The present preclinical and clinical study assessed the inflammatory response to a high-temperature-treated xenogeneic material (Bego-Oss) and the effects of this material on the occurrence of multinucleated giant cells, implantation bed vascularization, and regenerative potential. After evaluation of the material characteristics via scanning electron microscopy, subcutaneous implantation in CD-1 mice was used to assess the inflammatory response to the material for up to 60 days. The clinical aspects of this study involved the use of human bone specimens 6 months after sinus augmentation. Established histologic and histomorphometric analysis methods were applied. After implantation, the material was well integrated into both species without any adverse reactions. Material-induced multinucleated giant cells were observed in both species and were associated with enhanced vascularization. These results revealed the high heat treatment led to an increase in the inflammatory tissue response to the biomaterial, and a combined increase in multinucleated giant cell formation. Further clarification of the differentiation of the multinucleated giant cells toward so-called osteoclast-like cells or foreign-body giant cells is needed to relate these cells to the physicochemical composition of the material.

BackgroundSquamous cell carcinoma mainly afflicts patients older than 40 years of age however, few cases are seen in younger patients. The aim of this study therefore was to determine the incidence of squamous cell carcinoma of the oral cavity and oropharynx in patients less than 40 years of age with a view to assessing the prognosis over a period of time.MethodsThis was a 20 years retrospective review of patients who were histologically diagnosed with squamous cell carcinoma of the oral cavity and the oropharynx at the Department of Cranio-Maxillo-Facial Surgery of the Hannover Medical School, Germany and had not received treatment anywhere else. Records of these patients were analysed for age and sex distribution, tumour staging and differentiation, location, treatment given, recurrences and metastasis, time between diagnosis and death or last contact with patient, and possible cause of death. Comparisons were also made with patients older than 40 years of age.Results and discussionA total of 977 patients treated for squamous cell carcinoma of the oral cavity and the oropharynx in the 20-year period of this study were included. Thirty eight (3.9 %) of the overall patient population were under 40 years of age. Among these, 30 (78.9%) were males and 8 (21.1%) were females. The incidence was highest in the 30–39 year age group accounting for 31 (81.6%) of the 38 patients. The moderately differentiated carcinoma was commonest (24; 63.2%). The floor of the mouth had the highest number of tumours (15; 39.5%), but none was seen in the oropharynx. Surgery alone was the main stay of treatment given to 26 (68.4%) patients. At the end of the study period, 13 (34.2%) patients had died of the tumour and the 5-year survival rate was 66.2%. In the older patient group (>40 years), 42.7% died from the tumour and the 5-year survival rate was 57.6%.ConclusionThe results from the present study showed that young adults may have a better prognosis especially in terms of long term overall survival from oral and oropharyngeal carcinoma.

Purpose:The host tissue reaction to the xenogeneic bone substitute Bio-Oss™ (Geistlich Biomaterials, Wolhousen, Switzerland) was investigated focusing on the participating inflammatory cells and implantation bed vascularization.Materials and Methods:Bio-Oss™ was implanted subcutaneously into CD1 mice for up to 60 days and analyzed by means of specialized histological and histomorphometrical techniques after explantation.Results:Bio-Oss™ induced within the first 15 days an early high vascularization combined with a marked presence of multinucleated giant cells. The latter cells were associated mainly with the smaller sized granules within the implantation bed. Toward the end of the study the number of multinucleated giant cells decreased while the tissue reaction to the larger granules was mainly mononuclear.Conclusion:The results of the present study showed that smaller xenogeneic bone substitute granules induce multinucleated giant cells, whereas the larger-sized ones became integrated within the implantation bed by means of a mononuclear cell-triggered granulation tissue. Obviously, the presence of multinucleated giant cells within biomaterial implantation beds is not only related to the type of synthetic bone substitute material, but also to the granule size of the natural-based xenogeneic bone substitute material.

BackgroundOsteoinductive bone substitutes are defined by their ability to induce new bone formation even at heterotopic implantation sites. The present study was designed to analyze the potential osteoinductivity of two different bone substitute materials in caprine muscle tissue.Materials and methodsOne gram each of either a porous beta-tricalcium phosphate (β-TCP) or an hydroxyapatite/silicon dioxide (HA/SiO2)-based nanocrystalline bone substitute material was implanted in several muscle pouches of goats. The biomaterials were explanted at 29, 91 and 181 days after implantation. Conventional histology and special histochemical stains were performed to detect osteoblast precursor cells as well as mineralized and unmineralized bone matrix.ResultsBoth materials underwent cellular degradation in which tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cells and TRAP-negative multinucleated giant cells were involved. The ß-TCP was completely resorbed within the observation period, whereas some granules of the HA-groups were still detectable after 180 days. Neither osteoblasts, osteoblast precursor cells nor extracellular bone matrix were found within the implantation bed of any of the analyzed biomaterials at any of the observed time points.ConclusionsThis study showed that ß-TCP underwent a faster degradation than the HA-based material. The lack of osteoinductivity for both materials might be due to their granular shape, as osteoinductivity in goat muscle has been mainly attributed to cylindrical or disc-shaped bone substitute materials. This hypothesis however requires further investigation to systematically analyze various materials with comparable characteristics in the same experimental setting.