Digital modes are increasingly being used in the orthodontic practice as an alternative to conventional plaster models. The aim of the study was to evaluate the accuracy of a commercial 3-dimensional extraoral scanning device for space analysis.
Method:
Alginate impressions of 30 subjects with permanent dentition were taken and 30 sets of stone casts were manufactured. The stone casts were digitized using the 3D Ortho Insight Device. The arch length and the tooth mass were acquired for both models by two examiners. The first value was calculated using a flexible wire and millimeter ruler from mesial to the first molars and following the central grooves of the posterior teeth and the best fit of the outliers. The tooth mass was accessed for ten teeth by reassemble the greatest mesiodistal distance of each of these teeth starting from the second premolars. The respective measurements of the digital models were acquired using the Motion View software of the device. Results of both procedures were compared with nonparametric statistics using the Wilcoxon matched pairs signed ranks test.
Result:
The results showed no significant difference between a manually created versus digitally created arch form of the dentition in both the maxilla and mandible. However, there was a statistically significant difference in manual versus digital tooth size measurements. This difference was not clinically significant.
Conclusion:
Space analysis for diagnostic and treatment plan purposes with digital models have still some limitations and specific conditions should be taken into account in order this procedure to be accurately used in the orthodontic practice routine.