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Background and objectives:The interaction of mesenchymal stromal cells (MSC) and endothelial cells (EC) hold a promising perspective for the revascularization of osteoconductive bone grafts in defect regeneration. Co-culture methods of MSC and ES are used to facilitate in vivo bone modeling. However, cell–cell interactions and cell-matrix integrations are not yet fully understood. Following the hypothesis that MSC and EC interactions can lead to an optimized revascularization of osteoconductive bone grafts we analyzed the interactions of MSC and EC in trans-well as well as direct co-culture in vitro. In addition we evaluated the integration and differentiation of MSC and EC co-cultures on osteoconductive bone grafts. Methods: MSC and EC were labeled with fluorescent particles and seeded in monolayer and trans-well cultures. In addition MSC and EC co-cultures were established on two different osteoconductive bone grafts of different porosity and their differentiation analyzed using QT-PCR analysis for osteocalcin, vWf, VEGF as well as immunofluorecent labeling of CD31 and osteoprotegerin. Matrix integration was evaluated using 3D-imaging. Results: Results indicated an endothelial and osteogenic interaction of MSC and EC leading to interdependent osteogenic and angiogenic differentiation in co-cultures in comparison to trans-well and singular cultures. 3D-imaging revealed an evenly distributed MSC and EC differentiation and integration in osteoconductive bone grafts of different porosity. Conclusion: MSC and EC co-cultures can be used to create an osteoand angio-inductive bone graft in vitro. Thus prevascularized, osteogenic cell-matrix-structures offer a promising stepping stone for future in vivo defect regeneration.

The aim of the present retrospective study was to determine the long-term quality of life of patients who had undergone intraoral tumour resection. 135 patients with a malignant tumour located in the floor of the mouth and the adjacent area were enrolled in the study. A standard questionnaire was used to determine the physical functional status, the psychological status and social functioning of cancer patients (Schipper et al., 1984). The results were related to the T-stage, the size and the location of the intraoral soft tissue defect, the mode of reconstruction and the postoperative interval. The results showed a significant correlation of the Functional Living Index-Cancer (FLIC) score with the Karnowsky-Index. The values were significantly lower in the higher T-stages. The location of the soft tissue defect, the type of soft tissue reconstruction and discontinuity resections of the mandible were crucial for postoperative quality of life, inasmuch as bilateral defects with loss of mandibular continuity and myocutaneous flap reconstructions showed significantly lower FLIC values. Reconstruction of mandibular continuity did not contribute to an increase in FLIC values. Dysphagia, reflux of food through the lips and nose during meals, decreased appetite and persistent pain significantly decreased the FLIC scores. It is concluded, that the FLIC is suitable for the determination of life quality in cancer patients since the score has shown the potential to reflect differences in postoperative life quality with regard to surgical procedures and functional sequelae.

Summary The aim of the present study was to analyse the results of various reconstruction techniques of the facial skin with regard to general parameters such as the patients' age and health condition and to surgical parameters such as defect size, contamination of surgical fields and the type of reconstruction. 273 cases were evaluated, comprising local flaps (217), island flaps (21), free skin grafts (22) and cutaneous or myocutaneous distant flaps (13). The overall rate of major complications was 13.5%. No correlation was found with the age or impaired health of the patients nor did contamination by oral/nasal bacterial flora or the type of restoration show any significant correlation. The size of the defect turned out to be the only variable significantly related to the occurrence of complications (p = 0.0108). The complication rate observed following the repair of defects smaller than 30 mm in diameter was 7.5% while it rated 19.1% following the repair of defects larger than 30 mm. The overall rate of partial or total flap necrosis was low (2.9%). Secondary corrections and further surgical re-entry were required in 4.7% of all patients.

Purpose: The aim of this study was to determine the blood flow and the cutaneous sensibility of flaps after the repair of tumor-related defects of the facial skin. Patients and Methods: Fifty restorations (27 local flaps, 6 island flaps, 7 free skin grafts, and 10 microvascular grafts) were examined using laser Doppler flowmetry, two-point discrimination, and a pain and thermal sensibility testing device. The average postoperative interval was 62 months. Measurements were performed on the flap surface, the donor site, and the contralateral areas corresponding to the donor site and the former defect. Paired t-tests were used to assess statistically significant differences between the sites of measurement. Results: Results showed a rate of both blood flow and two-point discrimination on the surface of local flaps and island flaps that was not statistically different from the corresponding area of the unoperated side. Free skin grafts exhibited incomplete restoration of thermal sensibility and increased blood flow rates compared with the donor site. Large microvascular flaps showed complete loss of cutaneous sensibility in six cases, whereas partial restitution without reproducible two-point discrimination was found in the remaining patients after an average interval of 39 months. Flowmetry rates of microvascular flaps corresponded to those of the donor site and were significantly lower than those of the recipient site in the head and neck area.

