Influence of standardization on the precision (reproducibility) of dental cast analysis with virtual 3-dimensional models.
BACKGROUND
Virtual 3-dimensional (3D) models obtained by scanning of physical casts have become an alternative to conventional dental cast analysis in orthodontic treatment. If the precision (reproducibility) of virtual 3D model analysis can be further improved, digital orthodontics could be even more widely accepted. The purpose of this study was to clarify the influence of "standardization" of the target points for dental cast analysis using virtual 3D models. Physical plaster models were also measured to obtain additional information.


METHODS
Five sets of dental casts were used. The dental casts were scanned with R700 (3Shape, Copenhagen, Denmark) and REXCAN DS2 3D (Solutionix, Seoul, Korea) scanners. In this study, 3 system and software packages were used: SureSmile (OraMetrix, Richardson, Tex), Rapidform (Inus, Seoul, Korea), and I-DEAS (SDRC, Milford, Conn).


RESULTS
Without standardization, the maximum differences were observed between the SureSmile software and the Rapidform software (0.39 mm ± 0.07). With standardization, the maximum differences were observed between the SureSmile software and measurements with a digital caliper (0.099 mm ± 0.01), and this difference was significantly greater (P <0.05) than the 2 other mean difference values. Furthermore, the results of this study showed that the mean differences "WITH" standardization were significantly lower than those "WITHOUT" standardization for all systems, software packages, or methods.


CONCLUSIONS
The results showed that elimination of the influence of usability or habituation is important for improving the reproducibility of dental cast analysis.
Associate professor, Division of Orthodontics and Dentofacial Orthopedics, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Hokkaido, Japan. Electronic address: kazu@hoku-iryo-u.ac.jp.
Kazuo
K
Hayashi
Research assistant, Division of Orthodontics and Dentofacial Orthopedics, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Hokkaido, Japan.
Onejune
O
Chung
Private practice, Yongin, Korea.
Seojung
S
Park
Professor and chair, Department of Oral Anatomy, School of Dentistry, Seoul National University, Seoul, Korea.
Seung-Pyo
SP
Lee
Chief clinical officer, OraMetrix, Richardson, Tex.
Rohit C L
RC
Sachdeva
Professor and chair, Division of Orthodontics and Dentofacial Orthopedics, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Hokkaido, Japan.
Itaru
I
Mizoguchi
D000465:Algorithms; D002133:Calcium Sulfate / Q000737:chemistry; D003198:Computer Simulation; D017076:Computer-Aided Design / Q000592:standards / Q000706:statistics & numerical data; D003764:Dental Materials / Q000737:chemistry; D057918:Fiducial Markers; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data; D021621:Imaging, Three-Dimensional / Q000706:statistics & numerical data*; D003765:Models, Dental / Q000592:standards* / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012984:Software; D013499:Surface Properties; D014584:User-Computer Interface
D003764:Dental Materials; D002133:Calcium Sulfate