Comparative analyses of paediatric dental measurements using plaster and three-dimensional digital models

Recent advances in three-dimensional imaging have led to an increased interest in the application of computer-models in paediatric dentistry. However, in evidence-based paediatric dentistry the accuracy of new methods must be validated before they are introduced to clinical practice. We aimed to compare the accuracy of measurements of digital models obtained using a non-contact 3D measuring system, with direct measurements made on plaster models (gold standard) from children.

Twelve pairs of plaster models were obtained from children with deciduous dentition; tooth size, arch width, and arch length were examined. The same parts on each cast were measured twice with at least a 2-week interval between measurements with each method by four examiners. Linear mixed-effects model analyses were performed for comparison of values from the 2 different measurement methods.

The average difference between the 2 methods in measured values, derived from the final model, was <0.2 mm. Random effect of examiners was always the smallest component of variance, and frequently negligible.

Intraclass correlation coefficients were typically >90%.

These results suggest that primary dentition analysis of digital models has a high accuracy level, comparable to that of direct measurement of plaster models by digital calipers.