COMPARATIVE ASSESSMENT OF BOLTON RATIO MEASUREMENTS ON PLASTER AND DIGITAL DENTAL MODELS USING DIFFERENT MEASUREMENT TECHNIQUES

Accurate odontometric assessment is a fundamental component of orthodontic diagnosis and treatment planning. The Bolton analysis remains one of the most widely used methods for evaluating tooth-size discrepancies between the maxillary and mandibular dentitions; however, the increasing implementation of digital technologies necessitates validation of digital measurement techniques in comparison with conventional plaster model analysis. The present study aimed to compare Bolton ratio measurements obtained from plaster and digital dental models using different measurement approaches.

This analytical cross-sectional study included 30 sets of maxillary and mandibular dental models from patients aged 13–15 years with permanent dentition and various dental anomalies. Each plaster model was digitized to generate a corresponding virtual model. Mesiodistal tooth widths were measured using three techniques: vernier caliper on plaster models, digital caliper on plaster models, and virtual caliper on digital models using Dolphin Imaging 11.9 software. Based on these measurements, total and anterior arch lengths were calculated, and overall and anterior Bolton ratios were determined. Statistical analysis was performed using the Friedman test, Wilcoxon signed-rank test, and Kendall’s Tau correlation coefficient, with a significance level set at p < 0.05.

The results demonstrated generally high agreement among the three measurement techniques. Statistically significant differences were observed in several individual tooth measurements, particularly in the anterior region; however, these differences were small and clinically insignificant. Strong positive correlations were identified between manual measurement techniques, as well as between manual and digital methods for most odontometric parameters. Digital model measurements showed reliable concordance with conventional plaster model analysis.

In conclusion, odontometric evaluation and Bolton ratio analysis performed on digital dental models provide a reliable, accurate, and reproducible alternative to traditional plaster model measurements. The use of digital models facilitates workflow optimization, improves data storage, and supports precise orthodontic diagnosis and treatment planning, justifying their routine implementation in modern orthodontic practice.