Analysis of human mandibular movement.
The parametric electrical outputs of the six-transducer mandibulograph were used to analyze three-dimensional pathways, displacement profiles, and velocity profiles of selected mandibular areas during jaw movement. This was accomplished by means of digital computer implementation of derived mathematical equations of motion. Five jaw movements were studied: chewing, open-close, right lateral, left lateral and protrusive. The results demonstrate the analytical and diagnostic value of this method and provice new clarification and insight into the nature of mandibular movements. The following observations summarize the principal findings derived from the analysis of jaw movement patterns of a normal patient. The chewing jaw movement exhibited a smoothly coordinated sequence of events. Lateral jaw motion appeared to be prominent during the masticatory phase and throughout the movement cycle. Mastication was abruptly terminated by a vertical desscent of the mandible through the freeway space, until the condyles began their forward movement producing a rotation in the sagittal plane. T occlusal area continued its downward descent along a nearly vertical pathway producing a compressed figure eight pattern in the frontal plane. The open-close jaw movement exhibited minor periods of hesitancy. Jaw movement was initiated with a forward and downward movement of the condyle occurring at the same time as a downward and backward movement of the occlusal area. This motion produced a rotation in the sagittal plane about a moving axis which was not coincident with the intercondylar axis.  The general form of the command open-close jaw movement was that of noncoincident curved pathways in the sagittal plane with little lateral displacement. Closing jaw movement occurred with the condyle in a protruded position...
D000328:Adult; D003748:Dental Equipment; D005260:Female; D006801:Humans; D007574:Jaw Relation Record / Q000295:instrumentation*; D008334:Mandible / Q000502:physiology*; D008409:Mastication; D008953:Models, Anatomic; D008954:Models, Biological; D009068:Movement; D014159:Transducers; D014716:Vertical Dimension