Application of three-dimensional digital models for the morphometric analysis of predentition plasters : accuracy and precision

Aim: This study aimed to test the accuracy and precision of measurements of three-dimensional (3D) digital models from the pre-dentition period using a noncontact 3D measurement system (3D scanner) versus the gold standard method of direct measurements using a digital caliper on plaster models. Materials and methods: Ten pairs of plaster models were obtained from children during the predentition period. Linear measurements were performed using both methods. Three operators were trained in the use of both methods for this study. Measurements were performed with a minimum 2-week interval between measurements in a randomly chosen order. Results: The mean difference between the measured values using the two methods was <0.2 mm for each measurement. There was no linearity in the measurements using pre-dentition digital models. An ANOVA Gage R&R analysis revealed that there was no significant operator difference (P < 0.307). The rate of variation of the 3D scanner over the total variation was 2.8%. The ICC was 0.982 (P < 0.001), suggesting excellent interoperator agreement. Conclusion: The results suggest that measurements of digital 3D pre-dentition models are highly accurate and precise, and also comparable to measurements using the gold standard method