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OCCLUSION Cite this article: Meyer GB, Bernhardt O, Constantinescu MV, Fundamentals of Occlusion and Masticatory Function. Stoma Edu J. 2014; 116-122 FUNDAMENTALS OF OCCLUSION AND MASTICATORY FUNCTION Georg B. Meyer1a*, Olaf Bernhardt2b, Marian-Vladimir Constantinescu3c 1. Zentrum für Zahn- Mund-, und Kieferheilkunde, Universitätsmedizin Greifswald, Greifswald, Germany 2. Poliklinik für Zahnerhaltung, Parodontologie und Endodontologie, Universitätsmedizin Greifswald, Greifswald, Germany 3. Department of Prosthetic Dentistry, “Carol Davila” University of Medicine and Pharmacy Bucharest, Romania a. DMD, PhD, Dr hc, Professor and Chairman b. DMD, PhD, Professor c. DDS, PhD, Professor Abstract Aim: Craniomandibular dysfunction is an expression of the dysfunctional masticatory system. It may have diverse risk factors, like occlusal interferences, including traumatic amalgam fillings and other fillings. The article aims to present three cases of craniomandibular dysfunction generated by occlusal interferences. Methodology: Three patients with different forms of craniomandibular dysfunction were referred to dentist for evaluation and treatment. Results: Occlusal interferences were identified as the main risk factor for uncoordinated hyperactive muscles and for craniomandibular dysfunction diagnosed in three cases presented. After occlusal correction, muscular dysfunction disappeared. Conclusions: In case of reasonable suspicion of craniomandibular dysfunction, an estimate for the detailed clinical and possibly instrumental diagnostics and optionally (grinding teeth guare/bite splint) pre-treatment must be done. Only after pre-treatment definitive treatments can be planned and carried out. Keywords: craniomandibular dysfunction, occlusal interferences, masticatory function Physiological aspects of the masticatory function Received: 17 October 2013 Accepted: 24 November 2013 * Corresponding author: Professor Georg B. Meyer, DMD, PhD, Dr hc, Chairman Zentrum für Zahn-, Mund- und Kieferheilkunde, Ernst-Moritz-Arndt Universität, Rotgerberstraße 8, D-17475 Greifswald, Germany. Tel: +493834867130, Fax:+493834867171. e-mail: gemeyer@uni-greifswald.de 116 In the undisturbed masticatory system, the teeth are in neutral occlusion with each other (Fig. 1). That is why, the most important is the natural contact of the cusps and fissures of the antagonist teeth, in order that all the eccentric movements won’t bring any disturbance (Fig. 2). The temporo-mandibular joints are in statics but also in dynamics of the same growth-related geometry, in order to have the temporo-mandibular joints as “distal pairs of occlusion”. When loaded during chewing, the involved teeth will be depending on the consistency of the alimentary bolus to be crushed, and they will be deflected spatially within their physiological mobility (Fig. 3). This requires the elastic and damping properties of the periodontal apparatus. In this area there are nerve endings, on which on which are generally mechano-receptors (Fig. 4). The capture caused by the respective bolus changes the position of the teeth by approximately10 to 20 microns, which corresponds approximately to the thickness of a human hair. This information is passed via afferent nerve pathways (sensors) in the central nervous system (Fig. 5). Here, a coordination of afferents and a conversion via synaptic structures in efferent signals is induced, which are passed to the motor units of the muscles, so that finally in the right place (localization of the bolus) with adequate power use (consistency of the bolus) chewing can occur. Overall, these are physiological control loop mechanisms, programmed in the growth phase and matched, that is why, for example, grinding and clenching in children may be physiologically. Ultimately, in the adult undisturbed masticatory all the geometric occlusal forces and temporo-mandibular joint functions with neuromuscular function sequences are working together in harmony. Temporary psycho-emotional stress situations with a clenching of the teeth does not lead to any direct damage to normal mastication, but are apparently even planned by nature for reducing the stress. STOMA.EDUJ (2014) 1 (2)