Bone injuries that arise from trauma, cancer treatment, or infection are a major and growing global challenge. An increasingly ageing population plays a key role in this, since a growing number of fractures are due to diseases such as osteoporosis, which place a burden on healthcare systems. Current reparative strategies do not sufficiently consider cell-substrate interactions that are found in healthy tissues; therefore, the need for more complex models is clear. The creation of in vitro defined 3D microenvironments is an emerging topographically-orientated approach that provides opportunities to apply knowledge of cell migration and differentiation mechanisms to the creation of new cell substrates. Moreover, introducing biofunctional agents within in vitro models for bone regeneration has allowed, to a certain degree, the control of cell fate towards osteogenic pathways. In this research, we applied three methods for functionalizing spatially-confined electrospun artificial microenvironments that presented relevant components of the native bone stem cell niche. The biological and osteogenic behaviors of mesenchymal stromal cells (MSCs) were investigated on electrospun micro-fabricated scaffolds functionalized with extracellular matrix (ECM) proteins (collagen I), glycosaminoglycans (heparin), and ceramic-based materials (bioglass). Collagen, heparin, and bioglass (BG) were successfully included in the models without modifying the fibrous structures offered by the polycaprolactone (PCL) scaffolds. Mesenchymal stromal cells (MSCs) were successfully seeded in all the biofunctional scaffolds and they showed an increase in alkaline phosphatase production when exposed to PCL/BG composites. This research demonstrates the feasibility of manufacturing smart and hierarchical artificial microenvironments for studying stem cell behavior and ultimately the potential of incorporating these artificial microenvironments into multifunctional membranes for bone tissue regeneration

To investigate the prevalence of maxillary canine impaction and whether the impacted canine cases have had a potentially good or poor prognosis if interceptive treatment was practiced at earlier ages. Material and Methods: 1755 panoramic radiographs of patients, aged 13 to 60 years, attending the University of Babylon, College of Dentistry for the period from November 2016 to July 2018 were collected and assessed for the presence of impacted maxillary canines. Subsequently, four suggested prognostic factors for each impacted canine were analyzed and recorded. Results: The prevalence of maxillary canine impaction was 119 (6.78%) with 89 unilateral impaction and 30 bilateral impaction resulting in a total of 149 impacted canines. Regarding the gender, impaction was more evident in females 70 than in males 49 with no statistical significant difference. For the side, impaction was more prevalent on the left (77) than on the right (72), also with no statistical difference (p>0.05). Following the analysis of the four prognostic factors, most of the cases, 117 (78.5%) had at least one prognostic factor to be poor. Although 82 (55%) of the cases had at least one prognostic factor to be good, only 4 had all the prognostic factors to be good. Conclusion:Although the cases that had a potentially good prognosis were little (4 cases), interceptive extraction of primary canines would mostly be beneficial for these patients as it will minimize the treatment time, cost and complications.