Author/Authors :
Nouri، Mahtab نويسنده Associate Professor, Dentofacial Research Center, School of Dentistry, Shahid Beheshti University of Medical Sciences. Tehran, Iran , , Asefi، Sohrab نويسنده Department of Orthodontics, School of Dentistry, Shahid
Beheshti University of Medical Sciences, Tehran, IR
Iran , , Akbarzadeh Baghban، Alireza نويسنده , , Aminian، Amin نويسنده Department of Orthodontics, Kerman Dental School, Kerman Oral and Dental Diseases Research Center , , Shamsa، Mohammad نويسنده Microsoft Developer , , Massudi، Reza R نويسنده Shahid Beheshti University ,
Abstract :
Background: The accuracy and reproducibility of measurements in a locally made three dimensional
(3D) simulator was assessed and compared with manual caliper measurements.
Materials and Methods: A total of 20 casts were scanned by our laser scanner. Software
capabilities included dimensional measurements, transformation and rotation of the cast as
a whole, separation and rotation of each tooth and clip far. Two orthodontists measured the
intercanine width, intermolar width and canine, molar and arch depth on the casts and in 3D
simulator. For calculating the reliability coeffi cient and comparing random and systematic errors
between the two methods, intra-class correlation coeffi cient of reliability (ICC), Dahlberg and
paired t-test were used, respectively. The ICC and Dahlberg’s formula were also applied to
assess intra-examiner and inter-examiner reliability of measurements on the casts and in the
simulator (P < 0.05).
Results: Canine and molar depth measurements had low reliability on the casts. Reliability between
methods for the remaining three variables was 0.87, 0.98 and 0.98 in the maxilla and 0.92, 0.77 and
0.94 in the mandible, respectively. The method error was between 0.31 and 0.48 mm. The mean
intra-observer difference were 0.086 and 0.23 mm in the 3D method and caliper. The inter-observer
differences were 0.21 and 0.42 mm, respectively.
Conclusion: The maximum average absolute difference between the two methods was < 0.5 mm,
indicating that the new system is indeed clinically acceptable. The examiner reliability was higher
in 3D measurements.