title: Evaluation of the accuracy of linear measurements on lateral cephalograms obtained from cone-beam computed tomography scans with digital lateral cephalometric radiography: an in vitro study.
abstract: OBJECTIVE
  A cephalometric analysis especially designed for the patient who requires maxillofacial surgery was developed to use landmarks and measurements that can be altered by common surgical procedures. Identification of landmarks in cephalometry is very important and useful for orthognathic surgery. The aim of this study was to evaluate the accuracy of linear measurement based on digital lateral cephalograms (DLC) and on lateral cephalograms obtained from cone-beam computed tomography (CBCT) scans.
  
  
  METHODS
  The linear distances between anatomic landmarks on 6 dry human skulls were measured by 2 observers using digital calipers for sella-nasion (S-N), menton-nasion (M-N), anterior nasal spine-nasion (ANS-N), anterior nasal spine-posterior nasal spine (ANS-PNS), and pogonion-gonion (Pog-Go). Then, images were obtained by using DLCs and in lateral cephalograms obtained from CBCT scans. The measurement errors were calculated for each modality, compared with each other, and analyzed via SPSS software version 18.
  
  
  RESULTS
  For all lines (S-N, M-N, ANS-N, Pog-Go, and ANS-PNS), CBCT-derived values did not differ from actual dry skull dimensions (gold standard) (P > 0.05). In DLC, for S-N, M-N, ANS-N, and Pog-Go lines, measurements were significantly higher than actual measurements (P ≤ 0.05), but ANS-PNS values did not differ from actual measurements (P > 0.05).
  
  
  CONCLUSIONS
  The results showed that the values obtained in CBCT imaging compared with calculated values of the digital lateral cephalometry much closer to the actual distance are more accurate indicators of this type of imaging and that CBCT permits oral surgeons to visualize the position and surgical anatomy of the tooth as it will be seen in the operating theater and allows orthodontists to plan directional traction.
authors.affiliation: From the Department of Oral and Maxillofacial Radiology, Dental School of Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Shokri
authors.forename: Samira
authors.initials: S
authors.lastname: Khajeh
authors.forename: Atefeh
authors.initials: A
authors.lastname: Khavid
mesh_terms: D059925:Anatomic Landmarks / Q000000981:diagnostic imaging*; D002508:Cephalometry / Q000706:statistics & numerical data*; D002680:Chin / Q000000981:diagnostic imaging; D054893:Cone-Beam Computed Tomography / Q000706:statistics & numerical data*; D005147:Facial Bones / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000706:statistics & numerical data; D066298:In Vitro Techniques; D008334:Mandible / Q000000981:diagnostic imaging; D009295:Nasal Bone / Q000000981:diagnostic imaging; D015588:Observer Variation; D056948:Orthognathic Surgical Procedures / Q000379:methods; D010347:Patient Care Planning; D056739:Pterygopalatine Fossa / Q000000981:diagnostic imaging; D019252:Radiography, Dental, Digital / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012658:Sella Turcica / Q000000981:diagnostic imaging; D012886:Skull / Q000000981:diagnostic imaging*