title: Estimation of the position and orientation of the kinematic axis of the temporomandibular joint.
abstract: The kinematic axis refers to a theoretical intercondylar axis of the temporomandibular joint, which translates on a curved surface during all sagittal movements. In normal joints, the translation of this rotational axis is nearly reciprocal. Its estimation is arrived at in two steps: (i) axis points are estimated in several sagittal planes, using data of sagittal mandibular movements, and (ii) an axis is then fitted to them. Neither of them, however, takes into consideration any geometric constraints on the trajectories of the kinematic axis. To correct this theoretical inconsistency, this paper presents a technique capable of directly exploring the position and orientation of the axis. During exploration, the axis is evaluated by the extent of its motion range, which is approximated from trajectile data obtained at several points on the axis. The validity of this technique was verified, through experiments employing data of actual mandibular movements.
authors.affiliation: Graduate School of Science and Technology, Niigata University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Itoh
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: M
authors.initials: M
authors.lastname: Miyakawa
mesh_terms: D000328:Adult; D000465:Algorithms; D001696:Biomechanical Phenomena; D006801:Humans; D008297:Male; D008334:Mandible / Q000502:physiology; D008335:Mandibular Condyle / Q000502:physiology; D008954:Models, Biological; D009068:Movement; D016059:Range of Motion, Articular; D012399:Rotation; D013704:Temporomandibular Joint / Q000033:anatomy & histology / Q000502:physiology*