Abstract
The advances of digital technologies in dentistry have made significant changes in orthodontic diagnosis and treatment planning. Digital three-dimensional models are commonly used to perform dental arch and teeth measurements through intra-oral scanners and software. This study aimed to test the reliability of two softwares in measuring dental arch perimeters compared to the conventional one. Twenty-four pairs of stone models belonging to Iraqi children at the mixed dentition stage were selected and scanned with a laser scanner. Maxillary and mandibular dental arch perimeters were measured as a sum of four segments from central incisor to canine and from canine to the first molar on both sides using digital calipers (on stone models) Ortho Analyzer, and the Geomagic Design X software(on scanned models). Reliability has been evaluated by intra-class correlation coefficient and Bland-Altman plots, while systematic and proportional biases were evaluated by paired sample t-test and linear regression analysis, respectively. Non-significant differences were obtained for most measurements with good to excellent reliability. Digital technologies, including model scanning and software measurements can be used with adequate precision and reliability to assess dental arch perimeters as with stone models and conventional measurements with dental vernier.