PubMed ID (PMID): 26389133Pages 201-223, Language: English, GermanAhlers, M. Oliver / Bernhardt, Olaf / Jakstat, Holger A. / Kordaß, Bernd / Türp, Jens C. / Schindler, Hans-Jürgen / Hugger, Alfons
Mandibular movement recording has long been established as the method for the physiological design of indirect dental restorations. Condylar movement recording is the basis for individual, patient-specific programming of partially or fully adjustable articulators. The settings derived from these recordings can generally be used in both traditional mechanical and electronic virtual articulators. For many years, condylar movement recordings have also provided useful information about morphological conditions in the temporomandibular joints (TMJs) of patients with masticatory system dysfunction based on the recorded movement patterns. The latest clinical application for recorded jaw-motion analysis data consists of functional monitoring of the patient as a diagnostic and surveillance tool accompanying treatment. Published parameters for the analysis of such recordings already exist, but a standardized and practicable protocol for the documentation and analysis of such jaw-movement recordings is still lacking. The aim of this article by a multicenter consortium of authors is to provide an appropriate protocol with the documentation criteria needed to meet the requirements for standardized analysis of computer-assisted recording of condylar movements in the future.
Keywords: diagnosis, mandibular condyle, mandibular movement recordings, range of motion, reference standards, temporomandibular joint
PubMed ID (PMID): 26389134Pages 225-235, Language: English, GermanKordaß, Bernd / Ruge, Sebastian
Analysis of temporomandibular joint (TMJ) function using condylar path tracings is a challenge in functionally oriented dentistry. In most cases, reference points on the skin surface over the TMJ region are defined as "arbitrary", "individual" or "kinematic" condylar hinge axis points, which are displayed as "condylar paths" in motion. To what extent these reference points represent the actual condylar paths in each individual patient is ultimately unclear because the geometric relationship of the actual condyle to the selected reference point is usually unknown. Depending on the location of the point on the condyle and the centers of rotation of mandibular movement, these trajectories can vary greatly during combined rotational and sliding movements (eg, opening and closing movements of the mandible); this represents a grid of points located in the vicinity of the TMJ. To record the actual condylar path as the movement trajectory of a given point (eg, the condylar center), technological solutions are needed with which to link the tracing technology with the appropriate imaging technology capable of scanning the condyle, including the points of interest, and displaying them in real dynamic motion. Sicat Function (Sicat, D-Bonn) is such a solution. Sicat Function links cone beam computed tomography (CBCT) scans (made using the Galileos CBCT scanner; Sirona, Bensheim, Germany) with ultrasound-based, three-dimensional (3D) functional jaw movement recordings of the mandible (made using the JMT+ Jaw Motion Tracker; Sicat, Bonn, Germany). Digital images of the dental arches acquired with the intraoral scanner Cerec system (Sirona) can also be superimposed. This results in the generation of a 3D model of the bony mandible, including the TMJ, which reproduces the 3D real dynamic movement of the condyles simultaneously with that of the condylar paths at defined points (with the condylar centers being a particular point of interest). Sicat Function is an integrated, digital 3D solution for additional instrumental and imaging diagnosis of temporomandibular joint dysfunction (TMD). The primary indication for Sicat Function is persistent, arthrogenic TMD complaints that require additional studies for evaluation of bony structural components of the TMJ.
Keywords: Sicat Function, cone beam computed tomography (CBCT), functional analysis, condyle movement, TMJ diagnosis, TMD
PubMed ID (PMID): 26389135Pages 237-258, Language: English, GermanPascale, Andra Maria / Ruge, Sebastian / Hauth, Steffen / Kordaß, Bernd / Linsen, Lars
Die optimale Form und Position eines neuen Zahnmodells für einen Patienten wird heute mithilfe von CAD/ CAM-Software berechnet. In Bezug auf diese mögliche zukünftige Anwendung wird in der vorliegenden Arbeit eine unabhängige, interaktive "Stand alone"-Anwendung vorgestellt, die den menschlichen Kauvorgang sowie die durch ihn verursachte Verformung des Nahrungssubstrats simuliert. Dabei wird mithilfe von Kaubewegungssensoren eine präzise Darstellung der Kieferbewegung erzeugt. Das Substrat wird durch ein verformbares elastisches Modell dargestellt. Das Model basiert auf der linearen Finite-Elemente- Methode, welche die physikalische Genauigkeit erhält. Mithilfe einer Kollisionserkennung, basierend auf räumlicher Unterteilung, werden die Kräfte berechnet, die auf das verformbare Modell wirken. Anhand der berechneten Daten werden anschließend geometrische Elemente hinzugefügt, um die Information für den Anwender anzureichern. Das Ziel der Simulation besteht darin, dem Zahnarzt eine vollständige Szene zu präsentieren, in der hervorgehoben wird, wo die Zähne mit dem Substrat in Berührung kommen und wie viel Kraft an diesen Kontaktpunkten wirkt. Somit kann sie gegebenenfalls Hinweise darauf geben, ob der Zahn im Kauvorgang falsch benutzt wird. Eine Echtzeitinteraktivität ist erwünscht und wird innerhalb bestimmter Grenzen auch erreicht, die von der Komplexität der verwendeten geometrischen Modelle abhängen. Die vorgestellte Simulation ist ein erster Schritt hin zum übergeordneten Projektziel, die Zahnposition und -form unter Analyse eines virtuellen Kauvorgangs anhand realer Patientendaten interaktiv zu optimieren (Abb. 1).
Keywords: CAD/CAM, Cerec, Kauen, verformbares Modell, Substrat
PubMed ID (PMID): 26389136Pages 261-271, Language: English, GermanKooistra, Ronald
Incisors can sometimes become discolored due to trauma. In most cases, the trauma involves complicated fractures of dentin and enamel that necessitates immediate restorative treatment. In some cases, the trauma is minor and does not involve any structural damage to the tooth. In these cases, the pulp tissue reacts to the trauma, causing discoloration. In the following two cases involving anterior teeth, there were no changes visible at the apex of the incisor. We assumed that the pulp tissue remained vital to some degree and was able to react in several ways to the trauma. In both cases, we saw a change in color of a central incisor, combined with an irregularity in the position of the anterior teeth. The patients involved both explicitly wished to alter the color of the darker incisor in order to restore the harmony of their smiles.
Keywords: non-invasive veneers, IPS e.max CAD, Cerec Esthetic
Open AccessPubMed ID (PMID): 26389137Pages 273-286, Language: English, GermanBosch, Gabriel / Ender, Andreas / Mehl, Albert
Abrasion and erosion are two increasingly common indications for dental treatment. Thanks to modern digital technologies and new restorative materials, there are novel therapeutic approaches to restoring such losses of tooth structure in a virtually non-invasive manner. The case study in this article demonstrates one such innovative approach. The patient's severely abraded natural dentition was restored in a defect-driven, minimally invasive manner using high-performance composite materials in the posterior region, and the "sandwich technique" in the anterior region. The restorations were milled on an optimized milling machine with milling cycles adapted for the fabrication of precision-fit restorations with thin edges.
Keywords: bite raising, CAD/CAM, complex rehabilitation, high-performance composite, non-invasive, ultra-thin occlusal veneers, virtual articulation