Comparison of reliability, validity, and accuracy of linear measurements made on pre- and posttreatment digital study models with conventional plaster study models

Abstract

OBJECTIVES:To compare the accuracy of the linear measurements made on pre- and posttreatment three-dimensional (3D) scanned digital models with conventional plaster study models.MATERIALS AND METHODS:The study was conducted on pre- and posttreatment study models of 132 patients. A 3D model scanner was used to scan the plaster models to form 3D digital models. The measurements were made on the plaster models using digital Vernier calipers, and the 3D digital models were assessed for similar measurement using a software of the model scanner. The intraclass correlation for intraoperator error showed good correlations between the measurements made on conventional plaster models and digital models.RESULTS:Although the comparison of the linear measurements made by conventional and digital methods on both pre- and posttreatment study models using intraclass coefficient showed a good correlation, analysis of variance showed significant mean differences in the measurements of multiple variables in both the groups. The number of variables showing significant differences was more in the pretreatment group. The measurements obtained by Vernier calipers were generally higher than those of scanned pre- and posttreatment study models.CONCLUSION:The linear measurements made by conventional and digital methods showed statistically significant mean differences. The accuracy of recording can be affected by the severity of pretreatment malocclusion, but the deviations were not large enough to contradict the use of the digital models for orthodontic records.

Comparison between stone and digital cast measurements in mixed dentition

“…Consistent with our own result that manual overbite measurements were significantly increased (Table 1 ), the manual method has repeatedly been implicated in exaggerated overbite measurements [ 34 , 38 ]. Thus, in absolute terms of millimetres, smaller teeth should be expected to result in smaller overbite values, although inconsistent overbite measurements could also have been introduced by other factors such as incorrect probe angulation during manipulation of the traditional casts or rounding of the digital measurements to the nearest 0.5 mm.…”

The step further smile virtual planning: milled versus prototyped mock-ups for the evaluation of the designed smile characteristics

“…In this regard, we are conscious that our study provides some new evidence as well as new unanswered questions and further studies are certainly required. Moreover, the total diameter (CCw) showed the maximum deviation range compared to the other measurements in both milled and prototyped mock-ups, this could be attributed to the differences in the curvature of the arch in the canine region [35,36]. In this respect, caution must be taken when analyze this linear parameter for aesthetic rehabilitation purpose, in particular when standard 3D virtual templates are selected from the digital library available within digital smile design software.…”

Mesiodistal dimensions of teeth in Serbian orthodontic patients with hypodontia

“…Even though we did not evaluate the reliability or accuracy of digital versus plaster study model measurements, we thought we should mention that most studies published so far have found excellent reproducibility, reliability, and accuracy of measurements made on scanned digital models and the differences between measurements made on digital and plaster models were clinically acceptable and reproducible [28,29]. The software used in our research, Geomagic, was also used by Zhou et al [30] who found the mean difference between the plaster and virtual model measurements were approximately 0.05 mm.…”