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Updated: May 10, 2026
Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision
Published on: April 29, 2014
On the augmented reproducibility in measurements on 3D orthodontic digital dental models and the definition of
Wolfgang Jacquet1, Edgard Nyssen, Gabriele Ibel
1Vrije Universiteit Brussel, Department of Orthodontics - SOPA, Laarbeeklaan 103, 1090 Jette, Belgium. wjacquet@vub.ac.be
Objective:
The objective of this study was to explore digital measurement methodology on 3-dimensional (3D) dental models. Standardised manipulation and practices have lead to reliable measurements on plaster casts. Identifying landmarks on digital models or digitised plaster casts is fundamentally different from actual measurements. Three-dimensional models are represented on flat screens and landmarks are individually indentified. A procedure is proposed that resolves the deficiencies associated with a 2-dimensional (2D) display through an appropriate model representation and through local optimisation.
Methods:
Fifteen models (OrthoProof) were exported to a locally developed 3D point indication software package, in which two measurement approaches were implemented involving standard projection with and without local search. Nine linear measurements were obtained from plaster casts and digital models. Statistical analysis included correlation and Friedman s nonparametric analysis of variance (ANOVA).
Results:
For five out of nine linear measurements, digital indications yielded results significantly different from manual measurements (p = 0.05). Local search considerably improved measurement accuracy and reliability.
Conclusions:
Measurements on plaster casts can differ significantly from those obtained through digital identification methods. These differences prove to be clinically relevant. Standardisation and optimisation resulted in improved and extremely reliable digital measurements.
