Significance of endothelial progenitor cells (EPC) for tumorigenesis of head and neck squamous cell carcinoma (HNSCC): possible marker of tumor progression and neovascularization?

OBJECTIVES: Angiogenesis and neovascularisation plays a crucial role for tumorigenesis and tumor progression in head and neck squamous cell carcinoma (HNSCC). The aim of our study was to investigate the neovascularization capacity by endothelial progenitor cells (EPC) in tumor patient as a possible predictor for tumor progression and tumor stage. MATERIALS AND METHODS: Therefore, we investigated the cell number and biologic activity by cell migration and colony-forming ability of EPC. Cells were isolated from the peripheral venous blood of 79 patients who suffer HNSCC in different stages of disease. Thirty-three healthy individuals served as the control group. RESULTS: Significantly increased biological activities were reflected by expression of the migration rate (1027 ± 1510) in comparison to the control group (632 ± 269) and the clonal potency measured by colony-forming unit (CFU) (tumor patients (19.7 ± 12.3) vs. control group (10.84 ± 4.8)). To determine whether or not EPC number can be used as a valid prognostic marker for clinical outcome of tumor patients, we furthermore compared a "high EPC-number-subgroup" (HI) with a "low EPC-number-subgroup" (LO) in a Kaplan-Meier survival curve. The HI-subgroup shows herein clearly a worse outcome. CONCLUSIONS: Our findings indicate a possible pathway for EPC to play a critical role in the vasculogenesis and consequently in the progression of HNSCC. CLINICAL RELEVANCE: Our findings could serve as possible predictors for the neovascularisation potential in HNSCC tumor patients.

Ink-jet printout of radiographs on transparent film and glossy paper versus monitor display: an ROC analysis.

The aim of this study was to compare the depiction ability of small grayscale contrasts in ink-jet printouts of digital radiographs on different print media with CRT monitor. A CCD-based digital cephalometric image of a stepless aluminum wedge containing 50 bur holes of different depth was cut into 100 isometric images. Each image was printed on glossy paper and on transparent film by means of a high-resolution desktop inkjet printer at specific settings. The printed images were viewed under standardized conditions, and the perceptibility of the bur holes was evaluated and compared to the perceptibility on a 17-in CRT monitor. Thirty observers stated their blinded decision on a five-point confidence scale. Areas (Az) under receiver operating characteristics curves were calculated and compared using the pair wise sign tests. Overall agreement was estimated using Cohen's kappa device and observer bias using McNemar's test. Glossy paper prints and monitor display revealed significantly higher (P < 0.001) average Az values (0.83) compared to prints on transparent film (0.79), which was caused by higher sensitivity. Specificity was similar for all modalities. The sensitivity was dependent on the mean gray scale values for the transparent film.

Unifocal Langerhans cell histiocytosis of the oral mucosa.

A 24-year-old man was admitted for a painful gingival ulcer. Histology and immunohistochemistry of a lesional biopsy revealed the diagnosis of Langerhans cell histiocytosis (LCH). To rule out multifocal disease, a complete staging was performed. There was no evidence of bony lesions or any other organ involvement. The diagnosis of LCH restricted to the oral mucosa was established. The complete oral lesion was ablated by CO(2) laser and subsequently treated topically with triamcinolone acetonide. The patient is still in remission after one year of follow-up. LCH confined to the oral mucosa is rare. It presents usually as an inflammatory or ulcerative lesion, easily leading to misinterpretation and delayed diagnosis. Patients with limited unifocal mucocutaneous disease, as in the present case, usually have an excellent prognosis. However, the oral lesion may represent an early sign of LCH, predating and progressing to an aggressive life-threatening multiorgan disease.

Fully Digitally Guided Implant Surgery Based on Magnetic Resonance Imaging.

PURPOSE: The purpose of this study was to evaluate whether fully digitally guided implant surgery may be performed with sufficient accuracy based on printing virtually designed templates after matching a surface scan with the magnetic resonance imaging (MRI) dataset mimicking edentulous cases based on cadaver maxillae of pigs. MATERIALS AND METHODS: The palatal mucosa of five young pig cadavers was scanned with an intraoral scanner. High-resolution MRI of the jaws was performed, and the images were exported as DICOM files and uploaded into software for implant planning. Six implant osteotomies were virtually planned in each jaw. The intraoral surface scans were fused with the volumetric MRI data based on the palatal soft tissue, and virtual templates for guided implant surgery were created and exported as STL files. These were printed and the templates were used to perform flapless guided osteotomy, with the templates fitting on the soft tissue of the jaws alone. Cone beam computed tomography (CBCT) of the jaws was performed after osteotomy. These data were fused with the virtually planned osteotomies, and the 3D crestal, apical, and axial deviations between the virtually planned and physically performed osteotomies were determined. RESULTS: Matching the surface scans with the mucosa was possible in three cases automatically; additional manual corrections were necessary in two cases. Thirty osteotomies were performed by applying the printed mucosa-supported templates. The mean angular deviation between the planned and realized cavities was 3.29 degrees (0.3 to 11.1 degrees; SD = 2.5 degrees), the mean 3D apical deviation was 1.3 mm (0.22 to 3.98 mm; SD = 0.94 mm), and the mean crestal deviation was 1.76 mm (0.39 to 3.79 mm; SD = 0.88 mm). CONCLUSION: MRI in combination with the presented workflow may be used in edentulous cases for guided implant surgery. Further studies are needed to prove the promising accuracy of this alternative approach in clinical trials.

