Abstract
An accurate evaluation of tooth size and tooth size discrepancy is critically important in orthodontic diagnosis and treatment planning. The purpose of this study was to establish a new method to measure and assess tooth size and tooth size discrepancy with accuracy and reproducibility, named as circumferential tooth size (CFT), circumferential anterior tooth size ratio (CAR), circumferential overall tooth size ratio (COR) respectively. Total 128 dental models were scanned via Hirox digital stereomicroscope for the fabrication of the digital models. Dental models were selected on the basis of inclusion criteria. All the measurements were obtained with the accuracy of 0.1×10-6 mm; the mean and the SD for the CFT, CAR and COR were calculated. The developed norms for the CFT, demonstrated significantly greater values for males in relation to females. More precisely, there were statistically significant differences observed in different variables (*p≦0.05 to ***p≦0.001). CAR and COR ratio show slight greater value for males without any statistically significant differences. The findings provide valuable information that CFT cover the tooth size in all dimensional aspects. For the prediction of ideal occlusion to be achieved at the finishing stage, orthodontist needs to evaluate CAR and COR ratios via proposed method.