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Vertical Dimension (vertical + dimension)
Selected AbstractsRestoration for a Bruxism Patient with Lost Vertical DimensionJOURNAL OF PROSTHODONTICS, Issue 3 2000Henry Y. Wu DDS [source] Body frame dimensions are related to obesity and fatness: Lean trunk size, skinfolds, and body mass indexAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2010Maciej Henneberg We explore relationships between BMI and skinfolds and anthropometric variables reflecting variation in lean body frame. Data on the middle class adult Australian women (n = 1260) collected in 2002 during a National Body Size and Shape Survey were used. Standard measurements of stature, weight, skeletal dimensions (shoulder width, hip width, chest width, and depth, limb lengths), circumferences of head, trunk, limbs and triceps, subscapular and abdominal skinfolds were taken. Techniques for measurements of skeletal frame minimized the inclusion of adipose tissue thickness. Analysis of variance and parametric and nonparametric correlations were used. Vertical dimensions show weak correlations with fatness, while body frame circumferences and transverse dimensions are consistently, significantly, and substantially correlated with fatness, each explaining from 3 to 44% of variation in skinfold thickness. Skeletal dimensions explain up to 50% of variation in skinfold thickness (multiple regression). Especially high correlations with skinfold thickness occur for chest width, depth, and hip width (r range from 0.42 to 0.66). Body frame dimensions reflect largely trunk volume and the trunk/limb proportions. Larger lean trunk size is associated with greater fatness. Since the size of the abdominal cavity, and thus the gastrointestinal system (GI), is reflected in the trunk size, we speculate that larger frame may predispose to obesity in two ways: (1) larger stomachs require greater bulk of food to produce feeling of satiety as mediated through antral distension, (2) larger GIs may absorb more nutrients. Frame size may help to detect the risk of obesity among young adults. Am. J. Hum. Biol. 2010. © 2009 Wiley-Liss, Inc. [source] An evaluation of the Periotest® method as a tool for monitoring tooth mobility in dental traumatologyDENTAL TRAUMATOLOGY, Issue 2 2010Christine Berthold The aims of this study were to determine normal Periotest® values in the vertical and horizontal dimensions of periodontally healthy teeth in individuals aged 20,35 years and investigate the reliability of Periotest® in terms of intra-series and inter-series reproducibility before and after applying a dental trauma splint in vivo. Materials and methods:, Periotest® values were measured in periodontally healthy dental students (n = 33; mean age 24.7 years) at reproducible measuring points in the vertical and horizontal dimensions, before and after splint insertion. Three readings were taken per series to observe the intra-series reproducibility; three series were measured to test inter-series reproducibility (Friedman-test; P , 0.001). Two different wire-composite splints, 0.45 mm Dentaflex and 0.8 × 1.8 Strengtheners, were inserted and the Periotest® values were measured. Results:, The median Periotest® values before splinting were: canines -2.5, lateral incisors -0.9, and central incisors 0.0 for the vertical dimension, and canines 1.1, lateral incisors 3.2, and central incisors 3.6 for the horizontal dimension. The intra-series and inter-series Periotest® values were highly reproducible. Conclusion:, The Periotest® method provides highly reproducible results. Focused on dental trauma, the method can be applied diagnostically during the splint and follow-up period and for evaluating splint rigidity. [source] Cast titanium overlay denture for a geriatric patient with a reduced vertical dimensionGERODONTOLOGY, Issue 4 2005Satyabodh Guttal An older patient reporting to the dental surgery for his/her dental treatment is becoming a common occurrence. Improved oral hygiene has meant that teeth are retained for a longer time, along with the potential problems of attrition, decreased vertical dimension, temporomandibular joint discomfort/strain, and poor aesthetics. The case in question is that of a 65-year-old male patient who had severe attrition in the lower arch, temporomandibular joint pain and reduced vertical dimension. The maxillary arch had previously been restored with a fixed partial prosthesis. For restoration of the lower teeth, a removable cast titanium overlay denture was fabricated incorporating an increased vertical