title: Polygonal Area of Prosthesis Support with Straight and Tilted Dental Implants in Edentulous Maxillae.
abstract: OBJECTIVE
  The aim of this in vitro study was to assess the increase in the polygonal area of implant-retained prosthesis supports in edentulous maxillae with the use of tilted distal implants compared with the use of straight distal implants, using a variety of implant lengths.
  
  
  METHODS
  A total of 25 DICOM datasets of atrophic edentulous maxillae were provided. Bone augmentations in the molar region had to be avoided. Two straight reference implants were virtually inserted in the anterior region. Two additional implants were placed far distally on both sides (4 groups: [1] straight, 12-mm length; [2] straight, 10 mm; [3] straight, 8 mm; [4] tilted, 12-16 mm). The resulting implant-supported polygon was measured for each of the 4 groups using three-dimensional planning software.
  
  
  RESULTS
  The mean sagittal depth of the supported polygon in Group 1 was 9.9 mm (standard deviation [SD] 4.4) on the right and 10.2 mm (SD 4.4) on the left, and it was 33.7 mm (SD 5.8) in width. For Group 2, the mean sagittal depth was 11.5 mm (SD 5.0) on the right and 11.9 mm (SD 4.7) on the left, and the width was 35.2 mm (SD 5.6). The measurements for Group 3 were 13.8 mm (SD 4.9) deep on the right, 13.8 mm (SD 5.1) deep on the left, and 37.0 mm (SD 5.4) in width. For Group 4, the depth was 15.8 mm (SD 4.9) on the right and 16.4 mm (SD 5.8) on the left, and the width was 39.0 mm (SD 5.1).
  
  
  CONCLUSIONS
  The area of implant-retained prosthesis support can be enlarged by the use of tilted implants (12 to 16 mm in length, 42 to 45 degrees) compared to the use of straight 8-mm implants (resulting increase: about 15%).
authors.forename: Stefan
authors.initials: S
authors.lastname: Wentaschek
authors.forename: Karl Martin
authors.initials: KM
authors.lastname: Lehmann
authors.forename: Herbert
authors.initials: H
authors.lastname: Scheller
authors.forename: Gernot
authors.initials: G
authors.lastname: Weibrich
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Behneke
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054893:Cone-Beam Computed Tomography / Q000706:statistics & numerical data; D003758:Dental Implantation, Endosseous / Q000706:statistics & numerical data*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention / Q000706:statistics & numerical data*; D019094:Dental Prosthesis, Implant-Supported; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data; D021621:Imaging, Three-Dimensional / Q000706:statistics & numerical data; D007575:Jaw, Edentulous / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013499:Surface Properties; D014584:User-Computer Interface
chemical_list: D015921:Dental Implants