ABSTRACT
It has become clear that foods crushing is performed in the circumscribed region between functional cusps, that is, at "the main occluding area". However, it is not established to evaluate this area objectively. The purpose of this study was to establish the positional evaluation of the main occluding area quantitatively and evaluate the positional change depending on the age with this method. The subjects were fifteen adults and ten adolescents who had no stomatognathic disorder. Temporary Stopping was used as test material in this study. In order to analyze the position of the main occluding area, the projected centroid coordinate of the test material was calculated and projected onto the reference axis. It was possible to quantitatively evaluate positional changes of the main occluding area depending on growth process. As a result, the main occluding areas of the adults were significantly posterior to those of the adolescents and tended to be more stable. There was a significant difference in the occlusal contant area between two groups. The occlusal contact area had great influence on the stability of the main occluding area. However, besides occlusal contact area, there might be other factors which stabilized the main occluding area.
Subject(s)
Dental Occlusion, Centric , Mastication/physiology , Adolescent , Adult , Age Factors , Bicuspid/physiology , Dental Cements , Dental Stress Analysis , Female , Food , Humans , Male , Masseter Muscle/physiology , Maxillofacial Development , Molar/physiology , Temporal Muscle/physiologyABSTRACT
The purpose of this study was to investigate a suitable occlusal height for an implant prosthesis by examining the responses of the periodontal tissues around a natural antagonist. The subjects were three Japanese females with two posterior missing teeth restored by ITI system implants (Straumann). Two kinds of experimental implant prostheses were adjusted as follows; one was adjusted in heavy clenching (HC), and the other was adjusted in light clenching (LC). The periodontal pulsation, displacement during biting an occlusal force meter and the mobility of the antagonist were measured before and one week after temporary cementing HC and LC, and one week after removal. In each prosthesis, there was no significant difference in the amounts of the pulsation and mobility of the antagonist before and one week after cementing, and one week after removal (p>0.05). The displacement of the antagonist during biting the occlusal force meter did not change much during the conditions. The results of this study suggested that an implant prosthesis adjusted not only under heavy clenching but light clenching like crown restorations for natural teeth did not affect the periodontal tissues of the antagonist in a harmful manner.