dimension. Porcelain facings were placed to restore the aesthetics of the anterior teeth. The titanium was cast in a semi-automatic electric arc, pressure type casting machine. A titanium overlay denture with porcelain facing on the anterior teeth may provide a means of restoring a patient's concerns regarding aesthetics and function. [source] Serving God's Mission Together in Christ's Way: Reflections on the Way to Edinburgh 2010INTERNATIONAL REVIEW OF MISSION, Issue 1 2010Jacques Matthey This paper argues that missio Dei theology must continue to provide the basis for an ecumenical missiology, provided certain problems are revisited, in line with themes of the 2010 Edinburgh study process. Among them is the need for emphasizing the vertical dimension of a transformative spirituality, somehow neglected in earlier ecumenical theologies. Only this will prevent an over-estimation of humanity's capacities. Within a missio Dei theology the specific role of the church is to be reaffirmed: there is no way back behind integration, which remains a cornerstone of an ecumenical approach, provided it keeps a critical distance to dogmatic ecclesiologies that tend to hinder progress towards visible unity. The debate on gospel and culture has to be urgently taken up again, through a positive appreciation of syncretism and the related search for criteria in intercultural hermeneutics. This will lead to articulating pneumatological approaches to mission with Christologies. Indeed, the New Testament texts with the most universal horizon refer to Christ as Word or Wisdom and not to the Holy Spirit. The paper moves on to ask whether then the relevance of the biblical wisdom tradition should not feature more in missiology. It could provide fertile approaches to witness in a religiously plural and ecologically damaged world. Ecumenical mission should in future be shaped by wisdom as much as it has been by prophecy, and keep both traditions in creative tension. [source] Partial least squares path modelling for relations between baseline factors and treatment outcomes in periodontal regenerationJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2009Yu-Kang Tu Abstract Background: Some clinical outcome variables in periodontal research are mathematically coupled, and it is not feasible to include all the mathematically coupled variables in an ordinary least squares (OLS) regression analysis. The simplest solution to this problem is to drop at least one of the mathematically coupled variables. However, this solution is not satisfactory when the mathematically coupled variables have distinctive clinical implications. Material and Methods: Partial least squares (PLS) methods were used to analyse data from a study on guided tissue regeneration. Relationships between characteristics of baseline lesions and treatment outcomes after 1 year were analysed using PLS, and the results were compared with those from OLS regression. Results: PLS analysis suggested that there were multiple dimensions in the characteristics of baseline lesion: vertical dimension was positively associated with probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain, whilst horizontal dimension was negatively associated with the outcome. Baseline gingival recession had a negative association with PPD reduction but a small positive one with CAL gain. Conclusion: PLS analysis provides new insights into the relationships between baseline characteristics of infrabony defects and periodontal treatment outcomes. The hypothesis of multiple dimensions in baseline lesions needs to be validated by further analysis of different datasets. [source] Influence of occlusal vertical dimension on the masticatory performance during chewing with maxillary splintsJOURNAL OF ORAL REHABILITATION, Issue 8 2007L. W. OLTHOFF summary, Changing the occlusal vertical dimension is a common procedure in restorative dentistry, during treatment of patients with cranio-mandibular disorders, and during orthodontic and orthognathic treatment. The treatment may alter the length of the main jaw elevator muscles and the position of the mandibular head in the fossa temporalis. These changes may influence the bite forces that are generated during chewing and thus may affect the masticatory function. We measured the objective masticatory function, defined as masticatory performance, by determining an individual's capacity to pulverize a test food. The immediate influence of the increase in the occlusal vertical dimension on the masticatory performance was determined using three anatomical maxillary splints in