The application of dust suppressants is an effective technique to reduce fugitive emissions, but commercially available products are costly and may harm the environment. By contrast, wastes and ...by-products from food production and processing can be sustainable alternatives, as they are biodegradable, considered cost-effective and have adhesive properties. The study aimed to investigate the application potential of biogenic wastes and by-products from the food industry to control dust emissions from mine soils. Unconfined compressive strength tests (UCS) were conducted on medium- to coarse-grained sand treated with sixteen biomaterials at two different additive concentrations (2 wt%, 4 wt%). UCS tests showed that rinsing water from jam production (1,366 kPa), corn steep liquor (1,502 kPa), chicory vinasses (1,723 kPa), decantation syrup (2,026 kPa) and palatinose molasses (7,535 kPa) significantly enhanced the mechanical strength of the substrate (11 kPa), indicating a strong potential of these biomaterials as dust suppressants. Such biomaterials that contained biopolymers and not only mono- and disaccharides achieved on average higher UCS values, possibly due to the formation of 3D-network structures. Moreover, the data indicated a low potential for substances with high glucose and fructose content, as they had minor or no impact on soil strength.
Implications: The UCS test results indicate that food processing wastes and by-products can be sustainable alternatives to existing dust suppressants. Hence, the present study supports an environmentally friendly and cost-effective dust control of exposed surfaces at mine and mineral processing sites and provides new markets for the food industry's wastes and by-products. Moreover, this research extends our understanding of dust suppressant treatment of soils and contributes to evaluating biogenic food processing wastes and by-products as environmentally benign dust suppressants.
Abstract Background Conventional maxillofacial reconstruction often leads to suboptimal results due to inaccurate planning or surgical difficulties in adjusting a free flap and osteosynthesis plates ...into a three-dimensional defect. Objectives To justify the importance of patient-specific intraoperative guides in complex maxillofacial reconstruction. Clinical example A 40-year old patient underwent a left hemimaxillectomy for an adenoid cystic carcinoma of the palate. Six years later, massive recurrence required radical resection of the left orbit and reconstruction with cranial bone grafts and a free latissimus dorsi flap. Postoperative radiotherapy resulted in local osteoradionecrosis. Surgical revision and restoration of the maxillary defect with a prefabricated fibula flap was performed. The authors provide ample information on the application of computer-aided design and manufacturing (CAD-CAM) and rapid prototyping at each reconstructive step. Discussion Stereolithographic models enable simulation of the resective and reconstructive phases, prebending of reconstruction plates and fabrication of surgical guides. Conclusions Optimal restitution of complex maxillofacial defects requires meticulous planning of the surgical and prosthetic phases and effective transfer of the plan to the operating room through patient specific guides. CAD-CAM technology and stereolithographic models represent an effective strategy to achieve this. Improved patient outcomes and intraoperative efficiency certainly offset the inherent increase in costs.
Purpose The purpose of this study was to evaluate the error magnitude in the clinical application of face-bow devices. Technical and methodologic inaccuracies, as well as deviations from reference ...planes, were determined. Materials and Methods The presented method is part of a 3-dimensional virtual planning procedure for orthognathic surgery and included 15 patients with dentoskeletal deformities. Cone beam computed tomography datasets obtained from patients with a referenced face-bow plane and a centric registration splint were matched with cone beam computed tomography datasets of the registered plaster model of the maxilla mounted in an articulator. To assess potential sources of methodologic errors, angulations were measured between the virtual face-bow plane and the horizontal cross bar of the virtual articulator. To evaluate the reproducibility of the anatomic reference plane, angulations between the Frankfort plane and the horizontal cross bar of the articulator were measured. Statistical significance was set at P < .05 and tested by univariate analysis of variance. Results Technical and methodologic errors showed a mean deviation of 3.5°, with a median of 3.6° and SD of 2.7°. The values did not reach statistical significance ( P = .1). However, there was a significant error ( P < .05) in determining the position of the anatomic reference plane by face-bow transfer. The mean deviation was 7.7° (values ranged between 1.2° and 18.9°), with a median of 6.7° and SD of 5.3°. Conclusions In this study the traditional use of face-bow devices showed inaccuracies in model mounting as well as in assignment of anatomic reference planes. Three-dimensional virtual computer-assisted planning seems to be more accurate than conventional methods.
Reconstruction of complex defects involving the maxilla or mandible often requires transfer of free vascularized tissue. In the conventional approach, a flap is transferred to provide vital tissue, ...and subsequent shaping and debulking are required. The authors present their experience with prefabrication of vascularized fibular flaps. Since 1999, 48 prefabricated flaps have been used to reconstruct 28 maxillary and 20 mandibular defects. The technique involves two surgical steps (prefabrication and flap transfer) and requires accurate planning, done with a solid model of the skull. Correct positioning of the prefabricated flap is accomplished by using the occlusion as a guide. Planning includes fabrication of a provisional prosthesis that is fixed to the flap with implants. Putting the prosthesis into occlusion determines the position of the flap.
