Orthopädische Biomechanik

Das Buch beschreibt Gedankengänge und Vorgehensweisen der orthopädischen Biomechanik, den Kenntnisstand zu Belastung und Beanspruchung des Haltungs- und Bewegungsapparates sowie die Reaktion der Gewebe auf mechanische Einflüsse exakt, aber mit einem Minimum an mathematischer und physikalischer Argumentation. Es gliedert sich in die Abschnitte I Grundlagen aus der Mechanik II Grundlagen aus der Mathematik III Mechanische Aspekte des Haltungs- und Bewegungsapparates IV Übungsaufgaben mit ausgearbeiteten Lösungen Zahlreiche Abbildungen unterstützen die anschauliche Darstellung. Ein Buch für Orthopäden, Ingenieure, Naturwissenschaftler, Physiotherapeuten und Orthopädietechniker in den Bereichen Forschung und Entwicklung von Orthopädie und Rehabilitation.  <br/

Spine deviations and orthodontic treatment of asymmetric malocclusions in children

Background: The aim of this randomized clinical trial was to assess the effect of early orthodontic treatment for unilateral posterior cross bite in the late deciduous and early mixed dentition using orthopedic parameters. Methods: Early orthodontic treatment was performed by initial maxillary expansion and subsequent activator therapy (Münster treatment concept). The patient sample was initially comprised of 80 patients with unilateral posterior cross bite (mean age 7.3 years, SD 2.1 years). After randomization, 77 children attended the initial examination appointment (therapy = 37, control = 40); 31 children in the therapy group and 35 children in the control group were monitored at the follow-up examination (T2). The mean interval between T1 and T2 was 1.1 years (SD 0.2 years). Rasterstereography was used for back shape analysis at T1 and T2. Using the profile, the kyphotic and lordotic angle, the surface rotation, the lateral deviation, pelvic tilt and pelvic torsion, statistical differences at T1 and T2 between the therapy and control groups were calculated (t-test). Our working hypothesis was, that early orthodontic treatment can induce negative therapeutic changes in body posture through thoracic and lumbar position changes in preadolescents with uniltaral cross bite. Results: No clinically relevant differences between the control and the therapy groups at T1 and T2 were found for the parameters of kyphotic and lordotic angle, the surface rotation, lateral deviation, pelvic tilt, and pelvic torsion. Conclusions: Our working hypothesis was tested to be not correct (within the limitations of this study). This randomized clinical trial demonstrates that in a juvenile population with unilateral posterior cross bite the selected early orthodontic treatment protocol does not affect negatively the postural parameters

Sagittal jaw position in relation to body posture in adult humans – a rasterstereographic study

BACKGROUND: The correlations between the sagittal jaw position and the cranio – cervical inclination are described in literature. Only few studies focus on the sagittal jaw position and the body posture using valid and objective orthopaedic examination methods. The aim of this study was to test the hypothesis that patients with malocclusions reveal significant differences in body posture compared to those without (upper thoracic inclination, kyphotic angle, lordotic angle and lower lumbar inclination). METHODS: Eighty-four healthy adult patients (with a mean age = 25.6 years and ranging from 16.1 to 55.8 years) were examined with informed consent. The orthodontic examination horizontal overjet (distance between upper and lower incisors) was determined by using an orthodontic digital sliding calliper. The subjects were subdivided in respect of the overjet with the following results: 18 revealed a normal overjet (Class I), 38 had an increased overjet (Class II) and 28 had an reversed overjet (Class III). Rasterstereography was used to carry out a three – dimensional back shape analysis. This method is based on photogrammetry. A three-dimensional shape was produced by analysing the distortion of parallel horizontal white light lines projected on the patient's back, followed by mathematical modelling. On the basis of the sagittal profile the upper thoracic inclination, the thoracic angle, the lordotic angle and the pelvic inclination were determined with a reported accuracy of 2.8° and the correlations to the sagittal jaw position were calculated by means of ANOVA, Scheffé and Kruskal-Wallis procedures. RESULTS: Between the different overjet groups, no statistically significant differences or correlations regarding the analysed back shape parameters could be obtained. However, comparing males and females there were statistically significant differences in view of the parameters 'lordotic angle' and 'pelvic inclination'. CONCLUSION: No correlations between overjet and variables of the thoracic, lordotic or the pelvic inclination could be observed

Facial landmark localization by curvature maps and profile analysis

Introduction: Three-dimensional landmarks of the face are important for orthodontic examination, harmony assessment and treatment planning. Currently, facial landmarks are often measured by orthodontists via direct observation and manual soft tissue image analysis. This study wants to evaluate and present an objective method for measuring selected facial landmarks based on an analysis of curvature maps and of sagittal profile obtained by a laser-scanning method. Methods: The faces of 15 people were scanned in 3D by means of the laser scanner FastSCAN™. It allowed the recording of a curvature map of the face in under a minute, which depicted the distribution of Gaussian and mean curvatures. The median-sagittal profile line of the face was localized in this map, and a mathematical analysis comprising its first and second derivatives was performed. Anatomical landmarks were identified and facial measurements performed. To assess validity the obtained data were compared with manual measurements by orthodontists by means of Lin’s concordance correlation CCC coefficient and reliability was determined by consecutive measurements. Results: Facial landmarks, such as the soft tissue glabella and nasal tip, could be easily and accurately identified and located. Lin’s CCC showed substantial agreement between digital and manual measurements for 4 of the 7 distances evaluated. Larger discrepancies were due to inadequate image quality and scanning errors. Reliability of consecutive measurements by the same operator was excellent. Conclusions: In our pilot study the three-dimensional laser-scanning method FastSCAN™ allowed a reliable and accurate identification of anatomical landmarks of the face. The obtained distances between certain landmarks, such as the intercanthal distance, were largely consistent with those from manual measurements. Due to its easy and rapid implementation, the method facilitates facial analysis and could be a clinically valid alternative to manual measurements, when remaining problems in scanning accuracy can be resolved.<br