title: A posteriori registration and subtraction of panoramic compared with intraoral radiography.
abstract: OBJECTIVE
  To demonstrate the feasibility of panoramic image subtraction for implant assessment.
  
  
  METHODS
  Three titanium implants were inserted into a fresh pig mandible. One intraoral and 2 panoramic images were obtained at baseline and after each of 6 incremental (0.3, 0.6, 1.0, 1.5, 2.0, 2.5 mm) removals of bone. For each incremental removal of bone, the mandible was removed from and replaced in the holding device. Images representing incremental bone removals were registered by computer with the baseline images and subtracted. Assessment of the subtraction images was based on visual inspection and analysis of structured noise.
  
  
  RESULTS
  Incremental bone removals were more visible in intraoral than in panoramic subtraction images; however, computer-based registration of panoramic images reduced the structured noise and enhanced the visibility of incremental removals.
  
  
  CONCLUSIONS
  The feasibility of panoramic image subtraction for implant assessment was demonstrated.
authors.affiliation: Department of Medical Informatics, Aachen University of Technology, Aachen, Germany. deserno@ieee.org
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Deserno
authors.forename: Janaki Raman
authors.initials: JR
authors.lastname: Rangarajan
authors.forename: Jens
authors.initials: J
authors.lastname: Hoffmann
authors.forename: Urs
authors.initials: U
authors.lastname: Brägger
authors.forename: Regina
authors.initials: R
authors.lastname: Mericske-Stern
authors.forename: Norbert
authors.initials: N
authors.lastname: Enkling
mesh_terms: D000818:Animals; D003627:Data Interpretation, Statistical; D015921:Dental Implants; D007090:Image Interpretation, Computer-Assisted; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008334:Mandible / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D016300:Radiography, Bitewing / Q000379:methods*; D019252:Radiography, Dental, Digital / Q000295:instrumentation / Q000379:methods; D011862:Radiography, Panoramic / Q000379:methods*; D013382:Subtraction Technique; D013552:Swine
chemical_list: D015921:Dental Implants