a group of seven dentate subjects. The splints gave an increase in the occlusal vertical dimension of 2, 4 and 6 mm, respectively. Before we started the experiments the subjects practiced chewing with the splints during about 5 min. No significant differences were observed in masticatory performance among the conditions without and with the three splints. Thus, an increase in the occlusal vertical dimension up to 6 mm did not have a significant effect on the masticatory performance. Maxillary splints may be used to study the effect of occlusal factors on the chewing process by manipulating tooth shape and occlusal area of the splint. [source] Short-term effects of a mandibular advancement device on obstructive sleep apnoea: an open-label pilot trialJOURNAL OF ORAL REHABILITATION, Issue 8 2005G. AARAB summary, Obstructive sleep apnoea (OSA) is a common sleep disorder, which is, among others, associated with snoring. OSA has a considerable impact on a patient's general health and daily life. Nasal continuous positive airway pressure (nCPAP) is frequently used as a ,gold standard' treatment for OSA. As an alternative, especially for mild/moderate cases, mandibular advancement devices (MADs) are prescribed increasingly. Their efficacy and effectiveness seem to be acceptable. Although some randomized clinical trials (RCTs) have been published recently, most studies so far are case studies. Therefore, our department is planning a controlled RCT, in which MADs are compared with both nCPAP and a control condition in a parallel design. As a first step, an adjustable MAD was developed with a small, more or less constant vertical dimension at different mandibular positions. To test the device and the experimental procedures, a pilot trial was performed with 10 OSA patients (six mild, four moderate; one women, nine men; mean age = 47·9 ± 9·7 years). They all underwent a polysomnographic recording before as well as 2,14 weeks after insertion of the MAD (adjusted at 50% of the maximal protrusion). The apnoea,hypopnoea index (AHI) was significantly reduced with the MAD in situ (P = 0·017). When analysed as separate groups, the moderate cases showed a significantly larger decrease in AHI than the mild cases (P = 0·012). It was therefore concluded from this pilot study that this MAD might be an effective tool in the treatment of, especially, moderate OSA. [source] Association between condylar position, joint morphology and craniofacial morphology in orthodontic patients without temporomandibular joint disordersJOURNAL OF ORAL REHABILITATION, Issue 11 2003K. Kikuchi summary, The present study investigated condylar position and joint morphology in adolescent patients and elucidated the possible association between the joint structure and condylar position, and craniofacial morphology. Sixty-five adolescent patients were selected as subjects and their tomograms and lateral cephalograms were analysed. No significant differences in joint spaces were found between the right and left temporomandibular joints. Both the condyles in this population were located slight anteriorly in the glenoid fossa. With respect to the association between condylar position, joint morphology and craniofacial morphology, the ramus plane angle also exhibited significant negative correlations with posterior, lateral and medial joint spaces. Furthermore, there was a significant negative correlation between the gonial angle and the anterior joint space. These findings imply that the condyle was likely to show more posterior position in the glenoid fossa when the mandible exhibited clockwise rotation. In conclusion, the condyle in the adolescent subjects showed a symmetrical anterior position relative to the glenoid fossa. In addition, the joint spaces and it ratios were significantly related to the craniofacial morphology associated with vertical dimension. It is suggested that the condylar position may be affected by craniofacial growth pattern. [source] Influence of the thickness of the resin palatal vault on the closest speaking space with complete denturesJOURNAL OF ORAL REHABILITATION, Issue 10 2001G. Schierano The closest speaking space (CSS) has been considered stable over time, and therefore useful to determine the vertical dimension of occlusion (VDO) in edentulous patients. Clemençon affirms that, in complete denture wearers, CSS is not constant but depends on the thickness of the resin palatal vault, and that is the air volume needed to pronounce words to remain constant. The aim of this study was to evaluate Clemençon hypothesis in a group of