The objective of this pilot study was to study bone ingrowth into porous hydroxylapatite (HA) blocks using a polylactic membrane for guided tissue regeneration. Porous HA blocks were placed on both sides of the mandible and of the ilium in five Gottingen minipigs. On one side a polylactic membrane was used to cover the blocks. After 5 months, the blocks with the membrane covering showed complete bony penetration of the HA matrix both in the mandible and the ilium. The blocks without the membrane covering showed substantially less and irregular bone ingrowth after placement on the mandible and poor ingrowth after placement on the ilium. The newly formed bone in the blocks from the ilium showed a cancellous structure while bone tissue inside the blocks from the mandible exhibited a dense cortical appearance. The polylactic membrane was nearly completely degraded at the time of investigation.

The aim of this prospective study was to assess the impact of intraoral soft-tissue reconstruction on the development of quality of life after ablative surgery for oral cancer. A total of 107 patients were enrolled in the study during the period between 1997 and 1999. Quality of life was assessed by using the quality-of-life core questionnaire and the head and neck module of the European Organization for Research and Treatment of Cancer. The questionnaires were distributed to the patients preoperatively on the day of hospital admission and 3 months, 6 months, and 12 months postoperatively. A total of 53 patients filled in all questionnaires and were available for complete longitudinal analysis. The changes in the scores and the impact of defect size, location, and anatomy, the extent of mandibular resection, and the mode of soft-tissue reconstruction were tested longitudinally for statistical significance by using repeated-measures analysis of variance procedures. Of all parameters tested, the mode of soft-tissue reconstruction had the most profound impact on the development of quality of life after ablative surgery for oral cancer in that it was associated with statistically significant changes in the most domains or items associated with postoperative quality of life. In contrast to local flaps, revascularized soft-tissue repair with forearm flaps was associated with an intermittent deterioration of physical and functional scores but was followed by improvement until the end of the first year, and it even surpassed the preoperative baseline level in oral functional and social domains. In large-volume defects, which required repair by myocutaneous grafts, quality of life was not restored to the same extent, and physical, functional, and social domains remained significantly lower.

Dental implant materials serve a variety of purposes. The majority of them are used as intraosseous appliances in the jaw bones for permanent anchorage of tissue integrated prostheses. Successful clinical use of these materials is based on the integration into the adjacent bone tissue. Compromised bone conditions and periimplant bone defects can impair this interaction and require enhancement of osteogenesis to accomplish the desired level of bone implant contact. Established techniques use modifications of surface morphology and inorganic surface chemistry. Advanced strategies focus on the anchorage of bone matrix components to the material surface and on the delivery of osteogenic signaling molecules to enhance periimplant bone regeneration. Biologically active components are immobilized through a variety of procedures such as adsorption, covalent coupling, electrochemical surface modifications and self organized organic layers on the implant surface.

Purpose: The aim of the current study was to review the use of free tissue transfer for reconstruction of the skull base and for coverage of intracranial contents. Patients and Methods: From 1990 until 1996, revascularized flaps were transferred to the skull and the skull base in 11 patients in whom intracranial/extracranial resection of tumors of the skull base was performed in cooperation with the Department of Neurosurgery. The defects resulted from removal of squamous cell carcinomas (n = 4), basal cell carcinomas (n = 4), malignant melanoma, malignant schwannoma, and malignant meningioma. Defect repair was accomplished by revascularized transfer of latissimus dorsi muscle flaps in seven cases and rectus abdominis flaps and forearm flaps in two cases each. In five patients with extensive intracranial tumor spread, reconstruction was performed for palliative reasons. Results: A safe soft tissue closure of the intracranial and intradural space was achieved in all patients, whereas the contour of the facial skull and the neurocranium was satisfactorily restored at the same time. By using the entire length of the grafted muscle, the vascular pedicle could be positioned next to the external carotid artery and conveniently connected to the cervical vessels. The mean survival time of the patients with palliative treatment was 8.4 months, with an average duration of hospital stay of 24.5 days. Conclusions: Despite the increased surgical effort of revascularized tissue transfer, microvascular reconstruction of large skull base defects appears to be justified, even as a palliative measure.

The aim of the present investigation was to determine the magnitude of surgically produced periodontal damage to third molars before transplantation. For this purpose, 30 impacted third molars were retrieved by a tissue-conserving surgical technique whereas 30 others were removed by a conventional technique. The surgically induced damage to the periodontal membrane showed a variable histological pattern. A significant reduction of the damage to desmodontal fibers and the cementum was achieved by using a special technique of removal.