dental superimposition for tooth alignment and transformation with cloudcompare

Beurteilung der Zahnbewegung des Oberkiefer-Seitenzahns mittels digitaler Überlagerung

In 1999, digitally fabricated removable orthodontic appliances were made commercially available by Align (Align Technology Inc., Tempe, AZ). Originally, this system was designed to solve non-growing cases with mild to moderate crowding or close small spaces as an aesthetic alternative to traditional fixed edgewise appliances. With decades of improvements in computer-aided design and manufacturing (CAD/CAM), dental materials, and treatment planning, clear aligner therapy (CAT) has since been used to treat over 10 million patients with various malocclusions worldwide1. A recent retrospective study suggested that CAT is as effective as fixed appliance therapy for the teenage population with mild malocclusions, with significantly improved results in tooth alignment, occlusal relations, and overjet2. The number of appointments, emergency visits, and overall treatment time also had better outcomes for clear aligner therapy patients. Although CAT can be used to treat non-extraction, mild-to-moderate malocclusions in non-growing patients3,4, and shorten treatment duration and chair time5, it remains unclear whether the treatment is as effective as the gold standard of conventional labial braces4,6,7,8,9, especially for anteroposterior and vertical correction10.
ClinCheck is a software platform developed by Align to provide clinicians with virtual three-dimensional (3D) simulations of prospective tooth movements. Primarily concerned with the patient&#39;s initial status and the clinician&#39;s prescribed treatment plan, it can also be a visual communication tool for the patient. Any mismatch between the predicted and achieved results may require a mid-course correction, refinement, or conversion to fixed appliance therapy. Consequently, the reliability of software predictions has drawn increasing attention from investigators. Since Lagravere and Flores-Mir&#39;s systematic review published in 200511, investigations into the concordance between predicted models and post-treatment models have been measured in different ways, measurement methods including arch-length, inter-canine distance, overbite, overjet, midline deviation12, the American Board of Orthodontics objective grading system (ABO-OGS) reduction score13, upper and lower interdental width14, and measures derived from cone-beam computed tomography15.
Comparisons have also been made by superimposing 3D models16,17,18,19,20,21. For example, many current software platforms, such as ToothMeasure (internal software developed by Align Technology), can reproducibly superimpose two digital models using user-selected reference points on untreated teeth, palatal rugae, or dental implants. Since the predicted and achieved models usually do not include the palatal surfaces, many previous studies15,16,17,18 have used the untreated posterior teeth as references for superimposition, including the possibility of adding errors due to the relative movements of these teeth. These studies have been confined to anterior regions of the arch in relatively simple cases with spacing or mild to moderate crowding.
Gr&#252;nheid et al. used mathematical superimposition to quantify the discrepancies between virtual treatment plans and actual treatment outcomes to evaluate the accuracy of full-dentition CAT without stable anatomic structures in digital models20. Haouili et al. used the same method in a best-fit algorithm within the Compare software to conduct a prospective follow-up study on the efficacy of tooth movement with CAT21. The aim was to provide an update on the accuracy associated with emerging technology, i.e., SmartForce, SmartTrack aligner materials, and digital scans. Their findings of an improved overall accuracy from 41%17 to 50%21&#160;were encouraging but do not negate the possibility that some tooth movements are still not satisfactorily achievable with the clear aligner system.
When predicted and achieved, digital models include a common 3D reference independent of the dentition, such as palatal rugae, dental implants, or tori; they can be co-registered within the coordinate system of many suitable software platforms. If a tooth of interest is then segmented from one and transformed mathematically to match its displaced version in the other, the transformation matrix contains the complete information needed to describe the entire 3D transposition. Its content can be expressed as three translations and three rotations described by a formal convention. An example is found on the Invisalign ClinCheck Pro 3D control software, where the numerical parameters indicating the 3D tooth movements needed to move teeth to their predicted positions are shown in a tooth movement table.
While the initial and final (predicted) models from the planning software share a common coordinate system provided by the same software platform, their absence of palates restricts the possibility of co-registering with any other digital dentition model unless they possess identical dentition. In this context, it was hypothesized that the superimposition of software-predicted and post-treatment (achieved) models would be feasible. This feasibility arises from the availability of two pairs: initial and final (automatically superimposed during export from planning software) and another pair of pre-treatment and achieved models (superimposed using palatal rugae). These pairs could be registered using the pre-treatment dentition as a reference to align them with the Invisalign-initial model. Subsequently, the segmentation of individual teeth could be performed to assess differences in their positions and orientations. This assessment involves transposing teeth between the models, and the transformation matrices would enable a numerical quantification of the translations and re-orientations.
In this protocol, an approach to evaluate the effectiveness of CAT in addressing mild to moderate malocclusions in both adolescents and adults was introduced, specifically focusing on the maxillary posterior teeth. The null hypothesis was that there was no difference between the achieved and the planning software-predicted tooth position in the maxillary posterior teeth after the first series of clear aligners.

