[Study on mandibular position in occlusion during opening and closing movement in hemimandibulectomy patients--effect of difference of opening distance on mandibular position].
In the hemimandibulectomy patients the mandible is severely deviated and the occlusion is unstable, therefore the prosthodontic treatment for these patients is generally not successful. To investigate the stability of the mandibular position in occlusion of these patients, the differences of the range and the position of the mandible in occlusion between during the 5-mm opening and closing movement and during the 10-mm movement were analyzed three-dimensionally with the Jaw Movement Analyzer MM-JI-E. In this study, four hemimandibulectomy patients were selected as the subjects. The findings were as follows: 1. In three subjects, the range of the mandible in occlusion during the 10-mm opening and closing movement was larger than that during the 5-mm movement in almost all directions. On the contrary in one subject, the range of the mandible in occlusion during the 10-mm opening and closing movement was smaller than that during the 5-mm movement in almost all directions. 2. The relative relationship of the mandibular position in occlusion during the 10-mm opening and closing movement to that during the 5-mm movement varied in four subjects. In one subject, the mandible rotated horizontally towards the outside and moved upward. In another subject, the mandible rotated horizontally towards the inside and moved downward. In the other subject, the mandible moved inward and upward. In the other subject, the mandible moved outward and downward.
Ishiwata
H
H
Department for Stomatognathic dysfunction, Faculty of Dentistry, Tokyo Medical and Dental University.
D000368:Aged; D003766:Dental Occlusion; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000503:physiopathology* / Q000601:surgery; D008875:Middle Aged; D009055:Mouth / Q000503:physiopathology*; D009068:Movement; D011476:Prosthodontics