SciencePages 99-114, Language: English, GermanAini, Tuba / Güth, Jan-Frederik / Görl, Steffani
Die Initialtherapie mit Okklusionsschienen stellt einen entscheidenden Behandlungsschritt in der Therapie komplexer Rehabilitationen mit Veränderungen der Vertikaldimension dar. Ein wesentlicher Faktor für den Erfolg der Behandlung ist die Compliance des Patienten. Neben dem Wunsch der minimalinvasiven Vorgehensweise, kommen steigende Ansprüche der Patienten an Ästhetik und Funktion bereits in der provisorischen Phase hinzu, die mit der klassischen Okklusionsschiene nur unzureichend erfüllt werden können. Dies bedingt ein Umdenken im klinischen Alltag. Sind irreversible Maßnahmen erforderlich, erhöht eine ausreichende funktionelle und ästhetische Erprobung die Sicherheit des therapeutischen Vorgehens. Der Einsatz neuer Materialien und die Möglichkeit der digitalen Umsetzung führten zur Entwicklung neuer Behandlungskonzepte in der prothetischen Zahnmedizin. Im Folgenden soll exemplarisch der Einsatz von Polycarbonat als „neues“ Material für Schienen dargestellt werden, das es aufgrund der besonderen Materialeigenschaften ermöglicht, zahnfarbene, vollanatomische Schienen herzustellen, die dem späteren definitiven Zahnersatz ähneln. Das Konzept der „Münchner Schiene“ berücksichtigt die Aspekte der Funktion, Phonetik, Ästhetik und Minimalinvasivität und bildet damit ein innovatives und flexibles Vorbehandlungskonzept.
Keywords: Münchner Schiene, Polycarbonatschiene, Bisshebung, Schienentherapie, Vertikaldimension, Rekonstruktion, Erosion
SciencePages 115-128, Language: English, GermanKordaß, Bernd / Amlang, Alexandra / Hugger, Alfons / Behrendt, Christoph / Ruge, Sebastian
Evaluations of the regional baseline study (SHIP-1) with the Greifswald Digital Analyzing System (GEDAS)Sufficient occlusion is a basic prerequisite for the functional efficiency of the occlusal surfaces. Exactly where and in what number the occlusal contacts in the posterior region should be present for this purpose is controversial.
Aim: The present study investigated the number and location of occlusal contacts on posterior teeth without dental findings, ie, without caries or restorative restorations such as fillings, crowns, etc. Such natural posterior teeth were present in 709 subjects (males [m] = 446: 48.9 ± 13.04 years, females [f] = 283: 52.4 ± 14.23 years) of a subject collective of 1223 subjects (m = 648, f = 575) of the regional baseline study ‘Study of Health in Pomerania 1’ (SHIP-1).
Materials and method: Silicone bite registrations in habitual intercuspation (IP) were evaluated, whereby the test persons were asked to fix the bite block with biting force without biting firmly. The registrations were scanned with a document scanner in incident and transmitted light; a calibration strip was used to determine the transparency threshold of a layer thickness of 20 μm, below and equal to which the transparent zone was considered as a contact or contact area. The Greifswald Digital Analyzing System 2 (GEDAS 2) software was used to determine the number and location of occlusal contact areas tooth by tooth. To define the localization of the contacts, a cross with two concentric circles symmetric to the longitudinal fissure was superimposed on the occlusal surface; this resulted in four inner and four outer quadrants. Thus, the number of pixels in occlusal contact areas per inner and outer quadrant could be determined. The image resolution was 300 dpi.
Results: On average (median), the premolars had two occlusal contacts each, the posterior teeth had four to five, and Vieltooth 46 had six contacts. The right and left teeth did not differ in the frequency of occlusal contacts in the Mann-Whitney U test for independent samples. In the maxillary premolars, frequent contact areas were primarily located mesially on the inner and outer slopes of the palatal cusp. In the maxillary molars, the palatal slope of the distopalatal cusp and the inner slopes of the mesiopalatal and distopalatal cusps were frequently addressed. On the mandibular premolars, the inner slopes of the buccal cusps and the buccal slope of the distobuccal cusp were particularly frequently addressed; in teeth 35 and 45, the buccal slope of the mesiobuccal cusp was also somewhat more frequently addressed. Teeth 36 and 46 frequently had contact areas on the buccal slope of the distobuccal cusp as well as on the inner slopes of the distal cusps (distobuccal and distolingual), whereas teeth 37 and 47 tended to behave similarly.
Conclusion: Epidemiologically, the focus of the frequent contact areas on the respective supporting cusps of the maxillary and mandibular posterior teeth and a distribution of contacts stabilizing the tooth in its position in the dental arch through the interlocking were confirmed. It makes sense to take this into account when designing occlusal surfaces in the posterior region.
Keywords: occlusion, occlusal contacts, posterior teeth, epidemiology
Case ReportPages 129-143, Language: English, GermanMichael, Sarah Maria / Boldt, Johannes / Gierthmühlen, Petra
A digital workflow was used to fabricate complete dentures with different concepts of occlusion for a 65-year-old female patient using the Zirkonzahn digital denture system (Zirkonzahn, Gais, Italy). By using CAD/CAM technology and the related potentials for adjusting occlusal parameters, it was possible to develop dentures with a custom-adapted concept of occlusion based on the individual patient parameters in a time- and cost-efficient manner. After several weeks of trial wear, the patient preferred the complete dentures with sequential guidance in laterotrusion (with canine/premolar dominance) and 15-degree cusp angles due to better wearing comfort and masticatory performance. In summary, the digital workflow presented in the present article integrated important aspects of the patient’s dental history and enabled the creation of an occlusal concept individually adapted to her masticatory system.
Keywords: digital complete dentures, computer-aided design and manufacturing, CAD/CAM, bilateral balanced occlusion, sequential group function occlusion, mastication, patient comfort