Autor im Rampenlicht: 3D-Bewegungsbeurteilung von Oberkiefer-Seitenzähnen bei der Behandlung mit klaren Alignern

Messung der Oberkiefer-Seitenzahnbewegung: Eine Modellbewertung mit Gaumen- und Zahnüberlagerung

Dental movement assessment is important when evaluating orthodontic treatment outcomes. We are going to be demonstrating a method to evaluate three-dimensional movement of maxillary posterior teeth when they have undergone Clear Aligner treatment. This protocol offers a combination of several software tools, as well as palatal rugae and dentition as stable references.This combination allows for the superimposition and segmentation of individual teeth for the purpose of analyzing their movements and orientations. This protocols demonstrate a novel method to analyze the differences between software-predicted models and the actual treatment outcomes. By understanding the efficacy and the accuracy of software-predicted treatment, clinicians will have a better judgment planning the tooth movement.

Dentale Überlagerung für Zahnausrichtung und -transformation mit CloudCompare 

Starten Sie zunächst die Cloud Compare-Software auf dem Computer. Blenden Sie nach dem Importieren der segmentierten Kronendateien den Nachbehandlungszahn aus. Wählen Sie dann sowohl den versteckten Nachbehandlungszahn als auch den sichtbaren vorhergesagten Zahn aus.Wählen Sie nun die untere Ansicht und klicken Sie auf das Symbol Verschieben Drehen. Verwenden Sie die X-, Y- und Z-Ebenen, um den Zahn so zu drehen, dass der bukkale Höcker an der vertikalen Linie ausgerichtet ist. Wählen Sie die linke Seitenansicht aus und klicken Sie auf das Symbol Verschieben Drehen.Richten Sie dann die bukkalen und lingualen Höcker an der horizontalen Linie aus. Wählen Sie auf ähnliche Weise die Rückansicht und richten Sie die bukkalen und lingualen Höcker an der horizontalen Linie aus. Sobald alle Spitzen ausgerichtet sind, klicken Sie auf das Symbol zum Verschieben und zentrieren Sie den Zahn auf dem Raster in allen Ansichten.Blenden Sie nun den Nachbehandlungszahn ein und wählen Sie sowohl den vorhergesagten Zahn als auch den Nachbehandlungszahn aus. Drücken Sie auf das Symbol für die Ausrichtung der Registrierung, um den Nachbehandlungszahn über dem vorhergesagten Zahn zu registrieren. Klicken Sie dann auf OK.Wählen Sie dann den Nachbehandlungszahn. Kopieren Sie die Transformationsmatrix und klicken Sie auf Bearbeiten, gefolgt von Transformation anwenden, um die Transformationsmatrix einzufügen. Wählen Sie abschließend das Symbol für die Ölerwinkel, um die Rotations- und Linearbewegungen zwischen den vorhergesagten und den Nachbehandlungszähnen anzuzeigen.Die Winkelmaße für Rotation, Drehmoment und Spitze variierten stärker als die Entfernungsmaße für bukkale linguale, mesiale distale und okklusale Gingivatranslationen. Die mittleren Rotationsunterschiede für erste Prämolaren und zweite Prämolaren waren größer als zwei Grad. Das Drehmoment für alle Zahntypen wich erheblich von Null ab.Während die mittlere Differenz für zweite Prämolaren und erste Molaren weniger als minus zwei Grad betrug. Geringfügige Unterschiede wurden bei allen Anhängen beobachtet.

Research

JoVE Journal

Medicine

Dental Superimposition for Tooth Alignment and Transformation with CloudCompare

Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition

Since the introduction of Invisalign by Align Technology, Inc. in 1999, questions and debates have persisted regarding the precision of Invisalign (clear ...

Forschung

Medizin

Dental Palatal Superimposition of Pre- and Post-Treatment Digital Models in CloudCompare

Überlagerung von digitalen Modellen vor und nach der Behandlung in CloudCompare

Software-Model Preparation for Dental Superimposition and Tooth Crown Manipulation with Rhinoceros Software

Software-Modellvorbereitung für Zahnüberlagerungen und Zahnkronenmanipulation mit Rhinoceros Software

Superimposition of Software-Predicted and Post-Treatment Digital Dental Models with CloudCompare

Überlagerung von softwarevorhergesagten und nach der Behandlung durchgeführten digitalen Dentalmodellen mit CloudCompare

Dental Crown Segmentation Using Meshmixer

Segmentierung von Zahnkronen mit Meshmixer