edentulous patients rehabilitated with traditional maxillary denture and mandibular implant anchored overdenture. The CSS was determined by means of a kinematics method using the Elite System® at 30, 60, 90, 180, 360 days from delivery. The CSS was assessed twice at each stage: with the unmodified denture and a second time after thickening the resin palatal vault by 2 mm with a calibrated wax layer. The CSS after thickening the resin palatal vault was wider. The wider CSS observed can be because of oro-sensory feedback excited by contact between tongue and palatal vault. As hypothesized by Clemençon thickening the resin palatal vault could be a useful procedure to increase the VDO, in cases in which it is too low from the aesthetic stand point. [source] Finite element analysis on preferable I-bar clasp shapeJOURNAL OF ORAL REHABILITATION, Issue 5 2001Y. Sato An I-bar clasp is one of the most popular direct retainers for distal-extension removable partial dentures. However, no adequate information is available on preferable shape as determined by biomechanics. This study aimed (1) to investigate, by finite element analysis (FEA), the dimensions and stress of I-bar clasps having the same stiffness, and (2) to estimate a mechanically preferable clasp design. Three-dimensional FEA models of I-bar clasps were created with vertical and horizontal straight sections connected by a curved section characterized by six parameters: thickness of the clasp tip, width of the clasp tip, radius of the curvature, horizontal distance between the base and the vertical axis, vertical dimension between the tip and the horizontal axis, and taper (change of width per unit length along the axis). Stress was calculated with a concentrated load of 5 N applied 2 mm from the tip of the clasp in the buccal direction. A thinner and wider clasp having an taper of 0·020,0·023 and radius of curvature of 2·75,3·00 showed less stress. The results suggest that such a shape might be the preferable I-bar clasp shape as biomechanical viewpoint. [source] An Easy Technique to Obtain Articulated Casts Using the Palate for the Interocclusal RecordJOURNAL OF PROSTHODONTICS, Issue 3 2010DScD, Dalton Matos Rodrigues CD Abstract This article describes a highly efficient technique to obtain articulated casts. Interocclusal recording is carried out using the palate as an area of registration without having to remove or section provisional prostheses while also maintaining the established vertical dimension. [source] Improved laboratory results for fixed restorations using sequential tooth preparationJOURNAL OF PROSTHODONTICS, Issue 1 2000David W. Eggleston DDS Laboratory reference guides provided by the dentist help ensure optimum results in fixed prosthodontics. A technique is described in which a master cast is made before preparation of the last tooth to be treated. Through this technique, the laboratory prescription includes the dimensions of the new restorations in relation to those of the unprepared tooth replica on the master cast. Thus, the technician is afforded not only a precise guide to restoration contour and size, but also a helpful pretreatment record of the patient's vertical dimension. [source] Discrimination of extant Pan species and subspecies using the enamel,dentine junction morphology of lower molarsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009Matthew M. Skinner Abstract Previous research has demonstrated that species and subspecies of extant chimpanzees and bonobos can be distinguished on the basis of the shape of their molar crowns. Thus, there is potential for fossil taxa, particularly fossil hominins, to be distinguished at similar taxonomic levels using molar crown morphology. Unfortunately, due to occlusal attrition, the original crown morphology is often absent in fossil teeth, and this has limited the amount of shape information used to discriminate hominin molars. The enamel,dentine junction (EDJ) of molar teeth preserves considerable shape information, particularly in regard to the original shape of the crown, and remains present through the early stages of attrition. In this study, we investigate whether the shape of the EDJ of lower first and second molars can distinguish species and subspecies of extant Pan. Micro-computed tomography was employed to non-destructively image the EDJ, and geometric morphometric analytical methods were used to compare EDJ shape among samples of Pan paniscus (N = 17), Pan troglodytes troglodytes (N = 13), and Pan troglodytes verus (N = 18). Discriminant analysis indicates that EDJ morphology distinguishes among extant Pan species and subspecies with a high degree of reliability. The morphological differences in EDJ shape among the taxa are subtle and relate to the relative height and position of the dentine horns, the height of the dentine crown, and the shape of the crown base, but their existence supports the inclusion of EDJ shape (particularly those aspects of shape in the vertical dimension) in the systematic analysis of fossil hominin lower molars. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Effect of GBR in combination with deproteinized bovine bone mineral and/or enamel matrix proteins on the healing of critical-size defectsCLINICAL ORAL IMPLANTS RESEARCH, Issue 1 2004Nikolaos Donos Abstract Objectives: To evaluate the effect of guided bone regeneration (GBR) in combination with or without deproteinized bovine bone mineral (DBBM) and/or an enamel matrix derivative (EMD) on the healing of critical-size calvarial defects. Material and methods: Forty rats were used. In all animals, a standardized critical-size calvarial defect was created surgically. The animals were randomly allocated into 4 groups of 10 animals each. Group A: One calvarial defect was left untreated, while the galeal and the cerebral aspect of the contralateral defect were covered with a bioresorbable membrane (GBR). Group B: One calvarial defect was filled with EMD, while the contralateral defect was treated with GBR and EMD. Group C: One defect was filled with DBBM, while the contralateral defect was treated with combination of GBR and DBBM. Group D: One defect was filled with DBBM combined with EMD, while the contralateral defect was treated with combination of GBR, DBBM and EMD. The healing period was 4 months. Five specimens from each group were macerated and the length, the width and the vertical dimension (thickness) of the remaining defect were evaluated by a stereomicroscope. The remaining specimens in each group were analyzed histologically. Results: The defects of the macerated specimens that were left untreated or were treated only by EMD, DBBM and combination of EMD and DBBM did not present predictably complete healing of the defects. All the defects where GBR was applied alone or combined with DBBM and/or EMD presented always complete healing (P<0.05). The combined use of GBR with EMD and/or DBBM did not offer any significant advantage above GBR alone in terms of healing of the length and the width of the defect. However, the vertical dimension of the defect was significantly higher (P<0.05) in the GBR-treated specimens of Groups C and D. The histological analysis supported these findings. Conclusion: The predictability of bone formation in critical-size defects depends mainly on the presence or absence of barrier membranes (GBR). The combined use with deproteinized bovine bone mineral and/or enamel matrix proteins did not significantly enhance the potential for complete healing provided by the GBR procedure. Résumé Le but de cette étude a été d'évaluer l'effet de l'association de la ROG avec ou sans minéral osseux bovin déprotéiné (DBBM) et/ou un dérivé de la matrice amélaire (EMD) sur la guérison de lésions crâniennes. Cette étude a eu recours à quarante rats. Chez tous les animaux, une lésion crânienne standardisée de grandeur critique a été créée chirurgicalement. Les animaux ont été répartis au hasard en quatre groupes de dix. Groupe A : une lésion crânienne fût laissée sans traitement, tandis que les deux côtés de la lésion latérale étaient recouvertes par une membrane biorésorbable (ROG), groupe B : une lésion crânienne remplie avec EMD tandis que la lésion contralatérale était traitée avec GBR et EMD, groupe C : une lésion remplie avec DBBM et la lésion contralatérale traitée par GBR et DBBM, Groupe D : une lésion remplie avec DBBM combinée avec EMD tandis que la lésion contralatérale a été traitée par une combinaison de ROG, DBBM et EMD. La période de guérison était de quatre mois. Cinq spécimens de chaque groupe ont été macérés et la longueur, la largeur et l'épaisseur de la lésion restante ont étéévaluées au stéréomicroscope. Les autres spécimens de chaque groupe ont été analysés histologiquement. Les lésions des spécimens macérés laissées sans traitement ou qui avaient été traitées seulement par EMD, DBBM et une combinaison de EMD et DBBM ne produisaient pas de manière prévisible une guérison complète des lésions. Toutes les lésions où la ROG était appliquée seule ou en association avec DBBM et /ou EMD présentaient toujours une guérison complète (p<0,05). L'utilisation conjointe de la ROG