Das vom Deutschen Bundestag und vom Bundesarchiv herausgegebene Editionsprojekt Der Parlamentarische Rat 1848-1949 macht die wesentlichen Dokumente zuganglich, die wahrend der Beratung des ...Grundgesetztes entstanden sind. Dazu gehoren neben den Protokollen des Verfassungskonvents auf Herrenchiemsee vor allem die Mitschriften aus den Sitzungen der einzelnen Fachausschusse sowie des Plenums und des Hauptausschusses. Sie werden durch weitere Dokumente erganzt, welche Geschaftsordnungsfragen, die Interfraktionellen Besprechungen und auch die Beziehungen zu den Militarregierungen betreffen.
Between January of 1998 and May of 2002, 25 prefabricated osseous free flaps (23 fibula and two iliac crest flaps) were transferred in 24 patients to repair maxillary (six flaps) or mandibular (eight ...flaps) defects after tumor resection, severe maxillary (four flaps) or mandibular (one flap) atrophy (Cawood VI), maxillary (one flap) or mandibular (three flaps) defects after gunshot injury, and maxillary (two flaps) defects after traffic accidents. Prefabrication included insertion of dental implants, positioned with a drilling template in a preplanned position, and split-thickness grafting. Drilling template construction was based on the prosthetic planning. The template determined the position of the implants and the site and angulation of osteotomies, if necessary. The mean delay between prefabrication and flap transfer was 6 weeks (range, 4 to 8 weeks). While the flap was harvested, a bar construction with overdentures was mounted onto the implants. The overdentures were used as an occlusal key for exact three-dimensional positioning of the graft within the defect. The bar construction also helped to stabilize the horseshoe shape of the graft. The follow-up period ranged from 2 months to 4 years (mean, 21 months), during which time two total and three partial flap losses occurred. One total loss was due to thrombosis of the flap veins during the delay period, whereas the other total loss was caused by spasm of the peroneal artery. Two partial losses were due to oversegmentation of the flaps with necrosis of the distal fragment, whereas one partial loss was caused by disruption of the vessel from the distal part. Of the 90 implants that were inserted into the prefabricated flaps during the study period, 10 were lost in conjunction with flap failure; of the remaining 80 implants, four were lost during the observation period, for a success rate of 95 percent. Flap prefabrication based on prosthetic planning offers a powerful tool for various reconstructive problems in the maxillofacial area. Although it involves a two-stage procedure, the time for complete rehabilitation is shorter than with conventional procedures.
: The fibular flap can be used for a variety of indications. Recently, the treatment of four patients with severely atrophied upper jaws using a method to prefabricate the vascularized fibular graft ...has been published. This technique consists of a two‐stage operation procedure that allows simultaneous prosthodontic rehabilitation and immediate placement of dental implants. In this paper eight patients with 29 ITI implants (Straumann AG, Waldenburg, Switzerland) who had reconstruction of either the upper or lower jaw are presented. The aim of the study was (i) to evaluate the behavior of the newly formed soft tissue around implants inserted in the fibula by applying periodontal parameters, (ii) to monitor prospectively the integration of the implants in the fibular graft, and (iii) to assess the osseous integration of the fibular graft used for reconstruction of the upper or lower jaw. Two implants failed during the observation time because of avascular bone at the distal end of the fibular graft. Stabilization of the graft, however, was never compromised. Due to the prefabrication firmly attached gingiva‐like soft tissue could be provided preventing periimplant soft tissue inflammation and facilitating oral hygiene. After 1 year of observation the mean attachment level was similar to implants placed in original bone whereas vertical bone loss measured radiographically was lower in the present study. This may indicate that the remodeling of a bicortical bone requires a longer period of time compared with the bone of the alveolar crest. The prospective 1‐year results are promising but long‐term evaluation of periodontal and radiological parameters are required.