Surface-induced modulation of human mesenchymal progenitor cells. An in vitro model for early implant integration.

Clinical experience indicates that the surface architecture of dental implants has an important impact on their integration. This has been related to the finding that differentially treated substrates can modulate the expression of osteogenic markers in various bone-related cell lines and primary cells. Here, we investigated the influence of surface architecture on the differentiation of human mesenchymal progenitor cells (HMPC) from adult bone marrow, i. e. the cells likely involved in initial bone synthesis at the bone-implant interface. Cells were seeded on machine surfaced (MS) or sandblasted/acid etched (SE) titanium discs in agarose-coated dishes, and on polystyrene (PS) controls. On all substrates cell densities did not change between days 7 and 14. Cell numbers were higher on SE, likely due to increased attachment to the rougher material. Alkaline phosphatase activity (ALP) was similar on all substrates, whereas mRNA expression of bone sialoprotein (BSP) at day 14 was about tenfold higher on SE (p < 0.05%). The SE-related increase of BSP in progenitor cells indicates an earlier differentiation of immigrated cells and could thus explain earlier implant integration and shorter time to functional loading observed in the clinic. The in vitro model and BSP quantification could be used to screen for changes in osteogenic cell differentiation induced by specific implant surfaces, with potential relevance on the prediction of bone-implant integration.

[Late results of immediately loaded interforaminal implants]. / Spätergebnisse sofortbelasteter interforaminaler Implantate.

The aim of this retrospective study was to evaluate the late results of immediately loaded implants in the interforaminal area of edentulous mandibles treated with implant-supported overdentures. the study initially included 44 patients who received a total of 176 ITI implants (4 interforaminal implants per patient) of which 233 patients with 89 implants were controlled (drop out of 21 patients). Immediately after the operation a bar was fixed to the implants and loaded with a retained overdenture. The patients were followed from a minimum of 8 to a maximum of 18 years (average of 12.2 years). Three implants were lost. Five implants didn't pass the criteria of success. The results of this study show that the success rate of immediately loaded implants in the interforaminal region is similar to secondarily loaded implants. According to these data, the often demanded healing phase of four months is not necessary.

A prospective noninterventional study to document implant success and survival of the Straumann Bone Level SLActive dental implant in daily dental practice.

OBJECTIVES: Clinical studies to assess dental implants are common in implantology, but such studies are usually performed for specific indications and following a specific protocol with strict inclusion and exclusion criteria. The aim of the current study was to evaluate the Straumann Bone Level SLActive dental implant in a prospective, multicenter, noninterventional trial. METHOD AND MATERIALS: The implant could be used in whatever manner was deemed suitable by the clinician, within approved indications. No particular placement or loading protocol was specified. A total of 1,532 implants were placed in 852 patients in 123 centers in nine countries in the US and Europe. After exclusion of three countries due to patient enrollment and data issues, 759 patients with 1,355 implants were analyzed. RESULTS: Most patients received one or two implants (58.6% and 25.3% of patients, respectively), and 90% of cases were performed with a raised flap. A submerged healing protocol was significantly more prevalent in European centers, while transmucosal healing was significantly more prevalent in North American centers. After 1 year, 538 patients with 908 implants were available for evaluation. The cumulative implant survival and success rates were 98.5% and 96.0%, respectively. CONCLUSIONS: This prospective noninterventional study evaluated the use of Straumann Bone Level SLActive dental implants in a large number of patients. The cumulative survival and success rates were similar to those observed in controlled clinical trials, confirming this dental implant's clinical applicability in daily practice.

International Task Force on Volunteer Cleft Missions.

The International Task Force on Volunteer Cleft Missions was set up to provide a report to be presented at the Eighth International Congress of Cleft Palate and Associated Craniofacial Anomalies on September 12, 1997, in Singapore. The aim of the report was to provide data from a wide range of different international teams performing volunteer cleft missions and, thereafter, based on the collected data, to identify common goals and aims of such missions. Thirteen different groups actively participating in volunteer cleft missions worldwide were selected from the International Confederation of Plastic and Reconstructive Surgery's list of teams actively participating in volunteer cleft missions. Because of the time frame within which the committee had to work, three groups that did not respond by the stipulated deadline were omitted from the committee. The represented members and their respective institutions have undertaken more than 50 volunteer cleft missions to underdeveloped nations worldwide within the last 3 years. They have visited over 20 different countries, treating more than 3,500 patients worldwide. Based on the data collected and by consensus, the committee outlined recommendations for future volunteer cleft missions based on 1) mission objectives, 2) organization, 3) personal health and liability, 4) funding, 5) trainees in volunteer cleft missions, and 6) public relations. The task force believed that all volunteer cleft missions should have well-defined objectives, preferably with long-term plans. The task force also decided that it was impossible to achieve a successful mission without good organization and close coordination. All efforts should be made, and care taken, to ensure that there is minimal morbidity and no mortality. Finally, as ambassadors of goodwill and humanitarian aid, the participants must make every effort to understand and respect local customs and protocol. The main aims are to provide top-quality surgical service, train local doctors and staff, develop and nurture fledgling cleft programs, and, finally, make new friends.