avec EMD et/ou DBBM n'offrait aucun avantage significatif sur la ROG seule en termes de guérison de la longueur et de la largeur de la lésion. Cependant la dimension verticale était significativement plus importante (p<0,05) dans les spécimens traités ROG des groupes C et D. L'analyse histologique a étayé ces découvertes. La prévision d'une formation osseuse dans les lésions de taille critique dépend essentiellement de la présence ou de l'absence de membranes barrières (ROG). L'utilisation combinée du minéral osseux bovin déprotéiné et /ou des protéínes de la matrice amélaire n'augmentait pas de manière significative le potentiel d'une guérison complète apportée par le processus ROG. Zusammenfassung Ziele: Die Untersuchung des Effekts der GBR in Kombination mit oder ohne deproteiniertem bovinem Knochenmineral (DBBM) und/oder einem Schmelzmatrix Derivat (EMD) auf die Heilung von Defekten mit kritischer Grösse. Material & Methoden: Es wurden 40 Ratten verwendet. Bei allen Tieren wurde auf der Calvaria chirurgisch ein standardisierter Defekt mit einer kritischen Grösse kreiert. Die Ratten wurden zufällig in 4 Gruppen mit je 10 Tieren aufgeteilt. Gruppe A: Ein Calvariadefekt wurde unbehandelt belassen, während der kontralaterale Defekt sowohl auf der cerebralen als auch auf der galealen Seite mit einer bioresorbierbaren Membran abgedeckt wurde (GBR). Gruppe B: Ein Calvariadefekt wurde mit EMD gefüllt, während der kontralaterale Defekt mit GBR und EMD behandelt wurde. Gruppe C: Ein Defekt wurde mit DBBM gefüllt, während der kontralaterale Defekt mit einer Kombination von GBR und DBBM behandelt wurde. Gruppe D: Ein Defekt wurde mit einer Kombination aus DBBM und EMD gefüllt, während der kontralaterale Defekt mit einer Kombination von GBR, DBBM und EMD behandelt wurde. Die Heilungszeit betrug 4 Monate. Fünf Präparate von jeder Gruppe wurden mazeriert und es wurden die Länge, die Breite und vertikale Dimension (Dicke) des verbleibenden Defekts unter dem Stereomikroskop ausgewertet. Die übrigen Präparate jeder Gruppe wurden histologisch analysiert. Resultate: Die Defekte der mazerierten Präparate, welche unbehandelt belassen oder nur mit EMD,DBBM und einer Kombination von EMD und DBBM behandelt worden waren, zeigten keine voraussagbare komplette Heilung der Defekte. Alle Defekte, bei denen GBR allein oder in Kombination mit DBBM und/oder EMD appliziert worden war, zeigten immer eine komplette Heilung (P>0.05). Die Kombination von GBR mit EMD und/oder DBBM bot gegenüber der GBR allein keine signifikanten Vorteile bezüglich Ausheilung der Länge und Breite der Defekte. Jedoch war die vertikale Dimension der Defekte bei den GBR behandelten Präparaten der Gruppen C und D signifikant grösser (P>0.05). Die histologische Analyse unterstützte diese Befunde. Schlussfolgerung: Die Voraussagbarkeit der Knochenbildung in Defekten mit kritischer Grösse hängt hauptsächlich von der Präsenz oder Absenz von Barrieremembranen (GBR) ab. Die kombinierte Verwendung von deproteiniertem bovinem Knochenmineral und/oder Schmelzmatrix Proteinen verbesserte das Potential für eine komplette Defektausheilung durch das GBR Verfahren nicht signifikant. Resumen Objetivos: Evaluar el efecto de GBR en combinación con o sin mineral óseo bovino desproteinizado (DBBM) y/o derivado de la matriz del esmalte (EMD) en la cicatrización de defectos de tamaño crítico en el calvario. Material y Métodos: Se usaron cuarenta ratas. En todos los animales se creó quirúrgicamente un defecto estándar de tamaño crítico en el calvario. Los animales se alojaron aleatoriamente en 4 grupos de 10 animales. Grupo A: Un defecto del calvario se dejó sin tratar, mientras que los aspectos galeales y cerebrales del defecto contralateral se cubrieron con una membrana biorreabsorbible (GBR). Grupo B: Un defecto del calvario se rellenó con EMD, mientras que el defecto contralateral se trató con GBR y EMD. Grupo C: Un defecto se rellenó con DBBM, mientras el defecto contralateral se trató con una combinación de GBR y DBBM. Grupo D: UN defecto se rellenó con DBBM combinado con EMD, mientras que el defecto contralateral se trató con una combinación de GBR, DBBM y EMD. El periodo de cicatrización fue de 4 meses. Cinco especímenes de cada grupo se maceraron, y se evaluó la longitud, la anchura y la dimensión vertical (grosor) del defecto remanente por estereomicroscopía. Los especímenes restantes de cada grupo se analizaron histológicamente. Resultados: Los defectos de los especímenes macerados que se dejaron sin tratar o se trataron solo con EMD, DBBM y una combinación de EMD y DBBM no