Résumé
Le lambeau péroné peut être utilisé pour une variété d'indications. Récemment le traitement de quatre patients avec une atrophie sévère des mâchoires supérieures et utilisant une méthode pour préfabriquer un greffon péroné vascularisé a été publié. Cette technique consiste en une opération en deux étapes qui permet la réhabilitation prothétique simultanée et le placement immédiat des implants dentaires. Dans ce rapport huit patients avec 29 implants ITI (Straumann AG, Waldenburg, Switzerland) ont eu une reconstruction de la mâchoire supérieure ou inférieure. Le but de cette étude a été 1) d'évaluer le comportement des tissus mous nouvellement formés autour des implants insérés dans le péroné en appliquant les paramètres parodontaux, 2) de suivre d'une manière prospective l'intégration des implants dans le greffon péroné et 3) d'examiner l'intégration osseuse de l'implant péroné utilisé pour la reconstruction de ces mâchoires. Deux implants ont échoué durant la période d'observation parce que l'os alvéolaire n'était pas vasculariséà la partie distale du greffon. La stabilisation du greffon n'a cependant jamais été compromise. La préfabrication d'un tissu ressemblant à de la gencive préfabriquée a permit d'éviter l'inflammation gingivale et de faciliter l'hygiène buccale. Après une année d'observation le niveau d'attache moyen était semblable au niveau des implants placés dans l'os original tandis que la perte osseuse verticale mesurée radiographiquement était inférieure dans l'étude présente. Ceci peut indiquer que le remodelage de l'os bicortical requiert une période plus importante comparée à l'os du rebord alvéolaire. Ces résultats prospectifs à une année sont encourageants mais l'évaluation à long terme des paramètres parodontaux et radiologiques reste encore nécessaire.
Zusammenfassung
Der Fibula‐Lappen kann bei einer Vielzahl von Indikationen angewendet werden. Kürzlich wurde eine Publikation über die Behandlung von vier Patienten mit stark atrophierten Oberkiefern mittels vorfabrizierten vaskularisierten Fibula transplantaten veröffentlicht. Diese Technik besteht aus einer Operation in zwei Phasen, welche die Sofortimplantation von dentalen Implantaten und gleichzeitige prothetische Rekonstruction erlaubt. In diesem Artikel werden acht Patienten mit 29 Implantaten (Straumann AG, Waldenburg, Switzerland), bei welchen entweder eine OK‐ oder UK‐Rekonstruktion durchgeführt wurde, präsentiert. Das Ziel der Studie war (i) das Verhalten des neu gebildeten Gewebes um die Implantate, welche in die Fibula eingesetzt worden waren mittels parodontalen Parametern zu untersuchen, (ii) die Integration der Implantate in das Fibula‐Transplantat prospektiv aufzuzeichnen und (iii) die ossäre Integration des für die Rekonstruktion des OK oder UK verwendeten Fibula‐Transplantats zu ermitteln. Zwei Implantate zeigten während der Beobachtungsperiode Misserfolge wegen avaskulärem Knochen an den distalen Enden des Fibula‐Transplantats. Die Stabilisierung des Transplantats war jedoch niemals beeinträchtigt. Durch die Vorfabrizierung konnten gut angewachsene gingiva‐ähnliche Weichgewebe geschaffen werden, welche eine periimplantäre Entzündung der Weichgewebe verhinderten und die Mundhygiene erleichterten. Nach einer Beobachtungszeit von einem Jahr war das mittlere Attachmentniveau ähnlich dem von Implantaten, welche in alveolären Knochen inseriert worden waren, während der radiologisch gemessene Knochenverlust in der vorliegenden Studie geringer war. Dies könnte ein Indiz dafür sein, dass die Remodellierung eines bikortikalen Knochens im Vergleich zum Alveolarknochen längere Zeit benötigt. Die prospektiven Resultate nach einem Jahr sehen vielversprechend aus, aber es muss eine Auswertung der parodontalen und radiologischen Parameter über einen längeren Zeitraum durchgeführt werden.
Resumen
El colgajo peroneal puede ser usado para una variedad de indicaciones. Recientemente se ha publicado el tratamiento de cuatro pacientes con maxilares superiores severamente atróficos usando un método para prefabricar el injerto peroneal vascularizado. Esta técnica consiste en un procedimiento de operación de dos fases que permite la rehabilitación prostodóntica y la colocación inmediata de implantes dentales simultáneamente. En este artículo se presentan ocho pacientes con 29 implantes ITI (Strauman AG, Waldenburg) teniendo una reconstrucción de tanto el maxilar superior como del inferior. La intención del presente estudio fue (i) evaluar el comportamiento de del tejido blando neoformado alrededor de los implantes insertados en la tibia aplicando parámetros periodontales, (ii) monitorizar prospectivamente la integración de los implantes en el injerto perineal y (iii) valorar la integración ósea del injerto perineal usado para la reconstrucción del maxilar superior o inferior. Dos implantes fracasaron durante el periodo de observación debido a hueso sin vascularización en el final distal del injerto perineal. De todos modos, la estabilización del injerto no se vio nunca comprometida. Debido a la prefabricación se pudo suministrar un tejido blando tipo encía adherida previniendo inflamación del tejido blando periimplantario y facilitando la higiene oral. Tras un año de observación el nivel de inserción medio fue similar a los implantes insertados en las áreas de hueso original mientras que la pérdida de hueso vertical medida radiograficamente fue menor en el presente estudio. Esto puede indicar que el remodelado de un hueso bicortical requiere un periodo mas largo de tiempo comparado con el hueso de la cresta alveolar. Los resultados prospectivos de un año son prometedores pero se requieren evaluaciones de los parámetros periodontales y radiológicos a largo plazo.
