Franz Günter Sander

Learn More
An ultrastructural study of the cementum and periodontal ligament (PDL) changes after continuous intrusion with two different and controlled forces in humans was carried out. Twelve first upper premolars, at stage 10 of Nolla, orthodontically indicated for extraction from six patients (mean age 15.3) were used. They were divided into three experimental(More)
The paper demonstrates how to generate an individual 3D volume model of a human single-rooted tooth using an automatic workflow. It can be implemented into finite element simulation. In several computational steps, computed tomography data of patients are used to obtain the global coordinates of the tooth's surface. First, the large number of geometric data(More)
OBJECTIVE To evaluate the risk of root resorption, individual finite element models (FEMs) of extracted human maxillary first premolars were created, and the distribution of the hydrostatic pressure in the periodontal ligament (PDL) of these models was simulated. MATERIALS AND METHODS A continuous lingual torque of 3 Nmm and 6 Nmm respectively was applied(More)
Intrusion mechanics according to Burstone can be regarded as a practicable method for the intrusion of incisors. 1. By applying the NiTi-SE-steel uprighting spring, relatively constant forces can be exerted over a large range of intrusion on both sides of the anterior tooth archwire. 2. By bending a 150 degrees tip-back bend or a curvature into the steel(More)
OBJECTIVES Since the low friction of NiTi wires allows a rapid and efficient orthodontic tooth movement, the aim of this research was to investigate the friction and surface roughness of different commercially available superelastic NiTi wires before and after clinical use. The surface of all of the wires had been pre-treated by the manufacturer. (More)
INTRODUCTION The finite element method is a promising tool to investigate the material properties and the structural response of the periodontal ligament (PDL). To obtain realistic and reproducible results during finite element simulations of the PDL, suitable bio-fidelic finite element meshes of the geometry are essential. METHODS In this study, 4(More)
In this study 95 patients with a malocclusion type Angle class II were treated with a bite jumping appliance and the results achieved were compared with untreated class II patients. A clear improvement in the skeletal and dental relationships was observed. Significant changes were achieved yearly in the following: 1. the angle SNA was reduced (0.82(More)
Digital macro-photogrammetry (DMP) method was used to assess the 3-dimensional (3D) movement of the canine during retraction with a Hybrid Retractor (HR) spring (Forestadent, Pforzheim, Germany) following extraction of first premolars. Computer images of the canine were generated from multiple synchronous digital photos of a patient taken during clinical(More)
The goal of this study was to contribute to an understanding of how much expansion force is needed during a maxillary expansion (ME) and where bony reaction takes place. A finite element (FE) model of a dry human male skull was generated from CT scans. The FE model, which consists of cortical and cancellous bone and teeth, was loaded with the same force(More)
INTRODUCTION The main objectives of this study were to generate individual finite element models of extracted human upper first premolars, and to simulate the distribution of the hydrostatic pressure in the periodontal ligament (PDL) of these models for evaluation of the risk of root resorption. METHODS The individual extracted teeth were from a previous(More)