Korean J Orthod.  2016 Jan;46(1):13-19. 10.4041/kjod.2016.46.1.13.

Accuracy of Bolton analysis measured in laser scanned digital models compared with plaster models (gold standard) and cone-beam computer tomography images

  • 1Department of Dentistry, School of Dentistry, University of Alberta, Edmonton, Canada. manuel@ualberta.ca


The aim of this study was to compare the accuracy of Bolton analysis obtained from digital models scanned with the Ortho Insight three-dimensional (3D) laser scanner system to those obtained from cone-beam computed tomography (CBCT) images and traditional plaster models.
CBCT scans and plaster models were obtained from 50 patients. Plaster models were scanned using the Ortho Insight 3D laser scanner; Bolton ratios were calculated with its software. CBCT scans were imported and analyzed using AVIZO software. Plaster models were measured with a digital caliper. Data were analyzed with descriptive statistics and the intraclass correlation coefficient (ICC).
Anterior and overall Bolton ratios obtained by the three different modalities exhibited excellent agreement (> 0.970). The mean differences between the scanned digital models and physical models and between the CBCT images and scanned digital models for overall Bolton ratios were 0.41 +/- 0.305% and 0.45 +/- 0.456%, respectively; for anterior Bolton ratios, 0.59 +/- 0.520% and 1.01 +/- 0.780%, respectively. ICC results showed that intraexaminer error reliability was generally excellent (> 0.858 for all three diagnostic modalities), with < 1.45% discrepancy in the Bolton analysis.
Laser scanned digital models are highly accurate compared to physical models and CBCT scans for assessing the spatial relationships of dental arches for orthodontic diagnosis.


Three-dimensional scanner; Digital models; Dental cast analysis

MeSH Terms

Cone-Beam Computed Tomography
Dental Arch


  • Figure 1 Screenshot of imported scanned digital models using Ortho Insight three-dimensional software (Motionview Software LLC., Hixson, TN, USA).

  • Figure 2 Mesiodistal tooth width automatically calculated after digital separation of the teeth and automatic facial axis detection using Ortho Insight three-dimensional software (Motionview Software LLC., Hixson, TN, USA).

  • Figure 3 Landmarks represented by arrows on a cone-beam computed tomography (CBCT) slice (left) and a digitally bisected three-dimensional model obtained from the CBCT scans (right) using Avizo software (standard edition version 6.0; Mercury Computer System Inc., Chelmsford, MA, USA).

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