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The aim of the present study was to test whether or not the application of an in situ formed synthetic hydrogel made of polyethylene glycol (PEG) used as a biodegradable membrane for guided bone regeneration will result in the same amount of bone regeneration as with the use of an expanded polytetrafluoro-ethylene (ePTFE) membrane. In eight New Zealand White rabbits, four evenly distributed 6 mm diameter defects were drilled into the calvarial bone. Three treatment modalities were evenly distributed among the 32 defects: hydroxyapatite (HA)/tricalciumphosphate (TCP) granules covered at the outer and inner surface with a PEG membrane (test), HA/TCP granules covered at the outer and inner surface with an ePTFE membrane (positive control) and HA/TCP granules alone without membranes (negative control). After 4 weeks, the animals were sacrificed and the calvarial bones were removed. The area fraction of newly formed bone was determined by histomorphometrical analysis of the vertical sections from the middle of the defect and by micro-computed tomography of the entire defect. Multiple regression analysis (SAS GLM) was used to model the amount of new bone formation. The quantitative histomorphometric analysis clearly revealed higher values of newly formed bone for the two membrane groups compared with the negative control group. The average area fractions of newly formed bone measured within the former defect amounted to 20.3+/-9.5% for the PEG membrane, 18.9+/-9.9% for the ePTFE membrane, and 7.3+/-5.3% for the sites with no membrane. The micro-computed tomography also showed higher values of new bone formation for the PEG and for the ePTFE groups compared with the negative control group. The GLM revealed a highly significant effect of the treatment on the amount of bone formation (P=0.0048). The values for the negative control group were significantly lower than the ones found in the PEG membrane group (P=0.0017), whereas the ePTFE membrane group showed no significant difference from the PEG membrane group. It is concluded that the PEG membrane can be used successfully as a biodegradable barrier membrane in the treatment of non-critical-size defects in the rabbit skull, and leads to similar amounts of bone regeneration as an ePTFE membrane.

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In medicine, N-methyl pyrrolidone (NMP) has a long track record as a constituent in medical devices approved by the Food and Drug Administration and thus can be considered as a safe and biologically inactive small chemical. In the present study, we report on the newly discovered pharmaceutical property of NMP in enhancing bone regeneration in a rabbit calvarial defect model in vivo. At the cellular level, the pharmaceutical effect of NMP was confirmed, in particular, in combination with bone morphogenetic protein (BMP)-2, because NMP increased early and late markers for maturation of preosteoblasts and human bone marrow-derived stem cells in vitro. When we used the multipotent cell line C2C12 without autologous BMP expression, NMP alone had no effect on alkaline phosphatase activity, a marker for osteogenic transdifferentiation. Nevertheless, in combination with low BMP-2 doses, alkaline phosphatase activity was more than eight times as great. Thus, the pharmaceutical NMP mode of action is that of an enhancer of BMP activity. The dependency of the effects of NMP on BMP was confirmed in preosteoblasts because noggin, an extracellular BMP inhibitor, suppressed NMP-induced increases in early markers for osteoblast maturation in vitro. At the molecular level, NMP was shown to have no effect on the binding of BMP-2 to the ectodomain of the high-affinity BMP receptor IA. However, NMP further increased the phosphorylation of p38 and Smad1,5,8 induced by BMP-2. Thus, the small chemical NMP enhances BMP activity by increasing the kinase activity of the BMP receptor complex for Smad1,5,8 and p38 and could be employed as a potent drug for bone tissue regeneration and engineering.

