Tierexperimentelle Untersuchungen des frühen Osseointegrationsverhaltens von zylindrischen gegenüber konischen Implantaten in vivo

Diese Studie untersucht das frühe Einheilverhalten zweier Implantatsysteme im Bezug auf das Implantatdesign. Es handelt sich um konische, zur Sofortbelastung konzipierte Implantate. Als Referenzgruppe dient das zylindrische ITI® Implantat. Dazu wurden 30 Implantate je Gruppe in die Tibiaknochen von Göttingerminischweinen inseriert. Es wurden fotographische, histologische, rasterelektronenmikroskopische und histomorphometrische Untersuchungen durchgeführt. Die ITI-Implantate wiesen im Bereich der Spongiosa eine etwas dichtere Knochenapposition auf. Das knöcherne Interface bezog bei den konischen Implantaten den krestalen Anteil mit ein. Bei den zylindrischen Implantaten zeigte sich nach 7 und 28 Tagen ein schmaler Spalt nicht ossifizierten Gewebes. Die Ergebnisse zeigen positive Ergebnisse im Bezug auf das frühe Osseointegrationsverhalten beider Implantatsysteme. Sie sprechen weiterhin für eine Abhängigkeit der Ausformung des krestalen periimplantären Knochens vom Implantatdesign

Maxillary protraction using a hybrid hyrax-facemask combination

BACKGROUND: The aim of this in study was the evaluation of treatment outcomes after using a hybrid hyrax-facemask combination in growing class III patients. METHODS: Treatment of 16 children (mean age 9.5 ± 1.3 years) was investigated clinically and by means of pre- and post-treatment cephalograms. Changes in sagittal and vertical, and dental and skeletal values were evaluated and tested for statistically significant differences. RESULTS: All mini-implants remained stable during treatment. Mean treatment duration was 5.8 ± 1.7 months. There was a significant improvement in skeletal sagittal values: SNA, +2.0°; SNB, -1.2°; ANB, +3.2°; WITS appraisal, +4.1 mm and overjet, +2.7 mm. No significant changes were found concerning vertical skeletal relationships and upper incisor inclination. In relation to A point, the upper first molars moved mesially about 0.4 mm (P = 0.134). CONCLUSIONS: The hybrid hyrax-facemask combination seems to be effective for orthopaedic treatment in growing class III patients. Unwanted maxillary dental movements can be avoided due to stable skeletal anchorage

Utilisation combinée du Beneslider et d’appareils multi-bagues linguaux, mécaniques et procédure clinique

Depuis les dernières années, une tendance s’observe, lorsqu’il est nécessaire de distaler les molaires supérieures, à utiliser de façon préférentielle des appareils uniquement intra-oraux sollicitant le moins possible la coopération du patient. Malheureusement, la plupart des appareils de distalisation molaire habituellement utilisés en cas d’absence de coopération, engendrent des effets secondaires indésirables tels que la perte d’ancrage. De façon à minimiser ou éviter cette perte d’ancrage, les mini-vis sont d’un grand intérêt depuis quelques années; ceci par leur caractère faiblement invasif chirurgicalement et par leur faible coût. En utilisant la région antérieure du palais comme site d’insertion, le taux d’échec est extrêmement bas; il n’y a pas de risque d’atteinte radiculaire et les appareils sont à distance des mouvements orthodontiques provoqués. Fondées sur une documentation clinique explicite, les applications pratiques et rationnelles du Beneslider associé à des attaches linguales sont présentées. Par cette procédure, les extractions à l’arcade supérieure et les forces réactives à l’arcade mandibulaire entraînant une vestibulo-version des incisives peuvent être évitées avec une thérapeutique utilisant un appareil invisible

Amélioration de la stabilité des mini-implants orthodontiques

Dans le domaine de l’ancrage squelettique, le recours aux mini-implants orthodontiques ne cesse de se développer. Cependant, le principal problème reste leur taux relativement élevé de perte de 16,4 %. Si l’on analyse les publications traitant des causes de perte d’implants, il s’avère que l’insertion de mini-implants plus importants en taille dans la région antérieure et médiane du palais aboutit à une grande stabilité ainsi qu’à un taux élevé de succès. De plus, la stabilité du couplage mini-implant/suprastructure est déterminante dans le succès. L’utilisation de mini-implants dont la tête possède un pas de vis interne permet la mise en place vissée stable de différents types d’abutments (piliers). Grâce à de longues plaques perforées spéciales, il est possible de relier deux mini-implants entre eux et d’augmenter ainsi leur stabilité. Un système d’éléments préfabriqués permet l’élaboration rapide de différents types de mécaniques orthodontiques efficaces (systèmes mécaniques efficaces)

