Activation of the complement system by some gram-positive oral bacteria.

Actinomyces viscosus 19246, T₁₄V and T₁₄AV, Streptococcus mutans and Streptococcus sanguis consumed complement in vitro. Complement (C) profile analysis revealed that C₄ and C_3–9 were consumed concomitantly in unadsorbed human serum. In serum from which naturally occurring agglutinating antibodies had been removed, the same microorganisms caused C_3–9 consumption in the absence of a demonstrable loss of C₄ activity. Congenitally C₄-deficient guinea-pig serum (C₄D) supported a similar consumption of C_3–9. The Gram-positive plaque microorganisms tested activated serum complement by the classical as well as the alternate pathways. Dental plaque microorganisms may cause a similar activation of gingival crevicular fluid complement in vivo, thus resulting in complement-mediated inflammatory processes.     

Results from a study of the normal values in the vertical, sagittal and transversal plane of early mixed dentitions]

168 (21.7%) of 776 pupils from primary classes in Jena had normal tooth position and occlusion. 94 of them were selected for a longitudinal study. Up to now, they have been examined at the ages of 7 and 8 years. The evaluation of the results obtained showed differences with regard to age and sex. The data reported and the deviations observed may be considered reference values. They concrete the assessment of the growth and development in the orofacial system, facilitate the recognition of dysgnathias which must be treated and optimize the planning and performance of orthodontic treatment.     

Eigene Erfahrungen bei der Behandlung mit Funktionsreglern Typ I nach Fränkel

Zusammenfassung Auf Grund eigener Erfahrungen wird festgestellt, daß die Behandlungsweise nach Fränkel erst seit Propagierung der skelettierten Funktionsregler mit Aussicht auf Erfolg anwendbar ist. Es wird über gute Erfahrungen bei der Versorgung von 43 Patienten berichtet, welche wegen eines Schmalkiefers mit frontalem Engstand, eines Schmalkiefers mit engstehender oder lückiger Protrusion oder wegen eines genuinen Distalbisses in Behandlung standen und teilweise noch stehen.Mit 12 Abbildungen     

Periodontal repair in dogs: effect of root surface treatment with stannous fluoride or citric acid on root resorption

This study evaluated healing, with emphasis on root resorption, following root surface treatment with 1% aqueous stannous fluoride (SnF2), saturated citric acid (CA), or saline control (C) in conjunction with periodontal flap surgery. Supraalveolar periodontal defects were surgically created and immediately treated in the mandibular premolars in 6 beagle dogs. The defect height approximated 5 to 6 mm from the reduced alveolar bone to the cemento-enamel junction. Root treatments were rotated between experimental teeth within jaw quadrants and duplicated in left and right quadrants in the dogs. Flaps were raised to cover most of the crowns of the teeth and sutured. The dogs were sacrificed 12 weeks after surgery and tissue blocks with teeth and adjacent structures were processed for histometric analysis. SnF2-treated teeth healed with significantly longer junctional epithelium, less connective tissue repair to the root surface, and less bone regeneration than CA and C-treated teeth. New cementum formation was limited in all treatment groups. Root resorption was observed in almost all teeth exhibiting connective tissue repair, however to a lesser amount and not as frequent in SnF2 treated teeth due to limited connective tissue repair. No differences were found in amount and frequency of root resorption in CA and C-treated teeth. An inhibitory effect on root resorption of SnF2 could not be disclosed in this experiment, however, it may be concluded that CA treatment of the root surface in conjunction with reconstructive periodontal flap surgery does not seem to enhance root resorption.     

Applicability of osseointegrated oral implants in the rehabilitation of partial edentulism: a prospective multicenter study on 558 fixtures

Nine clinical centers using the Br?nemark System participated in a prospective study of 159 partially edentulous patients between 18 and 70 years of age. Clinical parameters evaluated were plaque index, gingivitis, pocket depth, bleeding index, tooth mobility, and stomatognathic function. Initially, 558 fixtures were placed and 521 remained in the study following prosthesis placement (199 prostheses in 154 patients). Fixtures were lost or unaccounted for because of nonintegration prior to prosthesis fabrication (19), patient withdrawal (11), prosthodontic reasons (6), and failure during prosthetic procedures (1). Failure was primarily attributable to unfavorable bone quality, sex (more in males), and smaller fixture size. Complications and failure related to other patient characteristics are presented. After 1 year of a 5-year study, preliminary results suggest that a success rate equal to or better than that obtained with edentulous patients may be expected.     

