title: Accuracy of cone-beam computed tomography in predicting the diameter of unerupted teeth.
abstract: BACKGROUND
  An accurate prediction of the mesiodistal diameter (MDD) of the erupting permanent teeth is essential in orthodontic diagnosis and treatment planning during the mixed dentition period. Our objective was to test the accuracy and reproducibility of cone-beam computed tomography (CBCT) in predicting the MDD of unerupted teeth. Our secondary objective was to determine the accuracy and reproducibility of 3 viewing methods by using 2 CBCT software programs, InVivoDental (version 4.0; Anatomage, San Jose, Calif) and CBWorks (version 3.0, CyberMed, Seoul, Korea) in measuring the MDD of teeth in models simulating unerupted teeth.
  
  
  METHODS
  CBCT data were collected on the CB MercuRay (Hitachi Medical Corporation, Tokyo, Japan). Models of unerupted teeth (n = 25), created by embedding 25 tooth samples into a polydimethylsiloxane polymer with a similar density to tissues surrounding teeth, were scanned and measured by 2 investigators. Repeated MDD measurements of each sample were made by using 3 CBCT viewing methods: InVivo Section, InVivo Volume Render (both Anatomage), and CBWorks Volume Render (version 3.0, CyberMed). These measurements were then compared with the MDD physically measured by digital calipers before the teeth were embedded and scanned.
  
  
  RESULTS
  All 3 of the new methods had mean measurements that were statistically significantly less (P <0.0001) than the physical method, adjusting for investigator and tooth effects. Specifically, InVivo Section measurements were 0.3 mm (95% CI, -0.4 to -0.2) less than the measurements with calipers, InVivo Volume Render measurements were 0.5 mm less (95% CI, -0.6 to -0.4) than those with calipers, and CBWorks Volume Render measurements were 0.4 mm less (95% CI, -0.4 to -0.3) than those with calipers.
  
  
  CONCLUSIONS
  Overall, there were high correlation values among the 3 viewing methods, indicating that CBCT can be used to measure the MDD of unerupted teeth. The InVivo Section method had the greatest correlation with the calipers.
authors.affiliation: School of Dentistry, University of California at San Francisco, San Francisco, CA 94143-0438, USA.
authors.forename: Emerald
authors.initials: E
authors.lastname: Nguyen
authors.forename: Darrell
authors.initials: D
authors.lastname: Boychuk
authors.forename: Maria
authors.initials: M
authors.lastname: Orellana
mesh_terms: D000704:Analysis of Variance; D054893:Cone-Beam Computed Tomography; D003818:Dentition, Mixed; D006801:Humans; D003765:Models, Dental; D009811:Odontometry; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012986:Software Validation; D018709:Statistics, Nonparametric; D019228:Tooth Crown / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014097:Tooth, Unerupted / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*