The purpose of this study was to compare digitized models with their current gold-standard plaster models for tooth-size discrepancy and Bolton analysis. Fifteen pairs of plaster models were obtained from orthodontic patients with permanent dentition. These were digitized and evaluated using the Bibliocast Cécile3 v2.5 software. Two examiners measured three times the mesiodistal width of all the teeth and the arch length, and determined the tooth-size discrepancy and Boltońs ratios. The plaster models were measured using a digital vernier caliper. Interclass correlation (ICC), mean differences and paired t-tests were used for comparisons and statistical analysis. The ICC of the digital models were 0.930 (0.852≤ICC<0.973) for the intra-examiner and 0.929 (0.829≤CCI<0.974) for the inter-examiner. The mean differences between plaster and digital models with respect to the anterior and overall Boltońs ratios for examiner 1 was 0.34mm for both and for examiner 2 were 0.28mm and 0.21mm respectively. Although digital model measurements were lower than plaster (p<0.05), these were considered clinically insignificant (differences<0.1mm). The determination of the tooth-size discrepancy and Bolton analysis using digital models and the Bibliocast Cécile3 software are an acceptable alternative to use in clinical practice.