Three-dimensional imaging of orthodontic models: a pilot study (original) (raw)

The Comparison of Diagnostic Measurements Using Two Different Three-Dimensional Digital Orthodontic Model Software Systems

The Journal of dentists, 2017

Objective: The purpose of this study was to evaluate and compare the reliability and accuracy of diagnostic measurements performed using two different three-dimensional (3D) digital orthodontic model software systems. Materials and Methods: The dental casts of 20 patients with permanent dentition were selected and scanned with an orthodontic 3D scanner (3Shape R700, Copenhagen, Denmark). Two different digital model software programs, Orthomodel (v.1.01, Orthomodel Inc., Istanbul, Turkey) and O3DM (v.2.0, O3DM Thunoegade, Aarhus C, Denmark) were used for diagnostic measurements including tooth width, Bolton discrepancies, intermolar and intercanine distances. A total of 34 measurements were calculated on each digital model. All measurements were repeated by the same observer over 10 randomly selected dental casts at least two weeks later for intraobserver reliability. Results were analyzed statistically. The paired samples t-test was used to compare the differences between the measurements obtained with both softwares. The intraobserver reliability was determined using Cronbach's alpha test. Results: Cronbach's alpha value indicated a very high level of reliability for all measurements. Orthomodel and O3DM software programs showed significant differences in the mesiodistal widths of some teeth and the sum of maxillary 6 teeth widths (p<0.05), but not in the Bolton ratios and transverse arch width measurements. Conclusions: Both digital model softwares demonstrated clinically acceptable measurements despite of the differences in some measurements essential for diagnosis and treatment planning.

Evaluation of the validity of tooth size and arch width measurements using conventional and three-dimensional virtual orthodontic models

The Angle orthodontist, 2003

Measurements and different analyses of dental casts are essential for precise diagnosis of an orthodontic case. At present, virtual computerized models, such as OrthoCAD, are available for clinicians, supplemented by dedicated software for performing needed measurements on them. The purpose of this study was to test the accuracy of measuring casts with the aid of calipers or OrthoCAD and compare these two techniques. Twenty setups using artificial teeth corresponding to various malocclusions were created. Impressions were taken of them, providing 20 plaster and 20 virtual orthodontic models. Measurements of mesiodistal tooth dimension as well as intercanine and intermolar width were made on both. Additionally, values of tooth size were calculated from the isolated artificial teeth removed from the setups and of arch width from the existing setups. The resulting values were compared by the use of nonparametric statistics, and methods' errors were also calculated. Results showed t...

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.

Traditional plaster casts and dental digital models: intra-examiner reliability of measurements

Progress in orthodontics

The aim of this study was to compare the intra-examiner reliability of measurements made on plaster cast and dental digital models. Five young patients with different occlusal patterns were selected and their dental casts and corresponding digital models were obtained. Twenty expert orthodontists were asked to measure two times both the traditional and digital models. The measurements taken included: lower inter-canine distance, lower inter-molar distance, lower right first molar mesio-distal length, lower right lateral incisor mesiodistal length and overbite. The absolute differences between the two sets of repeated measurements were computed for each of the five couples of parameters and compared with Student's paired T tests. Four parameters showed no statistical difference when the error of measurement of the traditional models was compared to the error of measurement of the digital models. They where the lower inter-canine distance (p = 0.11), the lower inter-molar distance...

An evaluation of concordance between linear measurements obtained from conventional, digital and reconstructed three-dimensional printed orthodontic models: An in vitro study

Acta Marisiensis - Seria Medica

Objective: To evaluate the potential use of digital and reconstructed three-dimensional printed models as an alternative to conventional plaster models by assessing the accuracy of their linear measurements. Methodology: Pre-treatment plaster models of 45 patients were selected from the archives of the Department of Orthodontics. Each physical plaster model was scanned and digitized using a three-dimensional (3D) laser surface scanning system (inEOS X5, Dentsply Sirona, Bensheim, Germany). The scanned STL files were later used to reconstruct models by 3D printing using Figure4® standalone 3D printer (3D systems, Rock Hill, South Carolina). Measurements of teeth 11 and 16, the transverse width of the upper jaw between the first molars (MM - intermolar width) and canines (CC - intercanine width) were done manually using a digital vernier caliper (Mitutoyo, Kawasaki, Japan), and the CAD Assistant software (Open cascade, Guyancourt, France). Intra examiner data, Intraobserver variabilit...