: Treatment of severe maxillary atrophy despite complex major surgery often ends up with an unsatisfactory result. This paper presents the augmentation of the maxilla with a prefabricated free ...vascularized fibula flap in combination with ITI® implants (Straumann AG, Waldenburg, Switzerland) in 4 patients. The technique of prefabrication for the reconstruction of maxillofacial defects is described based on the experience with 17 patients. The key points of this treatment are i) preoperative planning and fabrication of the drilling template; ii) prefabrication of the fibula with ITI® implants and performing of a “vestibuloplasty” using a skin graft; iii) technical construction and fabrication of the suprastructure and the denture; iv) reconstruction of the maxilla using the prefabricated fibula as free vascularized flap. The reconstructions with the fibula flaps were successful and the 18 ITI® implants that have been inserted showed good osseointegration without loss of attachment in all 4 patients after a mean observation period of 12 months.
Résumé
Le traitement des atrophies maxillaires sévères malgré une chirurgie majeure et complexe se termine souvent par un résultat non‐satisfaisant. Ce manuscript décrit l'épaississement du maxillaire à l'aide d'un lambeau d'os du péroné vascularisé et libre, préfabriqué et associéà des implants ITI® chez quatre patients. La technique de préfabriation pour la reconstruction des lésions maxillo‐faciales est décrite, basée sur l'expérience acquise avec 17 patients. Les quatre points forts de ce traitement sont 1) un programme préopératoire et la fabrication des plateaux de référence pour le forage, 2) la préfabrication de l'os du péroné avec les implants ITI® et la réalisation de la vestibuloplastie en utilisant une greffe de peau, 3) la construction et la fabrication de la superstructure et de la prothèse, 4) la reconstruction du maxillaire en utilisant l'os du péroné préfabriqué en tant que lambeau vascularisé libre. Les reconstructions avec les lambeaux du péroné ont bien réussi et les 18 implants ITI® insérés ont montré une bonne ostéoïntégration sans perte d'attache chez les quatre patients après une période d'observation moyenne de douze mois.
Zusammenfassung
Die Behandlung einer ausgedehnten Oberkieferatrophie endet trotz komplexen grösseren chirurgischen Eingriffen oft mit einem unbefriedigenden Resultat. Diese Arbeit stellt die Augmentation des Oberkiefers von 4 Patienten mit Hilfe eines vorgängig präparierten und durchbluteten Fibulalappens in Kombination mit ITI®‐Implantaten vor (Straumann AG, Waldenburg, Schweiz). Die nötigen Schritte zur Vorbereitung dieser Rekonstruktion von maxillofacialen Defekten wurden an Hand den Erfahrungen an 17 Patienten beschrieben. Die vier Schlüsselstellen dieser Behandlung sind: I) die präoperative Planung und die Herstellung der Bohrschablone; II) die Vorbereitung der Fibula mit ITI®‐Implantaten und die Herstellung einer “Vestibulumplastik” mit einem Hauttransplantat; III) technisches Design und Herstellung einer Suprastruktur mit Prothese; IV) die Rekonstruktion des Oberkiefers mit Hilfe einer vorbereiteten Fibula in Form eines freien durchbluteten Lappens. Die Rekonstruktionen mit den Fibulalappen waren alle erfolgreich und die 18 gesetzten ITI‐Implantate zeigten bei allen vier Patienten nach einer mittleren Beobachtungszeit von 12 Monaten eine gute Osseointegration ohne Attachmentverlust.
Resumen
El tratamiento de una atrofia maxilar severa a pesar de una cirugía mayor severa acaba frecuentemente con un resultado no satisfactorio. Este trabajo presenta el aumento del maxilar con un colgajo prefabricado libre vascularizado de peroné en combinación con implantes ITI® (Strauman AG, Waldenburg, Switzerland) en 4 pacientes. La técnica de la prefabricación para la reconstrucción de los defectos maxilofaciales se describe basada en la experiencia con 17 pacientes. Los cuatro puntos clave de este tratamiento son i) planificación preoperatoria y fabricación de las plantillas de perforación; ii) prefabricación del peroné con implantes ITI® y la realización de una vestibuloplastia usando un injerto cutáneo; iii) construcción técnica y fabricación de la supraestructura y la dentadura; iv) reconstrucción del maxilar usando el peroné como colgajo libre vascularizado. Las reconstrucciones con los colgajos de peroné tuivieron éxito y los 18 implantes ITI que se habian insertado mostraron una buena osteointegración sin perdida de inserción en los 4 pacientes después de un periodo medio de observación de 12 meses.
