronal and apical positions, angulation, and depth. The preoperative and postoperative computed tomographies were aligned in voxel-based registration software, which allowed comparison between virtually planned implant positions and actual implant positions. Data were analyzed with the t test (α=.05), ANOVA, and the Scheffé test.
  
  
  RESULTS
  Mean (standard deviation) values were as follows: apex, 2.33 ±1.20 mm (range, 0.51-6.31 mm); coronal, 1.88 ±1.02 mm (range, 0.2-5.0 mm); angle, 7.34 ±3.62 degrees (range, 0.19-16.57 degrees); and depth, 0.03 ±1.15 mm (range, -3.47 to 2.10 mm). The apex and coronal position and the angle differed significantly between the virtually planned and actually placed implants. Significant between-surgeon differences were found in implant depth and coronal position. The apex and coronal positions differed significantly between the upper and lower jaw, with better performance achieved in the upper jaw.
  
  
  CONCLUSIONS
  The results found statistically significant differences between the virtually planned and conventionally placed implants and among the 5 surgeons.
authors.affiliation: Part-time Lecturer, Faculty of Odontology, University Paris-Descartes, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Gillot
authors.affiliation: Part-time Lecturer, Faculty of Odontology, University Paris-Descartes, France. Electronic address: b.cannas@sapoimplant.net.
authors.forename: Bernard
authors.initials: B
authors.lastname: Cannas
authors.affiliation: Associate Professor, The Brånemark Clinic, Göteborg, Sweden.
authors.forename: Bertil
authors.initials: B
authors.lastname: Friberg
authors.affiliation: Associate Professor, Department of Oral and Maxillofacial surgery, Ziekenhuis Oosrt-Limburg, Genk, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Vrielinck
authors.affiliation: Associate Professor, Craniofacial Center, Hirslanden Clinic, Aarau, Switzerland.
authors.forename: Dennis
authors.initials: D
authors.lastname: Rohner
authors.affiliation: Medical Imaging Manager, Global Research & Product Development, Nobel Biocare, Göteborg, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Pettersson
mesh_terms: D002102:Cadaver; D003758:Dental Implantation, Endosseous / Q000706:statistics & numerical data*; D015921:Dental Implants / Q000706:statistics & numerical data*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008334:Mandible / Q000601:surgery*; D008437:Maxilla / Q000601:surgery*; D015588:Observer Variation; D010347:Patient Care Planning / Q000706:statistics & numerical data*; D013028:Space Perception / Q000502:physiology; D065855:Spatial Processing / Q000502:physiology; D025321:Surgery, Computer-Assisted / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods; D014584:User-Computer Interface
chemical_list: D015921:Dental Implants