Functional state of the mandible and rolling-gliding characteristics in the TMJ.
For the physiological intact stomatognathic system, the three main functional states (occlusat articular functions, free mandibular movements, and ideal bolus function) were biomechanically discussed concerning the structure of movement, rolling-gliding characteristics, and force transfer in the temporomandibular joint (TMJ). In all three cases, rolling is not possible in the TMJ since the instantaneous rotational axis is positioned outside of the joint-rolling is not necessary because the TMJ is not loaded by appreciable forces. In the aged stomatognathic system with a lost discus and considerable Loads in the TMJ, however, the attrition of the joint is eased by rolling movement at the articulating surfaces. The destruction of the discus can be seen as a physiological adaptation which brings back the joint to an original odontogen condition.
Kubein-Meesenburg
Dietmar
D
Department of Orthodontics, University of Göttingen, Robert-Koch-Strasse 40, D-37099 Göttingen, Germany. kubein@med.uni-goettingen.de
Fanghänel
Jochen
J
Ihlow
Dankmar
D
Lotzmann
Ulrich
U
Hahn
Wolfram
W
Thieme
Kirsten M
KM
Proff
Peter
P
Gedrange
Tomas
T
Nägerl
Hans
H
D000368:Aged; D000375:Aging; D001696:Biomechanical Phenomena; D006801:Humans; D008334:Mandible / Q000502:physiology*; D009043:Motor Activity; D009068:Movement; D012886:Skull / Q000502:physiology; D013704:Temporomandibular Joint / Q000254:growth & development / Q000502:physiology*