title: Measurement accuracy with a new dental panoramic radiographic technique based on tomosynthesis.
abstract: OBJECTIVE
  To investigate measurement errors and head positioning effects on radiographs made with new dental panoramic radiograph equipment that uses tomosynthesis.
  
  
  METHODS
  Radiographic images of a simulated human head or phantom were made at standard head positions using the new dental panoramic radiograph equipment. Measurement errors were evaluated by comparing with the true values. The phantom was also radiographed at various alternative head positions. Significant differences between measurement values at standard and alternative head positions were evaluated. Magnification ratios of the dimensions at standard and alternative head positions were calculated.
  
  
  RESULTS
  The measurement errors were small for all dimensions. On the measurements at 4-mm displacement positions, no dimension was significantly different from the standard value, and all dimensions were within ±5% of the standard values. At 12-mm displacement positions, the magnification ratios for tooth length and mandibular ramus height were within ±5% of the standard values, but those for dental arch width, mandibular width, and mandibular body length were beyond ±5% of the standard values.
  
  
  CONCLUSIONS
  Measurement errors on radiographs made using the new panoramic radiograph equipment were small in any direction. At 4-mm head displacement positions, no head positioning effect on the measurements was found. At 12-mm head displacement positions, the measurements for vertical dimensions were little affected by head positioning, while those for lateral and anteroposterior dimensions were strongly affected.
authors.affiliation: Department of Orthodontics, School of Dentistry, Asahi University, Gifu, Japan. nkitai@dent.asahi-u.ac.jp
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kitai
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Mukai
authors.forename: Manabu
authors.initials: M
authors.lastname: Murabayashi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawabata
authors.forename: Kaei
authors.initials: K
authors.lastname: Washino
authors.forename: Masato
authors.initials: M
authors.lastname: Matsuoka
authors.forename: Ichirou
authors.initials: I
authors.lastname: Shimizu
authors.forename: Akitoshi
authors.initials: A
authors.lastname: Katsumata
mesh_terms: D002508:Cephalometry / Q000295:instrumentation* / Q000379:methods; D061827:Dimensional Measurement Accuracy; D006801:Humans; D007091:Image Processing, Computer-Assisted; D056888:Patient Positioning; D019047:Phantoms, Imaging; D011858:Radiographic Magnification / Q000592:standards*; D011862:Radiography, Panoramic / Q000295:instrumentation* / Q000379:methods