title: Comparison of mesiodistal root angulation with posttreatment panoramic radiographs and cone-beam computed tomography.
abstract: BACKGROUND
  Orthodontists assess mesiodistal root angulations before, during, and after orthodontic treatment as an aid in establishing proper root position. Panoramic imaging has been useful for this purpose and is a valuable screening tool in diagnosis and planning treatment of orthodontic patients. Cone-beam computed tomography (CBCT) for imaging of the craniofacial complex creates the opportunity to evaluate 3-dimensional images compared with traditional 2-dimensional images. The purpose of this project was to compare mesiodistal root angulations by using posttreatment panoramic radiographic images and CBCT scans.
  
  
  METHODS
  Mesiodistal root angulations from panoramic images and CBCT scans of 35 orthognathic surgery patients after orthodontic treatment were compared. The panoramic images were measured by using VixWin (Gendex Dental Systems, Des Plaines, Ill), and the CBCT scans by using InvivoDental 3D (version 4.1, Anatomage, San Jose, Calif). The mesiodistal root angulation of each maxillary and mandibular tooth was measured by using the occlusal plane as the reference line. With an intercept-only linear regression for correlated data (with an unstructured covariance structure), the global test of whether the mean vector of all differences for the teeth is zero was performed separately for the 2 arches.
  
  
  RESULTS
  The global test for both arches was statistically significant (P <0.001), indicating an overall difference in root angulation between measurements from panoramic and CBCT images. There was no discernible pattern in the average differences between panoramic and CBCT measurements.
  
  
  CONCLUSIONS
  The assessment of mesiodistal tooth angulation with panoramic radiography should be approached with caution and reinforced by a thorough clinical examination of the dentition.
authors.affiliation: Department of Orthodontics, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Bouwens
authors.forename: Lucia
authors.initials: L
authors.lastname: Cevidanes
authors.forename: John B
authors.initials: JB
authors.lastname: Ludlow
authors.forename: Ceib
authors.initials: C
authors.lastname: Phillips
mesh_terms: D001641:Bicuspid / Q000000981:diagnostic imaging; D054893:Cone-Beam Computed Tomography; D003481:Cuspid / Q000000981:diagnostic imaging; D003724:Dental Arch / Q000000981:diagnostic imaging; D003766:Dental Occlusion; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007180:Incisor / Q000000981:diagnostic imaging; D008297:Male; D008310:Malocclusion / Q000000981:diagnostic imaging / Q000628:therapy*; D008334:Mandible / Q000000981:diagnostic imaging; D008437:Maxilla / Q000000981:diagnostic imaging; D008963:Molar / Q000000981:diagnostic imaging; D009971:Orthodontics, Corrective; D056948:Orthognathic Surgical Procedures; D011446:Prospective Studies; D011862:Radiography, Panoramic; D019227:Tooth Apex / Q000000981:diagnostic imaging; D014092:Tooth Root / Q000000981:diagnostic imaging*; D055815:Young Adult