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Updated: Jul 6, 2025

Measuring the Complete-arch Distortion of an Optical Dental Impression
Published on: May 30, 2019
Reliability of mixed dentition space analysis using a digital model obtained from an optical impression: a
Ayuko Okamoto1, Hiroyuki Karibe2, Satoshi Tanaka1
1Department of Pediatric Dentistry, School of Life Dentistry at Tokyo, The Nippon Dental University, 1-9-20 Fujimi Chiyoda-ku, Tokyo, 102-8159, Japan.
Objective:
While mixed dentition space analysis is a common practice in pediatric dentistry, digital models created using an intraoral scanner are not as widely used in clinical settings. This preliminary study used a very small sample size with one reference model and aimed to (1) compare the accuracy of mixed dentition space analysis using a digital model obtained from an optical impression with that of conventional plaster model-based analysis and (2) assess inter-examiner differences.
Results:
The space required for the mandibular permanent canine and premolars and arch length discrepancy were calculated using each model. The largest significant difference between plaster- and digital model-based analyses was identified when the right arch length discrepancy was considered (-0.49 mm; 95% confidence interval: -0.95-0.03); however, the value was considered clinically insignificant. Significant inter-examiner differences were observed for six items of the plaster model; however, no such differences were observed when using the digital model. In conclusion, digital model space analysis may have the same level of accuracy as conventional plaster model analysis and likely results in smaller inter-examiner differences than plaster model analysis.

