Integration and Application of Multimodal Measurement Techniques: Relevance of Photogrammetry to Orthodontics (original) (raw)
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A novel method of photogrammetry measurements of study models in orthodontics
Srpski arhiv za celokupno lekarstvo, 2018
Introduction/Objective. Rapid developments in information technologies lead to the wider use of digital representations of dental study models in orthodontics. Most popular way of digitizing the models is to use a 3D scanner and then perform measurements on 3D models, which requires additional and expensive hardware and software resources. In this paper we present an alternative approach based on the use of photogrammetry in the newly developed OrthoPhoto4D software that calculates and corrects perspective distortion errors. Methods. We measured individual tooth width for 24 teeth, 12 two-teeth segments as well as inter-molar and inter-canine distances on 50 models. Measurements are performed in OrthoPhoto4D software that uses four photographs of each model for measurements, uses QR codes for automation, calculates the camera position and corrects perspective distortion-caused errors in measurements. Obtained measurements are compared to ones obtained from models generated by struct...
Digital Dental Models: Is Photogrammetry an Alternative to Dental Extraoral and Intraoral Scanners?
Dentistry Journal, 2022
Background: 3D models are nowadays part of daily clinical practice. Photogrammetry is a brand-new method for transforming small objects into 3D models while keeping their original shape and size. The aim of this study was to evaluate the accuracy, in terms of precision and trueness, of a digital dental model acquired with photogrammetry compared with those obtained using extraoral scanners and intraoral scanners, starting from the same plaster model. Methods: A plaster model was converted into a digital model using photogrammetry, an extraoral scanner and an intraoral scanner. Different references were measured twice at a distance of 30 min for each model, on the digital models using the software Blender and on the plaster model using a calibre. The Interclass Correlation Coefficient was calculated for each pair of measurements. A volumetric analysis was performed by superimposing the digital models. The coefficient of variation was calculated. A two-way ANOVA test was conducted. Re...
Journal of Craniofacial …, 2010
Objectives: Set up 3D photogrammetric scanning system for precise landmarks measurements, without any physical contact, using a low-cost and non-invasive digital photogrammetric solution, for supporting several necessity in clinical orthodontics and/or surgery diagnosis. Materials and Methods: 30 coded targets were directly applied onto the subject's face on the soft tissue landmarks and then three simultaneous photos ware acquired using photogrammetry at room light conditions. For comparison a dummy head was digitized both with a photogrammetric technique and with the laser scanner Minolta Vivid 910i. Results: Automatic measures of face landmarks spatial position, distances and angles, were compared with the facial measurements done using laser scanning and a manual caliper. The adopted method gives higher precision than the others (0.022 mm average on points and 0.038 mm average on linear distances on a dummy head), it is simple, and can be adopted easily as a standard practice routine.
Three-dimensional imaging of orthodontic models: a pilot study
The European Journal of Orthodontics, 2007
Computer-based digital orthodontic models have been developed that have the potential to replace dental casts. The aim of this study was to examine the accuracy and reproducibility of measurements made on digital models. Ten sets of orthodontic study models were scanned using the Arius3D Foundation System and three-dimensional (3D) images were produced by computer software. Two examiners individually measured 11 parameters on the conventional casts and the digital models on two occasions. The parameters included mesio-distal crown diameter, intercanine and intermolar width, arch length, overjet, and incisor crown height. The measurement techniques were compared using paired t-tests, the coeffi cient of reliability, and by calculating mean values and the difference between methods. When comparing measurements made on digital models with those on dental casts, systematic errors were detected for fi ve of the 11 parameters at the 10 per cent level. Random errors were a cause of concern for measurements of three parameters. The most accurate and reproducible measurements were lower intercanine width (mean difference between measurements 0.05 ± 0.32 mm) and overjet (mean difference 0.07 ± 0.33 mm). Most parameters on the digital models can be reliably measured, and digital models can potentially eliminate the requirement for the production and storage of dental casts, but this will depend on cost.
