VALIDITY AND RELIABILITY OF MEASUREMENTS OF THE PARAMETERS OF SMILE AESTHETICS: A COMPARISON BETWEEN DIGITAL AND PLASTER MODELS

Abstract

This study aims to evaluate the validity and reliability of the TRIOS3 Color intraoral scanner

(3Shape A/S, Copenhagen, Denmark) and its associated Ortho Analyzer™ software in measuring

parameters of smile aesthetics compared with measurements on plaster casts. The study sample

comprised plaster casts and digital models obtained from 30 subjects. Height (H), mesiodistal

diameter (MDD) and connecting space (CS) of the anterior teeth were measured with a digital

calliper on the plaster models and with the orthodontic software on the digital models. Validity was

assessed using a 2-tailed paired t-test; the reliability of measurements for intra-examiner was

evaluated with the Intra-class Correlation Coefficient (ICC). There were no statistically significant

differences between the measurements made with the two methods. The ICC is 99% for height and

MDD measurements, slightly lower in the evaluation of the CS. Linear measurements made on

digital model have clinically acceptable accuracy and reliability. The TRIOS3 Color intraoral

scanner represents a valuable tool for dental practice, particularly in evaluating parameters of smile

aesthetics.