SUMMARY Among the ameloblastomas, the desmoplastic variation is rare. The desmoplastic ameloblastoma (DA) is characterized by specific clinical, imaging, and histological features. The here presented retrospective analysis investigated the clinicoradiographic features of an overall of 115 DA-cases, having been reported in literature from 1984 to 2008. DA showed a nearly equal male to female ratio (55/59) with a prevalence within the forth and fifth decades. Sixty-two lesions occurred in the mandible and fifty-one lesions in the maxilla. Clinically, a painless swelling with buccal extension was the most common presentation being found in 48 cases. Radiologically, the lesion often presented multilocular (49.3%; 36/73), mixed radiolucent/radiopaque (55.6%; 50/90) and with ill-defined borders (64.0%; 48/75). Whereas enucleation provided a recurrence rate of 21.1%, resection reduced this rate remarkably to 3.1%. The average period until recurrence was 36.9 months. Histologically, scattered epithelial nests and extensively desmoplasia were prominent features of DA. In conclusion, these retrospective results confirm the statement that DA is a variation among ameloblastomas. DA present clinicoradiographic and histologic distinct features, when compared with “conventional ameloblastomas”.

BackgroundAnxiety and depression have been identified as a common psychological distress faced by the majority of cancer patients. With the increasing number of cancer cases, increasing demands will be placed on health systems to address effective psychosocial care and therapy. The objective of this study was to assess the possible role of hope and optimism on anxiety and depression. We also wanted to investigate if there is a specific component of hope that could play a role in buffering anxiety and depression amongst cancer patients.MethodsA retrospective cross sectional study was conducted in the outpatient station of the Oral and Maxillofacial Surgery at the University of Hong Kong, Hong Kong SAR, PR-China. Fifty patients successfully treated for OC cancer were recruited after their informed consents had been obtained during the review clinic. During their regular follow-up controls in the outpatient clinic the patients compiled the hospital anxiety and depression scale (HADS), hope scale (HS) and the life orientation scale-revised (LOT-R).ResultsHope was negatively correlated with depression (r = -.55, p < .001) and anxiety (r = -.38, p < .05). Similar pattern was found between optimism and the latter adjustment outcomes (depression: r = -.55, p < .001; anxiety: r = -.35, p < .05). Regression analyses indentified that both hope and optimism were significant predictors of depression. Hope and optimism had equal association with depression (hope: β = .40 versus optimism: β = .38). Hope and optimism together were significantly predictive of anxiety, whereas neither hope nor optimism alone was significant individual predictors of anxiety.ConclusionsHope and optimism both negatively correlated with patients' level of anxiety and depression. Besides theoretical implications, this study brings forward relevant findings related to developing specific clinical psychological care in the field of oncology that to date has not been researched specifically in the field of oncology. The results of this study will help guide the direction of future prospective studies in the field of oncology. This will contribute significantly to increasing patients quality of life as well enabling health care facilities to provide all cancer patients a more holistic cancer care.

ObjectiveThis study aims to perform an evidence-based review on the quantitative data regarding coping processes related to posttraumatic growth in the field of oncology to facilitate understanding of posttraumatic growth in oral cavity cancer (OCC) patients.Material and methodsPubmed, Medline, and PsycINFO were used for the search and the reference list checked for each selected article. Full articles meeting the inclusion criteria were retrieved. Only English articles were included.ResultsThe initial search yielded 934 publications; 64 “potentially relevant papers” and 21 “effective” papers formed the basis of this review. Personality traits and social support lead to development of positive coping methods in cancer patients. Overriding influences are benefit finding and meaning making. Specific coping processes were identified to be significantly associated with posttraumatic growth in patients suffering from different cancers and a need for additional prospective research regarding specific processes and outcomes among oral cavity cancer patients. A proposed theoretical model based on the evidence of management of other cancer research fields is suggested for patients with OCC.ConclusionAn evidence-based review of coping strategies related to posttraumatic growth was performed which identified key coping strategies and factors that enhance coping processes. A conceptual model of coping strategies to enhance posttraumatic growth in OCC patients based on the scientific evidence attained is suggested to provide a more holistic approach to OCC management.

Background: The ameloblastic carcinoma is a rare malignant odontogenic tumor which rather occurs in the mandible than in the maxilla. Its rarity and in this context somewhat speculative histopathogenesis may account for diagnostic difficulties. Current classifications do not consider benign histopathological features at the primary and malignant features at the metastatic tumour site. Based on an evidence-based literature review, a recommendation for a novel classification is presented.