A System for Measurements of 3D Scanned Orthodontic Study Models
Contemporary materials, 2017
Plaster dental casts represent an important item in the process of diagnosis, therapy planning and documenting, both in orthodontics, as well as other areas of dentistry. Dental casts allow us to track occlusal contacts before the therapy as well as the changes during the growth and therapy. Although they do possess many positive features, due to the rapid advancements in technology, their negative sides have became more prominent leading to the more widespread use of digital 3D models as their replacement. In this paper, we present a web based system that allows us, after the casts have been scanned, to produce easily usable digital models, to store them and perform measurements on them. Performed measurements are suitable for futher processing and analysis.
Accuracy of Dental Monitoring 3D digital dental models using photograph and video mode
American Journal of Orthodontics and Dentofacial Orthopedics, 2019
This study aimed to test the accuracy of the 3-dimensional (3D) digital dental models generated by the Dental Monitoring (DM) smartphone application in both photograph and video modes over successive DM examinations in comparison with 3D digital dental models generated by the iTero Element intraoral scanner. Methods: Ten typodonts with setups of class I malocclusion and comparable severity of anterior crowding were used in the study. iTero Element scans along with DM examination in photograph and video modes were performed before tooth movement and after each set of 10 Invisalign aligners for each typodont. Stereolithography (STL) files generated from the DM examinations in photograph and video modes were superimposed with the STL files from the iTero scans using GOM Inspect software to determine the accuracy of both photograph and video modes of DM technology. Results: No clinically significant differences, according to the American Board of Orthodontics-determined standards, were found. Mean global deviations for the maxillary arch ranged from 0.00149 to 0.02756 mm in photograph mode and from 0.0148 to 0.0256 mm in video mode. Mean global deviations for the mandibular arch ranged from 0.0164 to 0.0275 mm in photograph mode and from 0.0150 to 0.0264 mm in video mode. Statistically significant differences were found between the 3D models generated by the iTero and the DM application in photograph and video modes over successive DM examinations. Conclusions: 3D digital dental models generated by the DM smartphone application in photograph and video modes are accurate enough to be used for clinical applications.
Examination of Scanner Precision by Analysing Orthodontic Parameters
Balkan Journal of Dental Medicine, 2017
Summary: 3D modelling in orthodontics is becoming an increasingly widespread technique in practice. One of the significant questions already being asked is related to determining the precision of the scanner used for generating surfaces on a 3D model of the jaw.: This research was conducted by generating a set of identical 3D models on Atos optical 3D scanner and Lazak Scan laboratory scanner, which precision was established by measuring a set of orthodontic parameters (54 overall) in all three orthodontic planes. In this manner we explored their precision in space, since they are used for generating spatial models – 3D jaws.: There were significant differences between parameters scanned with Atos and Lazak Scan. The smallest difference was 0.017 mm, and the biggest 1.109 mm.: This research reveals that both scanners (Atos and Lazak Scan), which belong to general purpose scanners, based on precision parameters can be used in orthodontics. Early analyses indicate that the reference s...
Soft Tissue Analysis and Cast Measurement in Orthodontics Using Digital Photogrammetry
2000
In orthodontics the lateral X-ray and its analysis is an important part of the diagnostic procedures since the discovery of X-ray and the introduction of cephalic measuring with almost parallel X-rays. Making lateral and frontal photographs of the patient represents another common diagnostic method in this particular medical subject area. But both methods only allow a two dimensional inspection of cephalic or facial structures. While making a lateral X-ray the patient is exposed to radiation. Furthermore, the bony structures of the cephalic skeleton are pictured as a summation, which increases the probability of misinterpretation of the measured values. With the three dimensional photogrammetric measurement of the facial skull using 5 standard views a new diagnostic resource is available to the orthodontist, which allows the non-tactile, radiation free acquisition of the measure points of the viscerocranium with an accuracy in the range of 0.1 mm. Particularly the spatial acquisitio...
3D HEAD SURFACE SCANNING TECHNIQUES FOR ORTHODONTICS
Journal of Medical …, 2005
The accuracy of the Minolta 9i 3D laser scanner is evaluated and conditions are defined for its usability in orthodontics. Experiments are described which helped determine optimal scanning conditions such as beam power, patient positioning, the number of scans per examination, and viewpoint selection.