Microstructural investigations of strain-related collagen mineralization

Distraction osteogenesis in rabbit mandibles after osteotomy can be used as an experimental model to study the microstructural features of mineralization of callus under defined mechanical loads. Our aim was to study the relation between the micromotions in the gap and the resulting features of mineralization of the matrix. We found that assembly of collagen and formation of crystals depended on the magnitude of the mechanical stress applied. At physiological bone strains (2000 microstrains), the callus had collagen type I in a mature bone-like extracellular arrangement, whereas at 20000 microstrains bundles were orientated predominantly towards the tension vector. Maximum loads (200000 microstrains) resulted in disorganized assembly of the collagen. Quantitative energy-dispersive analysis by X-rays confirmed that high strains were associated with substantially lower concentrations of calcium and phosphate. In contrast to bone-like apatitic formation of crystals at physiological strains, significantly fewer but larger crystals were detected by electron diffraction analysis in samples exposed to high strains. We suggest that mechanical stress regulates the assembly and mineralization of collagen during distraction osteogenesis.     

Behandlung von frontobasalen Traumen und Polytraumen

Background: This paper describes the historical development as well as current concepts of frontobasal fracture treatment by maxillofacial surgeons. Treatment concept: Based on the experience of many years a diagnostic and therapeutic treatment concept was developed, which proved to be adequate in 320 patients with 90 frontobasal fractures in the last five years.     

Recommendations for optimal distraction protocols for various animal models on the basis of a systematic review of the literature

The principles of orthopaedic distraction osteogenesis (DO) have been successfully applied to the craniofacial skeleton, but the latency time, rate and rhythm of distraction, and length of the consolidation period that are optimal for long-bone distraction may be suboptimal for craniofacial DO. The aim of this study was to provide recommendations for optimal distraction parameters in animal experimental research on craniofacial DO. The data used were from studies, added to the PubMed database between 1 January 1973 and 1 January 2007, on the outcome of DO resulting from variations in a single distraction parameter while standardizing the other distraction parameters. Although experimental animal group sizes were rather small, especially in those studies that used large animals, and both skeletally mature and immature animals were used, the (in most cases quantitative) data provided useful information on the optimal parameters in craniofacial DO. A latency period may not be necessary at all. Distraction should be performed at a rate of 1mm/day (this may be halved when small animals such as rats are used) preferably with a continuous rhythm, followed by a consolidation period of 6-8 weeks. These recommendations can be used as basic guidelines for further animal experimental studies on craniofacial DO.     

Properties of a new root-end filling material

The purposes of this investigation were 2-fold: to study the physical properties and sealing ability of Viscosity Enhanced Root Repair Material (VERRM); and, to compare them with Mineral Trioxide Aggregate (MTA). VERRM has a composition similar to mineral trioxide aggregate, with handling characteristics and consistency similar to commercially available materials such as IRM and Super EBA. The pH, setting times, solubility, radiopacity, dimensional change upon setting, and apical sealing ability of VERRM were evaluated and compared to that of ProRoot MTA (GMTA) and ProRoot MTA (Tooth Colored Formula) (WMTA). The results showed that VERRM had physical properties similar to WMTA. VERRM and WMTA showed significantly greater dye penetration than GMTA (p < 0.05) when used as a root-end filling material. There was no significant difference in depth of dye penetration between VERRM and WMTA. Further development of VERRM is indicated to produce a biocompatible root-end filling material with superior handling characteristics.     

Reconstruction of severely resorbed edentulous maxillae using osseointegrated fixtures in immediate autogenous bone grafts

A surgical technique for rehabilitation of severely resorbed edentulous maxillae using fixed prostheses or overdentures supported by osseointegrated fixtures in immediate autogenous corticocancellous bone grafts from the ilium is described. The results of the first 23 consecutively treated patients are reviewed. The mean observation time was 4.2 years (range 1 to 10 years). A total of 124 fixtures was originally placed into the grafts, supplemented with 16 fixtures inserted later into seven of the jaws. Throughout their observation period, 17 of the patients had continuously stable prostheses. The remaining five had overdentures, and one patient had resorted to a conventional complete denture. After 4 years, 12 of 16 patients had continuously stable prostheses. Corresponding values at 5 years were 7 of 8 patients. Calculated from the date of abutment connection, 82.1% and 81.6% of the original fixtures were clinically stable and radiographically osseointegrated after 4 and 5 years in function, respectively. From the date of fixture placement, the corresponding figures were 75.3% and 73.8%, respectively. The mean marginal bone loss after the first year of prosthesis function was 1.49 mm. The annual marginal bone loss thereafter was about 0.1 mm. The results indicate that this technique is worthwhile for patients with extreme maxillary atrophy and who cannot wear conventional complete dentures.