Early Class III treatment with Hybrid-Hyrax -Facemask in comparison to Hybrid-Hyrax-Mentoplate – skeletal and dental outcomes

Abstract Background Protraction of maxilla is usually the preferred and more commonly used treatment approach for skeletal Class III with a retrognathic maxilla. The aim of this study was the comparison of the skeletal and dental effects of two skeletally borne appliances for maxillary protraction: a) Hybrid-Hyrax in combination with facemask (FM), b) Hybrid-Hyrax in combination with Mentoplate (ME). Methods Thirty four Patients (17 facemask, 17 Mentoplate) were investigated by means of pre- and posttreatment cephalograms. The two groups matched with regard to treatment time, age gender and type of dentoskeletal deformity before treatment. Results Both groups showed a significant forward movement of A-point (FM GROUP: SNA + 2.23° ± 1.30°— p 0.000*; ME: 2.23° ± 1.43°— p 0.000*). B-Point showed a larger sagittal change in the FM Group (SNB 1.51° ± 1.1°— p 0.000*) compared to the ME group (SNB: − 0.30° ± 0.9°— p 0.070). The FM group showed a significant increase of the ML-NL + 1.86° ± 1.65° (p 0.000*) and NSL-ML + 1.17° ± 1.48 (p 0.006*). Upper Incisor inclination did not change significantly during treatment in both groups as well as the distance of the first upper Molar in relation to A-point. Conclusion Both treatments achieve comparable rates of maxillary protraction, without dentoalveolar side effects. Skeletal anchorage with symphysial plates in the mandible provides greater vertical control and might be the treatment of choice in high angle patients

Microstructural volumetric analysis of vertical alveolar ridge augmentation using autogenous tooth roots

Background: To volumetrically assess the bone microstructure following vertical alveolar ridge augmentation using differently conditioned autogenous tooth roots (TR) and second‐stage implant placement. Materials and methods: The upper premolars were bilaterally extracted in n = 4 beagle dogs and randomly assigned to either autoclavation (TR‐A) or no additional treatment (TR‐C). Subsequently, TR were used as block grafts for vertical alveolar ridge augmentation in both lower quadrants. At 12 weeks, titanium implants were inserted and left to heal 3 weeks. Microcomputed tomography was used to quantify bone volume per tissue volume (BV/TV), trabecular thickness (Tb.Th), and trabecular spacing (Tb.Sp) at vestibular (v) and oral (o) aspects along the implant and in the augmented upper half of the implant, respectively. Results: Median BV/TV [TR‐C: 51.33% (v) and 70.42% (o) vs TR‐A: 44.05% (v) and 64.46% (o)], Tb.th [TR‐C: 0.22 mm (v) and 0.27 mm (o) vs TR‐A: 0.23 mm (v) and 0.29 mm (o)] and Tb.Sp [TR‐C: 0.26 mm (v) and 0.13 mm (o) vs TR‐A: 0.29 μm (v) and 0.15 mm (o)] values were comparable in both groups. Conclusion: Both TR‐C and TR‐A grafts were associated with a comparable bone microstructure within the grafted area

Three dimensional anatomical exploration of the anterior hard palate at the level of the third ruga for the placement of mini-implants - a cone-beam CT study

AIM The aim of this retrospective investigation was to measure vertical bone thickness on the hard palate, determine areas with adequate bone for the insertion of orthodontic mini-implants (MIs), and provide clinical guidelines for identification of those areas. MATERIALS AND METHODS Pre-treatment records of 1007 patients were reviewed by a single examiner. A total of 125 records fulfilled the inclusion criteria and were further investigated. Bone measurements were performed on cone-beam computed tomography scans, at a 90° angle to the bone surface, on 28 predetermined and standardized points on the hard palate. Bone thickness at various areas was associated to clinically identifiable areas on the hard palate by means of pre-treatment plaster models. RESULTS Bone thickness ranged between 1.51 and 13.86mm (total thickness) and 0.33 and 1.65mm (cortical bone thickness), respectively. Bone thickness was highest in the anterior palate and decreased significantly towards more posterior areas. Plaster model analysis revealed that bone thickness was highest at the level of the third palatal ruga. CONCLUSIONS The areas on the anterior palate with adequate bone thickness for successful insertion of orthodontic MI correspond to the region of the third palatal ruga. These results provide stable and clinically identifiable landmarks for the insertion of palatal MIs