Mandibular instantaneous centers of rotation in patients with and without temporomandibular dysfunction.
METHODS
The free opening movement of the mandible was examined in 30 patients with and without dysfunctions, using the CADIAX electronic axiography system. All patients in the diseased group showed dysfunctions in the left temporomandibular joint. Half of the 20 asymptomatic patients were skeletal Class II, the other half skeletal Class III. Based on the data collected for the left temporomandibular joint, the movement of the mandible during the mouth-opening movement in the sagittal and vertical planes was described as the pathway over time of the various instantaneous centers of rotation (ICR), using physico-biomechanical factors.


CONCLUSIONS
It emerged that the ICR path in the patients with dysfunctions was irregular with erratic changes of direction. A harmonious ICR path beginning near the condyle was typical of the healthy group; as the mouth opened, the path moved toward downward backward and finally shifted toward forward and forward upward. Therefore, such an ICR path pattern can be used as an indicator in detecting dysfunctions.
Sadat-Khonsari
Reza
R
Department of Orthodontics, University of Hamburg, Germany. khonsari@uke.uni-hamburg.de
Fenske
Christian
C
Kahl-Nieke
Bärbel
B
Kirsch
Ingo
I
Jüde
Hans Dieter
HD
D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D002648:Child; D005260:Female; D006801:Humans; D007574:Jaw Relation Record / Q000295:instrumentation*; D008297:Male; D008312:Malocclusion, Angle Class II / Q000175:diagnosis* / Q000503:physiopathology; D008313:Malocclusion, Angle Class III / Q000175:diagnosis* / Q000503:physiopathology; D008334:Mandible / Q000503:physiopathology*; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013704:Temporomandibular Joint / Q000503:physiopathology; D013706:Temporomandibular Joint Dysfunction Syndrome / Q000175:diagnosis* / Q000503:physiopathology