No description available.

No description available.

The aim of this study was to describe the quantity and quality of the bacterial population ejected from the mouth during the process of removing fixed orthodontic appliances. Specifically, the aims were: 1. To estimate the total bacterial load of aerosol clouds generated during adhesive removal at the debond visit. 2. To estimate the numbers of different bacteria within that population and the depth within the human airway to which they may penetrate. 3. To examine and relationship between the patient's standard of oral hygiene and different methods of adhesive removal to the number and diversity of the sampled bacterial population. The study involved the sampling of ambient air adjacent to the patient's mouth, during the process of adhesive removal. Airborne particles were collected by an inertial impactor, which had six different levels simulating different levels in the human airway. Bacteria on the collected particles were cultured for analysis visually and by molecular techniques. The results showed that on average 75% of the bacteria sampled could not be cultured by conventional methods and required molecular analysis to determine their presence. Adhesive removal using a high speed, water-irrigated handpiece resulted in the production of a greater quantity of bacterially contaminated particles, compared the aerosol generated when using a slow speed handpiece. High speed debonding also resulted in those particles being of smaller size and having potential to penetrate deeper into the respiratory system than slow speed aerosol. The concentration or complexity of the bacterial population collected did not appear to be related to a patient's standard of oral hygiene, nor were these factors reduced by the use of a Chlorhexidine or sterile water pre-operative mouth rinse. Regardless of the method of adhesive removal, contaminated particles are generated in a range of sizes, a proportion of which have potential to be inhaled to the deepest level of the lung, i.e. the pulmonary alveoli. It is therefore important that clinical staff take appropriate measures to protect the airway during adhesive removal, e.g. the use of face masks.

Aim: To develop a method to study linear, angular and rotational tooth movements in three dimensions using a surface laser scanning technique. Design: An experimental methodological study. Material and methods: The Konica Minolta Vivid 910 non-contact surface laser scanner was used to convert plaster models into digital data, which were then analysed by Rapidform™2006 software.

No description available.

No description available.

The aims of this project were twofold. Firstly to compare the measurement error using digital Vernier callipers and a 3D laser scanner when using Little's Index of Irregularity on plaster study models. Secondly to establish whether the use of active or passive selfligating brackets results in faster initial tooth alignment than the use of conventional orthodontic brackets.

No description available.

A 3D imaging system (C3D®), based on the principles of stereophotogrammetry, has been developed for use in the assessment of facial changes following orthognathic surgery. Patients’ perception of their facial appearance before and after orthognathic surgery has been evaluated using standardised questionnaires, but few studies have tried to link this perception with the underlying two-dimensional cephalometric data. Comparisons between patients’ subjective opinions and 3D objective assessment of facial morphology have not been performed. Aims: (1) To test the reliability of the 3D imaging system; (2) to determine the effect of orthognathic surgery on the 3D soft-tissue morphology; (3) to assess skeletal changes following orthognathic surgery; (4) to evaluate soft-tissue to hard-tissue displacement ratios; (5) to ascertain the impact of orthognathic surgery on patients’ perception of their facial appearance and their psychosocial characteristics, (6) to explore the dentofacial deformity, sex and age on the psychosocial characteristics; (7) to evaluate the extent of compatibility between the cephalometric and the three-dimensional measurements and (8) to determine if the magnitude of facial soft-tissue changes affects the perception of facial changes at six months following surgery. Results and Conclusions: C3D imaging system was proved to be accurate with high reproducibility. The reproducibility of landmark identification on 3D models was high for 24 out of the 34 anthropometric landmarks (SD£0.5 mm). One volumetric algorithm in the Facial Analysis Tool had an acceptable accuracy for the assessment of volumetric changes following orthognathic surgery (mean error=0.314 cm3). The error of cephalometric method was low and the simulation of mandibular closure proved to be reproducible. 2D soft-tissue measurements were compatible with 3D measurements in terms of distances, but angular measurements showed significant differences (p<0.05).

Depuis une dizaine d’années, l’essor des minivis d’ancrage orthodontique a été grandissant jusqu’à devenir, aujourd’hui, un outil incontournable dans l’arsenal thérapeutique de l’orthodontiste. Très peu d’études ont été publiées quant à la nature de la réponse tissulaire face à l’insertion et la mise en charge de ces minivis. De plus, une partie des patients concernés par l’orthodontie étant des adolescents, il serait intéressant de savoir si le tissu osseux en croissance est propice à l’utilisation de ces dispositifs. L’influence de la nature du matériau sur cette réaction tissulaire reste également à définir. L’objectif de cette étude a été d’évaluer la biointégration de deux systèmes de minivis orthodontiques présents sur le marché, l’un en acier chirurgical et l’autre en titane-aluminium-vanadium, en conduisant une analyse clinique, histomorphométrique et microtomographique chez le porc en croissance. Les résultats ont montré que la réponse osseuse se caractérise, dans un os en croissance peu compact, par un épaississement des travées osseuses au contact des dispositifs, probablement pour résister à la contrainte locale. Le tissu osseux en croissance permet la biointégration des minivis d’ancrage orthodontique, mais le taux de succès relativement faible observé implique l’adaptation des protocoles cliniques par une analyse préalable du ratio os trabéculaire/os cortical, une augmentation du délai avant mise en charge, et l’application de forces légères. La réponse tissulaire est similaire, quel que soit le système étudié. L’acier chirurgical, grandement utilisé en orthopédie, présente donc un intérêt en orthopédie dento-faciale, dans une indication temporaire / The miniscrew implants are increasingly used over the last decade in orthodontics and gradually replacing the use of extraoral forces because of their greater efficiency and because their effectiveness is not subject to patient compliance. Few studies seeking to understand the response to orthodontic anchorage devices at bone-tissue interface have been published over the last ten years. Despite the large use of miniscrews in teenagers, very few have included young subjects in their protocol. Furthermore, despite the use of stainless steel miniscrew implants, no studies have investigated biointegration of such devices. The aim of the present study was to evaluate tissue response to immediately loaded miniscrew implants (of Ti6Al4V and of stainless steel) in growing pigs in order to answer to the following questions: Is it possible to implant and load miniscrew implants in a growing bone? Does stainless steel devices present the same biointegration than titanium devices? A clinical evaluation, and histomorphometrical and micro-CT analyses were performed. Results showed that the growing bone seems compatible with the orthodontic anchorage. In the growing pig with low bone density areas, the trabecular thickness increase appears as the bone response to withstand the local strains induced by loaded orthodontic miniscrews. Stainless steel devices presented similar behavior to the Ti6Al4V devices in pigs. This study showed the possibility to place stainless steel miniscrew implants for orthodontic anchorage in growing models