The advanced model definition and analysis of orthodontic parameters on 3D digital models

Srpski arhiv za celokupno lekarstvo

Introduction/Objective. Digital 3D modeling is slowly becoming an everyday orthodontic practice, and after two decades of research and development it is a basic element of e-orthodontics. The aim of this study was development and use of geometric entities on 3D digital models for diagnosing, planning and monitoring of orthodontic therapy, by using CAD (computer aided design) systems. Methods. Statistical analysis and synthesis of 54 orthodontic parameters (28 in the upper and 26 in the lower jaw), defining three hypotheses and their testing, the application of the t-test. Results. All three hypotheses are confirmed, convenience of using geometric entities, higher accuracy of 3D digital models, and more substantial displacement of teeth in the first six months of therapy (Student?s t-test). After the first six months, distances in the x?y plane (occlusal plane) were bigger in both the upper and the lower jaw; additionally, the distances in the y?z plane (medial plane) decreased on th...

On the augmented reproducibility in measurements on 3D orthodontic digital dental models and the definition of feature points

Objective: The objective of this study was to explore digital measurement methodology on 3-dimensional (3D) dental models. Standardised manipulation and practices have lead to reliable measurements on plaster casts. Identifying landmarks on digital models or digitised plaster casts is fundamentally different from actual measurements. Three-dimensional models are represented on flat screens and landmarks are individually indentified. A procedure is proposed that resolves the deficiencies associated with a 2-dimensional (2D) display through an appropriate model representation and through local optimisation. Methods: Fifteen models (OrthoProof) were exported to a locally developed 3D point indication software package, in which two measurement approaches were implemented involving standard projection with and without local search. Nine linear measurements were obtained from plaster casts and digital models. Statistical analysis included correlation and Friedman's nonparametric analysis of variance (ANOVA). Results: For five out of nine linear measurements, digital indications yielded results significantly different from manual measurements (p = 0.05). Local search considerably improved measurement accuracy and reliability. Conclusions: Measurements on plaster casts can differ significantly from those obtained through digital identification methods. These differences prove to be clinically relevant. Standardisation and optimisation resulted in improved and extremely reliable digital measurements.

The reliability and validity of measurements of human dental casts made by an intra-oral 3D scanner, with conventional hand-held digital callipers as the comparison measure

Forensic science international, 2017

Intra-oral 3D scanning of dentitions has the potential to provide a fast, accurate and non-invasive method of recording dental information. The aim of this study was to assess the reliability of measurements of human dental casts made using a portable intra-oral 3D scanner appropriate for field use. Two examiners each measured 84 tooth and 26 arch features of 50 sets of upper and lower human dental casts using digital hand-held callipers, and secondly using the measuring tool provided with the Zfx IntraScan intraoral 3D scanner applied to the virtual dental casts. The measurements were repeated at least one week later. Reliability and validity were quantified concurrently by calculation of intra-class correlation coefficients (ICC) and standard errors of measurement (SEM). The measurements of the 110 landmark features of human dental casts made using the intra-oral 3D scanner were virtually indistinguishable from measurements of the same features made using conventional hand-held ca...

Intra-Oral 3D Scanning for the Digital Evaluation of Dental Arch Parameters

Applied Sciences

Intra-oral scanning technology has brought a completely new approach to examination methods in dentistry. In comparison to traditional plaster casts, it allows more precise digital analysis of dental arch components during the treatment of dental disorders. Data acquired can also be used for the creation of three-dimensional (3D) models using 3D printers. This paper describes a data acquisition system, the mathematical processing of resulting three-dimensional model, and the statistical analysis of selected parameters of the dental arch. The study aims at comparing the results achieved from 20 models of the same individual acquired by different specialists. The proposed methodology includes mathematical rotation of objects into the optimal plane defined by the teeth tops’ location to increase the accuracy of the resulting parameters. The mean evaluated distances between canines (3-3) and premolars (5-5) are 24.29 mm and 37.98 mm, respectively, for the lower dental arch. The proposed...