Validity and Reliability of Arch Size Measurements Using Laser Scanned 3D Model

The purpose of this study was to evaluate the validity and reliability of orthodontic measurements made on laser scanned 3D models created with NextEngine laser scanner and ScanStudioHD software. The data sources were plaster dental models from the archives of School of Dental Sciences, Universiti Sains Malaysia. A total of 100 dental models with 800 variables were measured using the plaster dental casts and laser scanned 3D models. The arch width, arch length, arch perimeter, LII, OJ and OB were measured by digital caliper (DC) and ScanStudio HD software. The validity (accuracy) of the digital measurements showed no statistical difference in any of the measurements performed. The reliability coefficient values were comparable between laser scanned 3D models and measurements using DC, the ICC coefficients were statistically significant (p<0.001), and the values of coefficient were in the range of strong correlation. The results show that linear measurements of dental casts using laser scanned 3D models are valid and reliable and can be used for various clinical orthodontic procedures.