Biomechanical analysis of temporomandibular joint dynamics based on real-time magnetic resonance imaging.

Aim: The traditional hinge axis theory of temporomandibular joint (TMJ) dynamics is increasingly being replaced by the theory of instantaneous centers of rotation (ICR). Typically, ICR determinations are based on theoretical calculations or three-dimensional approximations of finite element models.

Materials And Methods: With the advent of real-time magnetic resonance imaging (MRI), natural physiologic movements of the TMJ may be visualized with 15 frames per second.

The variability of the curve of Spee : An analysis of multiple setups of the same Angle Class I patient case.

Purpose: The aim of this study was to examine possible parameters correlating to the shape of the curve of Spee (COS) by analyzing multiple setups of the same Angle class I patient case.

Methods: In all, 65 setups of the same Angle class I patient case were constructed. We measured the depth of the COS, length and width of the dental arch, steps, rotations, spaces and symmetry of the constructed setups.

Elongated styloid process in patients with temporomandibular disorders - Is there a link?

Background: Elongated styloid processes may display clinical signs that can easily be confused with symptoms associated with temporomandibular disorders (TMD). Thus, the present study aimed to investigate alterations of the styloid process in patients with TMD.

Methods: Temporomandibular joint (TMJ) X-ray images of 192 patients with RDC/TMD diagnoses were examined retrospectively.

Kinematics of cervical segments C5/C6 in axial rotation before and after total disc arthroplasty.

Purpose: The kinematical properties of C5/C6 segments in axial rotation are evaluated before and after total disc arthroplasty (TDA) with PRESTIGE-and BRYAN Cervical Disc (Medtronic) under flexion/extension as parameters and compared with those of C3/C4.

Methods: Eight human segments were stimulated by triangularly varying, axially directed torque (T (t)) under compressing static axial preloads. Using a 6D-measuring device with high resolution, the response of segmental motion was characterized by the instantaneous helical axis (IHA).

The description of the human knee as four-bar linkage.

Purpose: We investigate the dependence of the kinematics of the human knee on its anatomy. The idea of describing the kinematics of the knee in the sagittal plane using four-bar linkage is almost as old as kinematics as an independent discipline. We start with a comparison of known four-bar linkage constructions.