SummaryPost-natal skeletal stem cells expressing PRX1 (pnPRX1+) have been identified in the calvaria and in the axial skeleton. Here we characterize the location and functional capacity of the calvarial pnPRX1+ cells. We found that pnPRX1+ reside exclusively in the calvarial suture niche and decrease in number with age. They are distinct from preosteoblasts and osteoblasts of the sutures, respond to WNT signaling in vitro and in vivo by differentiating into osteoblasts, and, upon heterotopic transplantation, are able to regenerate bone. Diphtheria toxin A (DTA)-mediated lineage ablation of pnPRX1+ cells and suturectomy perturb regeneration of calvarial bone defects and confirm that pnPRX1+ cells of the sutures are required for bone regeneration. Orthotopic transplantation of sutures with traceable pnPRX1+ cells into wild-type animals shows that pnPRX1+ cells of the suture contribute to calvarial bone defect regeneration. DTA-mediated lineage ablation of pnPRX1+ does not, however, interfere with calvarial development.

Alveolar ridge preservation procedures are effective in minimizing postextraction hard tissue dimensional loss. The outcomes of these procedures are affected by morphology of extraction sockets, type of wound closure, type of grafting materials, use of barrier membranes, and use of growth factors.

The purpose of this systematic review was to compare the effectiveness of problem-based learning (PBL) with that of traditional (non-PBL) approaches in dental education. The search strategy included electronic and manual searches of studies published up to October 2012. The PICO (Population, Intervention, Comparator, and Outcome) framework was utilized to guide the inclusion or exclusion of studies. The search strategy identiied 436 articles, seventeen of which met the inclusion criteria. No randomized controlled trial was found comparing the effectiveness of PBL with that of lecture-based approach at the level of an entire curriculum. Three randomized controlled trials had evaluated the effectiveness of PBL at a single course level. The quality assessment rated four studies as being of moderate quality, while the other studies were assessed as being of weak quality. This review concludes that there are a very limited number of well-designed controlled studies evaluating the effectiveness of PBL in dental education. The data in those studies reveal that PBL does not negatively inluence the acquisition of factual knowledge in dental students and PBL enhances the ability of students in applying their knowledge to clinical situations. In addition, PBL positively affects students' perceived preparedness.

Background Gingival thickness, keratinized tissue width, and bone morphotype are three important parameters used to categorize periodontal phenotypes. These elements all play an important role in the maintenance of periodontal health. The aim of this review is to explore the importance of converting thin phenotype into a thick phenotype for periodontal health maintenance. Methods Three clinically relevant focused questions were defined to understand the role of gingival phenotype around teeth. 1) What are the factors affecting gingival phenotype (e.g., age, sex, dental arch, race, crown forms, etc.)? 2) Is there a difference between thin versus thick gingival phenotype in terms of gingival health? 3) Does the conversion of gingivae from a thin to thick gingival phenotype in sites without mucogingival defects help with periodontal health maintenance? Results Extensive electronic and manual literature search identified a total of 1,129 citations. After title, abstract, and full‐text screenings, 30 articles were included in the present review. Twenty‐five studies met the inclusion criteria and provided data for focused question 1. It was found that periodontal phenotype varies among different individuals and different areas of the mouth within the same individual. Asian individuals tend to have thinner gingival phenotype compared with white subjects. Eleven studies met the inclusion criteria for the focused question 2. Prevalence and severity of gingival recession was higher at the sites with thin gingiva compared with the sites with thicker gingiva. No studies provided data for focused question 3. Conclusions Available evidence indicates that subjects with thin and narrow gingiva tend to have more gingival recession compared with those with thick and wide gingiva. Currently, there is no published evidence to support conversion of thin to thick gingival phenotype in sites without gingival recession or mucogingival deformity.

Periodontal diseases are highly prevalent and are linked to several systemic diseases. The goal of periodontal treatment is to halt the progression of the disease and regenerate the damaged tissue. However, achieving complete and functional periodontal regeneration is challenging because the periodontium is a complex apparatus composed of different tissues, including bone, cementum, and periodontal ligament. Stem cell-based regenerative therapy may represent an effective therapeutic tool for periodontal regeneration due to their plasticity and ability to differentiate into different cell lineages. This review presents and critically analyzes the available information on stem cell-based therapy for the regeneration of periodontal tissues and suggests new avenues for the development of more effective therapeutic protocols.