Author/Authors :
Tehranchi, A Department of Orthodontics - School of Dentistry - Shahid Beheshti University of Medical Sciences, Tehran , Nouri, M , Massudi, R Department of Orthodontics - School of Dentistry - Shahid Beheshti University of Medical Sciences, Tehran , Katchooi, M School of Dentistry - Shahid Beheshti University of Medical Sciences, Tehran , Rahimi, H
Abstract :
Objective: The aim of this study was to evaluate the validity of computerized and manual
methods of dental cast analysis.
Materials and Methods: Twenty set-ups of upper and lower casts using artificial teeth
corresponding to various malocclusions were created for a diagnostic in vitro study. Values
of tooth size were calculated from the isolated artificial teeth out of the set-ups, results
were considered as a gold standard for the tooth size. Arch width was calculated from the
existing set-ups on the dentins.
Impressions were taken of the casts with alginate and duplicated with dental stone. Models
were measured with digital caliper manually. Then images were taken from the occlusal
views of the casts by a digital camera. Measurements were done on digital images with the
AutoCAD software.
The results of the computerized and manual methods were compared with the gold standard.
Intra class correlation coefficient of reliability was used to measure the accuracy of
the methods and the Friedman technique used to evaluate the significance of differences.
Results: Results indicated that all measurements were highly correlated, e.g. gold standard
and manual (0.9613-0.9991), gold standard and computerized (0.7118-0.9883), manual
and computerized (0.6734-0.9914). Statistically significant differences were present between
these methods (P<0.05), but they proved not to be clinically significant.
Conclusion: Manual measurement is still the most accurate method when compared to the
computerized measurements and the results of measurement by computer should be interpreted
with caution.