presentaron una cicatrización completa predecible de los defectos. Todos los defectos en los que se aplicó GBR sola o combinada con DBBM y/o EMD siempre presentó cicatrización completa (p<0.05). El uso combinado de GBR con EMD y/o DBBM no ofreció ninguna ventaja significativa sobre GBR solo en términos de cicatrización de la longitud y la anchura del defecto. De todos modos, la dimensión vertical del defecto fue significativamente mayor (p<0.05) in los grupos tratados con GBR de los grupos C y D. Los análisis histológicos apoyaron estos hallazgos. Conclusión: La predictibilidad de la formación de hueso en defectos de tamaño crítico depende principalmente de la presencia o ausencia de membranas de barrera (GBR). El uso combinado con mineral óseo bovino desproteinizado y/o proteínas de la matriz del esmalte no realzaron significativamente el potencial para la cicatrización completa suministrado por el procedimiento de GBR. [source] Alveolar ridge preservation with guided bone regeneration and a synthetic bone substitute or a bovine-derived xenograft: a randomized, controlled clinical trialCLINICAL ORAL IMPLANTS RESEARCH, Issue 7 2010Nikos Mardas Abstract Objectives: The aim of this randomized, controlled clinical trial was to compare the potential of a synthetic bone substitute or a bovine-derived xenograft combined with a collagen membrane to preserve the alveolar ridge dimensions following tooth extraction. Methods: Twenty-seven patients were randomized into two treatment groups following single tooth extraction in the incisor, canine and premolar area. In the test group, the alveolar socket was grafted with Straumann Bone Ceramic® (SBC), while in the control group, Bio-Oss® deproteinized bovine bone mineral (DBBM) was applied. In both groups, a collagen barrier was used to cover the grafting material. Complete soft tissue coverage of the barriers was not achieved. After 8 months, during re-entry procedures and before implant placement, the horizontal and vertical dimensions of the residual ridge were re-evaluated and trephine biopsies were performed for histological analysis in all patients. Results: Twenty-six patients completed the study. The bucco-lingual dimension of the alveolar ridge decreased by 1.1±1 mm in the SBC group and by 2.1±1 in the DBBM group (P<0.05). Both materials preserved the mesio-distal bone height of the ridge. No differences in the width of buccal and palatal bone plate were observed between the two groups. The histological analysis showed new bone formation in the apical part of the biopsies, which, in some instances, was in direct contact with both SBC and DBBM particles. The coronal part of the biopsies was occupied by a dense fibrous connective tissue surrounding the SBC and DBBM particles. Conclusion: Both biomaterials partially preserved the width and the interproximal bone height of the alveolar ridge. To cite this article: Mardas N, Chadha V, Donos N. Alveolar ridge preservation with guided bone regeneration and a synthetic bone substitute or a bovine-derived xenograft: a randomized, controlled clinical trial. Clin. Oral Impl. Res. 21, 2010; 688,698. [source] Foreign direct investment and the dark side of decentralizationECONOMIC POLICY, Issue 49 2007Sebastian G. Kessing SUMMARY Fiscal decentralization VERTICAL, HORIZONTAL, AND FDI Both in the developed and developing world, decentralization of fiscal policy is frequently argued to foster investment, because allowing investors to choose between competing locations should make it difficult for each jurisdiction to tax the investment's returns. We point out that this ,horizontal' dimension of decentralization cannot eliminate ex post incentives to tax investments once they are irreversibly located in a jurisdiction, and that the negative ex ante investment effects of such ,hold up' problems are actually stronger when decentralization inevitably leads to multiple levels of taxation power in each location. Empirically, we detect significant negative effects on FDI of the ,vertical' dimension of decentralization, measured by the number of government layers, in a data set containing many countries and many suitable control variables. Indicators of overall fiscal decentralization do not appear to affect the investment climate negatively per se, but our theoretical arguments and empirical results suggest that policymakers should consider very carefully the form and degree of government decentralization if they aim at improving the investment climate. , Sebastian G. Kessing, Kai A. Konrad and Christos Kotsogiannis [source] | ||||||||||||||||